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Yan M, Wang Z, Zhou H, Chen Y, Saeed M, Xu Y, Chen Y, Ni Z, Fang Z, Chen H. Exploring the potential of spore surface-displayed keratinase for feather waste degradation using high-throughput screening. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2025. [PMID: 40364644 DOI: 10.1002/jsfa.14361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2025] [Revised: 03/12/2025] [Accepted: 03/28/2025] [Indexed: 05/15/2025]
Abstract
BACKGROUND With the development of the global poultry industry, millions of tons of feathers are produced each year. A significant proportion is improperly discarded, leading to a substantial loss of keratin resources from feathers. Utilizing feathers in the feed industry could reduce costs substantially. However, the new fermented feed industry lacks acid-resistant keratinase, making it unable to convert feather keratin effectively in a lactic acid bacteria fermentation environment. RESULTS This study established a high-throughput screening method using spore surface-display to identify acid-resistant mutants generated by error-prone PCR. A mutant H4 (N43K/N143I) was obtained with a significant increase in activity under acidic conditions, and it was 1.34-fold more active than the wild type in a pH 5 environment. Bioinformatic analysis showed that the increase in stress resistance and activity of H4 was due to an increase in certain weak interaction forces and alterations in energy levels. The addition of H4 spore suspension as an enzyme preparation to feather meal fermentation feed with the participation of lactic acid bacteria improved the content of small peptides and free amino acids significantly. After being subjected to short-term high-temperature treatments, the H4 spore preparation was still able to degrade chicken feathers. CONCLUSION These results suggest that the spore surface-displayed keratinase mutant H4 has potential for improved effectiveness in feather degradation within the fermented feed industry. © 2025 Society of Chemical Industry.
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Affiliation(s)
- Mingchen Yan
- School of the Life Sciences, Jiangsu University, Zhenjiang, China
| | - Zhen Wang
- School of the Life Sciences, Jiangsu University, Zhenjiang, China
| | - Huimin Zhou
- School of the Life Sciences, Jiangsu University, Zhenjiang, China
| | - Yanzhen Chen
- School of the Life Sciences, Jiangsu University, Zhenjiang, China
| | - Muhammad Saeed
- School of the Life Sciences, Jiangsu University, Zhenjiang, China
- Department of Poultry Science, The Cholistan University of Veterinary and Animal Sciences, Bahawalpur, Pakistan
| | - Yudan Xu
- School of the Life Sciences, Jiangsu University, Zhenjiang, China
| | - Ying Chen
- School of the Life Sciences, Jiangsu University, Zhenjiang, China
| | - Zhong Ni
- School of the Life Sciences, Jiangsu University, Zhenjiang, China
| | - Zhen Fang
- School of the Life Sciences, Jiangsu University, Zhenjiang, China
| | - Huayou Chen
- School of the Life Sciences, Jiangsu University, Zhenjiang, China
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2
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Das S, Das A, Das N, Nath T, Langthasa M, Pandey P, Kumar V, Choure K, Kumar S, Pandey P. Harnessing the potential of microbial keratinases for bioconversion of keratin waste. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024; 31:57478-57507. [PMID: 38985428 DOI: 10.1007/s11356-024-34233-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Accepted: 06/30/2024] [Indexed: 07/11/2024]
Abstract
The increasing global consumption of poultry meat has led to the generation of a vast quantity of feather keratin waste daily, posing significant environmental challenges due to improper disposal methods. A growing focus is on utilizing keratinous polymeric waste, amounting to millions of tons annually. Keratins are biochemically rigid, fibrous, recalcitrant, physiologically insoluble, and resistant to most common proteolytic enzymes. Microbial biodegradation of feather keratin provides a viable solution for augmenting feather waste's nutritional value while mitigating environmental contamination. This approach offers an alternative to traditional physical and chemical treatments. This review focuses on the recent findings and work trends in the field of keratin degradation by microorganisms (bacteria, actinomycetes, and fungi) via keratinolytic and proteolytic enzymes, as well as the limitations and challenges encountered due to the low thermal stability of keratinase, and degradation in the complex environmental conditions. Therefore, recent biotechnological interventions such as designing novel keratinase with high keratinolytic activity, thermostability, and binding affinity have been elaborated here. Enhancing protein structural rigidity through critical engineering approaches, such as rational design, has shown promise in improving the thermal stability of proteins. Concurrently, metagenomic annotation offers insights into the genetic foundations of keratin breakdown, primarily predicting metabolic potential and identifying probable keratinases. This may extend the understanding of microbial keratinolytic mechanisms in a complex community, recognizing the significance of synergistic interactions, which could be further utilized in optimizing industrial keratin degradation processes.
