赤霉酸降解菌的筛选及其适宜降解条件的确定

[目的]筛选一株赤霉酸(GA3)降解菌并探讨其适宜的降解条件。[方法]利用仅含赤霉酸为唯一碳源的基础盐培养基,对前期驯化得到的对GA3具有较强耐受性的微生物进行筛选,获得了具有较强降解GA3能力的菌株G-6;采用单因素试验系统考察了不同因素对菌株G-6降解GA3效果的影响,确定了其适宜的降解条件。[结果]在培养时间为120 h、培养温度为30℃、初始pH为7.0、接种量(菌悬液OD600=1.000)为5.0%(V/V)、培养基中赤霉酸浓度为200 mg/L、摇床转速为140 r/min、250 ml锥形瓶培养基装量为40 ml的条件下,GA3降解率达到60.62%。[结论]为深入探讨GA3的生物降解途径提供了参考。

Screening of Gibberellic Acid-degrading Strains and the Optimization of Its Degradation Conditions

[Objective] To screen a gibberellic acid-degrading strain and investigate the optimization of its degradation conditions.[Method] An efficient gibberellic acid-degrading strain G-6 was screened from some domesticated strains tolerant to gibberellic acid(GA3) by using basal salt medium with gibberellic acid as its only carbon source.In this paper,the effects of various factors on GA3 degradation by G-6 were investigated by single factor test and its condition for GA3 degradation was determined.[Result] The rate of GA3 degradation was up to 60.62% when the strain was incubated in 250 ml conical flask containing 40 ml mineral medium with 200 mg/L of gibberellic acid,5.0% of bacterial suspension and pH 7.0 on a rotary shaker(140 r/min) at 30 ℃ for 120 h.[Conclusion] The research supplied references for the biodegradation pathway of GA3.