摘要
分离筛选脂肪酶高产菌株,为生物降解富含油脂的工业及生活污水提供菌种资源.从校园食堂附近土壤中分离微生物,结合中性红油脂平板筛选法与三丁酸甘油酯平板透明圈法筛选脂肪酶高产菌株.根据菌株形态特征、生理生化特性以及分子生物学特征鉴定高产菌株,进而利用酸碱滴定法定量测定脂肪酶酶活,探究该菌株产生脂肪酶的最适酶促反应温度、pH值等酶学性质.研究结果表明,筛选获得的脂肪酶产生菌SLB-1为革兰氏阳性芽孢杆菌;硝酸盐还原呈阳性,能够水解淀粉和液化明胶;基于16SrDNA的系统发育分析结果表明SLB-1菌株与登录号为NR116240甲基营养型芽孢杆菌(Bacillus methylotrophicus)处于同一最小分支,故将SLB-1菌株鉴定为甲基营养型芽孢杆菌,命名为B.methylotrophicus SLB-1,该菌株产脂肪酶的最适培养时间是24h,酶促反应的最适温度为30℃,最适pH值为7.0.本研究分离鉴定了脂肪酶产生菌Bacillus methylotrophicus SLB-1,且由该菌所产生的脂肪酶为中性常温酶.
In order to screen out efficient lipase-producing microorganisms, which can be used in the treat- ment of oily water generated from industry and oil-rich waste water discharge of daily life, microorganisms were isolated from the soil collected from the areas around a campus cafeteria, and high-yield lipase-produ- cing strains were screened by the neutral red grease plate screening method and the tributyrin transparent circle method. Then, a high-yield lipase-producing strain was identified based on its morphological, physi-ological and biochemical characteristics and molecular analysis. Moreover, enzymatic properties of lipase, including enzymatic reaction temperature, pH and so on, were explored through the acid-base titration method for the quantitative determination of the lipase activity. The results indicated that the high-yield li- pase-producing strain SLB-1 was screened out. SLB-1 was a strain of Gram-positive Bacillus, capable of hydrolyzing starch and liquefying gelatin. Phylogenetic analysis results based on the 16S rDNA sequences indicated that SLB-1 existed in the same minimum clade with B. methylotrophicus （accession Number. NRl16240）. Therefore, SLB-1 strain was identified to be B. rnethylotrophicus, which was named as B. rnethylotrophicus SLB-1. The optimal incubation time for B. rnethylotrophicus SLB-1 to produce lipase was 24 h, the optimal temperature of the enzymatic reaction was 30℃, and the optimum enzymatic reac- tion pH value was 7.0. In the study, a high-yield lipase-producing strain B. rnethylotrophicus SLB-1 was isolated, and the lipase produced by this strain was a neutral-pH and room-temperature enzyme.
出处
《西南大学学报（自然科学版）》
CAS
CSCD
北大核心
2017年第5期62-69,共8页
Journal of Southwest University(Natural Science Edition)
基金
国家自然科学基金(31601678)
重庆市基础与前沿研究计划重点项目(cstc2015jcyjys80001)
教育部留学回国人员科研启动基金项目(外交司留2015-311)
中央高校基本科研业务费专项(XDJK2017C039)
关键词
脂肪酶产生菌
筛选
菌种鉴定
酶学性质
lipase-producing bacteria
screening
strain identification
enzymatic property
作者简介
徐伟芳（1991-），女，安徽安庆人，硕士研究生，主要从事微生物代谢产物研究．
通信作者：谢洁，博士，副教授，硕士研究生导师．