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Affiliation(s)
- Sandeep Das
- Department of Microbiology, Assam University, Silchar, 788011, Assam, India
| | - Ankita Das
- Department of Microbiology, Assam University, Silchar, 788011, Assam, India
| | - Nandita Das
- Department of Microbiology, Assam University, Silchar, 788011, Assam, India
| | - Tamanna Nath
- Department of Microbiology, Assam University, Silchar, 788011, Assam, India
| | | | - Prisha Pandey
- Department of Biotechnology, Royal Global University, Guwahati, 781035, Assam, India
| | - Vijay Kumar
- Himalayan School of Biosciences, Swami Rama Himalayan University, Dehradun, India, 248016
| | - Kamlesh Choure
- Department of Biotechnology, AKS University, Satna, 485001, Madhya Pradesh, India
| | - Sanjeev Kumar
- Department of Life Sciences and Bioinformatics, Assam University, Silchar, 788011, Assam, India
| | - Piyush Pandey
- Department of Microbiology, Assam University, Silchar, 788011, Assam, India.
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3
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Yan M, Chen Y, Feng Y, Saeed M, Fang Z, Zhen W, Ni Z, Chen H. Perspective on Agricultural Industrialization: Modification Strategies for Enhancing the Catalytic Capacity of Keratinase. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024. [PMID: 38832583 DOI: 10.1021/acs.jafc.4c03025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2024]
Abstract
Keratinases is a special hydrolytic enzyme produced by microorganisms, which has the ability to catalyze the degradation of keratin. Currently, keratinases show great potential for application in many agricultural and industrial fields, such as biofermented feed, leather tanning, hair removal, and fertilizer production. However, these potentials have not yet been fully unleashed on an industrial scale. This paper reviews the sources, properties, and catalytic mechanisms of keratinases. Strategies for the molecular modification of keratinases are summarized and discussed in terms of improving the substrate specificity, thermostability, and pH tolerance of keratinases. The modification strategies are also enriched by the introduction of immobilized enzymes and directed evolution. In addition, the selection of modification strategies when facing specific industrial applications is discussed and prospects are provided. We believe that this review serves as a reference for the future quest to extend the application of keratinases from the laboratory to industry.
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Affiliation(s)
- Mingchen Yan
- School of the Life Sciences, Jiangsu University, Zhenjiang 212000, China
| | - Ying Chen
- School of the Life Sciences, Jiangsu University, Zhenjiang 212000, China
| | - Yong Feng
- School of the Life Sciences, Jiangsu University, Zhenjiang 212000, China
| | - Muhammad Saeed
- School of the Life Sciences, Jiangsu University, Zhenjiang 212000, China
| | - Zhen Fang
- Biofuels Institute, School of the Environment, Jiangsu University, Zhenjiang 212000, China
| | - Wang Zhen
- Biofuels Institute, School of the Environment, Jiangsu University, Zhenjiang 212000, China
| | - Zhong Ni
- School of the Life Sciences, Jiangsu University, Zhenjiang 212000, China
| | - Huayou Chen
- School of the Life Sciences, Jiangsu University, Zhenjiang 212000, China
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4
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Liu X, Lian M, Zhao M, Huang M. Advances in recombinant protease production: current state and perspectives. World J Microbiol Biotechnol 2024; 40:144. [PMID: 38532149 DOI: 10.1007/s11274-024-03957-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Accepted: 03/13/2024] [Indexed: 03/28/2024]
Abstract
Proteases, enzymes that catalyze the hydrolysis of peptide bonds in proteins, are important in the food industry, biotechnology, and medical fields. With increasing demand for proteases, there is a growing emphasis on enhancing their expression and production through microbial systems. However, proteases' native hosts often fall short in high-level expression and compatibility with downstream applications. As a result, the recombinant production of proteases has become a significant focus, offering a solution to these challenges. This review presents an overview of the current state of protease production in prokaryotic and eukaryotic expression systems, highlighting key findings and trends. In prokaryotic systems, the Bacillus spp. is the predominant host for proteinase expression. Yeasts are commonly used in eukaryotic systems. Recent advancements in protease engineering over the past five years, including rational design and directed evolution, are also highlighted. By exploring the progress in both expression systems and engineering techniques, this review provides a detailed understanding of the current landscape of recombinant protease research and its prospects for future advancements.
