Biosurfactant and ethanol co-production using Pseudomonas aeruginosa and Saccharomyces cerevisiae co-cultures and exploded sugarcane bagasse

Abstract

This work describes the co-fermentation to the simultaneous production of rhamnolipids and ethanol from exploded sugarcane bagasse (ESB) using Saccharomyces cerevisiae, Pseudomonas aeruginosa and crude enzyme complexes (CECs). The CECs were produced by Aspergillus niger in solid-state fermentation (SSF), using different levels of ESB, rice bran (RB) and corn cob (CC) as substrates. The best results for rhamnolipids (9.1 g/L, emulsification index of 84%, surface tension of 35 mN/m) and ethanol (8.4 g/L) were obtained after 86 h of fermentation of ESB (250 g/L, 30 °C), using CEC from SSF of ESB (20% wt/wt), RB (30% wt/wt) and water (50% wt/wt). It was also observed that the fermented bagasse had approximately the same calorific value of a bagasse in nature and could be used as a potential source of energy. These findings suggest that co-fermentation using P. aeruginosa, S. cerevisiae and ESB can be used in the successful co-production of rhamnolipids and ethanol, with the recovery of energy present in the fermented bagasse.