Abstract
Lignocellulosics, including the sugarcane bagasse, have considerable potential to the future production of biofuels and mitigation of carbon dioxides emissions. Microbial lipid produced by yeast fermentation using inexpensive and renewable carbon sources such as hemicellulosic hydrolysate from sugarcane bagasse is an alternative feedstock for biodiesel production and a potential solution for a bio-based economy. Hemicellulosic hydrolysate (H-H) from in natura sugarcane bagasse produced by acid hydrolysis was the carbon source (H-H medium) for batch and continuous fermentations of a previously selected strain of Lipomyces starkeyi. This yeast is able to use H-H as substrate to grow and to accumulate lipids; and cell growth is not inhibited by furfural, hydroxymethylfurfural (HMF) and acetic acid. Contrary, these compounds were consumed during the fermentation. During continuous culture at low dilution rate, 0.03 h- 1, higher lipid production, 3.7 g/L, is achieved when compared to batch culture, 2.3 g/L. In both cultures, arabinose was not consumed even after depletion of xylose and glucose. These results indicate the large potential of using the hemicellulose sugars of sugarcane bagasse for microbial oils production for additional biofuels manufacturing. Furthermore, L. starkeyi becomes a promising strain for lipid production from H-H and holds a great promise for biodiesel & biokerosene in a sugarcane biorefinery.
