反应详情

According to the present invention, the method for screening microbial strains with the lactic acid yield of more than about 75% may comprise directly measuring the lactic acid yield or screening the microbial strain having more sets of exogenous lactate dehydrogenase gene, and preferably, screening the microbial strain having more sets of exogenous lactate dehydrogenase genes. In a preferred embodiment of the present invention, screening is carried out in the culture medium containing calcium carbonate. Because the microbial strain having more sets of lactate dehydrogenase genes may generate much more lactic acid which can react with calcium carbonate to form calcium lactate having solubility higher than calcium carbonate, the original white culture medium containing calcium carbonate around the microbial colonies which may generate lactic acid will become transparent and form a clear zone. Accordingly, the microbial strain with higher yield of lactic acid will be obtained by selection of the microbial strain with bigger clear zone. On the other hand, the screening method may include transferring a reporter gene at the same time and measurement by measuring expression of the reporter gene. In a preferred embodiment of the present invention, the reporter gene is a drug resistance gene.

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