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14 pages, 3915 KiB

Open AccessFeature PaperArticle

Immobilization of Laccase in β-Cyclodextrin Composite Hydrogel for Efficient Degradation of Dye Pollutants

by Hong Zhang, Zhi Wang, Fengxi Li, Lei Wang and Bo Ren

Catalysts 2024, 14(8), 473; https://doi.org/10.3390/catal14080473 - 24 Jul 2024

Cited by 1 | Viewed by 1377

A stable and efficient biocatalyst was prepared by encapsulating Trametes versicolor laccase using an acrylic acid-grafted β-cyclodextrin hydrogel (Lac-CD-PAA). Scanning electron microscopy and nitrogen adsorption-desorption experiments showed that there were regularly distributed channels in the spongy Lac-CD-PAA. In addition, a large number of [...] Read more.

A stable and efficient biocatalyst was prepared by encapsulating Trametes versicolor laccase using an acrylic acid-grafted β-cyclodextrin hydrogel (Lac-CD-PAA). Scanning electron microscopy and nitrogen adsorption-desorption experiments showed that there were regularly distributed channels in the spongy Lac-CD-PAA. In addition, a large number of mesopores and macropores existed in the wall of the hydrogel lamellae. This network structure reduced the diffusion resistance of the hydrogel to the target substrate. The relative activity of the resulting Lac-CD-PAA could be maintained at 35.8% after six cycles of use. Lac-CD-PAA exhibited higher thermal and chemical stability compared to free laccase. The negative charge on the surface of Lac-CD-PAA gives it the ability to pretreat cationic dyes. In six consecutive methylene blue decolorization tests, Lac-CD-PAA decolorized better than free laccase. The results showed that the prepared β-cyclodextrin-based composite hydrogel was a good carrier for laccase. Full article

(This article belongs to the Special Issue Enzyme Catalysis and Enzyme Engineering)

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13 pages, 4485 KiB

Open AccessArticle

Environmental Dyeing and Functionalization of Silk Fabrics with Natural Dye Extracted from Lac

by Qinru Huang, Zhao Wang, Liwei Zhao, Xiaojuan Li, Haohao Cai, Shuang Yang, Maoli Yin and Jian Xing

Molecules 2024, 29(10), 2358; https://doi.org/10.3390/molecules29102358 - 16 May 2024

Cited by 9 | Viewed by 2778

Abstract

Most traditional synthetic dyes and functional reagents used in silk fabrics are not biodegradable and lack green environmental protection. Natural dyes have attracted more and more attention because of their coloring, functionalization effects, and environmental benefits. In this study, natural dyes were extracted [...] Read more.

Most traditional synthetic dyes and functional reagents used in silk fabrics are not biodegradable and lack green environmental protection. Natural dyes have attracted more and more attention because of their coloring, functionalization effects, and environmental benefits. In this study, natural dyes were extracted from lac and used for coloring and functionalization in silk fabrics without any other harmful dyes. The extraction conditions were studied and analyzed by the univariate method. The optimal extraction process was that the volume ratio of ethanol to water was 60:40 with a solid–liquid ratio of 1:10, and reacting under the neutrality condition for 1 h at 70 °C. Silk fabric can be dyed dark owing to the certain lifting property of lac. After being dyed by Al³⁺ post-medium, the levels of the washing fastness, light fastness, and friction fastness of silk fabric are all above four with excellent fastness. The results show that the dyed silk fabrics have good UV protection, antioxidation, and antibacterial properties. The UV protection coefficient UPF is 42.68, the antioxidant property is 98.57%, and the antibacterial property can reach more than 80%. Therefore, the dyeing and functionalization of silk fabrics by utilizing naturally lac dyes show broad prospects in terms of the application of green sustainable dyeing and functionalization. Full article

(This article belongs to the Section Natural Products Chemistry)

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14 pages, 2546 KiB

Open AccessArticle

Trametes versicolor Laccase-Based Magnetic Inorganic-Protein Hybrid Nanobiocatalyst for Efficient Decolorization of Dyes in the Presence of Inhibitors

by Sanjay K. S. Patel, Rahul K. Gupta, Karthikeyan K. Karuppanan, Deepak K. Padhi, Sampathkumar Ranganathan, Parasuraman Paramanantham and Jung-Kul Lee

Materials 2024, 17(8), 1790; https://doi.org/10.3390/ma17081790 - 13 Apr 2024

Cited by 10 | Viewed by 1923

Abstract

In the present investigation, an ecofriendly magnetic inorganic-protein hybrid system-based enzyme immobilization was developed using partially purified laccase from Trametes versicolor (TvLac), Fe₃O₄ nanoparticles, and manganese (Mn), and was successfully applied for synthetic dye decolorization in the presence [...] Read more.

