Biomolecules

Editorial

8 pages, 551 KiB

Open AccessEditorial

The Biomolecular Spectrum Drives Microbial Biology and Functions in Agri-Food-Environments

by Minaxi Sharma, Dhananjaya Pratap Singh, Kanchugarakoppal S. Rangappa, Marc Stadler, Pradeep Kumar Mishra, Roberto Nascimento Silva, Ram Prasad and Vijai Kumar Gupta

Biomolecules 2020, 10(3), 401; https://doi.org/10.3390/biom10030401 - 4 Mar 2020

Cited by 4 | Viewed by 4583

Abstract

Microbial biomolecules have huge commercial and industrial potential. In nature, biological interactions are mostly associated with biochemical and biological diversity, especially with the discovery of associated biomolecules from microbes. Within cellular or subcellular systems, biomolecules signify the actual statuses of the microorganisms. Understanding [...] Read more.

Microbial biomolecules have huge commercial and industrial potential. In nature, biological interactions are mostly associated with biochemical and biological diversity, especially with the discovery of associated biomolecules from microbes. Within cellular or subcellular systems, biomolecules signify the actual statuses of the microorganisms. Understanding the biological prospecting of the diverse microbial community and their complexities and communications with the environment forms a vital basis for active, innovative biotechnological breakthroughs. Biochemical diversity rather than the specific chemicals that has the utmost biological importance. The identification and quantification of the comprehensive biochemical diversity of the microbial molecules, which generally consequences in a diversity of biological functions, has significant biotechnological potential. Beneficial microbes and their biomolecules of interest can assist as potential constituents for the wide-range of natural product-based preparations and formulations currently being developed on an industrial scale. The understanding of the production methods and functions of these biomolecules will contribute to valorisation of agriculture, food bioprocessing and biopharma, and prevent human diseases related to the environment. Full article

(This article belongs to the Special Issue Biology, Biotechnology and Bioprospecting of Microbial Biomolecules)

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Research

Jump to: Editorial, Review

15 pages, 1262 KiB

Open AccessArticle

Improved Pullulan Production and Process Optimization Using Novel GA–ANN and GA–ANFIS Hybrid Statistical Tools

by Parul Badhwar, Ashwani Kumar, Ankush Yadav, Punit Kumar, Ritu Siwach, Deepak Chhabra and Kashyap Kumar Dubey

Biomolecules 2020, 10(1), 124; https://doi.org/10.3390/biom10010124 - 10 Jan 2020

Cited by 28 | Viewed by 4109

Abstract

Pullulan production from Aureobasidium pullulans was explored to increase yield. Non-linear hybrid mathematical tools for optimization of process variables as well as the pullulan yield were analyzed. The one variable at a time (OVAT) approach was used to optimize the maximum pullulan yield [...] Read more.

Pullulan production from Aureobasidium pullulans was explored to increase yield. Non-linear hybrid mathematical tools for optimization of process variables as well as the pullulan yield were analyzed. The one variable at a time (OVAT) approach was used to optimize the maximum pullulan yield of 35.16 ± 0.29 g/L. The tools predicted maximum pullulan yields of 39.4918 g/L (genetic algorithm coupled with artificial neural network (GA–ANN)) and 36.0788 g/L (GA coupled with adaptive network based fuzzy inference system (GA–ANFIS)). The best regression value (0.94799) of the Levenberg–Marquardt (LM) algorithm for ANN and the epoch error (6.1055 × 10⁻⁵) for GA–ANFIS point towards prediction precision and potentiality of data training models. The process parameters provided by both the tools corresponding to their predicted yield were revalidated by experiments. Among the two of them GA–ANFIS results were replicated with 98.82% accuracy. Thus GA–ANFIS predicted an optimum pullulan yield of 36.0788 g/L with a substrate concentration of 49.94 g/L, incubation period of 182.39 h, temperature of 27.41 °C, pH of 6.99, and agitation speed of 190.08 rpm. Full article

(This article belongs to the Special Issue Biology, Biotechnology and Bioprospecting of Microbial Biomolecules)

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15 pages, 1053 KiB

Open AccessArticle

Novel and Efficient Synthesis of Phenethyl Formate via Enzymatic Esterification of Formic Acid

by Minguk Shin, Jeongbae Seo, Yesol Baek, Taek Lee, Min Jang and Chulhwan Park

Biomolecules 2020, 10(1), 70; https://doi.org/10.3390/biom10010070 - 1 Jan 2020

Cited by 28 | Viewed by 7028

Abstract

Current methods for the production of esters, including chemical synthesis and extraction from natural sources, are hindered by low yields and environmental pollution. The enzymatic synthesis of these compounds could help overcome these problems. In this study, phenethyl formate, a commercially valuable formate [...] Read more.

Current methods for the production of esters, including chemical synthesis and extraction from natural sources, are hindered by low yields and environmental pollution. The enzymatic synthesis of these compounds could help overcome these problems. In this study, phenethyl formate, a commercially valuable formate ester, was synthesized using commercial immobilized lipases. The effects of specific enzymes, enzyme concentration, formic acid:phenethyl alcohol molar ratio, temperature, and solvent were studied in order to optimize the synthesis conditions, which were identified as 15 g/L of Novozym 435 enzyme, a 1:5 formic acid:phenethyl alcohol molar ratio, a 40 °C reaction temperature, and 1,2-dichloroethane as the solvent. Under these conditions, phenethyl formate was obtained in a conversion yield of 95.92%. In addition, when 1,2-dichloroethane was replaced with toluene as the solvent, the enzyme could be recycled for at least 20 reactions with a steady conversion yield above 92%, testifying to the economic aspects of the process. The enzymatic synthesis of phenethyl formate using the proposed method is more environmentally friendly than methods currently employed in academic and laboratory settings. Moreover, the method has the potential to enhance the value-added properties of formic acid owing to its downstream use in the production of commercially essential esters. Full article

(This article belongs to the Special Issue Biology, Biotechnology and Bioprospecting of Microbial Biomolecules)

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18 pages, 2136 KiB

Open AccessArticle

Plant Growth-Promoting Fungi (PGPF) Instigate Plant Growth and Induce Disease Resistance in Capsicum annuum L. upon Infection with Colletotrichum capsici (Syd.) Butler & Bisby

by Banu Naziya, Mahadevamurthy Murali and Kestur Nagaraj Amruthesh

Biomolecules 2020, 10(1), 41; https://doi.org/10.3390/biom10010041 - 26 Dec 2019

Cited by 73 | Viewed by 7333

Abstract

In the current study, a total of 70 fungi were isolated from the rhizosphere soil of chilli collected from six different districts of south Karnataka, India. All the rhizospheric fungi were evaluated for its antagonistic nature against Colletotrichum capsici—the causal agent of [...] Read more.

