摘要 |
Provided are a gene expressing cassette coding lactate dehydrogenase that is needed for prevention of deterioration in lactic acid yield and lactic acid production rate in continuous culture with simultaneous filtration of a yeast strain having a lactic acid-producing ability, which achieves high optical purity, high lactic acid yield and high lactic acid production rate simultaneously, a yeast strain having the cassette and a method of producing lactic acid by culturing the yeast strain. The lactate dehydrogenase-expressing cassette according to the present invention is a lactate dehydrogenase-expressing cassette, comprising a gene coding lactate dehydrogenase connected to a site downstream of a promoter, the promoter being a promoter of a gene showing a gene expression amount larger by 5 times or more than the average relative expression amount of all genes after 50 hours from start of culture in continuous culture with simultaneous filtration of a yeast strain having a lactic acid-producing ability. |