Production of polyhydroxybutyrate (PHB) by Parapedobacter sp. ISTM3 isolated from Mawsmai cave utilizing molasses as carbon source

Abstract

In the present study, a bacterial strain, Parapedobacter sp. ISTM3, isolated from the cave was screened for PHA (polyhydroxyalkanoate) production using molasses (agro-industrial waste) as carbon substrate. Additionally, the production of PHA was enhanced by using different carbon substrates, incubation time, and concentration of carbon substrate. Parapedobacter sp. ISTM3 was able to accumulate 31.73 ± 0.84% PHA of CDW before the optimization experiment. A total of 1.75 fold increase in PHA production has been seen after the optimization experiment as Parapedobacter sp. ISTM3 was able to produce 55.62 ± 0.44% PHA of CDW at optimized culture conditions (5% molasses and 72 h). GC–MS, FT-IR, and I H NMR analysis confirmed the presence of hydroxybutyric acid (3-HB) as a monomer which indicates the formation of polyhydroxybutyrate (PHB). The present study confirms the potential of Parapedobacter sp. ISTM3 for the production of PHA by utilizing an agro-industrial waste (molasses) and makes it a suitable candidate for mitigating plastic accumulation problems in the environment in near future. • Agro-industrial waste was bioconverted into PHA by Parapedobacter sp. ISTM3. • Parapedobacter sp. ISTM3 was able to accumulate 55.62% PHA as CDW within 72 h using 5% molasses as carbon substrates. • A 1.5 fold increase in PHA production was observed after the optimization of culture conditions.