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Affiliation(s)
- Xiufang Liu
- School of Food Science and Engineering, South China University of Technology, Guangzhou, 510641, China
- Guangdong Food Green Processing and Nutrition Regulation Technologies Research Center, Guangzhou, 510650, China
| | - Mulin Lian
- School of Food Science and Engineering, South China University of Technology, Guangzhou, 510641, China
- Guangdong Food Green Processing and Nutrition Regulation Technologies Research Center, Guangzhou, 510650, China
| | - Mouming Zhao
- School of Food Science and Engineering, South China University of Technology, Guangzhou, 510641, China
- Guangdong Food Green Processing and Nutrition Regulation Technologies Research Center, Guangzhou, 510650, China
| | - Mingtao Huang
- School of Food Science and Engineering, South China University of Technology, Guangzhou, 510641, China.
- Guangdong Food Green Processing and Nutrition Regulation Technologies Research Center, Guangzhou, 510650, China.
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5
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Gahatraj I, Roy R, Phukan BC, Kumar D, Pandey P, Kumar S, Borah A. Isolation, identification, and molecular characterization of potential keratinolytic fungus sp. from Southern Assam: relevance to poultry wastes and its biological management. Arch Microbiol 2024; 206:99. [PMID: 38351393 DOI: 10.1007/s00203-024-03842-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 01/03/2024] [Accepted: 01/08/2024] [Indexed: 02/16/2024]
Abstract
Feather waste is a highly prevalent form of keratinous waste that is generated by the poultry industry. The global daily production of feather waste has been shown to approach 5 million tons, typically being disposed of through methods such as dumping, landfilling, or incineration which contribute significantly to environmental pollutions. The proper management of these keratinous wastes is crucial to avoid environmental contamination. The study was carried out to isolate the keratinolytic fungi from the poultry disposal sites of different region of North-East India to evaluate its potential in bioremediation of the feathers wastes. Out of 12 fungal strains isolated from the sites, the fungus showing the highest zone of hydrolysis on both the skim milk and keratin agar medium was selected for the study and the molecular identification of the isolate was performed through DNA sequence analysis by amplifying the internal transcribed spacer (ITS) region. The sequence results showed higher similarity (above 95%) with Aspergillus spp. and was named Aspergillus sp. Iro-1. The strain was further analyzed for its feather degrading potential which was performed in submerged conditions under optimized conditions. The study showed that the strain could effectively degrade the feathers validated through weight loss method, and the structural deformations in the feathers were visualized through scanning electron microscopy (SEM). Aspergillus sp. Iro-1 was obtained from the southern region of Assam. It would be of great importance as the implementation of this sp. can help in the bioremediation of feathers wastes in this region. This is the first study of identification of feather degrading fungus from southern part of Assam (Barak).
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Affiliation(s)
- Indira Gahatraj
- Department of Life Science and Bioinformatics, Assam University, Silchar, 788011, India.
| | - Rubina Roy
- Department of Life Science and Bioinformatics, Assam University, Silchar, 788011, India
| | | | - Diwakar Kumar
- Department of Microbiology, Assam University, Silchar, 788011, India
| | - Piyush Pandey
- Department of Microbiology, Assam University, Silchar, 788011, India
| | - Sanjeev Kumar
- Department of Life Science and Bioinformatics, Assam University, Silchar, 788011, India
| | - Anupom Borah
- Department of Life Science and Bioinformatics, Assam University, Silchar, 788011, India.
