Maximal Triglyceride Production by Co-cultivation of Isochrysis galbana and Bacillus megaterium for Third-Generation Biofuels

The United States Department of Energy estimates that global energy consumption will double in the next two decades which will lead to extensive utilization of fossil fuels resulting in economic and environmental challenges. Although biofuels are a great alternative, the current generations cannot sustain the demand without threatening food supplies. Third-generation biofuels have lipids that can be converted into biodiesel, jet fuel, and gasoline. Despite these advantages, they are not produced commercially as the lipid yield of the natural strains are roadblocks in their large-scale use.This research aimed to increase TAG production in the microalgae Isochrysis galbana by inoculating it with Bacillus megaterium for more efficient biofuel yield. The study uses a bioreactor created using PVC pipes, 8-port sprinkler, CO2 tank and bottles to grow the microalgae. Secchi stick was used to measure optical density before extracting dried biomass with a french press. After conducting an ANOVA test to compare the samples, the p-value was lesser than 0.01. Later the post-hoc test was run and the groups were found to be significantly different especially for the 4x concentration versus 1x concentration. Results showed that through the co-cultivation of this algae and bacteria, TAG yields are increased. To support the findings of the experiment, bulk RNA sequencing data for Isochrysis galbana and Bacillus megaterium was compared to identify the pathways that were affected in the microalgae. The increase in biofuel productivity is crucial for the bioremediation of wastewater, the bioremoval of CO2 and for improving the economics.