链霉素抗性筛选吸水链霉菌高产农用抗生素菌株研究

农用抗生素作为一类生物农药，具有使用剂量低，环境相容性好，选择性强的特点，因此受到普遍重视。目前已发现的天然抗生素有约2／3来源于链霉菌。利用链霉菌产抗生素能力与链霉素抗性基因之间的对应关系来定向筛选正向突变株，是目前农用抗生素科研领域的研究热点。

Screening for Streptomyces Hygroscopicus Strains with High Production of Agricultural Antibiotics by Streptomycin Resistance

Objective]The research aimed to screen Streptomyces hygroscopicus strains with high production of agricultural antibiotics.Method]A strain of S.hygroscopicus was screened from the soil of Hainan Island.After natural screening and consecutive uhravidet induced mutation twice,S6-7 strain was obtained as the original strain then treated by UV irradiation and streptomycin resistance screening,and finally rescreened through shake-flask fermentation.Result]7 better strains were selected by primary screening from 62 single colonies which were picked out randomly.After 3 generations of consecutive cultivation on slant media and rescreening,5 strains presented obvious forward mutation.The forward mutation rate reached 8.06%,and the largest production increasing rate came up to 25.11%.Conclusion]By combining streptomycin resistance screening and conventional uhraviolet induced mutation,both the antibiotic-producing capacity and forward mutation screening efficiency of the original strain were greatly enhanced.