In the current study, a total of 70 fungi were isolated from the rhizosphere soil of chilli collected from six different districts of south Karnataka, India. All the rhizospheric fungi were evaluated for its antagonistic nature against Colletotrichum capsici—the causal agent of anthracnose disease—and eight isolates were found positive. The antagonistic fungi were further characterized for the production of plant growth-promoting traits wherein five isolates were recorded positive for all the traits tested and were also positive for root colonization. All five plant growth-promoting fungi (PGPF) were subjected to molecular characterization for identification up to the species level and the accession numbers were obtained from NCBI. The five isolates, namely NBP-08, NBP-45, NBP-61, NBP-66 and NBP-67, were further experimented with on susceptible seeds to evaluate its efficacy on seed and plant growth parameters along with induction of resistance against the anthracnose disease. The evaluated PGPF offered significant enhancement in seed and plant growth parameters with maximum improvement observed in seeds treated with NBP-61. Among the PGPF isolates, NBP-61 showed the maximum protection of 78.75%, while all the other isolates also showed significant protection against anthracnose disease compared to untreated plants. The higher accumulation of lignin and callose deposition along with enhanced defense enzyme activities in the PGPF-treated challenge-inoculated seedlings authenticated the protection offered by PGPF. The study evidenced the immense ability of PGPF in eliciting disease protection and enhancement of plant growth in chilli, which may act as a possible substitute for harmful chemicals. Full article

(This article belongs to the Special Issue Biology, Biotechnology and Bioprospecting of Microbial Biomolecules)

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32 pages, 5420 KiB

Open AccessArticle

Elicitation of Novel Trichogenic-Lipid Nanoemulsion Signaling Resistance Against Pearl Millet Downy Mildew Disease

by Boregowda Nandini, Hariprasad Puttaswamy, Harischandra Sripathy Prakash, Shivakanthkumar Adhikari, Sudisha Jogaiah and Geetha Nagaraja

Biomolecules 2020, 10(1), 25; https://doi.org/10.3390/biom10010025 - 23 Dec 2019

Cited by 65 | Viewed by 4720

Abstract

Nanoemulsion was formulated from membrane lipids of Trichoderma spp. with the non-ionic surfactant Tween 80 by the ultrasonic emulsification method. Nanoemulsion with a droplet diameter of 5 to 51 nm was obtained. The possible effects of membrane lipid nanoemulsion on pearl millet (PM) [...] Read more.

Nanoemulsion was formulated from membrane lipids of Trichoderma spp. with the non-ionic surfactant Tween 80 by the ultrasonic emulsification method. Nanoemulsion with a droplet diameter of 5 to 51 nm was obtained. The possible effects of membrane lipid nanoemulsion on pearl millet (PM) seed growth parameters and elicitation of downy mildew (DM) disease resistance in PM was analyzed to develop an eco-friendly disease management strategy. Seed priming with nanoemulsion illustrates significant protection and elevated levels of early defense gene expression. Lipid profiling of Trichoderma spp. reveals the presence of oleic acid as a major fatty acid molecule. The prominent molecule in the purified lipid fraction of T. brevicompactum (UP-91) responsible for the elicitation of induction of systemic resistance in PM host against DM pathogen was predicted as (E)-N-(1, 3-dihydroxyoctadec-4-en-2yl) acetamide. The results suggest that protection offered by the novel nanoemulsion formulation is systemic in nature and durable and offers a newer sustainable approach to manage biotrophic oomycetous pathogen. Full article

(This article belongs to the Special Issue Biology, Biotechnology and Bioprospecting of Microbial Biomolecules)

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23 pages, 6507 KiB

Open AccessArticle

Thrombolytic Potential of Novel Thiol-Dependent Fibrinolytic Protease from Bacillus cereus RSA1

by Chhavi Sharma, Gad Elsayed Mohamed Salem, Neha Sharma, Prerna Gautam and Rajni Singh

Biomolecules 2020, 10(1), 3; https://doi.org/10.3390/biom10010003 - 18 Dec 2019

Cited by 43 | Viewed by 5620

Abstract

The present study demonstrates the production and thrombolytic potential of a novel thermostable thiol-dependent fibrinolytic protease by Bacillus cereus RSA1. Statistical optimization of different parameters was accomplished with Plackett–Burman design and validated further by central composite design with 30.75 U/mL protease production. Precipitation [...] Read more.

The present study demonstrates the production and thrombolytic potential of a novel thermostable thiol-dependent fibrinolytic protease by Bacillus cereus RSA1. Statistical optimization of different parameters was accomplished with Plackett–Burman design and validated further by central composite design with 30.75 U/mL protease production. Precipitation and chromatographic approaches resulted in 33.11% recovery with 2.32-fold purification. The molecular weight of fibrinolytic protease was 40 KDa and it exhibited a broad temperature and pH stability range of 20–80 °C and pH 5–10 with utmost activity at 50 °C and pH 8, respectively. The protease retained its fibrinolytic activity in organic solvents and enhanced the activity in solutions with divalent cations (Mn²⁺, Zn²⁺, and Cu²⁺). The enzyme kinetics revealed K_m and V_max values of 1.093 mg/mL and 52.39 µg/mL/min, respectively, indicating higher affinity of fibrinolytic activity towards fibrin. Also, complete inhibition of fibrinolytic activity with DFP and a 2-fold increase with DTT and β-mercaptoethanol indicates its thiol-dependent serine protease nature. MALDI–TOF analysis showed 56% amino acid sequence homology with Subtilisin NAT OS = Bacillus subtilis subsp. natto. The fibrinolysis activity was compared with a commercial thrombolytic agent for its therapeutic applicability, and fibrinolytic protease was found highly significant with absolute blood clot dissolution within 4 h in in vitro conditions. The isolated fibrinolytic protease of Bacillus cereus RSA1 is novel and different from other known fibrinolytic proteases with high stability and efficacy, which might have wide medicinal and industrial application as a thrombolytic agent and in blood stain removal, respectively. Full article

(This article belongs to the Special Issue Biology, Biotechnology and Bioprospecting of Microbial Biomolecules)

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18 pages, 2790 KiB

Open AccessArticle

The IκB Kinase Inhibitor ACHP Targets the STAT3 Signaling Pathway in Human Non-Small Cell Lung Carcinoma Cells

by Jong Hyun Lee, Chakrabhavi Dhananjaya Mohan, Salundi Basappa, Shobith Rangappa, Arunachalam Chinnathambi, Tahani Awad Alahmadi, Sulaiman Ali Alharbi, Alan Prem Kumar, Gautam Sethi, Kwang Seok Ahn and Kanchugarakoppal S Rangappa

Biomolecules 2019, 9(12), 875; https://doi.org/10.3390/biom9120875 - 13 Dec 2019

Cited by 51 | Viewed by 4207

Abstract

STAT3 is an oncogenic transcription factor that regulates the expression of genes which are involved in malignant transformation. Aberrant activation of STAT3 has been observed in a wide range of human malignancies and its role in negative prognosis is well-documented. In this report, [...] Read more.

