Search Results (31)

Goats are considered to be the ideal climate-resilient animal species in the tropics. Fewer studies are documented assessing the heat stress response of caprine ruminal microbiota, which can also be a crucial indicator of the resilience and/or adaptability of animals. This study was conducted to comparatively assess the heat stress responses of two indigenous goat breeds, Nandidurga and Bidri, based on changes associated with the rumen fermentation pattern and distribution pattern of rumen microbiota. A total of 24 adult animals were randomly allocated into four groups of six animals each, NC (n = 6; Nandidurga control), NHS (n = 6; Nandidurga heat stress), BC (n = 6; Bidri control) and BHS (n = 6; Bidri heat stress). The animals were reared in climate chambers for a duration of 45 days wherein the NC and BC animals were maintained under thermoneutral temperature while the NHS and BHS animals were subjected to simulated heat stress. Heat stress was observed to significantly reduce the rumen ammonia, extracellular CMCase, intracellular carboxy methyl cellulase (CMCase) and total CMCase both in Nandidurga and Bidri goats. In addition to this, a significant reduction in acetate, propionate and total volatile fatty acids (VFAs) was observed in Nandidurga goats. The V3–V4 16s rRNA sequencing further revealed a significant alteration in the rumen microbiota in heat-stressed Nandidurga and Bidri goats. While both the breeds exhibited nearly similar responses in the rumen microbial abundance levels due to heat stress, breed-specific differences were also observed. Furthermore, the LEFSe analysis revealed a significant alteration in the abundances of microbes at the genus level, which were observed to be relatively greater in Bidri goats than Nandidurga goats. Furthermore, these alterations were predicted to impair the functional pathways, especially pathways associated with metabolism. This study therefore provided an insight into the rumen microbial dynamics in heat-stressed goats. Though both the breeds exhibited excellent resilience to the subjected heat stress, there were relatively less ruminal alterations in Nandidurga goats than in Bidri goats. Full article

Annually, a considerable amount of agricultural waste is produced leading to serious environmental pollution if not managed effectively. A wide range of bio-decomposers, including fungi, bacteria, and actinomycetes may break down the complex agro-residues in an eco-friendly way through secreting many cellulolytic and amylolytic enzymes. The present study aimed at exploring the ability of Frankia to degrade cellulose and starch and identifying the cellulase and α-amylase genes in Frankia genomes for potential agricultural waste degradation. Frankia alni ACN14a and Frankia casuarinae CcI₃ produced clear zones around growing hyphae on carboxymethyl cellulose (CMC) and starch substrates. The hydrolytic index (HI) ranged from 1 to 2.14 reflecting variation in their degradation efficacy. Quantification of CMCase (carboxymethyl cellulase) production in strain ACN14a presented the maximum activity (0.504 U/mL) under 1% CMC after 16 days whereas strain CcI₃ produced a weak activity after 6 days from incubation. Besides, amylase activity in strain ACN14a reached the highest value (3.215 U/mL) after 4 days of growing with 1% starch, while strain CcI₃ had the superior production (3.04 U/mL) after 12 days from 1% starch condition. Data mining and genome blasting led to the identification of multiple genes related to cellulose and starch degradation. Two endoglucanases (celA1, FRAAL4955 and celA2, FRAAL4956), two glycosyl hydrolase family 16 (FRAAL6120 and FRAAL2663), and one glycosyl hydrolase family 16 (Francci3_3843) were predicted in the two genomes. Likewise, the α-amylase genes (FRAAL5900) from Frankia alni ACN14a and (Francci3_3679) from strain CcI₃ were identified. The gene expression of endo-1, 4-beta-glucanase (celA2, FRAAL4956) revealed the maximum increment in its mRNA abundance under 0.25% CMC exposure and showed a 3.3-fold increase. Frankia capability to degrade cellulose and starch represents a critical process in nutrient cycling and environment protection. Full article

