【摘要】 为筛选较优的产青霉素酰化酶的菌种,我们从9个属的232株细菌中选出了19株产青霉素酰化酶的大肠杆菌,其中,AS 1.76和E110为最好。还对大肠杆菌AS 1.76的产酶条件进行了研究。结果表明,最适的培养基成分是（%）:蛋白胨1,苯乙酸0.2,玉米浆0.3,氯化钠0.5;在250毫升的三角瓶中装30毫升培养基时,通气量正合适;培养基的初始pH以7.0为佳;培养时间15小时。在未加玉米浆的培养基中,少量的Fe²⁺ （5微克/毫升）对酶形成有刺激作用,过量的Fe²⁺ （大于10微克/毫升）是不利的;在培养基中添加0.3%的玉米浆能降低Fe²⁺ 对酶形成毒害作用。更多还原

【Abstract】 From 232 bacterial strains includingnine genera, we selected out 19 penicillinacylase-producing strains （all of whichbelong to E. coli）.Among them, AS1.76 and E 110 are the most promisingones. Conditions for the production of pe-nicillin acylase by E. coli AS 1.76 havebeen investigated. The medium, mostsuitable for fermentation, consists ofpeptone 1%, phenylacetic acid 0.2%,corn-steep liquor 0.3% and NaCl 0.5%.Optimal conditions for enzyme produc-tion were as follows:250 ml shake flaskfilled with 30 ml medium, initial pH 7.0;temperature, 28℃;incubation period,15 hr. Keeping low Fe²⁺ concentration（5μg/ml） may promote formation ofpenicillin acylase in the medium withoutcorn-steep liquor, but Fe²⁺concentrationbeyond 10 μg/ml was unadvisable forproduction of this enzyme. A 0.3% ofcorn-steep liquor should reduce the in-hibition of Fe²⁺for the production of theenzyme.更多还原