Single cell oil production on molasses by XXXX strains overexpressing DGA2 in multicopy.

@entity1568 @entity11609 @entity969 @entity505 @entity375 @entity10057
UNASSIGNED: @entity10057 is a promising platform for single cell oil production. It is well-known for its metabolism oriented toward utilization of hydrophobic substrates and accumulation of storage lipids. Multiple copies of DGA2 under constitutive promoter were introduced into the Q4 strain, a quadruple mutant deleted for the four acyltransferases (  dga1,   dga2,   lro1, and   are1) to improve lipid accumulation. The Q4-DGA2 x3 strain contains three copies of DGA2. Further increase in accumulation was accomplished by blocking the b-oxidation pathway through MFE1 gene deletion yielding Q4-  mfe DGA2 x3. In order to use molasses as a substrate for single cell oil production, @entity969 utilization was established by expressing the @entity375 @entity11609 gene yielding Q4- @entity11609 DGA2 x3 and Q4-  mfe @entity11609 DGA2 x3. During cultivation on @entity969 medium with a @entity505 to @entity1568 ratio of 80, both strains accumulated more than 40  % of lipids, which was a 2-fold increase in lipid storage. Q4-  mfe @entity11609 DGA2 x3 accumulated more lipids than Q4- @entity11609 DGA2 x3 (49 vs. 43  %) but yielded less biomass (13.7 vs. 15  g/L). When grown on 8  % (v/v) molasses, both strains accumulated more than 30  % of lipids after 3  days, while biomass yield was higher in Q4- @entity11609 DGA2 x3 (16.4 vs. 14.4  g/L). Further addition of molasses at 72  h resulted in higher biomass yield, 26.6  g/L for Q4- @entity11609 DGA2 x3, without modification of lipid content. This work presents genetically modified strains of @entity10057 as suitable tools for direct conversion of industrial molasses into value added products based on single cell oils.