Agaricus bisporus is popular worldwide because of its high nutritional value and low cost. Low-temperature storage is a common storage method used for the production and sales of A. bisporus cultivation spawn, but few studies have focused on the physiological and biochemical mechanisms associated with low-temperature storage of A. bisporus cultivation spawn. In this study, we examined A. bisporus spawn samples stored for different refrigeration periods (0, 20, 40, 60, 80, and 100 days), measured changes in the activities of four key extracellular enzymes and performed transcriptomic and metabolomic analyses. The results of the enzymatic assays revealed that the activities of carboxymethyl cellulase (CMCase), amylase, and acid protease initially decreased before increasing, whereas laccase activity showed the opposite trend. This pattern may represent an energy supply mechanism adopted by A. bisporus to cope with low temperatures, where extracellular enzymes indirectly influence survival by mediating substrate decomposition. Further correlation analysis on the basis of CMCase activity changes revealed 148 carboxymethyl cellulase-correlated metabolites (CCMs) and 514 carboxymethyl cellulase-correlated genes (CCGs) (p ≤ 0.05), and significance was determined at FDR < 0.05 with a fold change > 1.5. Among these, 56.08% of the CCMs and 63.04% of the CCGs presented positive correlations with CMCase activity, whereas 43.92% and 36.96% presented negative correlations, respectively. Integrated multiomics analysis revealed significant variations in metabolic flux and gene expression across different storage durations. Two CCMs (ketoleucine and 3-methyl-2-oxovaleric acid) gradually decreased in expression, whereas two CCGs (AbbBCAT and AbbAACS) increased in expression. This study provides novel insights into the molecular adaptation of A. bisporus spawn to refrigeration, highlighting the importance of branched-chain amino acid metabolism in the cold stress response and storage stability. Full article

Efficient hydrolysis of cellulose in agricultural waste (e.g., coconut fiber) is critical for biorefining processes such as second-generation bioethanol (2G ethanol) production. However, free cellulases suffer from low thermal stability and challenges in recovery. To address this, we developed cross-linked enzyme aggregates (CLEAs) combined with magnetic nanoparticles (magnetic CLEAs, m-CLEAs) to enhance enzyme stability and reusability. In this context, solutions of ethanol, acetone, and ammonium sulfate were used to prepare enzymatic aggregates, with subsequent use of glutaraldehyde and magnetic nanoparticles to obtain the biocatalysts. The addition of bovine serum albumin (BSA) protein was also tested to improve immobilization. Biocatalysts with ethanol and acetone performed better. Acetone (AC) and BSA yielded the highest enzymatic activities (287.27 ± 42.59 U/g for carboxymethyl cellulase (CMCase) with Celluclast; 425.37 ± 48.11 U/g for CMCase with Cellic CTec2). Magnetic nanoparticles were incorporated to expand the industrial applicability, producing m-CLEAs with excellent thermal stability and high catalytic activities. The m-CLEA–Celluclast–AC–BSA–GA 5% maintained 58% of its activity after 72 h at 70 °C. The m-CLEA–Celluclast-AC–BSA–GA 2.5% proved effective in hydrolyzing coconut fiber and isolated cellulose, producing up to 0.91 ± 0.01 g/L of glucose and 2.7 ± 0.15 g/L of glucose, respectively, after 72 h. Therefore, this approach supports sustainability by using coconut fiber, which is often discarded into the environment. Full article