STAT3 is an oncogenic transcription factor that regulates the expression of genes which are involved in malignant transformation. Aberrant activation of STAT3 has been observed in a wide range of human malignancies and its role in negative prognosis is well-documented. In this report, we performed high-throughput virtual screening in search of STAT3 signaling inhibitors using a cheminformatics platform and identified 2-Amino-6-[2-(Cyclopropylmethoxy)-6-Hydroxyphenyl]-4-Piperidin-4-yl Nicotinonitrile (ACHP) as the inhibitor of the STAT3 signaling pathway. The predicted hit was evaluated in non-small cell lung cancer (NSCLC) cell lines for its STAT3 inhibitory activity. In vitro experiments suggested that ACHP decreased the cell viability and inhibited the phosphorylation of STAT3 on Tyr705 of NSCLC cells. In addition, ACHP imparted inhibitory activity on the constitutive activation of upstream protein tyrosine kinases, including JAK1, JAK2, and Src. ACHP decreased the nuclear translocation of STAT3 and downregulated its DNA binding ability. Apoptosis was evidenced by cleavage of caspase-3 and PARP with the subsequent decline in antiapoptotic proteins, including Bcl-2, Bcl-xl, and survivin. Overall, we report that ACHP can act as a potent STAT3 signaling inhibitor in NSCLC cell lines. Full article

(This article belongs to the Special Issue Biology, Biotechnology and Bioprospecting of Microbial Biomolecules)

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16 pages, 2487 KiB

Open AccessArticle

RSM–GA Based Optimization of Bacterial PHA Production and In Silico Modulation of Citrate Synthase for Enhancing PHA Production

by Apoorva Rao, Shafiul Haque, Hesham A. El-Enshasy, Vineeta Singh and Bhartendu Nath Mishra

Biomolecules 2019, 9(12), 872; https://doi.org/10.3390/biom9120872 - 12 Dec 2019

Cited by 43 | Viewed by 6039

Abstract

The inexhaustible nature and biodegradability of bioplastics like polyhydroxyalkanoates (PHAs) make them suitable assets to replace synthetic plastics. The eventual fate of these eco-friendly and non-toxic bioplastics relies upon the endeavors towards satisfying cost and, in addition, execution necessity. In this study, we [...] Read more.

The inexhaustible nature and biodegradability of bioplastics like polyhydroxyalkanoates (PHAs) make them suitable assets to replace synthetic plastics. The eventual fate of these eco-friendly and non-toxic bioplastics relies upon the endeavors towards satisfying cost and, in addition, execution necessity. In this study, we utilized and statistically optimized different food (kitchen-/agro-) waste as a sole carbon/nitrogen source for the production of PHA at a reduced cost, indicating a proficient waste administration procedure. Seven different types of kitchen-/agro-waste were used as unique carbon source and four different types of nitrogen source were used to study their impact on PHA production by Bacillus subtilis MTCC 144. Among four different studied production media, mineral salt medium (MSM) (biomass: 37.7 g/L; cell dry weight: 1.8 g/L; and PHA: 1.54 g/L) was found most suitable for PHA production. Further, carbon and nitrogen components of MSM were optimized using one-factor-at-a-time experiments, and found that watermelon rind (PHA = 12.97 g/L) and pulse peel (PHA = 13.5 g/L) were the most suitable carbon and nitrogen sources, respectively, in terms of PHA (78.60%) recovery. The concentrations of these factors (sources) were statistically optimized using response surface methodology coupled with the genetic algorithm approach. Additionally, in order to enhance microbial PHA production, the interaction of citrate synthase, a key enzyme in the TCA cycle, with different known inhibitors was studied using in silico molecular docking approach. The inhibition of citrate synthase induces the blockage of the tricarboxylic cycle (TCA), thereby increasing the concentration of acetyl-CoA that helps in enhanced PHA production. Molecular docking of citrate synthase with different inhibitors of PubChem database revealed that hesperidin (PubChem compound CID ID 10621), generally present in citrus fruits, is the most efficient inhibitor of the TCA cycle with the binding score of –11.4 and warrants experimental validation. Overall, this study provides an efficient food waste management approach by reducing the production cost and enhancing the production of PHA, thereby lessening our reliance on petroleum-based plastics. Full article

(This article belongs to the Special Issue Biology, Biotechnology and Bioprospecting of Microbial Biomolecules)

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17 pages, 2785 KiB

Open AccessArticle

Characterization of Terpene Synthase from Tea Green Leafhopper Being Involved in Formation of Geraniol in Tea (Camellia sinensis) Leaves and Potential Effect of Geraniol on Insect-Derived Endobacteria

by Ying Zhou, Xiaoyu Liu and Ziyin Yang

Biomolecules 2019, 9(12), 808; https://doi.org/10.3390/biom9120808 - 30 Nov 2019

Cited by 25 | Viewed by 4570

Abstract

When insects attack plants, insect-derived elicitors and mechanical damage induce the formation and emission of plant volatiles that have important ecological functions and flavor properties. These events have mainly been studied in model plants, rather than crop plants. Our study showed that tea [...] Read more.

When insects attack plants, insect-derived elicitors and mechanical damage induce the formation and emission of plant volatiles that have important ecological functions and flavor properties. These events have mainly been studied in model plants, rather than crop plants. Our study showed that tea green leafhopper (Empoasca (Matsumurasca) onukii Matsuda), a major pest infesting tea attack significantly induced the emission of geraniol from tea leaves, but did not affect the crude enzyme activity of geraniol synthase in tea leaves. An enzyme extract of E. (M.) onukii specifically produced geraniol from geraniol diphosphate. Furthermore, a terpene synthase (EoTPS) was isolated from E. (M.) onukii. This terpene synthase was able to convert geraniol diphosphate to geraniol in vitro. In addition, geraniol had in vitro ability to inhibit the growth of Acinetobacter johnsonii that is endobacterial isolated from E. (M.) onukii. This information illustrates that elicitors from piercing-sucking insects can induce the formation of volatiles from crop plants and advances our understanding of the roles of plant volatiles in the interaction among crops-insects-microorganisms. Full article

(This article belongs to the Special Issue Biology, Biotechnology and Bioprospecting of Microbial Biomolecules)

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14 pages, 2239 KiB

Open AccessArticle

Proteomic Response of Pseudomonas putida KT2440 to Dual Carbon-Phosphorus Limitation during mcl-PHAs Synthesis

by Justyna Możejko-Ciesielska and Luísa S. Serafim

Biomolecules 2019, 9(12), 796; https://doi.org/10.3390/biom9120796 - 28 Nov 2019

Cited by 13 | Viewed by 4031

Abstract

Pseudomonas putida KT2440, one of the best characterized pseudomonads, is a metabolically versatile producer of medium-chain-length polyhydroxyalkanoates (mcl-PHAs) that serves as a model bacterium for molecular studies. The synthesis of mcl-PHAs is of great interest due to their commercial potential. Carbon and phosphorus [...] Read more.

Pseudomonas putida KT2440, one of the best characterized pseudomonads, is a metabolically versatile producer of medium-chain-length polyhydroxyalkanoates (mcl-PHAs) that serves as a model bacterium for molecular studies. The synthesis of mcl-PHAs is of great interest due to their commercial potential. Carbon and phosphorus are the essential nutrients for growth and their limitation can trigger mcl-PHAs’ production in microorganisms. However, the specific molecular mechanisms that drive this synthesis in Pseudomonas species under unfavorable growth conditions remain poorly understood. Therefore, the proteomic responses of Pseudomonas putida KT2440 to the limited carbon and phosphorus levels in the different growth phases during mcl-PHAs synthesis were investigated. The data indicated that biopolymers’ production was associated with the cell growth of P. putida KT2440 under carbon- and phosphorus-limiting conditions. The protein expression pattern changed during mcl-PHAs synthesis and accumulation, and during the different physiological states of the microorganism. The data suggested that the majority of metabolic activities ceased under carbon and phosphorus limitation. The abundance of polyhydroxyalkanoate granule-associated protein (PhaF) involved in PHA synthesis increased significantly at 24 and 48 h of the cultivations. The activation of proteins belonging to the phosphate regulon was also detected. Moreover, these results indicated changes in the protein profiles related to amino acids metabolism, replication, transcription, translation, stress response mechanisms, transport or signal transduction. The presented data allowed the investigation of time-course proteome alterations in response to carbon and phosphorus limitation, and PHAs synthesis. This study provided information about proteins that can be potential targets in improving the efficiency of mcl-PHAs synthesis. Full article

