利用制霉菌素抗性筛选赤霉素高产菌株的研究

利用紫外、亚硝基胍以及复合诱变的方法,采用制霉菌素抗性筛选,选育赤霉素高产突变株.在磁力搅拌下,菌悬液先后经过浓度为3.0 mg/mL亚硝基胍30 min和紫外线(30 W,20 cm距离)45 s诱变,得到抗制霉菌素的赤霉菌突变株.进一步摇瓶复筛,获得赤霉素高产菌株,其中菌株ZNL-1产赤霉素效价达到2 170 μg/mL,较之诱变前发酵效价平均提高了16.7％.经10次斜面传代,菌株ZNL-1产素水平稳定,菌株遗传稳定性较好.表明,赤霉菌抗制霉菌素的抗性与赤霉素高产之间存在对应关系.

Screening of High-yield Gibberellin-producing Strain from Nystatin Resistant Mutants

In order to obtain high-yield gibberellin strain,the Gibberella fujikuroi 978# of gibberellin-producing fungus was treated with ultraviolet radiation,NTG and UV+NTG,respectively.A series of nystatin resistant mutants were screened by primary screening method with plate culture containing nystatin,after the 978# strain suspension was treated with 3.0 mg/mL NTG for 30 min,followed by UV irradiation(30 W,20 cm distance)for 45 s under magnetic stirring.After second selected among them,most were determined as high yield gibberellin producing strains,a strain ZNL-1 whose productivity of gibberellin was 13.6% higher than that of its parent was obtained;its’ fermentation potential was 2 170 μg/mL.The strain ZNL-1 had good hereditary stability by inoculating 10 times.It was suggested that gibberellin-produced capacity of Gibberella fujikuroi be correlated significantly with the resistance to nystatin.