production and optimization of biodiesel by oleaginous microorganisms using agrowaste

Abstract

Increasing demand and changes in pricing of fossil-derived fuel led researchers to find the productive path to meet the current energy requirement. These objectives can be achieved by using lignocellulosic wastes as a source of food for microbes having the ability to accumulate oil. Microorganisms possessing more than 20% w/w of lipids on dry weight are termed as oleaginous microorganisms. Oleaginous microorganisms are proven useful in the production of biodiesel. Coastal water was screened for the presence of these microorganisms. Potent lipid accumulator has been isolated from the selected sample. After studying morphology, biochemical, and 16s rRNA sequencing analysis, the organism was identified as Bacillus paralicheniformis (OQ202112). They can produce polyunsaturated fatty acids (PUFAs) de novo using PUFA synthase/polyketide synthase. The fatty acid profile revealed the presence of oleic and linoleic acids as major components. They produced 3.3 g/L lipids with 5.5 g/L total dry weight. Lipid extraction was carried out by Bligh and Dyer method and oil was transesterified by methanol using NaOH as a catalyst. The yield of fatty acid methyl esters was 86.2%. The fuel obtained met with the standards given by the American Society for Testing and Materials and ASAM. Cetane rating 61 suggests good quality of the biodiesel produced. Thus, the isolated organism possesses potential to be used as a biodiesel producer. newline