Novel lactic acid bacterium and method for producing l-lactic acid using same

Abstract

L-Lactic acid fermentation using non-edible biomass requires a lactic acid bacterium suitable for fermentation using a mixture comprising oligosaccharides or mixed saccharides produced by enzymatic treatment of cellulose and hemicellulose, so that simultaneous saccharification and fermentation are enabled. Further, it must be taken into consideration that use of pentoses such as xylose derived form non-edible biomass as the raw material provides lactic acid as well as equimolar acetic acid, which halves the molar yield of lactic acid, and high concentration L-lactic acid induces fermentation inhibition, which makes it difficult to produce L-lactic acid at high yield. The present invention provides a novel lactic acid bacterium that can solve these problems. With the lactic acid bacterium of the present invention, L-lactic acid showing a high optical purity of 99.9% or higher can be efficiently produced by using a mixture of glucose and cellobiose as a raw material without substrate inhibition and substantially without generation of by-products. The method of the present invention is applicable to efficient production of L-lactic acid from a non-edible biomass raw material.

Dependencies are inferred from the claim text.