Circular Economy Involving Microbial Consortia in Consolidated Bioprocesses to Produce Biofuels

The application of circular economy has positioned as one of the pillars of the sustainable global agenda through the insertion of waste biotransformation into a variety of high-value compounds such as biofuels, which significantly reduce the concerns associated with environmental pollution such as the generation of greenhouse gases and final disposal expenses. In this context, the production of biofuels using lignocellulosic biomass is attractive since they are generated in large volumes, as well as the minimization, generation, treatment and disposal of wastes. This review addresses the sustainable production of biofuels through the use of microbial consortia in consolidated bioprocesses (CBP), presenting advantages and drawbacks of the use of synthetic microbial consortia (e.g., those designed by different mechanisms such as genetic modification) against native consortia (NC) isolated from different ecosystems to reduce costs and residence times. In addition, challenges and current perspectives to apply NC towards the generation of biofuels are comprehensively revisited since these consortia present excellent stability and resistance to change in environmental conditions or system disturbances. This offers an outstanding capacity to biodegrade numerous biomass resources (i.e., substrate), since they split complex metabolic tasks to achieve a remarkable performance, replacing the metabolic design representing a cutting-edge option for CBPs implemented in a sustainable biorefinery to generate biofuels in order to potentiate the use of biomass in the circular economy. Graphical Abstract A circular economy which involves consolidated bioprocesses to produce biofuels. The circular process includes: food lost and waste, native consortia, biorefinery, biofuel and renewable biomass.