Production and characterization of PHB from a novel isolate Comamonas sp. from a dairy effluent sample and its application in cell culture

•First report on PHB nanomatrices and solid walled matrices from Comamonas sp.•Both matrices showed almost 100% survival of H9c2 cells.•Under optimized conditions PHB yield from Comamonas sp. was 0.523 g/g.

In the present study, media engineering was carried out to optimize various process parameters affecting fermentation for PHB production by Comamonas sp. The optimum conditions for PHB production were yeast extract concentration of 1%, pH 6.0 and inoculum concentration of 5.5%. Under optimized conditions the PHB yield was 0.523 g/g. The extracted polymer was characterized by FTIR and 1H NMR. Nanomatrices and solid walled matrices were prepared using the extracted PHB. Cytotoxic studies revealed that both solid walled and nanomatrices prepared from the extracted PHB showed almost 100% survivals of H9c2 cells. This is the first report on application of extracted PHB from Comamonas sp. as an extracellular matrix for cell culture.