(This article belongs to the Special Issue Biology, Biotechnology and Bioprospecting of Microbial Biomolecules)

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17 pages, 4336 KiB

Open AccessArticle

Endo-β-1,3-glucanase (GH16 Family) from Trichoderma harzianum Participates in Cell Wall Biogenesis but Is Not Essential for Antagonism Against Plant Pathogens

by Marcela Suriani Ribeiro, Renato Graciano de Paula, Aline Raquel Voltan, Raphaela Georg de Castro, Cláudia Batista Carraro, Leandro José de Assis, Andrei Stecca Steindorff, Gustavo Henrique Goldman, Roberto Nascimento Silva, Cirano José Ulhoa and Valdirene Neves Monteiro

Biomolecules 2019, 9(12), 781; https://doi.org/10.3390/biom9120781 - 26 Nov 2019

Cited by 33 | Viewed by 5256

Abstract

Trichoderma species are known for their ability to produce lytic enzymes, such as exoglucanases, endoglucanases, chitinases, and proteases, which play important roles in cell wall degradation of phytopathogens. β-glucanases play crucial roles in the morphogenetic-morphological process during the development and differentiation processes in [...] Read more.

Trichoderma species are known for their ability to produce lytic enzymes, such as exoglucanases, endoglucanases, chitinases, and proteases, which play important roles in cell wall degradation of phytopathogens. β-glucanases play crucial roles in the morphogenetic-morphological process during the development and differentiation processes in Trichoderma species, which have β-glucans as the primary components of their cell walls. Despite the importance of glucanases in the mycoparasitism of Trichoderma spp., only a few functional analysis studies have been conducted on glucanases. In the present study, we used a functional genomics approach to investigate the functional role of the gluc31 gene, which encodes an endo-β-1,3-glucanase belonging to the GH16 family in Trichoderma harzianum ALL42. We demonstrated that the absence of the gluc31 gene did not affect the in vivo mycoparasitism ability of mutant T. harzianum ALL42; however, gluc31 evidently influenced cell wall organization. Polymer measurements and fluorescence microscopy analyses indicated that the lack of the gluc31 gene induced a compensatory response by increasing the production of chitin and glucan polymers on the cell walls of the mutant hyphae. The mutant strain became more resistant to the fungicide benomyl compared to the parental strain. Furthermore, qRT-PCR analysis showed that the absence of gluc31 in T. harzianum resulted in the differential expression of other glycosyl hydrolases belonging to the GH16 family, because of functional redundancy among the glucanases. Full article

(This article belongs to the Special Issue Biology, Biotechnology and Bioprospecting of Microbial Biomolecules)

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17 pages, 2285 KiB

Open AccessArticle

Preparation and Evaluation of the ZnO NP–Ampicillin/Sulbactam Nanoantibiotic: Optimization of Formulation Variables Using RSM Coupled GA Method and Antibacterial Activities

by Nidhi Sharma, Vineeta Singh, Asheesh Kumar Pandey, Bhartendu Nath Mishra, Maria Kulsoom, Nandita Dasgupta, Saif Khan, Hesham A. El-Enshasy and Shafiul Haque

Biomolecules 2019, 9(12), 764; https://doi.org/10.3390/biom9120764 - 21 Nov 2019

Cited by 16 | Viewed by 4167

Abstract

Nanoparticles (NPs) possessing antibacterial activity represent an effective way of overcoming bacterial resistance. In the present work, we report a novel formulation of a nanoantibiotic formed using Ampicillin/sulbactam (Ams) and a zinc oxide nanoparticle (ZnO NP). ‘ZnO NP–Ams’ nanoantibiotic formulation is optimized using [...] Read more.

Nanoparticles (NPs) possessing antibacterial activity represent an effective way of overcoming bacterial resistance. In the present work, we report a novel formulation of a nanoantibiotic formed using Ampicillin/sulbactam (Ams) and a zinc oxide nanoparticle (ZnO NP). ‘ZnO NP–Ams’ nanoantibiotic formulation is optimized using response surface methodology coupled genetic algorithm approach. The optimized formulation of nanoantibiotic (ZnO NP: 49.9 μg/mL; Ams: 33.6 μg/mL; incubation time: 27 h) demonstrated 15% enhanced activity compared to the unoptimized formulation against K. pneumoniae. The reactive oxygen species (ROS) generation was directly proportional to the interaction time of nanoantibiotic and K. pneumoniae after the initial lag phase of ~18 h as evident from 2s’-7’-Dichlorodihydrofluorescein diacetate assay. A low minimum inhibitory concentration (6.25 μg/mL) of nanoantibiotic formulation reveals that even a low concentration of nanoantibiotic can prove to be effective against K. pneumoniae. The importance of nanoantibiotic formulation is also evident by the fact that the 100 μg/mL of Ams and 25 µg of ZnO NP was required individually to inhibit the growth of K. pneumonia, whereas only 6.25 μg/mL of optimized nanoantibiotic formulation (ZnO NP and Ams in the ratio of 49.9: 33.6 in μg/mL and conjugation time of 27 h) was needed for the same. Full article

(This article belongs to the Special Issue Biology, Biotechnology and Bioprospecting of Microbial Biomolecules)

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12 pages, 2024 KiB

Open AccessArticle

Poly-(γ-glutamic acid) Production and Optimization from Agro-Industrial Bioresources as Renewable Substrates by Bacillus sp. FBL-2 through Response Surface Methodology

by Da-Young Song, Lebaka Veeranjaneya Reddy, Dimitris Charalampopoulos and Young-Jung Wee

Biomolecules 2019, 9(12), 754; https://doi.org/10.3390/biom9120754 - 20 Nov 2019

Cited by 24 | Viewed by 4739

Abstract

We optimized culture conditions using Bacillus sp. FBL-2 as a poly-(γ-glutamic acid) (PGA) producing strain isolated from cheonggukjang. All experiments were performed under aerobic conditions using a laboratory scale 2.5 L fermentor. We investigated the effects of fermentation parameters (temperature, pH, agitation, and [...] Read more.

We optimized culture conditions using Bacillus sp. FBL-2 as a poly-(γ-glutamic acid) (PGA) producing strain isolated from cheonggukjang. All experiments were performed under aerobic conditions using a laboratory scale 2.5 L fermentor. We investigated the effects of fermentation parameters (temperature, pH, agitation, and aeration) and medium components (glutamic acid, citric acid, and yeast extract) on poly-(γ-glutamic acid) production, viscosity, and dry cell mass. A non-optimized fermentation method (1.5 vvm, 350 rpm, and 37 °C) yielded PGA, viscosity, and dry cell mass at levels of 100.7 g/L, 483.2 cP, and 3.4 g/L, respectively. L-glutamic acid, citric acid, and yeast extract supplementation enhanced poly-(γ-glutamic acid) production to 175.9 g/L. Additionally, the production of poly-(γ-glutamic acid) from rice bran and wheat bran was assessed using response surface methodology (central composite rotatable design). Agricultural byproducts (rice bran and wheat bran) and H₂SO₄ were selected as factors, and experiments were performed by combining various component concentrations to determine optimal component concentrations. Our experimentally-derived optimal parameters included 38.6 g/L of rice bran, 0.42% of H₂SO₄, 28.0 g/L of wheat bran, and 0.32% of H₂SO₄. Under optimum conditions, rice bran medium facilitated poly-(γ-glutamic acid) production of up to 22.64 g/L, and the use of wheat bran medium yielded up to 14.6 g/L. Based on a validity test using the optimized culture conditions, poly-(γ-glutamic acid) was produced at 47.6 g/L and 36.4 g/L from these respective mediums, and both results were higher than statistically predicted. This study suggests that rice bran can be used as a potential alternative substrate for poly-(γ-glutamic acid) production. Full article

