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Hendrick Q, Nnolim NE, Nontongana N, Nwodo UU. Sphingobacterium multivorum HNFx produced thermotolerant and chemostable keratinase on chicken feathers. Biologia (Bratisl) 2022. [DOI: 10.1007/s11756-022-01126-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Zhang J, Su C, Kong XL, Gong JS, Liu YL, Li H, Qin J, Xu ZH, Shi JS. Directed evolution driving the generation of an efficient keratinase variant to facilitate the feather degradation. BIORESOUR BIOPROCESS 2022; 9:38. [PMID: 38647843 PMCID: PMC10992214 DOI: 10.1186/s40643-022-00524-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Accepted: 03/12/2022] [Indexed: 11/10/2022] Open
Abstract
Keratinases can specifically degrade keratins, which widely exist in hair, horns, claws and human skin. There is a great interest in developing keratinase to manage keratin waste generated by the poultry industry and reusing keratin products in agriculture, medical treatment and feed industries. Degradation of keratin waste by keratinase is more environmentally friendly and more sustainable compared with chemical and physical methods. However, the wild-type keratinase-producing strains usually cannot meet the requirements of industrial production, and some are pathogenic, limiting their development and utilization. The main purpose of this study is to improve the catalytic performance of keratinase via directed evolution technology for the degradation of feathers. We first constructed a mutant library through error-prone PCR and screened variants with enhanced enzyme activity. The keratinase activity was further improved through fermentation conditions optimization and fed-batch strategies in a 7-L bioreactor. As a result, nine mutants with enhanced activity were identified and the highest enzyme activity was improved from 1150 to 8448 U/mL finally. The mutant achieved efficient biodegradation of feathers, increasing the degradation rate from 49 to 88%. Moreover, a large number of amino acids and soluble peptides were obtained as degradation products, which were excellent protein resources to feed. Therefore, the study provided a keratinase mutant with application potential in the management of feather waste and preparation of protein feed additive.
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Affiliation(s)
- Jing Zhang
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Life Sciences and Health Engineering, Jiangnan University, Lihu Avenue No. 1800, Wuxi, 214122, People's Republic of China
- National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, School of Biotechnology, Jiangnan University, Wuxi, 214122, People's Republic of China
- Jiangsu Provincial Engineering Research Center for Bioactive Product Processing, Jiangnan University, Wuxi, 214122, People's Republic of China
| | - Chang Su
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Life Sciences and Health Engineering, Jiangnan University, Lihu Avenue No. 1800, Wuxi, 214122, People's Republic of China
| | - Xiao-Li Kong
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Life Sciences and Health Engineering, Jiangnan University, Lihu Avenue No. 1800, Wuxi, 214122, People's Republic of China
| | - Jin-Song Gong
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Life Sciences and Health Engineering, Jiangnan University, Lihu Avenue No. 1800, Wuxi, 214122, People's Republic of China.
| | - Yan-Lin Liu
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Life Sciences and Health Engineering, Jiangnan University, Lihu Avenue No. 1800, Wuxi, 214122, People's Republic of China
| | - Heng Li
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Life Sciences and Health Engineering, Jiangnan University, Lihu Avenue No. 1800, Wuxi, 214122, People's Republic of China
| | - Jiufu Qin
- Science Center for Future Foods, Jiangnan University, Wuxi, 214122, People's Republic of China
| | - Zheng-Hong Xu
- National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, School of Biotechnology, Jiangnan University, Wuxi, 214122, People's Republic of China
- Jiangsu Provincial Engineering Research Center for Bioactive Product Processing, Jiangnan University, Wuxi, 214122, People's Republic of China
| | - Jin-Song Shi
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Life Sciences and Health Engineering, Jiangnan University, Lihu Avenue No. 1800, Wuxi, 214122, People's Republic of China.
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