Production of poly(3-hydroxybutyrate) from whey by fed-batch culture of recombinant Escherichia coli in a pilot-scale fermenter

Production of poly(3-hydroxybutyrate) [P(3HB)] from whey by fed-batch culture of recombinant Escherichia coli CGSC 4401 harboring a plasmid containing the Alcaligenes latus polyhydroxyalkanoate (PHA) biosynthesis genes was examined in a 30 1 fermenter supplying air only. With lactose below 2 g 1^-1, cells grew to 12 g dry cell 1^-1 with 9% (w/w) P(3HB) content. Accumulation of P(3HB) could be triggered by increasing lactose to 20 g 1^-1. By employing this strategy, 51 g dry cell 1^-1 was obtained with a 70% (w/w) P(3HB) content after 26 h. The productivity was 1.35 g P(3HB) 1^-1 h^-1. The same fermentation strategy was used in a 300 1 fermenter, and 30 g dry cell 1^-1 with 67% (w/w) P(3HB) content was obtained in 20 h.