Screening, optimization and characterization of poly hydroxy butyrate from fresh water microalgal isolates

Abstract

ABSTRACT Microalgae, especially Chlorella sp., have been used for centuries as food and currently their biotechnological potential is notable for the presence of several compounds relevant to the market, like PHB. Microalgae are appealing because of the increasing demand for biopolymers like PHB. Therefore, the present study is aimed to determine the efficacy of biomass production and yield of PHB producing microalgae isolated and identified by phylogenetic analysis. The parameter was optimized as pH 7, temperature 30°C, under sunlight with 0.2% of sodium bicarbonate for higher biomass and PHB production. The extracted PHB were characterized through SEM, EDAX, XRD and FT-IR. In GC-MS analysis the major peak represents Benzyl butyl phthalate confirming the polymer of PHB. DSC-TGA, was performed and the melting peak of PHB was found as 342.1°C conferring to thermogravimetric analysis, the range of temperature for rapid thermal degradation of PHB was at 418°C to 420°C with the degradation peaking at 418.2°C the total weight loss within this temperature range was 98.5%. Hence, maximum 80% of PHB was produced from Chlorella sp. in addition to sequestering CO2.