Authors: Zhuo Liu Xinqing Zhao Fengwu Bai
Publish Date: 2012/07/21
Volume: 97, Issue: 10, Pages: 4361-4368
Abstract
Xylanase is the enzyme complex that is responsible for the degradation of xylan however novel xylanase producers remain to be explored in marine environment In this study a Streptomyces strain M11 which exhibited xylanase activity was isolated from marine sediment The 16S rDNA sequence of M11 showed the highest identity 99 to that of Streptomyces viridochromogenes The xylanase produced from M11 exhibited optimum activity at pH 60 and the optimum temperature was 70 °C M11 xylanase activity was stable in the pH range of 60–90 and at 60 °C for 60 min Xylanase activity was observed to be stable in the presence of up to 5 M NaCl Antibioticresistant mutants of M11 were isolated and among the various antibiotics tested streptomycin showed the best effect on obtaining xylanase overproducer Mutant M11110 isolated from 10 μg/ml streptomycincontaining plate showed 14 higher xylanase activities than that of the wildtype strain An analysis of gene rpsL encoding ribosomal protein S12 showed that rpsL from M11110 contains a K88R mutation This is the first report to show that marinederived S viridochromogenes strain can be used as a xylanase producer and utilization of ribosome engineering for the improvement of xylanase production in Streptomyces was also first successfully demonstrated
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