紫外诱变吸水链霉菌选育高产农用抗生素菌株

Breeding of Agricultural Antibiotic-producing Strain of Streptomyce hygroscopius with High Yield by Ultraviolet Mutagenesis

[目的]为抗生素产生菌在农业生产中的应用奠定基础。[方法]以小麦赤霉菌为指示菌,以从吸水链霉菌海南变种S101菌株分离到的S510菌株为出发菌株,经紫外诱变后分别采用琼脂块法和二级摇瓶复筛法对其进行初筛和复筛,以选育出高产菌株,分析发酵培养基pH值和培养时间对发酵液效价的影响。[结果]当发酵培养基的pH值为5.5-6.5时,发酵液效价较高,最适pH值为6.0。发酵液的效价在72 h后可维持在较稳定的范围内,最佳发酵时间为96 h。通过连续2次紫外诱变,菌株的产抗生素能力比初始菌株提高了30.06%。将获得菌株在斜面培养基上连续传代5次后,仍有稳定的遗传性状。[结论]采用紫外诱变法选育该链霉菌是有效的。

[ Objective ] The research aimed to lay the foundation for the application of antibiotic-producing bacteria in the agricultural production. [Method] With Fusarium gramineaum as indicative bacteria, strain S510 isolated from Hainan variation strain S101 of Streptomyces hygroscopicus was taken as the original strain. The ultraviolet mutagenesis, primary screening and secondary screening were made on strain S510 by using agar block method and shaking flask secondary screening method resp. to breed the high-yield strain. The effects of pH value and culture time of fermentation medium on the titer of fermentation liquid were analyzed. [Result] When pH value of fermentation medium was 5.5 - 6.5, the titer of fermentation liquid was higher. The optimum pH value was 6.0. The titer of fermentation liquid could maintain in a stable range after 72 h and the optimum fermnentation time was 96 h. Through 2 times of continuous ultraviolet mutagenesis, the ability of producing antibiotic by this swain was increased by mere than 30.06% than that of the original strain. After the obtained swains were continuously subcuhured on the slant medium for 5 generations, it still had stable genetic characteristics. [Conclusion] Breeding this Streptomyces by the method of ultraviolet mutagenesis was effective.