Experimental design and syntrophic microbial pathways for biofuel production from sugarcane bagasse under thermophilic condition

Abstract

The molecular mechanisms behind the bioconversion of sugarcane bagasse into biofuel by promising metabolic pathways were studied, suggesting that proteolytic, cellulolytic and methanogenic microorganisms such as Coprothermobacter, Clostridium, and Methanothermobacter, respectively, took an important syntrophic role in lignocellulosic-derived fuel production. The mixed acid fermentation was the main route to the acetic, formic, butyric, and propionic acid production by acid-forming bacteria. Some aspects of biotechnological application of such metabolic pathways were evaluated from a central composite design, in which the effect of incubation temperature (from 45.8 to 74.2 °C) and yeast extract concentration (from 0.58 to 3.42 g/L) on hydrogen production were assessed. The interaction between these factors significantly affected the hydrogen production, which reached the highest value (17.3 mmol/L) using 3.42 g/L of yeast extract at 60 °C, and favored a plastic and physiological diverse microbial community related to bioconversion of SCB.