学术
Keratinase production and keratin degradation by a mutant strain of Bacillus subtilis
Cheng-gang CAI[1] Bing-gan LOU[2] Xiao-dong ZHENG[1]
[1]College of Food Science and Biosystem Engineering, Zhejiang University, Hangzhou 310029, China [2]Institute of Biotechnology, Zhejiang University, Hangzhou 310029, China
文章出处:
《浙江大学学报：B卷英文版》-2008年1期 -60-67页
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文献标识码:
A
相关文章:
Keratinase production and keratin degradation by a mutant strain of Bacillus subtilis
Abstract:
A new feather-degrading bacterium was isolated from a local feather waste site and identified as Bacillus subtilis based on morphological, physiochemical, and phylogenetic characteristics. Screening for mutants with elevated keratinolytic activity using N-methyl-N＇-nitro-N-nitrosoguanidine mutagenesis resulted in a mutant strain KD-N2 producing keratinolytic activity about 2.5 times that of the wild-type strain. The mutant strain produced inducible keratinase in different substrates of feathers, hair, wool and silk under submerged cultivation. Scanning electron microscopy studies showed the degradation of feathers, hair and silk by the keratinase. The optimal conditions for keratinase production include initial pH of 7.5, inoculum size of 2% （v/v）, age of inoculum of 16 h, and cultivation at 23 ℃. The maximum keratinolytic activity of KD-N2 was achieved after 30 h. Essential amino acids like threonine, valine, methionine as well as ammonia were produced when feathers were used as substrates. Strain KD-N2, therefore, shows great promise of finding potential applications in keratin hydrolysis and keratinase production.[著者文摘]
Key words:
Bacillus subtilis, Keratin, Keratin degradation, Keratinase production, N-methyl-N＇-nitro-N-nitrosoguanidine （MNNG） mutagenesis
基金资助:
Project （No. 3057130） supported by the National Natural Science Foundation of China
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