利用代谢阻遏解除的枯草芽孢杆菌 KCC103 在 SSF 中利用高葡萄糖的农业残余培养基超生产α-淀粉酶。

Hyper-production of alpha-amylase from agro-residual medium with high-glucose in SSF using catabolite derepressed Bacillus subtilis KCC103.

机构信息

Department of Biotechnology, Indian Institute of Technology Madras, Chennai, India.

出版信息

J Basic Microbiol. 2010 Aug;50(4):336-43. doi: 10.1002/jobm.200900199.

DOI:10.1002/jobm.200900199

PMID:20586062

Abstract

In Bacillus subtilis KCC103, alpha-amylase is hyper-produced and alpha-amylase synthesis is not subject to catabolite repression. The alpha-amylase was produced from KCC103 by solid-state fermentation (SSF) using agro-residues and oil cakes as growth substrates. The KCC103 was also tested for its resistance to repression by hyper level (>10% w/w) of glucose and xylose on alpha-amylase production in SSF. Among growth media containing various combinations of agro-residues, the medium with wheat bran and sunflower oil cake supported highest enzyme production (20700 IU (g dry wt)(-1)). The alpha-amylase production was enhanced (4.2 folds) by optimizing the growth substrate and the process parameters: the optimal conditions were wheat bran:sun flower oil cake ratio-1:1 (w/w), substrate particle size-500 mum, substrate to flask volume-1:100 (w/v), initial substrate moisture content-90% (v/w), inoculum size-35%, initial medium pH-7.0, growth temperature-37 degrees C and cultivation time-48 h. alpha-Amylase production was further enhanced up to 1.7 folds when SSF was carried out using optimized medium supplemented with sugars or yeast extract (1% w/v) under optimized conditions. Supplementation of biomass sugars, glucose or xylose at 20% (w/w), did not repress the synthesis of alpha-amylase showing the hyper-tolerance of KCC103 to repression by simple sugars on alpha-amylase production in SSF.

摘要

在枯草芽孢杆菌 KCC103 中，α-淀粉酶大量产生，且α-淀粉酶的合成不受分解代谢物阻遏。采用固态发酵（SSF），以农业废弃物和油饼作为生长基质，从 KCC103 中生产α-淀粉酶。还通过测试 KCC103 对 SSF 中高浓度（>10%w/w）葡萄糖和木糖对α-淀粉酶生产的阻遏作用来检测其抗性。在含有各种农业废弃物组合的生长培养基中，含有麦麸和葵花油饼的培养基支持最高的酶产量（20700 IU（g 干重）（-1））。通过优化生长基质和工艺参数来提高α-淀粉酶的产量（增强了 4.2 倍）：最佳条件是麦麸：葵花油饼比例为 1:1（w/w），基质粒径为 500 微米，基质与瓶体积比为 1:100（w/v），初始基质水分含量为 90%（v/w），接种量为 35%，初始培养基 pH 值为 7.0，培养温度为 37°C，培养时间为 48 小时。当在优化条件下使用优化培养基进行 SSF 时，补充糖或酵母提取物（1%w/v）可使α-淀粉酶的产量进一步提高到 1.7 倍。在 20%（w/w）的浓度下补充生物质糖、葡萄糖或木糖不会抑制α-淀粉酶的合成，表明 KCC103 对 SSF 中简单糖对α-淀粉酶生产的阻遏具有超耐受性。