Growth associated polyhydroxybutyrate production by the novel Zobellellae tiwanensis strain DD5 from banana peels under submerged fermentation.

In view of environmental pollution by fossil fuel-based plastics, it has become imperative to find out an alternative biodegradable plastic for sustainability. In this context, polyhydroxy butyrate (PHB) production was carried out by the Zobellella sp. DD5 using inexpensive banana peels as the carbon source. Under optimized condition, 1.13 g/L (47.3%) of PHB was produced by the bacteria in growth associated mechanism. The CO group of PHB was detected from the high intense absorption band (1719 cm-1) of FTIR spectroscopic analysis. NMR and GC-MS results are also identical with the chemical shift signal CH, CH2 and CH3 group of PHB. The PHB is crystalline in nature and degree of crystallinity (Xc) - 34.38%, melting temperature (Tm) - 169 °C, thermal decomposition temperature (Td) - 248 °C as detected by XRD and DTA respectively. Rough surface morphology of PHB film was validated by AFM and SEM imaging that improves biodegradability of the PHB. The Young's modulus, tensile strength and elongation at break depicted hard and brittle nature of PHB. Fluorescence-activated cell sorting (FACS) confirmed cytocompatibility of PHB at 500 μg/mL in human embryonic kidney (HEK-293) cell line. The non-cytotoxic PHB can be used for various biomedical and agricultural applications in future.