离子注入选育L(＋)-乳酸耐酸菌及去中和剂发酵研究

Studies on Screening of Rhizopus oryzae Bearing L(+)-lactic Acid by Ion Beam Implantation and the Fermentation Without Neutralization

为了获得可用于原位分离藕联发酵的耐乳酸菌株,以米根霉RE3303为出发菌株,在投糖浓度为50g/L,氮源为3.0g/L尿素的条件下,进行离子注入选育,得到L(+)-乳酸耐酸菌株RK4002,不添加中和剂,经30h的摇瓶发酵,L(+)-乳酸产量达32.32g/L,产率达1.08g/(L.h),为出发菌株的1.7倍,且可在24g/L的耐乳酸平板上生长,具有一定的应用潜力。

In order to get a strain which can bear high lactic acid for ISPR （in situ product removal） under the fermentation condition of glucose 50g/L, Urea 3.0g/L, the original strain Rhizopus oryzae RE3303 was mutated by ion beam implantation. A mutant RK4002 bearing higher lactic acid was screened, the concentration of L（＋）-lactic acid reached 32.32 g/L after 30 h shake-flask cultivation without any neutralization. The productivity was 1.08g/（L .h）, which was a 146% increase compared with the original strain. RK4002 could also grow on PDA plate containing 24g/L lactic acid, which showed potential for industrial use.