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Zhang J, Liang M, Wu L, Yang Y, Sun Y, Wang Q, Gao X. Bioconversion of feather waste into bioactive nutrients in water by Bacillus licheniformis WHU. Appl Microbiol Biotechnol 2023; 107:7055-7070. [PMID: 37750916 DOI: 10.1007/s00253-023-12795-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 08/23/2023] [Accepted: 09/13/2023] [Indexed: 09/27/2023]
Abstract
Feathers become hazardous pollutants when deposited directly into the environment. The rapid expansion of the poultry industry has significantly increased feather waste, necessitating the development of new ways to degrade and utilize feathers. This study investigated the ability of Bacillus licheniformis WHU to digest intact chicken feathers in water. The results indicated that yields of free amino acids, bioactive peptides, and keratin-derived nano-/micro-particles were improved in bacteria- versus purified keratinase-derived feather hydrolysate. Bacteria-derived feather hydrolysate supplementation induced health benefits in mice, including significantly increased intestinal villus height and zonula occludens-1 protein expression, as well as increased secretory immunoglobulin A levels in the intestinal mucosa and superoxide dismutase activity in serum. Additionally, feather hydrolysate supplementation modulated the mouse gut microbiota, reflected by increased relative abundance of probiotics such as Lactobacillus spp., decreased relative abundance of Proteobacteria at the phylum level and pathogens such as Staphylococcus spp., and increased Bacteroidota/Firmicutes ratio. This study developed a simple, cost-effective method to degrade feathers by B. licheniformis WHU digestion, yielding a hydrolysate that can be directly used as a bioactive nutrient resource. The study findings have applications in the livestock, poultry, and aquaculture industries, which have high demands for cheap protein. KEY POINTS: • Bacillus licheniformis could degrade intact feather in water. • The resulting feather hydrolysate shows prebiotic effects on mouse.
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Affiliation(s)
- Jing Zhang
- School of Pharmacy, Southwest Medical University, Luzhou, 646000, Sichuan, China
| | - Manyu Liang
- School of Pharmacy, Southwest Medical University, Luzhou, 646000, Sichuan, China
| | - Lijuan Wu
- Department of Endocrinology, The Affiliated Traditional Chinese Medicine Hospital of Southwest Medical University, Luzhou, 646000, Sichuan, China
| | - Yanhong Yang
- School of Pharmacy, Southwest Medical University, Luzhou, 646000, Sichuan, China
| | - Yingjie Sun
- School of Pharmacy, Southwest Medical University, Luzhou, 646000, Sichuan, China
| | - Qin Wang
- School of Pharmacy, Southwest Medical University, Luzhou, 646000, Sichuan, China.
- Dazhou Vocational College of Chinese Medicine, Tongchuan District, Luojiang Town, Dazhou, 635000, China.
| | - Xiaowei Gao
- School of Pharmacy, Southwest Medical University, Luzhou, 646000, Sichuan, China.
- Dazhou Vocational College of Chinese Medicine, Tongchuan District, Luojiang Town, Dazhou, 635000, China.
- Green Pharmaceutical Technology Key Laboratory of Luzhou, Southwest Medical University, Luzhou, 646000, Sichuan, China.