In the present investigation, an ecofriendly magnetic inorganic-protein hybrid system-based enzyme immobilization was developed using partially purified laccase from Trametes versicolor (TvLac), Fe₃O₄ nanoparticles, and manganese (Mn), and was successfully applied for synthetic dye decolorization in the presence of enzyme inhibitors. After the partial purification of crude TvLac, the specific enzyme activity reached 212 U∙mg total protein⁻¹. The synthesized Fe₃O₄/Mn₃(PO₄)₂-laccase (Fe₃O₄/Mn-TvLac) and Mn₃(PO₄)₂-laccase (Mn-TvLac) nanoflowers (NFs) exhibited encapsulation yields of 85.5% and 90.3%, respectively, with relative activities of 245% and 260%, respectively, compared with those of free TvLac. One-pot synthesized Fe₃O₄/Mn-TvLac exhibited significant improvements in catalytic properties and stability compared to those of the free enzyme. Fe₃O₄/Mn-TvLac retained a significantly higher residual activity of 96.8% over that of Mn-TvLac (47.1%) after 10 reuse cycles. The NFs showed potential for the efficient decolorization of synthetic dyes in the presence of enzyme inhibitors. For up to five reuse cycles, Fe₃O₄/Mn-TvLac retained a decolorization potential of 81.1% and 86.3% for Coomassie Brilliant Blue R-250 and xylene cyanol, respectively. The synthesized Fe₃O₄/Mn-TvLac showed a lower acute toxicity towards Vibrio fischeri than pure Fe₃O₄ nanoparticles did. This is the first report of the one-pot synthesis of biofriendly magnetic protein-inorganic hybrids using partially purified TvLac and Mn. Full article

(This article belongs to the Special Issue Nanoarchitectonics in Materials Science)

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12 pages, 1509 KiB

Open AccessArticle

Xenobiotic Removal by Trametes hirsuta LE-BIN 072 Activated Carbon-Based Mycelial Pellets: Remazol Brilliant Blue R Case Study

by Olga. A. Glazunova, Konstantin V. Moiseenko and Tatyana V. Fedorova

Water 2024, 16(1), 133; https://doi.org/10.3390/w16010133 - 29 Dec 2023

Cited by 7 | Viewed by 1841

Abstract

As a toxic xenobiotic compound, the anthraquinone dye Remazol Brilliant Blue R (RBBR) poses a serious threat to aquatic ecosystems. In the present study, the ability of Trametes hirsuta to remove RBBR from the medium was investigated, and the role of adsorption by [...] Read more.

As a toxic xenobiotic compound, the anthraquinone dye Remazol Brilliant Blue R (RBBR) poses a serious threat to aquatic ecosystems. In the present study, the ability of Trametes hirsuta to remove RBBR from the medium was investigated, and the role of adsorption by fungal mycelium and biodegradation by fungal enzymes was evaluated. It was shown that the whole fungal culture was able to remove up to 97% of the dye within the first four hours of incubation. Based on enzymatic activities in the culture broth, laccases were proposed to be the main enzymes contributing to RBBR degradation, and RT-qPCR measurements demonstrated an increase in transcription for the two laccase genes—lacA and lacB. Composite mycelial pellets of T. hirsuta with improved adsorption ability were prepared by adding activated carbon to the growth medium, and the induction of laccase activity by carbon was shown. For composite pellets, the RBBR decolorization degree was about 1.9 times higher at 1 h of incubation compared to carbon-free pellets. Hence, it was shown that using fungal mycelium pellets containing activated carbon can be an effective and economical method of dye removal. Full article

(This article belongs to the Special Issue Advanced Biotechnologies for Water and Wastewater Treatment)

