一株枯草芽孢杆菌的水解酶特性及其对盐胁迫的响应  

Hydrolase properties of a strain of Bacillus subtilis and its response to salt stress

作　　者：李巧玲 李爱博 黄志远 张小平 卞方圆 钟哲科 LI Qiaoling;LI Aibo;HUANG Zhiyuan;ZHANG Xiaoping;BIAN Fangyuan;ZHONG Zheke(China National Bamboo Research Center,Key Laboratory of Bamboo Forest Ecology and Resource Uilization of National Forestry and Grassland Administration,Hangzhou 310012,China;Research Institute of Subtropical Forestry,Chinese Academy of Forestry,Hangzhou 311400,China)

机构地区：[1]国家林业和草原局竹子研究开发中心,竹林生态与资源利用国家林业和草原局重点实验室,杭州310012 [2]中国林业科学研究院亚热带林业研究所,杭州311400

出　　处：《生态学杂志》2023年第8期2032-2039,共8页Chinese Journal of Ecology

基　　金：浙江省省院合作林业科技项目(2020SY01)资助。

摘　　要：为筛选用于分解高盐有机废水有机碳的微生物资源,本研究采用稀释涂布法和脱色圈平板试验法,从竹笋加工废弃物中分离筛选得到1株耐盐产酶细菌,通过形态学、扫描电镜观察、生理生化特征、16S rRNA基因序列分析鉴定菌株。采用单因素控制法优化菌株生长条件,并测定了盐胁迫下菌株的生长及蛋白酶、纤维素酶、淀粉酶等水解酶的酶活力。结果表明:(1)得到1株耐盐性能好且有机碳分解能力强的枯草芽孢杆菌(Bacillus stubilis)ACP81。它能够在浓度为1%~19%NaCl溶液中生长,在1%NaCl时菌株生长状况最优,5%NaCl为该菌株的半抑制浓度。(2)在半抑制浓度(5%NaCl)培养下,菌株培养液中的纤维素酶、中性蛋白酶和β-淀粉酶的酶活力分别为72.4、3.2和0.3 U·mL^(-1)。(3)盐胁迫下,菌株ACP81的纤维素酶和β-淀粉酶酶活随着NaCl浓度增加而增加,而中性蛋白酶则呈相反趋势,且世代时间逐渐变长。分离得到的枯草芽孢杆菌ACP81达到中度嗜盐菌的盐度耐受范围,并且在高渗环境中具有产纤维素酶和β-淀粉酶的优势,可作为高盐有机废水的生化处理的候选菌株。To screen microbial resources for decomposing organic carbon in high-salt organic wastewater,one strain of salt-tolerant enzyme-producing bacterium was isolated and screened from bamboo shoot processing waste by dilution coating method and decolorization circle plate test method.The strain was identified based on morphology,scanning electron microscopy observation,physiological and biochemical characteristics,and 16S rRNA gene sequence analysis.A single-factor control method was used to optimize the growth conditions of the strain.The growth of the strain under salt stress and the activities of hydrolytic enzymes(protease,cellulose,and amylase)were measured.A salt-tolerant and organic carbon decomposing strain of Bacillus stubilis ACP81 was obtained,which was able to grow in NaCl solutions with concentrations ranging from 1%to 19%,with optimal growth at 1%NaCl and 5%NaCl as the semi-inhibitory concentration of the strain.The activity of cellulase,neutral protease,andβ-amylase in the culture of the strain was 72.4,3.2,and 0.3 U·mL^(-1)respectively at the semi-inhibitory concentration(5%NaCl).Under salt stress,the cellulase andβ-amylase activities of strain ACP81 increased with increasing NaCl salt concentration,while the neutral protease showed an opposite trend and the generation time became gradually longer.The isolated Bacillus subtilis ACP81 reached the salinity tolerance range of moderately salinity-loving bacteria and had an advantage of cellulase andβ-amylase production in hypertonic environment,which can be used as a candidate strain for biochemical treatment of high-salt organic wastewater.

关 键 词：枯草芽孢杆菌 半抑制浓度 耐盐水解酶 世代时间 

分 类 号：X172[环境科学与工程—环境科学] X703