[目的]为苏氨酸基因工程菌的构建和苏氨酸的工业化生产奠定基础.[方法]以谷氨酸棒杆菌为出发菌株,采用紫外线(UV)诱变和硫酸二乙酯(DES)复合诱变进行诱变处理并筛选出AHV抗性突变株.[结果]用细菌选择性平板选出产酸菌株266株,用纸层析法从中选出产苏氨酸菌株3株,其产苏氨酸量分别为0.18、0.12和0.08 g/L.在AHV浓度为0、1.5和3.0 g/L的平板上,菌株X1的菌落多且大;在AHV浓度为4.5 g/L的平板上,其菌落少且小;在AHV浓度为6.0和7.5 g/L的平板上仅有几个小菌落.传代试验表明只有菌株UV-3能稳定产酸,产量比出发菌株高55.6%.在AHV浓度为4.5、6.0和7.5 g/L的平板上,菌株UV-3的菌落多且大;在AHV浓度为9.0 g/L的平板上,其菌落少且小;在AHV浓度为10.5 g/L的平板上仅有几个小菌落.[结论]该试验成功选育出了一株稳定、高产并具有AHV抗性的L-苏氨酸产生菌.%[Objective] The research aimed to lay a foundation for the construction of threonine-gene engineering bacteria and the industrial production of threonine. [Method] With Corynebacterium glutamicum as original strains, they were treated by UV mutagenesis and combined mutagenesis of UV and diethyl sulfate and their mutants with resistance to AHV were screened out. [Result] Two hundred and sixty-six producing strains of acid were selected out by bacterial-selective plate, then 3 producing strains of threonine were selected out from them by paper chromatography and their threonine outputs were 0.18, 0.12 and 0.08 g/L resp. The colonies of strain X1 were many and big on the plates with AHV concn. of 0, 1.5 and 3.0 g/L, they were few and small on the plates with AHV concn. of 4.5 g/L and there were only a few small colonies on the plates with AHV concn. of 6.0 and 7.5 g/L. The passage experiment showed that only the strain UV-3 could produce amino acid stably, its output was 55.6% higher than that of original strain. The colonies of strain UV-3 were many and big on the plates with AHV concn. of 4.5, 6.0 and 7.5 g/L, they were few and small on the plates with AHV concn. of 9.0 g/L and there were only a few small colonies on the plates with AHV concn. of 10.5 g/L. [Conclusion] A stable and high-yield strain with resistance to AHV, which could produce L-threonine, were bred out successfully in the experiment.
展开▼
