Lipidomics for the production of biosurfactants

The yeast Starmerella bombicola is known for the commercial production of the biosurfactant sophorolipids. Sophorolipids are surface-active molecules consisting of a disaccharide and a fatty acyl chain. Furthermore, the yeast can utilize various lipophilic substrates such as vegetable oils, alkanes and fatty acid esters and converts them to free fatty acids; the substrate of the sophorolipids biosynthetic pathway. In addition, the yeast has a very active de novo fatty acid synthesis; also in the absence of a lipophilic carbon source reasonable amounts of sophorolipids are obtained. While the production level of sophorolipids is already high (400g/l); some efforts are still necessary for the synthesis of new-to-nature sophorolipids1. The production of these molecules by modified Starmerella bombicola strains or by using special substrates is in some cases less efficient and requires further optimization. On the one hand, the efficiency is lower because special substrates are lost due to catabolic pathways. On the other hand, some modified strains are less productive than the wild type yeast. The blockage of these catabolic pathways and a better availability of lipophilic carbon sources can be a solution. By means of lipidomics, the detailed lipid composition of the whole cell will be determined, as well as the effects of genetic modifications and different production conditions on the present lipophilic compounds. By merging lipidomics data to other information (genomics, transcriptomics and proteomics data), a metabolic network can be made. Based on this model new metabolic engineering strategies can be found to target specific genes. The new strains will then be evaluated based on growth and viability of the strain; and on the purity, stability, yield and absence of byproducts of the product. The fundamental knowledge about the lipidome of Starmerella bombicola will hence lead to a better production platform for the synthesis of economic valuable new-to-nature sophorolipids.

Jaar van publicatie:2015