产胞外乳糖酶耐冷菌株Comamonas sp.的筛选鉴定及酶学性质研究  

Isolation and characterization of a cold-adapted β-galactosidase-producing strain

作　　者：林国秀[1] 李珍[1] 罗盛莲[1] 游霞[1] 丁聪聪[1] 张杰[1] 

机构地区：[1]四川大学生命科学学院生物资源与生态环境教育部重点实验室,四川成都610064

出　　处：《工业微生物》2013年第2期38-44,共7页Industrial Microbiology

基　　金：国家科技支撑计划(批准号:2007BAC18B00);四川省应用基础项目(批准号:2007J13-077)

摘　　要：利用含有X-gal的琼脂平板和摇瓶发酵法,从若尔盖高原土壤中筛选产β-半乳糖苷酶低温菌株。经过菌落形态及16S rDNA序列分析,初步鉴定该菌株为Comamonas sp.菌株特性以及粗酶性质研究表明:该菌株于250 mL锥形瓶中装液量为40 mL,温度为15℃,初始pH值为5.5的条件下培养48h后菌体量达到最大值;所产胞外β-半乳糖苷酶的反应最适pH值为7.0,最适温度为40℃,具有一定的热稳定性;金属离子Mg^(2+)对该酶酶活具有明显的促进作用,而Cu^(2+)、Ca^(2+)、Cd^(2+)、Zn^(2+)对其酶活具有强烈的抑制作用,其中Cu^(2+)能完全抑制其活性。Abstract By using plates containing X-gal and flask shaking fermentation, a cold-adapted β-galactosidase producing strain was screened from soil samples of the Rolg（e） plateau. According to morphological identification and 16S rDNA se- quence analysis, the strain was identified as Comamonas sp. and designated as Comamonas sp. L12. The characteristics of the strain and its crude enzyme properties analysis indicated that the optimum culture conditions were 40 mL medium in 250 mL Erlenmeyer flask and initial pH 5.5 at 15 ℃ for 48 h. The optimum reaction pH and temperature of the crude en- zyme of this β-galactosidase was 7.0 and 40 ℃, respectively. The enzyme was thermal stable. The activity of this β-gal- actosidase was activated by Mg^2＋ and inhibited by Cu^2＋、Ca^2＋、Cd^2＋、Zn^2＋, and totally inhibited by Cu^2＋ .

关 键 词：Comamonas SP 胞外酶 乳糖酶 筛选 酶学性质 

分 类 号：TQ920.6[轻工技术与工程—发酵工程]