PRODUCTION OF ORGANIC ACIDS FROM XYLOSE RICH HYDROLYSATE BY BACTERIAL FERMENTATION

摘要

This invention relates to the metabolic evolution of a microbial organism previously optimized for producing an organic acid in commercially significant quantities under fermentative conditions using a hexose sugar as sole source of carbon in a minimal mineral medium. As a result of this metabolic evolution, the microbial organism acquires the ability to use pentose sugars in non-detoxified lignocellulosic hydrolysate for its growth while retaining the original growth kinetics, the rate of organic acid production and the ability to use hexose sugars as a source of carbon. More specifically, this invention provides bacterial strains that have the ability to produce succinic acid using non-detoxified lignocellulosic hydrolysate as the source of organic carbon. This invention also discloses the genetic changes in the microorganism that arise during the course of metabolic evolution in the presence of non-detoxified lignocellulosic hydrolysate.