1株产L-天冬氨酸酶大肠埃希菌噬菌体分离和生理特性初步研究

Bacteriophage Strain against L-Aspartase Producing Escherichia coli

对产L-天冬氨酸酶大肠埃希菌噬菌体进行分离和生理特性研究,有助于为生产过程中噬菌体污染的防治提供指导。采用双层平板法对噬菌体进行分离纯化。利用透射电镜观察噬菌体形态。进行噬菌体全基因组测序和比对。通过测定不同处理条件下噬菌体活性,研究温度、p H、有机溶剂氯仿、去垢剂SDS对噬菌体的影响。从噬菌体污染的L-天冬氨酸酶生产菌种大肠埃希菌HY-05C发酵培养液中分离出1株噬菌体。电镜结果表明,该噬菌体由呈多面体对称的头部和极短的尾部构成。基因组测序和比对结果表明,噬菌体与T7样噬菌体的相似性最高。生理特性研究表明,噬菌体对高温和去垢剂SDS敏感,对有机溶剂氯仿不敏感;最适p H为7.0,碱性条件下活力较为稳定,酸性条件容易失活。噬菌体保藏编号为CICC 80001。

Carry out isolation and physiological characteristics study on the bacteriophage against L-aspartase producing E. coli conduces to control the phage contamination during the production process. The phage was isolated and purified adopting double-layer plate method. And the phage morphology was determined using transmission electron microscopy（ TEM）. The phage omni-genome was sequenced and compared with gene bank. The effects of temperature,p H,organic solvent chloroform and detergent SDS on phage was determined by measuring the phage activity under different treatment conditions. A bacteriophage was isolated from L-aspartase producing E. coli strain HY-05 C culture broth with phage contamination. The bacteriophage had a symmetrical head of regular polygon and short tails.Genome sequence and comparison results showed that it had a close relationship with T7 like bacteriophage. Research of the bacteriophage physiological characteristics showed that it was sensitive to high temperatures and SDS,but insensitive to chloroform,fairly stable in p H 7. 0 and alkaline conditions,however,unstable under acidic condition. Bacteriophage preservation number is CICC 80001.