微波辐照选育L-乳酸高产菌的生物学特性研究

Study on screening high yield L-actic acid producing strain Lactobacillus casei by microwave mutagenesis and biological characters of mutant strain

在低功率微波条件下,采用水循环冷却器,对干酪乳杆菌鼠李糖亚种(Lactobacillus casei subsp.rhamnosus)X1-12进行诱变处理,在微波功率400 W,辐照时间3 min的诱变条件下得到L-乳酸产量为115.8 g/L的突变株W3-9,比原始菌株X1-12提高了57.98%,连续遗传8代,产酸性状稳定.通过原始菌株和突变株的生理生化实验,可知微波辐照后的菌株生物学特性发生部分改变.

This paper focuses on the mutagenic influence of microwave irradiation on Lactobacillus casei subsp, rhamnosus X1 - 12 under the condition of low-power radiation and circulating cooling water. Under the microwave power of 400W and irradiation length of 3 min, a mutant strain W3 - 9 of high producing L - actic acid was found by screening. The L - actic acid production of which are 115.8 g/L and the improvement of L - actic acid produced are up to 57.98% comparing with the parent strain X1 - 12. And its properties of highly producing L - actic acid remained stable after many times of subculture and storage for two months. The physiological biochemical comparison experiments indicated that some different biological characters existed after microwave radiation between the parent strains and the mutant ones.