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7
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Chen X, Peng Z, Ji X, Zhang J. Reducing Cellular Autolysis of Bacillus subtilis to Improve Keratinase Production. ACS Synth Biol 2023; 12:3106-3113. [PMID: 37677132 DOI: 10.1021/acssynbio.3c00458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/09/2023]
Abstract
Bacillus subtilis has been shown to be an excellent expression host for keratinases due to its powerful secretion system. However, cellular autolysis limits its production capacity. Here, we selected seven genes with significantly upregulated transcript levels from 15 genes associated with cellular autolysis as knockout targets by qRT-PCR and constructed a total of 127 strains to reduce cellular autolysis. Among them, the biomass of B. subtilis BSΔXLPC-ker deficient in xpf, lytC, pcfA, and cwlC increased by 57%. This was confirmed by cell staining, green fluorescent protein imaging, and extracellular nucleic acid leakage assay. Keratinase activity was increased by 1.46-fold in the 5 L fermenter. In addition, the activities of nattokinase and subtilisin E were also increased by 1.50-fold and 1.43-fold, respectively, in the modified chassis cells, which further confirms the generalizability of the strategy. Thus, reducing cellular autolysis to increase the ability of B. subtilis to produce subtilisins is promising.
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Affiliation(s)
- Xiwen Chen
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China
- Engineering Research Center of Ministry of Education on Food Synthetic Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China
- Jiangsu Province Engineering Research Center of Food Synthetic Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China
| | - Zheng Peng
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China
- Engineering Research Center of Ministry of Education on Food Synthetic Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China
- Jiangsu Province Engineering Research Center of Food Synthetic Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China
| | - Xiaomei Ji
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China
- Engineering Research Center of Ministry of Education on Food Synthetic Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China
- Jiangsu Province Engineering Research Center of Food Synthetic Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China
| | - Juan Zhang
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China
- Engineering Research Center of Ministry of Education on Food Synthetic Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China
- Jiangsu Province Engineering Research Center of Food Synthetic Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China
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8
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Revankar AG, Bagewadi ZK, Bochageri NP, Yunus Khan T, Mohamed Shamsudeen S. Response surface methodology based optimization of keratinase from Bacillus velezensis strain ZBE1 and nanoparticle synthesis, biological and molecular characterization. Saudi J Biol Sci 2023; 30:103787. [PMID: 37705700 PMCID: PMC10495650 DOI: 10.1016/j.sjbs.2023.103787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 08/11/2023] [Accepted: 08/18/2023] [Indexed: 09/15/2023] Open
Abstract
The increasing demands of keratinases for biodegradation of recalcitrant keratinaceous waste like chicken feathers has lead to research on newer potential bacterial keratinases to produce high-value products with biological activities. The present study reports a novel keratinolytic bacterium Bacillus velezensis strain ZBE1 isolated from deep forest soil of Western Ghats of Karnataka, which possessed efficient feather keratin degradation capability and induced keratinase production. Production kinetics depicts maximum keratinase production (11.65 U/mL) on 4th day with protein concentration of 0.61 mg/mL. Effect of various physico-chemical factors such as, inoculum size, metal ions, carbon and nitrogen sources, pH and temperature influencing keratinase production were optimized and 3.74 folds enhancement was evidenced through response surface methodology. Silver (AgNP) and zinc oxide (ZnONP) nanoparticles with keratin hydrolysate produced from chicken feathers by the action of keratinase were synthesized and verified with UV-Visible spectroscopy that revealed biological activities like, antibacterial action against Bacillus cereus and Escherichia coli. AgNP and ZnONP also showed potential antioxidant activities through radical scavenging activities by ABTS and DPPH. AgNP and ZnONP revealed cytotoxic effect against MCF-7 breast cancer cell lines with IC50 of 5.47 µg/ml and 62.26 µg/ml respectively. Characterizations of nanoparticles were carried out by Fourier transform infrared spectroscopy, scanning electron microscopy with energy dispersive X-ray, X-ray diffraction, thermogravimetric analysis and atomic force microscopy analysis to elucidate the thermostability, structure and surface attributes. The study suggests the prospective applications of keratinase to trigger the production of bioactive value-added products and significant application in nanotechnology in biomedicine.
