Identification and characterization of a purple nonsulfur bacterium isolated from coastal area of Hai Phong for using in production of unsaturated fatty acid (omega 6,7,9)

Abstract

Purple nonsulfur bacteria are a group of diverse biotechnological applications, particularly in producing functional food rich in unsaturated fatty acids. In this study, a purple nonsulfur bacterium strain HPB.6 was chosen based on its strong growth, high lipid production and synthesis of unsaturated fatty acid (omega 6, 7, 9). The studying on biological characteristics showed that strain HPB.6 comprises ovoid-rod shaped cells with diameter of 0.8 - 1.0 µm, none motile, Gram negative stained. The cells divide by binary fission and contain bacteriochlorophyll a (Bchl a). This bacterium grew well on medium with carbon and nitrogen sources such as acetate, succinate, pyruvate, butyrate, glutamate, arginine, leucine, tyrosine, alanine, methionine, threonine, glutamine, yeast extract and NH4Cl. This selected strain grew well on medium with salt concentrations from 1.5 - 6.0 % (optimum 3 %), pH from 5.0 to 8.0 (optimum at pH 6.5) and could withstand Na2S at 0.4 - 5.2 mM. All the data and particularly 16S rRNA analysis received demonstrated that HPB.6 strain belongs to the species Rhodovulum sulfidophilum.