Effect of pH on the production of PHB by Acaligenes eutrophus from whey

The production of polyhydroxybutrate(PHB) by Alcaligenes eutrophus NCIB 11599 was studied in a synthetic medium from whey as a sole carbon source. Especially pH-effect was treated and compared in this study. At the end of fermentation (A) unadjusted to pH, the dry cell weight, PHB concentration, and PHB conversion rate were 10.3g/L, 3.1g/L, and 30%, respectively. At the end of fermentation (B) adjusted to $pH(7.0{\sim}7.5)$, the dry cell weight, PHB concentration, and PHB conversion rate were 12.5g/L, 4.8g/L, and 41%, respectively. PHB conversion rate was about 10% higher on the fermentation (B) than on the fermentation (A).