Expression cassette for lactase dehydrogenase, transformed yeast and method of producing lactic acid

摘要

A gene expressing cassette codes 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 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.

主权项

1. An isolated expression cassette, comprising a gene encoding a lactate dehydrogenase connected to a site downstream of a promoter, wherein the promoter is a promoter of a SED1 gene consisting of the base sequence shown by SEQ ID NO: 1.