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Affiliation(s)
- Archana G. Revankar
- Department of Biotechnology, KLE Technological University, Hubballi, Karnataka 580031, India
| | - Zabin K. Bagewadi
- Department of Biotechnology, KLE Technological University, Hubballi, Karnataka 580031, India
| | - Neha P. Bochageri
- Department of Biotechnology, KLE Technological University, Hubballi, Karnataka 580031, India
| | - T.M. Yunus Khan
- Department of Mechanical Engineering, College of Engineering, King Khalid University, Abha 61421, Saudi Arabia
| | - Shaik Mohamed Shamsudeen
- Department of Diagnostic dental science and Oral Biology, College of Dentistry, King Khalid University, Abha 61421, Saudi Arabia
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Ji X, Peng Z, Song J, Zhang G, Zhang J. Fusion of Substrate-Binding Domains Enhances the Catalytic Capacity of Keratinases and Promotes Enzymatic Conversion of Feather Waste. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023; 71:11579-11586. [PMID: 37462367 DOI: 10.1021/acs.jafc.3c03064] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/03/2023]
Abstract
The unique role of keratinases in keratin hydrolysis has garnered huge interest in the recovery of feather waste. However, owing to the high hydrophobicity of feather keratins, the catalytic capacity of keratinases for hydrolyzing feathers is typically low. In this study, we aimed to improve the keratinase feather hydrolysis efficiency by fusing a substrate-binding domain into the enzyme. We screened several carbohydrate-binding modules (CBMs) and linking peptides. We selected the most promising candidates to construct, clone, and express a fusion keratinase enzyme KerZ1/CBM-L8 with a feather hydrolysis efficiency of 7.8 × 10-8 g/U. Compared with those of KerZ1, KerZ1/CBM-L8 has a feather hydrolysis efficiency that is 2.71 times higher, a kcat value that is 179% higher, which translates to higher catalytic efficiency, and Km and binding constant (K) values that are lower, which indicate a higher KerZ1/CBM-L8-keratin binding affinity. Moreover, the number of binding sites to the substrate (N), determined using isothermal titration calorimetry, was 24.1 times higher than that of KerZ1. Thus, the fusion of the substrate-binding domain improved the binding ability of the keratinase enzyme to the hydrophobic substrate, which improved its feather hydrolysis efficiency. Therefore, using the fusion keratinase would significantly improve the recovery of feather waste.
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Affiliation(s)
- Xiaomei Ji
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
- Science Center for Future Foods, Jiangnan University, Wuxi 214122, China
- Engineering Research Center of Ministry of Education on Food Synthetic Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Zheng Peng
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
- Science Center for Future Foods, Jiangnan University, Wuxi 214122, China
- Engineering Research Center of Ministry of Education on Food Synthetic Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Jie Song
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
- Science Center for Future Foods, Jiangnan University, Wuxi 214122, China
- Engineering Research Center of Ministry of Education on Food Synthetic Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Guoqiang Zhang
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
- Science Center for Future Foods, Jiangnan University, Wuxi 214122, China
- Engineering Research Center of Ministry of Education on Food Synthetic Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Juan Zhang
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
- Science Center for Future Foods, Jiangnan University, Wuxi 214122, China
- Engineering Research Center of Ministry of Education on Food Synthetic Biotechnology, Jiangnan University, Wuxi 214122, China
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10
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Research progress on the degradation mechanism and modification of keratinase. Appl Microbiol Biotechnol 2023; 107:1003-1017. [PMID: 36633625 DOI: 10.1007/s00253-023-12360-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 12/23/2022] [Accepted: 12/31/2022] [Indexed: 01/13/2023]
Abstract
Keratin is regarded as the main component of feathers and is difficult to be degraded by conventional proteases, leading to substantial abandonment. Keratinase is the only enzyme with the most formidable potential for degrading feathers. Although there have been in-depth studies in recent years, the large-scale application of keratinase is still associated with many problems. It is relatively challenging to find keratinase not only with high activity but could also meet the industrial application environment, so it is urgent to exploit keratinase with high acid and temperature resistance, strong activity, and low price. Therefore, researchers have been keen to explore the degradation mechanism of keratinases and the modification of existing keratinases for decades. This review critically introduces the basic properties and mechanism of keratinase, and focuses on the current situation of keratinase modification and the direction and strategy of its future application and modification. KEY POINTS: •The research status and mechanism of keratinase were reviewed. •The new direction of keratinase application and modification is discussed. •The existing modification methods and future modification strategies of keratinases are reviewed.
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