(This article belongs to the Special Issue Biology, Biotechnology and Bioprospecting of Microbial Biomolecules)

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18 pages, 2809 KiB

Open AccessArticle

Genomic, Transcriptomic and Enzymatic Insight into Lignocellulolytic System of a Plant Pathogen Dickeya sp. WS52 to Digest Sweet Pepper and Tomato Stalk

by Ying-Jie Yang, Wei Lin, Raghvendra Pratap Singh, Qian Xu, Zhihou Chen, Yuan Yuan, Ping Zou, Yiqiang Li and Chengsheng Zhang

Biomolecules 2019, 9(12), 753; https://doi.org/10.3390/biom9120753 - 20 Nov 2019

Cited by 20 | Viewed by 3185

Abstract

Dickeya sp., a plant pathogen, causing soft rot with strong pectin degradation capacity was taken for the comprehensive analysis of its corresponding biomass degradative system, which has not been analyzed yet. Whole genome sequence analysis of the isolated soft-rotten plant pathogen Dickeya sp. [...] Read more.

Dickeya sp., a plant pathogen, causing soft rot with strong pectin degradation capacity was taken for the comprehensive analysis of its corresponding biomass degradative system, which has not been analyzed yet. Whole genome sequence analysis of the isolated soft-rotten plant pathogen Dickeya sp. WS52, revealed various coding genes which involved in vegetable stalk degradation-related properties. A total of 122 genes were found to be encoded for putative carbohydrate-active enzymes (CAZy) in Dickeya sp. WS52. The number of pectin degradation-related genes, was higher than that of cellulolytic bacteria as well as other Dickeya spp. strains. The CAZy in Dickeya sp.WS52 contains a complete repertoire of enzymes required for hemicellulose degradation, especially pectinases. In addition, WS52 strain possessed plenty of genes encoding potential ligninolytic relevant enzymes, such as multicopper oxidase, catalase/hydroperoxidase, glutathione S-transferase, and quinone oxidoreductase. Transcriptome analysis revealed that parts of genes encoding lignocellulolytic enzymes were significantly upregulated in the presence of minimal salt medium with vegetable stalks. However, most of the genes were related to lignocellulolytic enzymes, especially pectate lyases and were downregulated due to the slow growth and downregulated secretion systems. The assay of lignocellulolytic enzymes including CMCase and pectinase activities were identified to be more active in vegetable stalk relative to MSM + glucose. However, compared with nutrient LB medium, it needed sufficient nutrient to promote growth and to improve the secretion system. Further identification of enzyme activities of Dickeya sp.WS52 by HPLC confirmed that monosaccharides were produced during degradation of tomato stalk. This identified degradative system is valuable for the application in the lignocellulosic bioenergy industry and animal production. Full article

(This article belongs to the Special Issue Biology, Biotechnology and Bioprospecting of Microbial Biomolecules)

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14 pages, 4893 KiB

Open AccessArticle

Molecular Characterization of a Novel Cold-Active Hormone-Sensitive Lipase (HaHSL) from Halocynthiibacter Arcticus

by Ly Thi Huong Luu Le, Wanki Yoo, Changwoo Lee, Ying Wang, Sangeun Jeon, Kyeong Kyu Kim, Jun Hyuck Lee and T. Doohun Kim

Biomolecules 2019, 9(11), 704; https://doi.org/10.3390/biom9110704 - 5 Nov 2019

Cited by 10 | Viewed by 3533

Abstract

Bacterial hormone-sensitive lipases (bHSLs), which are homologous to the catalytic domains of human HSLs, have received great interest due to their uses in the preparation of highly valuable biochemicals, such as drug intermediates or chiral building blocks. Here, a novel cold-active HSL from [...] Read more.

Bacterial hormone-sensitive lipases (bHSLs), which are homologous to the catalytic domains of human HSLs, have received great interest due to their uses in the preparation of highly valuable biochemicals, such as drug intermediates or chiral building blocks. Here, a novel cold-active HSL from Halocynthiibacter arcticus (HaHSL) was examined and its enzymatic properties were investigated using several biochemical and biophysical methods. Interestingly, HaHSL acted on a large variety of substrates including tertiary alcohol esters and fish oils. Additionally, this enzyme was highly tolerant to high concentrations of salt, detergents, and glycerol. Furthermore, immobilized HaHSL retained its activity for up to six cycles of use. Homology modeling suggested that aromatic amino acids (Trp²³, Tyr⁷⁴, Phe⁷⁸, Trp⁸³, and Phe²⁴⁵) in close proximity to the substrate-binding pocket were important for enzyme activity. Mutational analysis revealed that Tyr⁷⁴ played an important role in substrate specificity, thermostability, and enantioselectivity. In summary, the current study provides an invaluable insight into the novel cold-active HaHSL from H. arcticus, which can be efficiently and sustainably used in a wide range of biotechnological applications. Full article

(This article belongs to the Special Issue Biology, Biotechnology and Bioprospecting of Microbial Biomolecules)

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30 pages, 3050 KiB

Open AccessArticle

Impact of Plant Growth Promoting Rhizobacteria in the Orchestration of Lycopersicon esculentum Mill. Resistance to Plant Parasitic Nematodes: A Metabolomic Approach to Evaluate Defense Responses Under Field Conditions

by Kanika Khanna, Anket Sharma, Puja Ohri, Renu Bhardwaj, Elsayed F. Abd_Allah, Abeer Hashem and Parvaiz Ahmad

Biomolecules 2019, 9(11), 676; https://doi.org/10.3390/biom9110676 - 31 Oct 2019

Cited by 58 | Viewed by 5811

Abstract

The present study deals with biological control of Meloidogyne incognita in 45-days old Lycopersicon esculentum, inoculated with Pseudomonas aeruginosa(M1) and Burkholderia gladioli (M2). The improved plant growth and biomass of nematode infested Plant growth promoting rhizobacteria (PGPR) inoculated plants was observed. [...] Read more.

The present study deals with biological control of Meloidogyne incognita in 45-days old Lycopersicon esculentum, inoculated with Pseudomonas aeruginosa(M1) and Burkholderia gladioli (M2). The improved plant growth and biomass of nematode infested Plant growth promoting rhizobacteria (PGPR) inoculated plants was observed. Remarkable reduction in the numbers of second stage juvenile (J2s), root galls was recorded after treatment of microbes relative to experimental controls. Moreover, the lowered activities of oxidative stress markers (H₂O₂ (hydrogen peroxide), O₂⁻ (superoxide anion), malondialdehyde (MDA)) was estimated in plants after rhizobacterial supplementation. Higher activities of enzymatic (SOD (Superoxide dismutase), POD (Guaiacol peroxidase), CAT (Catalase), GPOX (Glutathione peroxidase), APOX (Ascorbate peroxidase), GST (Glutathione-S-transferase), GR (Glutathione reductase), DHAR (Dehydroascorbate reductase), PPO (Polyphenol oxidase)) and non-enzymatic (glutathione, ascorbic acid, tocopherol) antioxidants were further determined in nematode infected plants following the addition of bacterial strains. The upregulation of photosynthetic activities were depicted by evaluating plant pigments and gas exchange attributes. An increase in the levels of phenolic compounds (total phenols, flavonoids, anthocyanins), osmoprotectants (total osmolytes, carbohydrates, reducing sugars, trehalose, proline, glycine betaine, free amino acids) and organic acids (fumaric, succinic, citric, malic acid) were reflected in infected plants, showing further enhancement after application of biocontrol agents. The study revealed the understanding of plant metabolism, along with the initiative to commercially exploit the biocontrol agents as an alternative to chemical nematicides in infected fields for sustainable agriculture. Full article

