Concomitant strain of Bacillus vallismortis BR2 and Escherichia coli Khodavandi-Alizadeh-2 for Biocatalytic Synthesis of Fatty Acid Methyl Ester from Waste Oil Feedstock

Abstract

Bacillus vallismortis BR2 and Escherichia coli Khodavandi-Alizadeh-2 lipases (E.C.3.1.1.3) were used to produce fatty acid methyl ester (FAME), a sustainable source of fuel. The lipase activity was measured using the titrimetric method after it was extracted from a solid fermented substrate in phosphate buffer. The use of Central Composite Design to optimize condition parameters was examined, while qualitative and quantitative assessments of FAME samples were performed using GC-MS with MSD in scan mode and selective ion monitoring. Lipase activity peaked at 24 h and then declined as the incubation time went on. The independent variables, such as pH, temperature, agitation, incubation time and enzyme quantity, all had an effect on biodiesel yield since they were all significant in the rate of biodiesel yield. FAME yield increased significantly after adding 1 to 2 mL of enzyme and a pH range of 4.57143 to 7.42857, but thereafter declined. The chromatograms indicated a peak of cis-10-Heptadecanoic acid methyl ester with concentrations of 39.95 mg/L and 58.95 mg/L in the FAME molecules. The viscosity (3.67 m3/s), specific gravity (0.813 g/cm3), flash point (102.70 °C), cetane number (55.52), and pour point (-24 °C) of the fuel were also measured. The synthesized biodiesel from the spent oil through the synergic enzymes were found to be a simple, effective, and sustainable fuel production process, as well as a potential means of eliminating pollution caused by haphazard waste cooking oil disposal.