Polyhydroxybutyrate (PHB) Production and Mutagenesis of Halophile isolates from the East African Rift Salt Lake

Abstract

Polyhydroxybutyrate are considerably of human interest due to its outstanding properties as bioplastic to effectively replace polyethylene. In this study, halophiles were used for the production of bioplastics. Current studies investigated the isolation of halophilic bacteria from the samples of Lake Natron, one of the salt lakes of the East African Rift. Halobacterium medium was used for the isolation of the strains at 37 o C and pH 8.0. A strategical approach for high PHB production was implemented in which high carbon source in the form of dextrose was given to the bacteria at regular intervals, without increasing the nitrogen source. Further studies were carried out on random mutagenesis approach [physical (UV) and chemical (Acridine orange)] for enhancing the production of PHB. The PHB was extracted using sodium hypochlorite digestion process followed by chloroform extraction technique. PHB was identified by Thin Layer Chromatography, FTIR and NMR techniques. Among the mutants, UV-mutant produced the highest PHB yield of 29.63% compared to the wild type whose PHB yield was 20%. Acridine orange mutant showed an increased PHB yield from 20% to 28%. 16s rRNA sequence of the strain1 was carried out and the Bacterium was identified as Virgibacillus marismortui.