The valorization of agricultural residues, particularly corn stover, represents a sustainable approach for resource utilization and protein production in which high-performing microbial strains are essential. This study systematically evaluated fungal lignocellulolytic capabilities during corn stover solid-state fermentation and employed atmospheric and room-temperature plasma (ARTP) mutagenesis to enhance the degradative capacity of Trichoderma longibrachiatum. Comparative screening revealed that T. longibrachiatum exhibited superior comprehensive degradation of the major lignocellulosic components compared to other tested strains. ARTP mutagenesis yielded mutant strain TL-MU07, which displayed significantly enhanced enzymatic capabilities with improvements in FPase (22.1%), CMCase (10.1%), and xylanase (16.1%) activities, resulting in increased cellulose degradation (14.6%) and protein accumulation (14.7%). Proteomic analysis revealed 289 significantly differentially expressed proteins, with pathway enrichment demonstrating enhancement of glycosaminoglycan degradation, amino sugar metabolism, and membrane remodeling. Key mechanistic adaptations included downregulation of Zn(2)-C6 transcriptional repressors, upregulation of detoxification enzymes (ALDH-like proteins), and enhanced secretory pathway components. The ARTP-derived mutant strain TL-MU07 represents a valuable microbial resource for agricultural waste bioconversion, offering enhanced lignocellulolytic capabilities for industrial applications while elucidating specific proteomic changes associated with improved biomass degradation efficiency for sustainable protein production in the circular bioeconomy. Full article

Citric acid by-products in animal feed pose a sustainability challenge. Bacillus species are commonly used for fermenting and improving the nutritional quality of feedstuffs or by-products. An experiment was conducted to enhance the nutritional value of citric acid by-products through fermentation with Bacillus subtilis I9 for animal feed. The experiment was carried out in 500 mL Erlenmeyer flasks with 50 g of substrate and 200 mL of sterile water. Groups were either uninoculated or inoculated with B. subtilis I9 at 10⁷ CFU/mL. Incubation occurred at 37 °C with automatic shaking at 150 rpm under aerobic conditions for 0, 24, 48, 72, and 96 h. Inoculation with B. subtilis I9 significantly increased Bacillus density to 9.3 log CFU/mL at 24 h (p < 0.05). CMCase activity gradually increased, reaching a maximum of 9.77 U/mL at 72 h. After 96 h of fermentation with inoculated B. subtilis I9, the citric acid by-product exhibited a significant decrease (p < 0.05) in crude fiber by 10.86%, hemicellulose by 20.23%, and cellulose by 5.98%, but an increase in crude protein by 21.89%. Gross energy decreased by 4% after inoculation with B. subtilis in comparison to the uninoculated control (p < 0.05). Additionally, the non-starch polysaccharide (NSP) degradation due to inoculation with B. subtilis I9 significantly reduced (p < 0.05) NSP by 24.37%, while galactose, glucose, and uronic acid decreased by 22.53%, 32.21%, and 18.11%, respectively. Amino acid profile content increased significantly by more than 12% (p < 0.05), including indispensable amino acids such as histidine, isoleucine, lysine, methionine, phenylalanine, tryptophan, and valine and dispensable amino acids like alanine, aspartic acid, glutamic acid, glutamine, glycine, proline, and tyrosine. Furthermore, citric acid by-products inoculated with B. subtilis I9 exhibited changes in the cell wall structure under scanning electron microscopy, including fragmentation and cracking. These results suggest that fermenting citric acid by-products with B. subtilis I9 effectively reduces dietary fiber content and improves the nutritional characteristics of citric acid by-products for use in animal feed. Full article

The objective of this study was to assess the cellulase production of four fungi: Aspergillus terreus NIH2624, Aspergillus clavatus NRRL1, Aspergillus versicolor CBS583.65 and Aspergillus phoenicis ATCC3157, under submerged cultivation conditions. When these fungi were cultured in shake flasks using Mandels and Weber’s minimal medium with 1% sugarcane bagasse as a carbon source and 1.8 g/L of rice bran extract as a nitrogen source, A. terreus showed maximum cellulase production (filter paper activity (FPase) 3.35 U/mL; carboxymethyl cellulase activity (CMCase) 1.69 U/mL). Consequently, A. terreus was selected for the optimization study for cellulase production. Among the different tested carbon sources, A. terreus showed higher CMCase activity when it was cultivated on delignified sugarcane bagasse (1.64 U/mL) and higher FPase activity on sugarcane straw (7.95 U/mL). Regarding the nitrogen sources, the maximum FPase activity was observed when using rice bran (FPase, 8.90 U/mL) and soybean meal (FPase, 9.63 U/mL). The optimized fermentation medium (minimal medium with delignified sugarcane bagasse and rice bran as carbon and nitrogen sources, respectively) resulted in an enzymatic cocktail mainly composed of xylanases, with a maximum activity of 1701.85 U/mL for beechwood xylan, 77.12 U/mL for endoglucanase and 21.02 U/mL for cellobiohydrolase. Additionally, the enzymatic cocktail showed efficient activities for β-glucosidase, β-xylanase, arabinofuranosidase and lytic polysaccharide monoxygenases (LPMOs). This cellulase enzyme solution has the potential to efficiently hydrolyze lignocellulosic biomass, producing second-generation sugars in biorefineries. Full article

