产D-氨基酰化酶菌株的筛选及活性菌株A55的初步研究  

Screening of D-Aminoacylase-Producing Microorganisms and Preliminary Study of Active Strain A55

作　　者：倪孟祥[1] 席焕鸽 

机构地区：[1]中国药科大学生命科学与技术学院,江苏南京210009

出　　处：《化学与生物工程》2014年第5期44-48,共5页Chemistry & Bioengineering

摘　　要：从氨基酸类化工厂附近土样中筛选产D-氨基酰化酶的菌株,并对活性较高的菌株进行了菌种鉴定及培养条件的初步优化。利用N-乙酰基甲硫氨酸作为分离培养基中的唯一碳氮源,从8份土样中筛选了约500株菌,其中菌株A55酶活力及稳定性均较高。通过形态学观察、生理生化特征测定及16SrDNA系统发育分析对菌株A55进行菌种鉴定,并采用单因素法考察了影响D-氨基酰化酶合成的因素。结果表明,菌株A55属于耐寒短杆菌,其最佳产酶发酵条件为:培养温度30℃,培养基初始pH值7,摇床转速200r·min-1,摇瓶装样量15%,培养时间48h。另外,碳氮源的添加虽然有利于菌体的生长,但是不利于D-氨基酰化酶的合成。We conducted a screening program for microorganisms with D-aminoacylase activity from the soil nearby a chemical plant producing amino acids,identified the strain with better activity and optimized its culture conditions primarily.Approximately 500strains were screened from eight soil samples by using the isolation medium with N-acetyl-methionine as the sole carbon and nitrogen sources,among which strain A55with higher enzyme activity and stability was identified according to the morphological characteristics,physio-biochemical characteristics and 16SrDNA phylogenetic analysis.Factors influencing D-aminoacylase synthesis were studied by single factor method.The results showed that strain A55was classified within Brevibacterium frigoritolerans,its optimum fermentation conditions for enzyme production were as follows：culture temperature 30℃,culture initial pH value 7,shaker speed 200r·min-1,loaded liquid 15% and strain age 48h.Furthermore,although adding carbon or nitrogen sources was beneficial to the growth of bacteria,not to the synthesis of D-aminoacylase.

关 键 词：D-氨基酰化酶 菌株筛选 菌株鉴定 发酵优化 

分 类 号：TQ927[轻工技术与工程—发酵工程]