Comparative polyhydroxyalkanoates production by anaerobic bacteria through submerged and solid-state fermentation

PHAs are the bio-polyester synthesized by aerobic and anaerobic bacteria as energy storage granule. However, its synthesis by anaerobes is an imperative part of their physiology via assimilating broad range of substrates than aerobes. Thus, 03 Gram positive anaerobic/facultative PHAs producers viz., Bifidobacterium sp. FM3, Actinomyces sp. CM4 & Bifidobacterium sp. FM5 were selected. Among them, Bifidobacterium sp. FM3 showed higher biomass production in mineral salt medium comprised of glucose & peptone as carbon & nitrogen source at pH 9, temperature 37 o C, inoculum 10% and incubation period 72 h. Under optimized condition, Bifidobacterium sp. FM3 produced 0.89 and 1.5 g/L of PHAs through submerged and solid-state fermentation. IR spectra of PHAs illustrated a strong absorption peak at 1718.50 cm -1 representing C = O functional group of PHB. It is the first report demonstrating PHAs production by Bifidobacterium sp. through different bioprocess technology, which may pave the way of further research.