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14 pages, 6581 KiB

Open AccessArticle

VEGFR2 Expression Correlates with Postnatal Development of Brain Arteriovenous Malformations in a Mouse Model of Type I Hereditary Hemorrhagic Telangiectasia

by Chul Han, Candice L. Nguyen, Lea Scherschinski, Tyler D. Schriber, Helen M. Arthur, Michael T. Lawton and Suk Paul Oh

Biomedicines 2023, 11(12), 3153; https://doi.org/10.3390/biomedicines11123153 - 27 Nov 2023

Cited by 4 | Viewed by 1850

Abstract

Brain arteriovenous malformations (BAVMs) are a critical concern in hereditary hemorrhagic telangiectasia (HHT) patients, carrying the risk of life-threatening intracranial hemorrhage. While traditionally seen as congenital, the debate continues due to documented de novo cases. Our primary goal was to identify the precise [...] Read more.

Brain arteriovenous malformations (BAVMs) are a critical concern in hereditary hemorrhagic telangiectasia (HHT) patients, carrying the risk of life-threatening intracranial hemorrhage. While traditionally seen as congenital, the debate continues due to documented de novo cases. Our primary goal was to identify the precise postnatal window in which deletion of the HHT gene Endoglin (Eng) triggers BAVM development. We employed SclCreER(+);Eng^2f/2f mice, enabling timed Eng gene deletion in endothelial cells via tamoxifen. Tamoxifen was given during four postnatal periods: P1–3, P8–10, P15–17, and P22–24. BAVM development was assessed at 2–3 months using latex dye perfusion. We examined the angiogenic activity by assessing vascular endothelial growth factor receptor 2 (VEGFR2) expression via Western blotting and Flk1-LacZ reporter mice. Longitudinal magnetic resonance angiography (MRA) was conducted up to 9 months. BAVMs emerged in 88% (P1–3), 86% (P8–10), and 55% (P15–17) of cases, with varying localization. Notably, the P22–24 group did not develop BAVMs but exhibited skin AVMs. VEGFR2 expression peaked in the initial 2 postnatal weeks, coinciding with BAVM onset. These findings support the “second hit” theory, highlighting the role of early postnatal angiogenesis in initiating BAVM development in HHT type I mice. Full article

(This article belongs to the Special Issue Vascular Malformation: From Pathophysiology, Clinical Manifestations to Novel Therapeutic Approaches)

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13 pages, 2572 KiB

Open AccessArticle

Improved Laccase Encapsulation in Copper-Doped Zeolitic Imidazolate Framework-8 for Reactive Black 5 Decolorization

by Shuyu Yu, Yibo Lu, Dandan Du, Rankun Wu, Xiang Ji and Hao Li

Processes 2023, 11(10), 2937; https://doi.org/10.3390/pr11102937 - 10 Oct 2023

Cited by 2 | Viewed by 1706

Abstract

As the largest group of synthetic dyes, azo dyes can pose various health and environmental risks due to their widespread use and challenging degradation. Laccases are efficient green biocatalysts for the degradation of organic pollutants. Herein, we report the in situ packaging of [...] Read more.

As the largest group of synthetic dyes, azo dyes can pose various health and environmental risks due to their widespread use and challenging degradation. Laccases are efficient green biocatalysts for the degradation of organic pollutants. Herein, we report the in situ packaging of laccase in copper-doped zeolitic imidazolate framework-8 (ZIF-8) for the decolorization of reactive black 5, which is a model azo dye. The immobilization support (Cu5/mZIF-8) was obtained via lowering the precursor ratio of ZIF-8 and incorporating copper ions during the synthesis process. Cu5/mZIF-8 were found to be nanospheres with an average diameter of around 150 nm. Laccase encapsulated in Cu5/mZIF-8 showed an activity recovery of 75.6%, which was 2.2 times higher than that of the laccase embedded in ZIF-8. Meanwhile, the immobilized laccase (Lac@Cu5/mZIF-8) showed a higher catalytic activity in organic solvents than that of the free enzyme. In the presence of a mediator, Lac@Cu5/mZIF-8 could remove 95.7% of reactive black 5 in 40 min. After four consecutive cycles, the dye decolorization efficiency declined to 28%. About four transformation products of reactive black 5 were identified via LC-MS analysis, and the potential decolorization mechanism was proposed. The results indicated that the immobilized laccase could be used as an efficient biocatalyst in dye decolorization. Full article

