12C6+离子对阿维链霉菌累进辐照诱变效应研究

选用12C6+ 离子束对阿维链霉菌诱变选育高产菌株与原始菌株进行辐照诱变, 研究其累进辐照效应。实验结果表明,在辐照剂量为10 Gy时, 原始菌株比诱变高产菌株存活率高, 抗辐射能力强;辐照剂量高于30 Gy时,诱变高产菌株比原始菌株存活率高, 抗辐射能力强。原始菌株正突变率最高的辐照剂量为50 Gy, 致死率99.43%,正突变率最高, 达34.2%;对诱变高产菌株辐照剂量为30 Gy,致死率94.97%,正突变率最高, 达23.5% 。累进辐照效应降低了最佳辐照剂量。 Mutagenic effect on the mutant high producing strain ZJAV Y1 203 and the original strain ZJAV A1 irradiated by ion beam of 12C6+ have been investigated. The experimental results indicated that the original strain has higher survival rate and stronger resistance to radiation than mutant high producing Strain at dose of 10 Gy. The mutant high producing strain has higher survival rate and stronger resistance to radiation than the original strain at the dose higher than 30 Gy. The lethality was 97% and the highest rate of orthomutation was 34.2%, when ZJAV A1 was irradiated by 50 Gy 12C6+ beam. The lethality was 94.97% and the highest rate of orthomutation was 23.5% when ZJAV Y1 203 was irradiated by 30 Gy 12C6+ beam. The best radiation dose is decreased by progressivity irradiation.     

阿佛曼链霉菌的~(12)C离子辐照效应及高产菌株选育

选用12C6+离子辐照诱变阿维菌素B1a产生菌ZJAV-A1,研究其诱变效应。实验结果表明,12C6+离子辐照剂量50Gy时致死率97%,正突变率最高可达到34.2%。通过12C6+离子诱变处理,结合平板培养基及斜面培养基的正突变菌株筛选,最终获得一株稳定性良好,阿维菌素B1a组分产量稳定在4460—4588μg/ml之间,较出发菌株提高11.1%—14.7%的突变株ZJAV-Y1-203。     

Influence of 12C6+ ion irradiation on mutant avermitilis

The effects of ¹²C⁺⁶ ion irradiation on colony morphology and mycelia morphology, as well as on mutation rate have been studied in the B1a high-product strains (ZJAV-Y1-203) mutated by heavy ion irradiation and compared with that in the original strain (ZJAV-A-1). After irradiating the rate of a straw hat colony type having a high ability of producing B1a in ZJAV-Y1-203 strains was higher than that found in ZJAV-A-1 strains. When strains were cultured in a liquid medium for 24 hours, the mycelium becoming thinner could be observed in all of the irradiated ZJAV- Y1-203 groups, but only in the ZJAV-A-1 groups irradiated at the dose of 50 Gy or more. The early growth of mycelium was inhibited in the ZJAV- Y1-203 group irradiated with a high dose. The highest positive mutation rate (23.5%) of ZJAV - Y1 - 203 was reached at the lower dose of 30 Gy while the highest positive mutation rate of 34.2% in ZJAV-A-1 appeared at 50 Gy.