摘要
【目的】利用筛选培养基,从肉牛瘤胃液中分离筛选产乙酰酯酶的细菌菌株,并研究菌株的产酶特征。【方法】利用厌氧培养技术,以木质素为唯一碳源,筛选并驯化所得菌株。根据菌株16S rDNA序列分析、革兰氏染色、伊红美蓝培养基培养、甲基红试验和柠檬酸盐利用试验,鉴定菌株。采用对-硝基苯乙酯测定酶活力。【结果】筛选得到产乙酰酯酶活力较高细菌菌株RB1,初步鉴定为Escherichia coli。菌株RB1的生长曲线表明,0 42 h为菌株的延迟期,42 60 h为菌株的对数期,60 66 h为菌株的稳定期,66 86 h为菌株的衰亡期。菌株所产乙酰酯酶最适温度为40°C,最适pH为8.0,在最适温度与pH条件下,培养基中添加玉米秸秆粉,乙酰酯酶最高酶活力达到0.52 U/mL。【结论】筛选获得产乙酰酯酶的细菌菌株RB1,其乙酰酯酶活力高于已报道的菌株,是一株具有研究和应用潜力的产乙酰酯酶的菌株。
[Objective] The aim of this study was to screen acetylesterase-producing strain and to investigate its characteristics. [Methods] Anaerobic culture technique was used in screening and acclimatization of strain, and alkali lignin was a sole carbon source. The strain was identi- fied by analyzing the sequence of 16S rDNA, Gram staining, Eosin Methylene Blue test, Methyl red test, and citrate utilization test. Acetylesterase was determined by ethyl p-nitrobenzoate. [Results] Acetylesterase-producing strain RB 1 was isolated from rumen fluid of beef. It was identified as Escherichia coli. The growth curve showed that 0-42 h was lag phase, 42-60 h was log phase, 60-66 h was stationary phase, and 66-86 h was death phase. The optimum temperature for the acetylesterase was 40 °C, and the optimum pH was 8.0. The highest enzyme activity was 0.52 U/mL under optimum temperature and pH, and corn stover powder as a carbon source. [Conclusion] Strain RB1 was an acetylesterase-producing strain with application potential.
出处
《微生物学通报》
CAS
CSCD
北大核心
2012年第6期781-788,共8页
Microbiology China
基金
吉林省科技发展计划项目(No.20110723)
吉林大学基本科研业务费专项资金项目(No.2009.12-2011.12)
吉林大学"985工程"项目(No.450091001009)
国家自然科学基金项目(No.31101337)
关键词
乙酰酯酶
筛选
鉴定
酶学性质
Acetylesterase, Isolation, Identification, Enzyme characteristics
