Biofuel generations: New insights into challenges and opportunities in their microbe-derived industrial production

Biofuels, produced from organic materials such as plants, animal waste, and wood chips etc. offer a sustainable and renewable alternative to fossil fuels. The biofuel production in terms of thousand barrels of oil equivalent per day was 1914.00 in 2022 worldwide. The demand is set to expand 38 billion liters over 2023–28, nearly 30 per cent increase in the last five years with bioethanol & biodiesel accounting for about two third share. First-generation biofuels are derived from food crops, while second-generation biofuels are made from non-food crops like switchgrass, algae, and agricultural waste. Microbe-derived biofuels are ecologically sound on account of fewer greenhouse gas emissions and are more sustainable than conventional fossil fuels. However, there are challenges associated with producing biofuels, including land use competition, feedstock cost and availability, technical limitations, sustainability issues, and infrastructure and market constraints. Second-generation biofuels and third-generation algae-based biofuels have the potential to condense our dependence on fossil fuels and reassure sustainable agriculture and forestry practices. Fourth-generation biofuels use genetically modified microorganisms to convert sunlight and CO2 into biofuels directly while as fifth-generation biofuels are still in the research and development stage and are expected to use synthetic biology to create completely synthetic biofuels. Advanced biofuels from non-food feedstocks like algae, agricultural byproducts, and municipal solid waste are ecologically more well-founded than first-generation biofuels. Biorefinery mediated biomass conversion to biofuels is more energy efficient more productive and ecologically all-encompassing than conventional refineries. Synthetic biology approaches such as genetic engineering, directed evolution, genome editing is used to expand the thruput and efficiency of microorganisms in the production course of biofuels. Overall, the production of biofuels from microorganisms has the potential to be an economically and environmentally sustainable method of generating renewable energy. With continued innovation and emphasis on sustainability, microbe-derived biofuels could become a substantial part of the evolution towards a more renewable and sustainable energy future. The concerns as a result of climate change have dictated a rethink in policy pertaining to transportation infrastructure. One possible alternative to existing setup of fossil fuels is the biofuels produced as result of efficient microflora that make the use of renewable carbon stocks. Advanced biofuels that could mimic the petroleum-based fuels pose a limited scope on account of the challenging costs. The computational biology in context to synthetic enzyme production could amplify the production process beyond doubt. In this review, we discuss the new insights into challenges and opportunities of the generation wise biofuels besides the advancements made in microflora in various biofuel generations.