Utilization of sugarcane molasses as the main carbon source for the production of polyhydroxyalkanoates from Enterobacter cloacae

•Petrochemical plastics are not biodegradable and so their widespread usage has several bad consequences on the ecosystem.•Polyhydroxyalkanoates (PHAs) are produced by bacteria under certain certain conditions of nutrient stress, carbon abundance, etc.•PHAs are completely biodegradable and have many features similar to that of conventional plastics, making them suitable biodegradable alternatives.•But the costs associated with PHA production has been hindering this transition towards them.•In this study, we have used cheap sugarcane molasses to produce 4.13 - 4.98 g/L or 48 - 56% PHA from Enterobacter cloacae, and have thus demonstrated the ability of this microbe to cheaply produce impressive yields of PHA. Polyhydroxyalkanoates (PHAs) are biodegradable polymers that otherwise exhibit many properties similar to that of conventional, non-biodegradable plastics. Hence, they are considered as potential substitutes for non-biodegradable plastics. But industrial production and commercialization of PHA have been hindered greatly due to the high cost requirements, especially those involved in the provision of suitable carbon sources. In this study, sugarcane molasses was used as a cheap carbon source for PHA production using a wild strain of Enterobacter cloacae isolated from sugarcane extract. This isolate was selected for PHA production based on Sudan Black B staining, and it was subsequently identified by performing BLASTn using its 16S rRNA sequence (GenBank accession number: ON314993). The PHA yield was studied under varying conditions of initial pH, molasses concentration and inoculum concentration. The highest yield of 4.13 - 4.98 g/L or 48 - 56% PHA was obtained after 48-60 h incubation at initial pH 7, molasses concentration 4% and inoculum concentration 2%. After downstream processing, the extracted PHA was characterized by FTIR spectroscopy. It is concluded that E. cloacae has the potential to utilize sugarcane molasses as a cheap carbon source to yield impressive amounts of PHA, and that it should be considered a candidate for further studies and for the cheaper industrial production of PHA. : [Display omitted]