重离子束诱变选育谷氨酸高产菌株

High-yield glutamic acid strain screened by heavy ion irradiation

采用中能12C6+离子束辐照诱变谷氨酸生产菌谷氨酸棒杆菌,结合3种选择性培养基初筛突变菌株,通过摇瓶复筛谷氨酸高产菌株,并进行批次发酵实验。结果表明,经80 Me V/u碳离子束辐照后,受照菌存活率发生显著变化,通过选择性平板初筛、摇瓶复筛选育出1株高产菌株GM006,菌体生长和发酵有较大改进,其发酵最高产酸达121.10 g/L,比出发菌株提高了10.09%,糖酸转化率达60.55%,比原始菌株提高10.09%。该GM006突变株是很有前景的谷氨酸工业生产菌,同时证明重离子束是一种高效的辐射诱变源。

12C6＋ ion beam was used to irradiate glutamic acid-producing strains, and the strains producing higher glutamate were screened by three selective breeding mediums, and then the mutants were fermented by shake flask experiments. Finally the mutants were measured by several fermentation experiments. The results showed that the survival rate of corynebacterium glutamicum changed significantly after irradiation with 80 MeV/u 12C6＋ ion beam, and a high-yield strain GM006 was finally obtained through the two screening steps of selecting plate and shaking flask fermentation. The growth rate and glutamic acid yielding of GM006 were remarkably improved. The conversion rate of glucose was 60.55%, which increased by 10.09% compared with the original strain. The highest content of glutamic acid reached 121.10 g/L, and increased by 10.09 % compared with the original strain. This mutant will have broad application prospect as a glutamic acid producing strain, and it is also proved that the heavy ions beam is an efficient radiation resource for microorganism breeding.