The spectrum of enzymes required for complete lignocellulosic waste hydrolysis is too diverse to be secreted by a single organism. An alternative is to employ fungal co-cultures to obtain more diverse and complete enzymatic cocktails without the need to mix enzymes during downstream processing. This study evaluated the co-cultivation of Aspergillus brasiliensis and Trichoderma reesei RUT-C30 in different conditions using sugarcane bagasse as the carbon source. The resulting enzymatic cocktails were characterized according to the impact of strain inoculation time on enzymatic activities and proteome composition. Data revealed that the profile of each enzymatic extract was highly dependent on the order in which the participating fungi were inoculated. Some of the co-cultures exhibited higher enzyme activities compared to their respective monocultures for enzymes such as CMCase, pectinase, β-glucosidase, and β-xylosidase. Analysis of the T. reesei RUT-C30 and A. brasiliensis co-culture secretome resulted in the identification of 167 proteins, with 78 from T. reesei and 89 from A. brasiliensis. In agreement with the enzymatic results, proteome analysis also revealed that the timing of inoculation greatly influences the overall secretome, with a predominance of T. reesei RUT-C30 proteins when first inoculated or in simultaneous inoculation. Full article

Brown-rot fungi are large fungi that can decompose the cell walls of wood; they are notable for their secretion of diverse and complex enzymes that synergistically hydrolyze natural wood cellulose molecules. Fomitopsis pinicola (F. pinicola) is a brown-rot fungus of interest for its ability to break down the cellulose in wood efficiently. In this study, through a combination of rDNA-ITS analysis and morphological observation, the wood decay pathogen infecting Korean pine (Pinus koraiensis Siebold and Zucc.) was identified. Endoglucanase (CMCase) and β-glucosidase were quantified using the DNS (3,5-Dinitrosalicylic acid) method, and the cellulase activity was optimized using a single-factor method and orthogonal test. The results revealed that the wood-decaying fungus NE1 identified was Fomitopsis pinicola with the ITS accession number OQ880566.1. The highest cellulase activity of the strain reached 116.94 U/mL under the condition of an initial pH of 6.0, lactose 15 g·L⁻¹, KH₂PO₄ 0.5 g·L⁻¹, NH₄NO₃ 15 g·L⁻¹, MgSO₄ 0.5 g·L⁻¹, VB₁ 0.4 g·L⁻¹, inoculated two 5 mm fungal cakes in 80 mL medium volume cultured 28 °C for 5 days. This laid a foundation for improving the degradation rate of cellulose and biotransformation research, as well as exploring the degradation of cellulose by brown rot fungi. Full article