(This article belongs to the Special Issue Novel Materials/Technologies for the Adsorption and Removal of Antibiotics from Aqueous Solution)

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24 pages, 4809 KiB

Open AccessArticle

Improvement of Laccase Production by Thielavia terrestris Co3Bag1. Enhancing the Bio-Catalytic Performance of the Native Thermophilic TtLacA via Immobilization in Copper Alginate Gel Beads

by Marina Gutiérrez-Antón, Alejandro Santiago-Hernández, Johan Rodríguez-Mendoza, Claudia Cano-Ramírez, Ismael Bustos-Jaimes, Guillermo Aguilar-Osorio, Jorge E. Campos and María Eugenia Hidalgo-Lara

J. Fungi 2023, 9(3), 308; https://doi.org/10.3390/jof9030308 - 28 Feb 2023

Cited by 8 | Viewed by 2904

Abstract

A 32-fold increase in laccase activity production by the thermophilic biomass-degrading fungus T. terrestris Co3Bag1 was achieved when the microorganism was grown on a modified medium containing fructose, sodium nitrate, and copper. A 70 kDa laccase (TtLacA), produced under the above [...] Read more.

A 32-fold increase in laccase activity production by the thermophilic biomass-degrading fungus T. terrestris Co3Bag1 was achieved when the microorganism was grown on a modified medium containing fructose, sodium nitrate, and copper. A 70 kDa laccase (TtLacA), produced under the above conditions, was purified, immobilized in copper alginate gel beads, and characterized. TtLacA, both free and immobilized enzymes, exhibited optimal activity at pH 3.0, at a temperature of 65 and 70 °C, respectively, although both displayed 70% of activity from 40 to 70 °C. Free and immobilized enzymes retained at least 80% of relative activity in the pH range from 3 to 4.6. Immobilized TtLacA manifested a 2.3-fold higher thermal stability than the free form of the enzyme at 60 and 70 °C. Immobilized TtLacA retained 95% initial activity for six consecutive reuse cycles at 60 °C, and also retained 86% of initial activity after 12 days of storage at 4 °C. Based on the biochemical features, thermophilic TtLacA may be an efficient enzyme for dye decolorization and other industrial applications at high temperatures or acidic conditions. This work represents the first report about the immobilization and biochemical characterization of a thermophilic laccase from a member of the genus Thielavia. Full article

(This article belongs to the Special Issue Extremophile Fungi: An Arising Novel Field in Perspective)

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14 pages, 3073 KiB

Open AccessArticle

Inside the Scriptorium: Non-Invasive In Situ Identification of Dyes in Illuminated Manuscripts by Microspectrofluorimetry and Multivariate Analysis: The Crescenzago Choir Books (End 15th Century) as a Case Study

by Margherita Longoni, Noemi Hopes, Federico Rossi, Miriam Rita Tessera, Marco Petoletti and Silvia Bruni

Heritage 2023, 6(2), 2006-2019; https://doi.org/10.3390/heritage6020108 - 15 Feb 2023

Cited by 2 | Viewed by 2367

Abstract

In the present work, a method is proposed that combines spectrofluorimetry with multivariate analysis (cluster and principal components) to non-invasively investigate natural dyes used, mainly in the form of lakes, in illuminations. First, a consistent number of mock-up samples of red and purple [...] Read more.

In the present work, a method is proposed that combines spectrofluorimetry with multivariate analysis (cluster and principal components) to non-invasively investigate natural dyes used, mainly in the form of lakes, in illuminations. First, a consistent number of mock-up samples of red and purple lakes (from brazilwood, madder, kermes, cochineal, lac dye, folium and orcein) were prepared following the recipes reported in ancient treatises, then the experimental conditions for their non-invasive investigation were optimized by benchtop instrumentation and transferred to a portable microprobe suitable for in situ analyses. For all the coloring materials examined, it was thus possible to obtain a satisfactory grouping of samples containing the same dye. The analytical protocol was finally extended to the characterization of dyes in the Crescenzago choir books, illuminated manuscripts dating back to the end of the 15th century. Full article

(This article belongs to the Special Issue Photon-Based Techniques for the Examination of Cultural Heritage Artifacts)

