A novel unhairing enzyme produced by heterologous expression of keratinase gene (kerT) in Bacillus subtilis
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To promote enzymatic unhairing for leather production, a new unhairing enzyme is developed. The Keratinase (kerT) gene, which is amplified from B. amyloliquefaciens TCCC11319 by PCR, is expressed in B. subtilis WB600. The recombinant KerT reduces the collagenolytic protease content as well as improving the keratinase content effectively. Therefore, the improved keratinase leads to the obviously unhairing effect, whereas the low collagenolytic protease ensures the integrity of collagen fibers in hide. It represents, the leather grain surface isn’t destroyed thereby the value of finished leather can be maintained. In addition, by analyzing the properties of KerT, tits activity isn’t inhibited with Na+, K+ and Ca2+ which are commonly used in leather production. The freeze-dried fermentation broth can be used directly as unhairing enzyme without addition of traditional sulfide chemicals. By evaluating the properties of unhaired hide, the results show that the collagen degradation ability of this new unhairing enzyme is slightly and it does not cause any adverse effects on the leather quality. Besides, this unhairing enzyme doesn’t further degrade collagen in the time range of 8 h to 24 h, thus it is safely and easy-control in actual production. In conclusion, the enzymatic unhairing method with recombinant KerT has the potential to be more sustainable and efficient alternative than current sulphur-lime method, and it does not require the further purification thereby saving the cost.
KeywordsUnhairing enzyme Heterologous expression KerT gene
This work was financially supported by The National Key Research and Development Program of China (Grant No. 2017YFB0308401), National Natural Science Foundation of China (Grant No. 21808170), and Shandong Provincial Natural Science Foundation (Grant No. ZR201807260006).
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Conflict of interest
The authors declare that they have no conflict of interest.
This article does not contain any studies with human participants or animals performed by any of the authors.
- Lopéz LM, Viana CA, Errasti ME, Garro ML, Martegani JE, Mazzilli GA, Freitas CD, Araújo ÍM, da Silva RO, Ramos MV (2017) Latex peptidases of Calotropis procera for dehairing of leather as an alternative to environmentally toxic sodium sulfide treatment. Bioprocess Biosyst Eng 40(9):1391–1398PubMedCrossRefGoogle Scholar
- Verma A, Pal HS, Singh R, Agarwal S (2011) Potential of alkaline protease isolated from thermoactinomyces sp. RM4 as an alternative to conventional chemicals in leather industry dehairing process. Int J Agric Environ Biotechnol 4:173–178Google Scholar
- Wang B, Yang W, McKittrick J, Meyers MA (2016) Keratin: Structure, mechanical properties, °C currence in biological organisms, and efforts at bioinspiration. Prog Mater Sci 76:229–318Google Scholar
- Zeng Y, Yang Q, Wang YN, Zhou J, Shi B (2016) Neutral protease assisted low-sulfide hair-save unhairing based on pH-sensitivity of enzyme. J Am Leather Chem Assoc 111(9):345–353Google Scholar
- Zhang J, Li B, Liao X, Du G, Chen J (2013) Expression and characterization of extreme alkaline, oxidation-resistant keratinase from Bacillus licheniformis in recombinant Bacillus subtilis WB600 expression system and its application in wool fiber processing. World J Microbiol Biotechnol 29(5):825–832PubMedCrossRefGoogle Scholar