Screening of a strain of chitinase producing Paenibacillus polymyxa A1 and investigation on its fermentation conditions for chitinase production
A strain of chitinase producing bacteria was isolated from soil,and was identified to be Paenibacillus polymyxa based on its morphological,physiological and biochemical characteristics and 16S rDNA sequencing.The strain was named as A1.Chitin,chitosan and starch can induce A1 to produce chitinase.The adding of urea in medium improved the production of chitinase.The fermentation conditions for chitinase production were determined as follows:the fermentation medium consisting of 1％ chitin (120 mesh),0.05％ MgSO4 ·7H2O,1.2％ CO (NH2) 2,05％ NaCl,0.03％ KH2PO4,0.07％ K2HPO4,0.3％ yeast extract powder,pH4.5,starter culture age 12 h,inoculum size 1％,fermenting at 37 ℃ for 78 h.Under such conditions,the chitinase activity achieved 0.549 U/mL.At the exponential phase,the rising of chitinase production curve slightly lagged behind the growth curve of A1,at the decline phase,the falling of chitinase production curve was slightly earlier than the falling of growth curve.The results indicated that the mRNA of the chitinase was unstable.
国家科技期刊平台
NSTL
万方数据
维普