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7 pages, 1152 KiB

Open AccessCommunication

Recovery of Lac Resin from the Aqueous Effluent of Shellac Industry

by Gaurav Badhani, Shruti Yadav, Elen Reji and Subbarayappa Adimurthy

Sustain. Chem. 2023, 4(1), 1-7; https://doi.org/10.3390/suschem4010001 - 21 Dec 2022

Cited by 5 | Viewed by 3831

Abstract

Shellac and aleuritic acid manufacturing industries generate a lot of alkaline aqueous effluent during the process of manufacture of shellac and aleuritic acid from the seedlac/sticklac. The generated effluent contains lac resin, lac wax, lac dye and other water-soluble organic acids. Shellac industries [...] Read more.

Shellac and aleuritic acid manufacturing industries generate a lot of alkaline aqueous effluent during the process of manufacture of shellac and aleuritic acid from the seedlac/sticklac. The generated effluent contains lac resin, lac wax, lac dye and other water-soluble organic acids. Shellac industries in India face problems with the disposal of aqueous effluent due to the presence of considerable amounts of natural organic molecules and the dark colour solution. To address these problems, we have developed a novel method for the selective recovery of the lac resin from the alkaline aqueous effluent of shellac manufacturing industry. The recovered lac resin has been characterized by ¹³C-NMR, FT-IR and melting point and the data were compared with standard industrial-grade resin. The recovered lac resin was evaluated by the lac manufacturing industry for commercial applications. Full article

(This article belongs to the Special Issue Alternative Solvents for Green Chemistry)

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14 pages, 3539 KiB

Open AccessReview

Unraveling the Role of Lac Insects in Providing Natural Industrial Products

by Nawaz Haider Bashir, Huanhuan Chen, Shahzad Munir, Weiwei Wang, Hang Chen, Yong-Kang Sima and Jiandong An

Insects 2022, 13(12), 1117; https://doi.org/10.3390/insects13121117 - 5 Dec 2022

Cited by 9 | Viewed by 11795

Abstract

In the current era, products made from organic materials enjoy a privileged position because of their inherent safety. The eco-friendly properties of natural lac resins have increased their demand in many industries. It is secreted by sucking insects (Hemiptera, Kerriidae) and comprises three [...] Read more.

In the current era, products made from organic materials enjoy a privileged position because of their inherent safety. The eco-friendly properties of natural lac resins have increased their demand in many industries. It is secreted by sucking insects (Hemiptera, Kerriidae) and comprises three major components, viz., resin, dye, and wax. Lac insects are generally bivoltine in nature and are distributed in tropical and sub-tropical regions with complex multi-trophic habitats. Because of their sedentary habits, lac insects are more vulnerable to predators, parasitoids, squirrels, and rats, leading to a more than 50% reduction in production yield. To increase lac production, advanced-level molecular research is required to figure out the mechanism behind lac synthesis and secretion to improve lac yield and quality. The present review highlights metamorphosis, sexual dimorphism, multi-trophic habitat, host plants, and natural enemies of lac insects, lac composition, and applications, emphasizing the role of microbes, potential lac genes, and lac synthesis mechanisms in enhancing lac quality and production. The information provided here might be useful for lac researchers and for stakeholders aiming to make their products more eco-friendly. Full article

(This article belongs to the Special Issue Insects and Art)

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23 pages, 199201 KiB

Open AccessArticle

Investigation of Gold Gilding Materials and Techniques Applied in the Murals of Kizil Grottoes, Xinjiang, China

by Jie Yang, Zhibo Zhou, Tianji Lu and Ling Shen

Appl. Sci. 2022, 12(21), 11202; https://doi.org/10.3390/app122111202 - 4 Nov 2022

Cited by 7 | Viewed by 2414

Abstract

The present work reports the identification of inorganic and organic materials applied in gildings of Kizil Grottoes mural paintings, located in the western part of China. A total of 10 gold gilding samples were collected from caves dated in the fourth–seventh century AD. [...] Read more.