The improper treatment of crop straw not only leads to resource wastage but also adversely impacts the ecological environment. However, the application of microorganisms can accelerate the decomposition of crop straw and improve its utilization. In this study, cellulose-degrading microbial strains were isolated from naturally decayed corn straw and screened using Congo red staining, along with assessing variations in carboxymethyl cellulase (CMCase) activity, filter paper enzyme (FPase) activity and β-glucosidase (β-Gase) activity, as well as the degradation rate. The eight strains, namely Neurospora intermedia isolate 29 (A1), Streptomyces isolate FFJC33 (A2), Gibberella moniliformis isolate FKCB-009 (A3), Fusarium fujikuroi isolate EFS3(2) (A4), Fusarium Fujikuroi isolate FZ04 (A5), Lysine bacillus macroides strain LNHL43 (B1), Bacillus subtilis strain MPF30 (B2) and Paenibacilli lautus strain ALEB-P1 (C), were identified and selected for microbial strain consortium design based on their high activities of CMCase, FPase and β-Gase. The fungi, bacteria and actinomycete strains were combined without antagonistic effects on corn straw decomposition. The results showed the A2B2 combination had a significantly higher FPase at 55.44 U/mL and β-Gase at 25.73 U/mL than the other two strain combinations (p < 0.05). Additionally, the degradation rate of this combination was 40.33%, which was considerably higher than that of the other strains/consortia. The strain combination A4B2C also had superior enzyme activity, including CMCase with a value of 35.03 U/mL, FPase with a value of 63.59 U/mL and β-Gase with a value of 26.15 U/mL, which were significantly different to those of the other three strain combinations (p < 0.05). Furthermore, seven single microbial strains with high cellulase activities were selected to construct various microbial consortiums for in situ composting in order to evaluate their potential. Taken as a whole, the results of composting, including temperature, moisture content, pH, E4/E6 value and seed germination index, indicated that the microbial strain consortium consisting of Neurospora intermediate isolate 29, Fusarium fujikuroi isolate EFS3(2), Fusarium fujikuroi isolate FZ04, Lysinibacillus macrolides, Lysinibacillus sphaericus, Bacillus subtilis and Paenibacillus lautus was advantageous for corn straw decomposition and yielded high-quality compost. The screened flora was able to effectively degrade corn straw. This study provides a novel solution for the construction of a microbial consortium for the composting of corn straw. Full article

Enzymatic degradation of cellulosic biomass represents the most sustainable and environmentally friendly method for producing liquid biofuel, widely utilized in various commercial processes. While cellulases are predominantly produced by bacteria and fungi, the enzymatic potential of cellulase-producing yeasts remains significantly less explored. In this study, the yeast strain Trichosporon insectorum, isolated from the gut of the coprophagous beetle Gymnopleurus sturmii, was utilized for cellulase production in submerged fermentation. A central composite design was employed to optimize cellulase production, with substrate concentration, temperature, and pH as dependent variables. The highest CMCase activity of 0.71 IU/mL was obtained at 1% substrate concentration, pH 5, and an incubation temperature of 40 °C for 72 h of fermentation using cellulose as a carbon source. For FPase production, the high value was 0.23 IU/mL at 0.5% CMC, pH 6, and an incubation temperature of 40 °C for 72 h. After purification, the enzymes produced by T. insectorum represent 39% of the total proteins. The results of this study offer an alternative strategy for utilizing various carbon sources, both soluble (CMC, carboxymethylcellulose) and insoluble (cellulose), to efficiently produce cellulase for the degradation of lignocellulosic materials. This approach holds promising benefits for sustainable waste management. Full article

The industrial processing of coconut to produce valuable foods, such as water and milk, generates large volumes of waste, especially the fruit shell. Despite this, material can be used in bioprocess applications, e.g., the production of enzymes, its recalcitrance hinders the cultivation of microorganisms, and low productivity is usually achieved. In this study, the production of cellulolytic enzymes through solid-state fermentation (SSF) and their extraction was investigated using the green coconut fiber pretreated by steam explosion, followed by alkali. The fungus Trichoderma reesei CCT-2768 was cultivated, using an experimental design, to study the effect of the water activity and the amount of biomass in the reactor. The combination of the pretreatment strategies yielded more porous biomass, with less hemicellulose (5.38%, compared to 10.15% of the raw biomass) and more cellulose (47.77% and 33.96% in the pretreated and raw biomasses, respectively). The water activity significantly affected the production of cellulases, with maximum activity yielded at the highest investigated value (0.995). Lastly, the extraction of the enzymes from the cultivation medium was studied, and a 9 g/L NaCl solution recovered the highest CMCase and FPase activities (5.19 and 1.19 U/g, respectively). This study provides an important contribution to the valorization of the coconut residue through (i) the application of the steam explosion technology to optimize the production of cellulases using the SSF technology and (ii) their extraction using different solvents. Full article

