摘要
从土壤中筛选到132株能分泌胞外弹性蛋白酶的细菌,经复筛得5株产酶在100u/ml以上,其中No.17-87菌每毫升发酵液含酶120单位,经鉴定为芳香黄杆菌。该菌在26℃发酵21小时酶产量即达峰值。从发酵液中分离纯化得到聚丙烯酰胺凝胶电泳均一的酶制品。SDS-PAGE测得分子量为21300,最适作用温度为50℃,最适作用pH为7.4,在pH4.5—9.5范围内稳定,重金属离子Fe^(3+)、Zn^(2+)、Cu^(2+)、Cr^(3+)、CO^(2+)、Ni^(2+)、Hg^(2+)和Ag^+等严重抑制酶活性。
132 strains bacteria secreting extracellular elastase were isolated from soil samples, 5 of them poccessed considerably high elastiolytic activity of more than 100u/ml. The highest-yield strain No. 17-87 was characterized as Flavobacterium odoratum, studies on the condition of elastase production revealed that its optimum carbohydrate and nitrogen source were glucose and casein respectively, and that it could utilize fowl ferther meal and wheat bran to give 80% relative yield. The culture exhibited maximum elastase activity at 26℃ for 21 hours, the productivity could be increased when the aeration was improved. The PAGE-homogenous elastase preparation was obtained from the culture broth by (NH4)2SO4 fractionation, DEAE-cellulose column chromatography and gel filtration on Sephadex G-75. The molecular weight was determined to be 21380 by SDS-PAGE, the elastiolytic activity was optimal at pH7. 4 and 50℃, The enzyme was stable over the range of pH4. 5-9.5 and below 40℃, but the activity was inhibited completely by Fe^(3+) , Zn^(2+), Cu^(2+), Cr^(3+), Co^(2+), Ni^(2+), Hg^(2+), Ag^+.
出处
《微生物学报》
CAS
CSCD
北大核心
1995年第1期50-57,共8页
Acta Microbiologica Sinica
关键词
芳香黄杆菌
胞外弹性蛋白酶
产酶条件
发酵
Flavobacterium odoratum , Extracellular elastase, Termentation condition, Enzyme purification and properties