The present work reports the identification of inorganic and organic materials applied in gildings of Kizil Grottoes mural paintings, located in the western part of China. A total of 10 gold gilding samples were collected from caves dated in the fourth–seventh century AD. In this research, optical microscopy, scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDX), UV fluorescence microscopy, and pyrolysis gas chromatography–mass spectrometry (Py-GC/MS) analyses were carried out to clarify the mordant materials and the coating materials on the foils. This research reports some new finds of the gilding technique in Kizil grottoes, such as oil and lac resin being used as mordant to provide a binding medium for gold gilding, gold powder probably being used as pigment, and some organic dyes being well preserved under gold foil. These interesting findings not only provide scientific evidence for us to understand the materials and techniques of gold gildings on Kizil Grottoes murals, but also illustrate material trade and technique exchanges along the Silk Road in the past. Full article

(This article belongs to the Special Issue Organic Materials in the Wall Paintings)

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12 pages, 2089 KiB

Open AccessArticle

Characterization of Potential Molecular Markers in Lac Insect Kerria lacca (Kerr) Responsible for Lac Production

by Nawaz Haider Bashir, Weiwei Wang, Xiaofei Ling, Jinwen Zhang, Qin Lu, Rui He and Hang Chen

Insects 2022, 13(6), 545; https://doi.org/10.3390/insects13060545 - 14 Jun 2022

Cited by 2 | Viewed by 3701

Abstract

Kerria lacca (Kerr) is an important lac insect extensively used in industrial products in the form of resin, wax and dye. The scarce knowledge on molecular markers for K. lacca is a barrier in elucidating genetic information. Our study identified a total of [...] Read more.

Kerria lacca (Kerr) is an important lac insect extensively used in industrial products in the form of resin, wax and dye. The scarce knowledge on molecular markers for K. lacca is a barrier in elucidating genetic information. Our study identified a total of 16,921 single-nucleotide polymorphisms (SNPs), and 6231 insertions and deletions (InDels)—of which, intergenic variation accounted for 41.22% and 56.30%, and exonic variation accounted for 39.10% and 17.46%, of SNPs and InDels, respectively. Observation of SNPs suggested that nucleotide substitution frequency and transition to transversion (Ts/Tv) ratio were highest at the late adult stage, 3.97, compared to at the other stages, with a genome-wide Ts/Tv ratio of 2.95. The maximum number of SNPs, 2853 (16.86%), was identified in chromosome 8, while the lowest, 1126 (6.65%), was identified in chromosome 7. The maximum and minimum numbers of InDels were located on chromosome 1 and 7, with 834 (13.38%) and 519 (8.33%), respectively. Annotation showed that highest numbers of exonic and intergenic SNPs were present at the late adult stage, whereas the maximum number of InDels was found at the larval stage. On the basis of gene function, 47 gene variations were screened and 23 candidate genes were identified in associations with lac production. Concluding work will enhance knowledge on molecular markers to facilitate an increase in lac production in K. lacca as well as other lac insects. Full article

(This article belongs to the Special Issue Insects and Art)

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17 pages, 4520 KiB

Open AccessArticle

Biochemical and Structural Properties of a High-Temperature-Active Laccase from Bacillus pumilus and Its Application in the Decolorization of Food Dyes

by Tao Li, Xiuxiu Chu, Zhaoting Yuan, Zhiming Yao, Jingwen Li, Fuping Lu and Yihan Liu

Foods 2022, 11(10), 1387; https://doi.org/10.3390/foods11101387 - 11 May 2022

Cited by 17 | Viewed by 2986

Abstract

A novel laccase gene isolated from Bacillus pumilus TCCC 11568 was expressed, and the recombinant laccase (rLAC) displayed maximal activity at 80 °C and at pH 6.0 against ABTS. rLAC maintained its structural integrity at a high temperature (355 K) compared to its [...] Read more.

