Isolation, screening, and characterization of polyhydroxyalkanoate (PHA)-producing Cellulosimicrobium cellulans: A promising approach for eco-friendly biopolymer production

The replacement of synthetic plastics with eco-friendly biopolymers is a notable approach in the modern world. Polyhydroxyalkanoates (PHAs) have gained a lot of attention among researchers in recent decades. This study aimed to isolate and screen microorganisms capable of producing PHA from composite samples. Several composting unit samples were collected and used to isolate 15 distinct colonies which were then screened for PHA synthesis. Three isolates-SS2, SSNA 1a, and SF2-showed promising PHA production. Among these isolates, SS2 had the highest PHA content of 70.1%. The isolate SS2 was determined as Cellulosimicrobium cellulans DSM 43879 by gene sequencing. The polymer produced by SS2 was further characterized. The presence of carbonyl groups and ester linkages in the PHA polymer was established by Fourier transform infrared analysis. The polymer's crystalline nature was validated by X-ray powder diffraction measurement. Scanning electron microscope study revealed thread-like forms with a rough surface while energy dispersive X-ray analysis revealed a low impurity content that was primarily composed of carbon and oxygen with traces of other elements. Overall, the findings indicate C. cellulans potential as an ideal candidate for efficient PHA synthesis supporting its commercial potential in diverse applications.