title: Production of D-lactic acid from defatted rice bran by simultaneous saccharification and fermentation.
abstract: Production of d-lactic acid from rice bran, one of the most abundant agricultural by-products in Japan, is studied. Lactobacillus delbrueckii subsp. delbrueckii IFO 3202 and defatted rice bran powder after squeezing rice oil were used for the production. Since the rice bran contains polysaccharides as starch and cellulose, we coupled saccharification with amylase and cellulase to lactic acid fermentation. The indigenous bacteria in the rice bran produced racemic lactic acid in the saccharification at pH 6.0-6.8. Thus the pH was controlled at 5.0 to suppress the growth of the indigenous bacteria. L. delbrueckii IFO 3202 produced 28 kgm(-3) lactic acid from 100 kgm(-3) rice bran after 36 h at 37 degrees C. The yield based on the amount of sugars soluble after 36-h hydrolysis of the bran by amylase and cellulase (36 kgm(-3) from 100 kgm(-3) of the bran) was 78%. The optical purity of produced d-lactic acid was 95% e.e.
authors.affiliation: Department of Materials Science and Technology, Niigata University, 2-8050 Ikarashi, Niigata 950-2181, Japan. tctanaka@eng.niigata-u.ac.jp
authors.forename: Takaaki
authors.initials: T
authors.lastname: Tanaka
authors.forename: Masahiro
authors.initials: M
authors.lastname: Hoshina
authors.forename: Suguru
authors.initials: S
authors.lastname: Tanabe
authors.forename: Kenji
authors.initials: K
authors.lastname: Sakai
authors.forename: Sadami
authors.initials: S
authors.lastname: Ohtsubo
authors.forename: Masayuki
authors.initials: M
authors.lastname: Taniguchi
mesh_terms: D050260:Carbohydrate Metabolism; D002241:Carbohydrates; D004043:Dietary Fiber / Q000378:metabolism*; D005285:Fermentation / Q000502:physiology*; D006863:Hydrogen-Ion Concentration; D019344:Lactic Acid / Q000096:biosynthesis*; D048668:Lactobacillus delbrueckii / Q000378:metabolism; D012275:Oryza / Q000378:metabolism*; D011134:Polysaccharides / Q000378:metabolism; D013997:Time Factors
chemical_list: D002241:Carbohydrates; D004043:Dietary Fiber; D011134:Polysaccharides; D019344:Lactic Acid