A novel laccase gene isolated from Bacillus pumilus TCCC 11568 was expressed, and the recombinant laccase (rLAC) displayed maximal activity at 80 °C and at pH 6.0 against ABTS. rLAC maintained its structural integrity at a high temperature (355 K) compared to its tertiary structure at a low temperature (325 K), except for some minor adjustments of certain loops. However, those adjustments were presumed to be responsible for the formation of a more open access aisle that facilitated the binding of ABTS in the active site, resulting in a shorter distance between the catalytic residue and the elevated binding energy. Additionally, rLAC showed good thermostability (≤70 °C) and pH stability over a wide range (3.0–10.0), and displayed high efficiency in decolorizing azo dyes that are applicable to the food industry. This work will improve our knowledge on the relationship of structure–function for thermophilic laccase, and provide a candidate for dye effluent treatment in the food industry. Full article

(This article belongs to the Special Issue Environmentally Friendly Manufacturing of Food Additives and Functional Ingredients)

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15 pages, 4422 KiB

Open AccessArticle

Combination of Pre- and Post-Mercerization Processes for Cotton Fabric

by Lina Lin, Tiancheng Jiang, Yonghong Liang, Wenju Zhu, Umarsharif Y. Inamdar, Md. Nahid Pervez, Rahul Navik, Xiaojun Yang, Yingjie Cai and Vincenzo Naddeo

Materials 2022, 15(6), 2092; https://doi.org/10.3390/ma15062092 - 11 Mar 2022

Cited by 19 | Viewed by 5682

Abstract

The dyeing process commonly deteriorates the luster of pre-mercerized cotton fabric, so post-mercerization processes are regularly applied to compensate for this. Herein, the influence of combining pre-mercerization with CS (caustic solution) or LA (liquid ammonia) and post-mercerization with CS or LA on the [...] Read more.

The dyeing process commonly deteriorates the luster of pre-mercerized cotton fabric, so post-mercerization processes are regularly applied to compensate for this. Herein, the influence of combining pre-mercerization with CS (caustic solution) or LA (liquid ammonia) and post-mercerization with CS or LA on the morphological structure, dyeing performance, tensile strength, and stiffness of woven cotton fabric was investigated. The crystallinity index values greatly decreased from 73.12 to 51.25, 58.73, 38.42, and 40.90% after the combined mercerization processes of LA–LA, CS–CS, LA–CS, and CS–LA, respectively. Additionally, the CS–LA- and LA–CS-treated samples exhibited a mixture of cellulose II and cellulose III allomorphs. The combined mercerization processing of cotton fabric resulted in slightly worse thermal stability. The LA and CS pre-mercerization processes increased the dye exhaustion, although the former decreased the dye fixation rate while the latter increased it by 4% for both dyes. The color strength of the dyed cotton fabric increased after both post-mercerization processes. Moreover, the fabric stiffness and mechanical properties showed an increasing trend due to the combined mercerization efforts. Full article

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13 pages, 2281 KiB

Open AccessArticle

Characterization of a Recombinant Laccase B from Trametes hirsuta MX2 and Its Application for Decolorization of Dyes

by Yitong Jia, Qianqian Huang, Lanlan Zhu and Chengyuan Pan

Molecules 2022, 27(5), 1581; https://doi.org/10.3390/molecules27051581 - 27 Feb 2022

Cited by 16 | Viewed by 3064

Abstract

Trametes hirsuta is able to secrete laccase isoenzymes including constitutive and inducible forms, and has potential application for bioremediation of environmental pollutants. Here, an inducible group B laccase from T. hirsuta MX2 was heterologously expressed in Pichia pastoris, and its yield reached [...] Read more.

Trametes hirsuta is able to secrete laccase isoenzymes including constitutive and inducible forms, and has potential application for bioremediation of environmental pollutants. Here, an inducible group B laccase from T. hirsuta MX2 was heterologously expressed in Pichia pastoris, and its yield reached 2.59 U/mL after 5 days of methanol inducing culture. The optimal pH and temperature of recombinant laccase (rLac1) to 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) were 2.5 and 60 °C, respectively. Metal ions showed different effect on rLac1 which Mg²⁺, Cu²⁺, and K⁺ increased enzyme activity as their concentration increased, whereas Zn²⁺, Na⁺, and Fe²⁺ inhibited enzyme activity as their concentration increased. rLac1 showed good tolerance to organic solvents, and more than 42% of its initial activity remained in 10% organic solvents. Additionally, rLac1 exhibited a more efficient decolorization ability for remazol brilliant blue R (RBBR) than for acid red 1 (AR1), crystal violet (CV), and neutral red (NR). Molecular docking results showed RBBR has a stronger binding affinity with laccase than other dyes by interacting with substrate binding cavity of enzyme. The results indicated rLac1 may be a potential candidate for dye removal from textile wastewater. Full article

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