Strategies to Control Microbial Lipid Production

Microbial lipid, especially produced by yeasts, consists mainly of triacylglycerides with fatty acid compositional profile similar to those of the commercial vegetable oil. Microbial lipid production is an aerobic biochemical process that generates intracellular lipid using organic substrates, usually carbohydrates and related materials. Because carbohydrates can be supplied by lignocellulosic materials, microbial lipid has recently been considered as alternative source for biodiesel industry. In literature, lipid accumulation was usually controlled by nitrogen starvation. During the past few years, we took a closer look at the mechanisms that control lipid accumulation. We demonstrated that phosphate limitation, sulfate limitation, and the presence of particular organic compounds could also promote lipid accumulation, albeit the culture was nitrogen-rich. Therefore, we were able to use more complex raw materials for lipid production upon selective or combinatory utilization of those control methods. In addition, we were able to develop new culture modes to improve lipid productivity. During the conference, we wish to share these results in this area.