(This article belongs to the Special Issue Biology, Biotechnology and Bioprospecting of Microbial Biomolecules)

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20 pages, 2637 KiB

Open AccessArticle

Microbial Fortification Improved Photosynthetic Efficiency and Secondary Metabolism in Lycopersicon esculentum Plants Under Cd Stress

by Kanika Khanna, Sukhmeen Kaur Kohli, Puja Ohri, Renu Bhardwaj, Asma A. Al-Huqail, Manzer H. Siddiqui, Ghada Saleh Alosaimi and Parvaiz Ahmad

Biomolecules 2019, 9(10), 581; https://doi.org/10.3390/biom9100581 - 7 Oct 2019

Cited by 42 | Viewed by 4114

Abstract

Environmental stress including heavy metal pollution is increasing at high speed and is polluting the cultivable land. Consequently, it results in affecting human population through entering into food chain. The current study aims that Cd stress (0.4 mM) led to toxicity and deleterious [...] Read more.

Environmental stress including heavy metal pollution is increasing at high speed and is polluting the cultivable land. Consequently, it results in affecting human population through entering into food chain. The current study aims that Cd stress (0.4 mM) led to toxicity and deleterious effects on 45-day-old Lycopersicon esculentum plants. The use of rhizobacterial strains underlines the main hypothesis of the present research that have been exploited in order to alleviate the Cd induced stress in plants and promoting their growth sidewise. The morphological parameters, plant pigments, and gaseous exchange parameters were estimated and found to be reduced in plants due to Cd toxicity. Along with this, the levels of phenolic compounds and osmoprotectants were stimulated in plants raised in Cd spiked soils. In addition, free amino acid content was reduced in plants under Cd treatment. It was revealed that these bacterial strains Pseudomonas aeruginosa (M1) and Burkholderia gladioli (M2) when inoculated to tomato plants improved the morphological characteristics and enhanced photosynthetic attributes. Moreover, the level of phenolic compounds and osmoprotectants were further enhanced by both the inoculating agents independently. However, in situ localization studies of phenol accumulation in root sections was found to be enhanced in Cd treated plants as revealed through higher intensity of yellowish-brown colour. The supplementation of bacterial strains further accumulated the phenols in Cd stressed root sections as evidenced through increased colour intensity. Therefore, the present study suggested that bacterial strains mitigates Cd stress from tomato plants through improving morphological, physiological and metabolite profiles. Consequently, the present research advocates the best utilization of rhizobacteria as stress alleviators for sustainable agriculture. Full article

(This article belongs to the Special Issue Biology, Biotechnology and Bioprospecting of Microbial Biomolecules)

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25 pages, 4114 KiB

Open AccessArticle

Statistically Designed Medium Reveals Interactions between Metabolism and Genetic Information Processing for Production of Stable Human Serum Albumin in Pichia pastoris

by Nitu Maity and Saroj Mishra

Biomolecules 2019, 9(10), 568; https://doi.org/10.3390/biom9100568 - 4 Oct 2019

Cited by 6 | Viewed by 4968

Abstract

Human serum albumin (HSA), sourced from human serum, has been an important therapeutic protein for several decades. Pichia pastoris is strongly considered as an expression platform, but proteolytic degradation of recombinant HSA in the culture filtrate remains a major bottleneck for use of [...] Read more.

Human serum albumin (HSA), sourced from human serum, has been an important therapeutic protein for several decades. Pichia pastoris is strongly considered as an expression platform, but proteolytic degradation of recombinant HSA in the culture filtrate remains a major bottleneck for use of this system. In this study, we have reported the development of a medium that minimized proteolytic degradation across different copy number constructs. A synthetic codon-optimized copy of HSA was cloned downstream of α–factor secretory signal sequence and expressed in P. pastoris under the control of Alcohol oxidase 1 promoter. A two-copy expression cassette was also prepared. Culture conditions and medium components were identified and optimized using statistical tools to develop a medium that supported stable production of HSA. Comparative analysis of transcriptome data obtained by cultivation on optimized and unoptimized medium indicated upregulation of genes involved in methanol metabolism, alternate nitrogen assimilation, and DNA transcription, whereas enzymes of translation and secretion were downregulated. Several new genes were identified that could serve as possible targets for strain engineering of this yeast. Full article

(This article belongs to the Special Issue Biology, Biotechnology and Bioprospecting of Microbial Biomolecules)

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11 pages, 2178 KiB

Open AccessArticle

Improved Cordycepin Production by Cordyceps militaris KYL05 Using Casein Hydrolysate in Submerged Conditions

by Soo Kweon Lee, Ju Hun Lee, Hyeong Ryeol Kim, Youngsang Chun, Ja Hyun Lee, Hah Young Yoo, Chulhwan Park and Seung Wook Kim

Biomolecules 2019, 9(9), 461; https://doi.org/10.3390/biom9090461 - 7 Sep 2019

Cited by 37 | Viewed by 6728

Abstract

Cordycepin, a beneficial bioactive product specifically found in Cordyceps, has received attention in various bioindustrial applications such as in pharmaceuticals, functional foods, and cosmetics, due to its significant functions. However, low productivity of cordycepin is a barrier to commercialization. In this study, [...] Read more.

Cordycepin, a beneficial bioactive product specifically found in Cordyceps, has received attention in various bioindustrial applications such as in pharmaceuticals, functional foods, and cosmetics, due to its significant functions. However, low productivity of cordycepin is a barrier to commercialization. In this study, Cordyceps militaris was mutated by UV irradiation to improve the cordycepin production. The highest producer KYL05 strain was finally selected and its cordycepin production was increased about 1.5-fold compared to wild type. In addition, the effects of culture conditions were fundamentally investigated. Optimal conditions were as follows: pH 6, temperature of 25 °C, shaking speed of 150 rpm, and culture time of 6 days. Effects of medium component on cordycepin production were also investigated by using various carbon and nitrogen sources. It was found that glucose and casein hydrolysate (CH) were most effective as carbon and nitrogen sources in cordycepin production (2.3-fold improvement) with maximum cordycepin production of about 445 mg/L. In particular, production was significantly affected by CH. These results should be of value in improving the efficiency of mass production of cordycepin. Full article

(This article belongs to the Special Issue Biology, Biotechnology and Bioprospecting of Microbial Biomolecules)

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16 pages, 7516 KiB

Open AccessArticle

Mycogenic Selenium Nanoparticles as Potential New Generation Broad Spectrum Antifungal Molecules

by Shreya M. Joshi, Savitha De Britto, Sudisha Jogaiah and Shin-ichi Ito

Biomolecules 2019, 9(9), 419; https://doi.org/10.3390/biom9090419 - 28 Aug 2019

Cited by 188 | Viewed by 7339

Abstract

The current challenges of sustainable agricultural development augmented by global climate change have led to the exploration of new technologies like nanotechnology, which has potential in providing novel and improved solutions. Nanotools in the form of nanofertilizers and nanopesticides possess smart delivery mechanisms [...] Read more.

