Exploring Star Fruit Extract as an Alternative Substrate for Polyhydroxyalkanoates Production by Bacillus licheniformis NJ04

Polyhydroxyalkanoates (PHA) production from diverse group of microorganisms has been a topic for extensive research for several decades. Despite this extensive research explorations, commercialization of PHA is still facing major hurdles, mainly due to the high cost involved in PHA production and recovery. This study was designed to determine a sustainable approach to produce PHA using an underutilized fruit extract. The major novelty of this research work is the use of starfruit (Averrhoa carambola L.), a tropical fruit, as a substrate for PHA production employing Bacillus licheniformis NJ04. Commercialization of PHA production can help to tackle global issues like raising microplastic pollution and biomagnification. The maximum PHA production reported in this work was 3.8 g/L under optimized conditions like temperature of 37 °C, pH 7 under shaking conditions (120 rpm) with 2% glycerol and starfruit extract as a carbon source after 72 h of incubation. The extracted PHA was further characterized through (FTIR) Fourier-transform infrared radiation, differential scanning calorimetry (DSC), Thermogravimetric analysis (TGA), X-Ray diffraction (XRD), and Proton Nuclear magnetic resonance (1H NMR). Thus, the present work highlights a novel strategy for using starfruit waste as a cost-effective substrate for PHA production.