Effect of total nutrient feed on production of poly-3-hydroxybutyrate by Methylobacterium sp. ZP24 grown on sugars

sp. ZP24 is able to produce poly-3-hydroxybutyrate (PHB) from sucrose and lactose. As the production of PHB is growth-associated, a strategy of intermittent feeding of sugars and other nutrients was assessed for obtaining high yields of the polymer. Higher PHB synthesis was obtained at increased sugar feed rates. Cellular PHB contents of 63% and 71%, with productivities of up to 0.354 and 0.645 g PHB/l h were obtained from sucrose and lactose, respectively. A short-duration semicontinuous production level of up to 2.4 g PHB/l h was achieved in the lactose fermentation. Journal of Industrial Microbiology & Biotechnology (2000) 25, 276–279.