Microorganism and method for lactic acid production

摘要

The present invention relates generally to compositions and methods for producing lactic acid using a lactic acid producing microorganism. More specifically, the present invention relates to methods for producing lactic acid with high yield, high concentration and high volumetric productivity through biological fermentation by Enterococcus faecalis, or recombinant microorganisms transformed to produce lactate dehydrogenase using the lactate dehydrogenase-encoding genes derived from E. faecalis.

主权项

1. A genetically modified lactic acid producing Enterococcus faecalis bacterium, comprising a polynucleotide encoding a lactate dehydrogenase, wherein said polynucleotide comprises a nucleotide sequence selected from the group consisting of:
(a) a nucleotide sequence having at least 95% sequence identity across the entire polynucleotide to the sequence of SEQ ID NO: 1 or 2 wherein said nucleotide sequence encodes a lactate dehydrogenase; or (b) a nucleotide encoding a protein having at least 95% sequence identity to SEQ ID NO: 3 or 4 and having lactate dehydrogenase activity; andwherein lactic acid production is conducted at a pH between 5.0 and 3.0.