New trends in bioprocesses for lignocellulosic biomass and CO₂ utilization

Innovation and technology are seen today as key points in the transition to a greener and more sustainable economy. In this sense, the development of new processes able to result in reduced emissions and levels of CO₂ in the atmosphere has been considered essential to support this transition and, at the same time, promote economic growth. Several techno-economic and life cycle assessment studies have shown promising data when sugars derived from lignocellulosic biomass are used as carbon source for fermentation processes. The use of CO₂ as carbon source for fermentation is another smart concept for reusing this molecule while minimizing its emissions to the atmosphere. However, the large-scale implementation of biomass-based and CO₂-based processes still require significant research efforts to result in robust and cost-competitive technologies. This paper discusses some promising approaches able to advance this research area including potential strategies for process intensification (enzymatic hydrolysis using high solid loading, simultaneous saccharification and fermentation, fermentation with downstream process integration), robust microbial strains for application in biomass-based and CO₂-based bioprocesses, microbial co-cultivation systems, greener technologies for lignocellulosic biomass fractionation, among others. A critical evaluation of sustainability aspects including techno-economic and life cycle assessment is also provided. Overall, this study contributes with information on innovative trends able to advance the development of greener bioprocesses.