A critical review of challenges and advances to produce 2G biodiesel with oleaginous microorganisms and lignocellulose.

Lignocellulose as carbon source and oleaginous microorganisms including yeast, bacterium, and fungi, have been studied extensively for oil and biodiesel production, however, several bottlenecks and challenges remain unresolved. Today commercial biodiesel production is stuck at the first generation using oleaginous seeds as palm, soybean, and others, but commercial oil production from oleaginous microorganisms is not cost-effective and sustainable. Before fermentation is necessary to get rich-sugars liquor from lignocellulose, but this is very difficult because lignin affects both enzyme activity and oleaginous microorganism growth, then hydrolysis is a process that easily could be stopped by several changes in adequate conditions that sometimes is almost impossible has the control as the strain ability to produce enzymes or cellulose polymerization degree by origin of lignocellulose. The oil production in the bioprocess is a challenge too because fermentations of oleaginous microorganisms are aerobic which means the need to supply oxygen constant during fermentation, this consumes energy, besides lipid production is low, and the lipid yield decreases in the extraction process. In this small review discuss those troubles related to sustainable lipid production with oleaginous microorganisms and lignocellulose as carbon source.