链霉素抗性筛选吸水链霉菌高产农用抗生素菌株研究

目的]筛选吸水链霉菌的高产农用抗生素菌株。方法]从海南土壤中筛选出1株吸水链霉菌,以经过自然分离和2次紫外诱变的S6-7为出发菌株,经过紫外光照射辅以链霉素抗性筛选后,再进行摇瓶发酵复筛。结果]从62株随机挑选的单菌落中初筛出7株较好菌株,经斜面连续传代3次后复筛,发现5株菌株具有较好的正突变,正突变率可达8.06%,效价最高提高25.11%。结论]将链霉素筛选法与传统紫外诱变法相结合,使菌株的产素能力有较大提高,而且极大地提高了菌种正向突变的筛选效率。

Study on the streptomycin resistance screening of Streptomyces hygroscopicus strains highly producing agricultural antibiotics

Objective] The aim of the research was to screen Streptomyces hygroscopicus strains highly producing agricultural antibiotics.Method] A strain of S.hygroscopicus was screened from the soil of Hainan Island.After natural screening and consecutive ultraviolet induced mutation twice,S6-7 strain was obtained as the original strain which was 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 showed obvious forward mutation.The forward mutation rate reached 8.06%,and the largest production increasing rate come up to 25.11%.Conclusion] By combining streptomycin resistance screening and conventional ultraviolet induced mutation,both the antibiotic-producing capacity and forward mutation screening efficiency of the original strain were greatly enhanced.