An abundance of refractory cellulose is the key limiting factor restricting the resource utilization efficiency of silkworm (Bombyx mori) excrement via composting. Screening for cellulose-degrading bacteria is likely to provide high-quality strains for the safe and rapid decomposition of silkworm excrement. In this study, bacteria capable of degrading cellulose with a high efficiency were isolated from silkworm excrement and the conditions for cellulase production were optimized. The strains were preliminarily screened via sodium carboxymethyl cellulose culture and staining with Congo red, rescreened via a filter paper enzyme activity test, and identified via morphological observation, physiological and biochemical tests, and phylogenetic analysis of the 16S rDNA sequence. Enzyme activity assay was performed using the 3,5-dinitrosalicylic acid method. DC-11, a highly cellulolytic strain, was identified as Bacillus subtilis. The optimum temperature and pH of this strain were 55 °C and 6, respectively, and the filter paper enzyme activity (FPase), endoglucanase activity (CMCase), and exoglucanase activity (CXase) reached 15.40 U/mL, 11.91 U/mL, and 20.61 U/mL. In addition, the cellulose degradation rate of the treatment group treated with DC-11 was 39.57% in the bioaugmentation test, which was significantly higher than that of the control group without DC-11 (10.01%). Strain DC-11 was shown to be an acid-resistant and heat-resistant cellulose-degrading strain, with high cellulase activity. This strain can exert a bioaugmentation effect on cellulose degradation and has the potential for use in preparing microbial inocula that can be applied for the safe and rapid composting of silkworm excrement. Full article

Light is known to impact various aspects of Trichoderma, with possible implications for industrial and agricultural applications. In this study, we investigated the irradiation of Trichoderma atroviride with blue light using a laser source system. We determined the cellulase and protease activities and the effects of UV–Vis absorption of the filtrated culture on conidia formation, dimension, and behavior, and on the apparent chlamydospore abundance, as a function of irradiation duration, dose of irradiation, and moment of irradiation. We show that the effects on the enzymatic activities range from positive to neutral to negative. Compared with previous studies, our stimulation with light does not show a drastic negative effect on the cellulase (CMC-ase) activity, but it seems to delay the maximum activity over time. The effects on the proteases are partially in agreement with the only previous study reported for the light effects on protease activity. The number of conidia is increased upon irradiation, representing an expected behavior, and we show for the first time to the best of our knowledge that the conidia dimensions and chlamydospore number also increase. Our data also suggest that the highest dose resulted in the conidia clustering around the liquid–air interface, suggesting an increased hydrophobic character. Full article

Cellulase and xylanase have been widely studied for bioconversion processes and applied in various industries. The high cost of these enzymes remains to be the major bottleneck for large-scale commercial application of lignocellulosic biorefinery. The use of agroindustrial residues and weeds as fermentation substrates is an important strategy to increase cellulolytic enzymes production and reduce costs. Penicillium crustosum was newly isolated and selected to study its enzyme production during solid-state fermentation (SSF). Natural and pretreated water hyacinth (WH) biomass was used as support, substrate and inducer of cellulases and xylanases. Thermochemical pretreatments of WH biomass at 121 °C and sulfuric acid at three concentrations (0.2, 0.6 and 1 M) were assayed. The pretreatments of WH biomass released mono- and oligo-saccharides that favored fungal growth and enzymes production on SSF. WH is a cost-effective substrate-support and inducer, which to be used as a solid medium, was impregnated with a saline solution, containing only (NH₄)₂SO₄, KH₂PO₄ y MgCl₂. Maximum cellulases (carboxymethylcellulase (CMCase)) and xylanases productions of P. crustosum cultured on SSF were reached using the WH pretreated biomass with H₂SO₄ 0.6 M and 121 °C. The simultaneous CMCase and xylanases production reached (647.51 and 4257.35 U/g dry WH, respectively) are among the highest values ever reported. Full article