A novel lactic acid bacterium for the production of high purity l-lactic acid, Lactobacillus paracasei subsp. paracasei CHB2121

Fermentation-derived lactic acid has several potential industrial uses as an intermediate carbon chemical and a raw material for biodegradable polymer. We therefore undertook the identification of a novel bacterial strain that is capable of producing high concentrations of lactic acid and has potential commercial applications. A novel l(+)-lactic acid producing bacterium, Lactobacillus paracasei subsp. paracasei CHB2121 was isolated from soil obtained near an ethanol production factory and identified by 16S rRNA gene sequence analysis and characterization using an API 50 CHL kit. L. paracasei subsp. paracasei CHB2121 efficiently produced 192 g/L lactic acid from medium containing 200 g/L of glucose, with 3.99 g/(L·h) productivity, and 0.96 g/g yield. In addition, the optical purity of the produced lactic acid was estimated to be 96.6% l(+)-lactic acid. The newly identified L. paracasei subsp. paracasei CHB2121 efficiently produces high concentrations of lactic acid, and may be suitable for use in the industrial production of lactic acid.

► A novel l(+)-lactic acid (LA) producing bacterium was isolated.
► Typical concentration of LA produced fermentatively is less than 15% (w/v).
►  The development of a novel strain is needed for the commercial production of LA.
► The strain CHB2121 produces 192 g/L LA.