Optimization of polyhydroxybutyrate production by β-carotene producing strain of Micrococcus sp.

Optimization of the polyhydroxybutyrate (PHB) production by a pigmented Micrococcus sp. was done by using
glucose, sucrose, lactose and fructose as carbon sources, initial pH between 6.0 and 8.0, fermentation temperature of
30 and 37°C, inoculum of 5, 10 and 15% v/v and by submerged/aerobic fermentation. Maximum production of
polyhydroxyalkanoates (PHA) was at 37°C in sucrose containing pH 6.0 under aerobic conditions. Overall, the PHB
production ranged between 35 and 40% of the dry cell weight. In GC analysis, PHA and PHB produced the same peak.
The UV-visible spectrophotometer and HPLC analysis of the pigment indicated presence of (β-carotenoids with absorption
maxima at 454 and 348 nm.