Deciphering the role of Enterobacter cloacae as a green whole-cell biocatalyst for production of Calophyllum inophyllum biodiesel

Marine bacteria are renowned for their resilience to extreme conditions such as variable temperatures and high salinity. Producing biodiesel through whole-cell biocatalysts derived from marine bacteria is an innovative and eco-friendly approach to biofuel production, leveraging the unique enzymatic abilities of microorganisms adapted to extreme marine environments. Their manufacturing costs and environmental footprint are significantly lowered as they involve fewer purification stages, function under gentler conditions, and generate less waste. Calophyllum inophyllum has been selected for this study because its high local abundance ensures a reliable and readily available biomass source, making it ideal for investigating its potential in biodiesel production. A marine lipolytic bacterial strain, BF2, with taxonomic identification as a salt-tolerant Enterobacter cloacae strain, has been evaluated by 16S rRNA gene sequencing results. The work involves experimenting with the novel ideation of a nutrient fortification method in the matrix, a loofah sponge, accompanied by the identification of the optimum conditions for transesterification of C. inophyllum oil. The immobilized enzyme converted the seed oil into biodiesel using transesterification. With a 6:1 ideal methanol-to-oil ratio, 30% (w/w) of catalyst, and 8% (w/w) of water content, the process produced a maximum conversion of 90.2% for fatty acid methyl ester. Performance and emissions analysis have been performed to compare the efficiency of the B10 and B20 blends with the commercial diesel. The results revealed that, under full load conditions, B10 decreased hydrocarbon and carbon monoxide emissions by 18.33% and 14.01%, respectively, while B20 decreased hydrocarbon and carbon monoxide emissions by 31.67% and 25.44%, respectively. Furthermore, with B10 and B20, smoke opacity declined by 0.29% and 1.76%, respectively. However, NO emission shows some rise; increases for B10 and B20 were 5.14% and 8.43%, respectively.