农用抗生素高产菌株的筛选分离及诱变育种

该实验分离得到4株产农用抗生素菌株，编号1#～4#。 以厚垣镰孢霉（Fusarium chlamydosporum）、枯草芽孢杆菌（Bacillus subtilis）、大肠杆菌（Escherichia coli）、金黄色葡萄球菌（Staphylococcus aureus）作为指示菌，测定其发酵液的抑菌活性，并对抑菌 活性菌株进行诱变育种。 结果表明，菌株1#对枯草芽孢杆菌（B. subtilis）和金黄色葡萄球菌（S. aureus）抑菌圈直径＞10 mm，抑菌 活性较好。 采用紫外诱变、重金属激活沉默基因复活诱变两种方法诱变菌株1#后，对厚垣镰孢霉、枯草芽孢杆菌、大肠杆菌、金黄 色葡萄球菌抑菌作用分别增加了25.68%、32.11%、34.85%、28.28%。 形态学观察及生理生化实验结果初步鉴定菌株1#为链霉菌属（Streptomyces sp.）。

Screening,isolation and mutation breeding of strain with high yield agricultural antibiotic

Four agricultural antibiotic-producing strains were screened and numbered as 1#-4#. Using Fusarium chlamydosporum, Bacillus subtilis, Es- cherichia coli, Staphylococcus aureus as indicator microbes, the antibacterial activities of fermentation broth were determined and strains with an- tibacterial activity were mutated breeding. The results showed that inhibitory effects of strain 1# on B. subtilis and S. aureus were better, and the in- hibitory zone diameters were more than 10 mm. Inhibitory effects of strain 1# mutated by UV-mutation and heavy metal activating silent genes on F. chlamydosporum, B. subtilis, E. coli and S. aureus increased by 25.68%, 32.11%, 34.85% and 28.28%, respectively. The strain 1# was preliminarily identified as Streptomyces sp. by morphological observation and physiological and biochemical experiments.