The current challenges of sustainable agricultural development augmented by global climate change have led to the exploration of new technologies like nanotechnology, which has potential in providing novel and improved solutions. Nanotools in the form of nanofertilizers and nanopesticides possess smart delivery mechanisms and controlled release capacity for active ingredients, thus minimizing excess run-off to water bodies. This study aimed to establish the broad spectrum antifungal activity of mycogenic selenium nanoparticles (SeNPs) synthesized from Trichoderma atroviride, and characterize the bioactive nanoparticles using UV–Vis spectroscopy, dynamic light scattering (DLS), Fourier transform infrared (FT-IR), X-ray diffraction (XRD), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), and high-resolution transmission electron microscopy (HR-TEM). The synthesized nanoparticles displayed excellent in vitro antifungal activity against Pyricularia grisea and inhibited the infection of Colletotrichum capsici and Alternaria solani on chili and tomato leaves at concentrations of 50 and 100 ppm, respectively. The SEM-EDS analysis of the bioactive SeNPs revealed a spherical shape with sizes ranging from 60.48 nm to 123.16 nm. The nanoparticles also possessed the unique property of aggregating and binding to the zoospores of P. infestans at a concentration of 100 ppm, which was visualized using light microscope, atomic force microscopy, and electron microscopy. Thus, the present study highlights the practical application of SeNPs to manage plant diseases in an ecofriendly manner, due to their mycogenic synthesis and broad spectrum antifungal activity against different phytopathogens. Full article

(This article belongs to the Special Issue Biology, Biotechnology and Bioprospecting of Microbial Biomolecules)

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10 pages, 1212 KiB

Open AccessCommunication

Poly-β-Hydroxybutyrate Production by the Cyanobacterium Scytonema geitleri Bharadwaja under Varying Environmental Conditions

by Manoj K. Singh, Pradeep K. Rai, Anuradha Rai, Surendra Singh and Jay Shankar Singh

Biomolecules 2019, 9(5), 198; https://doi.org/10.3390/biom9050198 - 21 May 2019

Cited by 40 | Viewed by 4634

Abstract

The production of poly-β-hydroxybutyrate (PHB) under varying environmental conditions (pH, temperature and carbon sources) was examined in the cyanobacterium Scytonema geitleri Bharadwaja isolated from the roof-top of a building. The S. geitleri produced PHB and the production of PHB was linear with the [...] Read more.

The production of poly-β-hydroxybutyrate (PHB) under varying environmental conditions (pH, temperature and carbon sources) was examined in the cyanobacterium Scytonema geitleri Bharadwaja isolated from the roof-top of a building. The S. geitleri produced PHB and the production of PHB was linear with the growth of cyanobacterium. The maximum PHB production (7.12% of dry cell weight) was recorded when the cells of S. geitleri were at their stationary growth phase. The production of PHB was optimum at pH 8.5 and 30 °C, and acetate (30 mM) was the preferred carbon source. Full article

(This article belongs to the Special Issue Biology, Biotechnology and Bioprospecting of Microbial Biomolecules)

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18 pages, 4384 KiB

Open AccessArticle

Profiling the Bacterial Diversity in a Typical Karst Tiankeng of China

by Gaozhong Pu, Yanna Lv, Lina Dong, Longwu Zhou, Kechao Huang, Danjuan Zeng, Ling Mo and Guangping Xu

Biomolecules 2019, 9(5), 187; https://doi.org/10.3390/biom9050187 - 14 May 2019

Cited by 21 | Viewed by 6126

Abstract

While karst tiankengs have a higher capacity to act as safe havens for biodiversity in changing climates, little is known about their soil microorganisms. To fill this gap, we investigate the distribution and driving factors of the bacterial community in karst tiankeng systems. [...] Read more.

While karst tiankengs have a higher capacity to act as safe havens for biodiversity in changing climates, little is known about their soil microorganisms. To fill this gap, we investigate the distribution and driving factors of the bacterial community in karst tiankeng systems. There is a significant difference in the soil characteristics between the inside and the outside of a karst tiankeng. At the karst tiankeng considered in this study, the bacterial composition, in terms of the operational taxonomic unit (OTU), was found to be significantly different in different soil samples, taken from diverse sampling sites within the collapsed doline or the external area, and showed a high habitat heterogeneity. The dominant phylum abundances vary with the sampling sites and have their own indicator taxa from phylum to genus. Unlike the primary controlling factors of plant diversity, the microclimate (soil moisture and temperature), soil pH, and slope dominated the distribution of the bacterial community in karst tiankeng systems. Our results firstly showed the distribution characteristics of bacterial communities and then revealed the importance of microhabitats in predicting the microbial distribution in karst tiankeng systems. Full article

(This article belongs to the Special Issue Biology, Biotechnology and Bioprospecting of Microbial Biomolecules)

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17 pages, 5419 KiB

Open AccessFeature PaperArticle

Cytosporone B as a Biological Preservative: Purification, Fungicidal Activity and Mechanism of Action against Geotrichum citri-aurantii

by Chunxiao Yin, Hongxin Liu, Yang Shan, Vijai Kumar Gupta, Yueming Jiang, Weimin Zhang, Haibo Tan and Liang Gong

Biomolecules 2019, 9(4), 125; https://doi.org/10.3390/biom9040125 - 29 Mar 2019

Cited by 16 | Viewed by 4169

Abstract

To prevent citrus decay caused by Geotrichum citri-aurantii, 12 natural products were isolated from two endophytic fungi, in which cytosporone B was shown to have excellent bioactivity for control of G. citri-aurantii with median effect concentration (EC₅₀) of 26.11 μg/mL [...] Read more.

To prevent citrus decay caused by Geotrichum citri-aurantii, 12 natural products were isolated from two endophytic fungi, in which cytosporone B was shown to have excellent bioactivity for control of G. citri-aurantii with median effect concentration (EC₅₀) of 26.11 μg/mL and minimum inhibitory concentration (MIC) of 105 μg/mL, and also significantly reduced the decay of sugar orange during the in vivo trials. In addition, cytosporone B could alter the morphology of G. citri-aurantii by causing distortion of the mycelia and loss of membrane integrity. Differentially expressed genes (DEGs) between cytosporone B-treated and -untreated samples were revealed by Illumina sequencing, including 3540 unigenes. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses showed that most DEGs were related to metabolic production and cell membrane. These findings suggest cytosporone B is a promising biological preservative to control citrus decay and reveal the action mechanism of cytosporone B in relation to the destruction of the fungal cell membrane at both morphological and molecular levels. Full article

(This article belongs to the Special Issue Biology, Biotechnology and Bioprospecting of Microbial Biomolecules)

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14 pages, 2831 KiB

Open AccessArticle

The Effect of Cytochalasans on the Actin Cytoskeleton of Eukaryotic Cells and Preliminary Structure–Activity Relationships

by Robin Kretz, Lucile Wendt, Sarunyou Wongkanoun, J. Jennifer Luangsa-ard, Frank Surup, Soleiman E. Helaly, Sara R. Noumeur, Marc Stadler and Theresia E.B. Stradal

Biomolecules 2019, 9(2), 73; https://doi.org/10.3390/biom9020073 - 19 Feb 2019

Cited by 38 | Viewed by 6490

Abstract

In our ongoing search for new bioactive fungal metabolites, two new cytochalasans were isolated from stromata of the hypoxylaceous ascomycete Hypoxylon fragiforme. Their structures were elucidated via high-resolution mass spectrometry (HR-MS) and nuclear magnetic resonance (NMR) spectroscopy. Together with 23 additional cytochalasans [...] Read more.

