POLY-BETA-HYDROXYBUTYRATE PRODUCTION BY LACTIC-ACID BACTERIA

Poly-beta-hydroxybutyrate was determined in lactic acid bacteria belon ging to the genera Lactobacillus, Lactococcus, Pediococcus and Strepto coccus. Lactobacilli were grown in MRS broth, the others were grown in Elliker broth medium. Cell biomass was obtained by centrifugation. Th e cell walls were lysed with sodium hypochlorite. Poly-beta-hydroxybut yrate was extracted using chloroform in a Soxhlet system. Then it was converted to crotonic acid using sulfuric acid and the amount of croto nic acid was measured spectrophotometrically. The yield of poly-beta-h ydroxybutyrate (% of cell dry weight) of Lactobacillus species was 6.6 -35.8%. The values for Lactococcus, Pediococcus and Streptococcus spec ies were 9.0-20.9, 1.1-8.0 and 6.8-17.2, respectively. It was observed that one of the Lactobacillus species did not produce poly-beta-hydro xybutyrate. Generally, Lactobacillus species produced more poly-beta-h ydroxybutyrate than the other tested bacteria and no significant corre lation was observed between poly-beta-hydroxybutyrate production and c ell density of the cultures. (C) 1998 Federation of European Microbiol ogical Societies. Published by Elsevier Science B.V.