In our ongoing search for new bioactive fungal metabolites, two new cytochalasans were isolated from stromata of the hypoxylaceous ascomycete Hypoxylon fragiforme. Their structures were elucidated via high-resolution mass spectrometry (HR-MS) and nuclear magnetic resonance (NMR) spectroscopy. Together with 23 additional cytochalasans isolated from ascomata and mycelial cultures of different Ascomycota, they were tested on their ability to disrupt the actin cytoskeleton of mammal cells in a preliminary structure–activity relationship study. Out of all structural features, the presence of hydroxyl group at the C7 and C18 residues, as well as their stereochemistry, were determined as important factors affecting the potential to disrupt the actin cytoskeleton. Moreover, reversibility of the actin disrupting effects was tested, revealing no direct correlations between potency and reversibility in the tested compound group. Since the diverse bioactivity of cytochalasans is interesting for various applications in eukaryotes, the exact effect on eukaryotic cells will need to be determined, e.g., by follow-up studies involving medicinal chemistry and by inclusion of additional natural cytochalasans. The results are also discussed in relation to previous studies in the literature, including a recent report on the anti-Biofilm activities of essentially the same panel of compounds against the pathogenic bacterium, Staphylococcus aureus. Full article

(This article belongs to the Special Issue Biology, Biotechnology and Bioprospecting of Microbial Biomolecules)

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Review

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21 pages, 878 KiB

Open AccessReview

Antifungal Agents in Agriculture: Friends and Foes of Public Health

by Veronica Soares Brauer, Caroline Patini Rezende, Andre Moreira Pessoni, Renato Graciano De Paula, Kanchugarakoppal S. Rangappa, Siddaiah Chandra Nayaka, Vijai Kumar Gupta and Fausto Almeida

Biomolecules 2019, 9(10), 521; https://doi.org/10.3390/biom9100521 - 23 Sep 2019

Cited by 225 | Viewed by 14432

Abstract

Fungal diseases have been underestimated worldwide but constitute a substantial threat to several plant and animal species as well as to public health. The increase in the global population has entailed an increase in the demand for agriculture in recent decades. Accordingly, there [...] Read more.

Fungal diseases have been underestimated worldwide but constitute a substantial threat to several plant and animal species as well as to public health. The increase in the global population has entailed an increase in the demand for agriculture in recent decades. Accordingly, there has been worldwide pressure to find means to improve the quality and productivity of agricultural crops. Antifungal agents have been widely used as an alternative for managing fungal diseases affecting several crops. However, the unregulated use of antifungals can jeopardize public health. Application of fungicides in agriculture should be under strict regulation to ensure the toxicological safety of commercialized foods. This review discusses the use of antifungals in agriculture worldwide, the need to develop new antifungals, and improvement of regulations regarding antifungal use. Full article

(This article belongs to the Special Issue Biology, Biotechnology and Bioprospecting of Microbial Biomolecules)

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26 pages, 2200 KiB

Open AccessReview

Microbial Pyrrolnitrin: Natural Metabolite with Immense Practical Utility

by Shraddha Pawar, Ambalal Chaudhari, Ratna Prabha, Renu Shukla and Dhananjaya P. Singh

Biomolecules 2019, 9(9), 443; https://doi.org/10.3390/biom9090443 - 3 Sep 2019

Cited by 68 | Viewed by 7289

Abstract

Pyrrolnitrin (PRN) is a microbial pyrrole halometabolite of immense antimicrobial significance for agricultural, pharmaceutical and industrial implications. The compound and its derivatives have been isolated from rhizospheric fluorescent or non-fluorescent pseudomonads, Serratia and Burkholderia. They are known to confer biological control against [...] Read more.

Pyrrolnitrin (PRN) is a microbial pyrrole halometabolite of immense antimicrobial significance for agricultural, pharmaceutical and industrial implications. The compound and its derivatives have been isolated from rhizospheric fluorescent or non-fluorescent pseudomonads, Serratia and Burkholderia. They are known to confer biological control against a wide range of phytopathogenic fungi, and thus offer strong plant protection prospects against soil and seed-borne phytopathogenic diseases. Although chemical synthesis of PRN has been obtained using different steps, microbial production is still the most useful option for producing this metabolite. In many of the plant-associated isolates of Serratia and Burkholderia, production of PRN is dependent on the quorum-sensing regulation that usually involves N-acylhomoserine lactone (AHL) autoinducer signals. When applied on the organisms as antimicrobial agent, the molecule impedes synthesis of key biomolecules (DNA, RNA and protein), uncouples with oxidative phosphorylation, inhibits mitotic division and hampers several biological mechanisms. With its potential broad-spectrum activities, low phototoxicity, non-toxic nature and specificity for impacts on non-target organisms, the metabolite has emerged as a lead molecule of industrial importance, which has led to developing cost-effective methods for the biosynthesis of PRN using microbial fermentation. Quantum of work narrating focused research efforts in the emergence of this potential microbial metabolite is summarized here to present a consolidated, sequential and updated insight into the chemistry, biology and applicability of this natural molecule. Full article

(This article belongs to the Special Issue Biology, Biotechnology and Bioprospecting of Microbial Biomolecules)

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23 pages, 1723 KiB

Open AccessReview

Microbial Beta Glucosidase Enzymes: Recent Advances in Biomass Conversation for Biofuels Application

by Neha Srivastava, Rishabh Rathour, Sonam Jha, Karan Pandey, Manish Srivastava, Vijay Kumar Thakur, Rakesh Singh Sengar, Vijai K. Gupta, Pranab Behari Mazumder, Ahamad Faiz Khan and Pradeep Kumar Mishra

Biomolecules 2019, 9(6), 220; https://doi.org/10.3390/biom9060220 - 6 Jun 2019

Cited by 101 | Viewed by 13454

Abstract

The biomass to biofuels production process is green, sustainable, and an advanced technique to resolve the current environmental issues generated from fossil fuels. The production of biofuels from biomass is an enzyme mediated process, wherein β-glucosidase (BGL) enzymes play a key role in [...] Read more.

The biomass to biofuels production process is green, sustainable, and an advanced technique to resolve the current environmental issues generated from fossil fuels. The production of biofuels from biomass is an enzyme mediated process, wherein β-glucosidase (BGL) enzymes play a key role in biomass hydrolysis by producing monomeric sugars from cellulose-based oligosaccharides. However, the production and availability of these enzymes realize their major role to increase the overall production cost of biomass to biofuels production technology. Therefore, the present review is focused on evaluating the production and efficiency of β-glucosidase enzymes in the bioconversion of cellulosic biomass for biofuel production at an industrial scale, providing its mechanism and classification. The application of BGL enzymes in the biomass conversion process has been discussed along with the recent developments and existing issues. Moreover, the production and development of microbial BGL enzymes have been explained in detail, along with the recent advancements made in the field. Finally, current hurdles and future suggestions have been provided for the future developments. This review is likely to set a benchmark in the area of cost effective BGL enzyme production, specifically in the biorefinery area. Full article

(This article belongs to the Special Issue Biology, Biotechnology and Bioprospecting of Microbial Biomolecules)

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