Increasing lipid production in oleaginous yeast
Disclosed are methods and compositions for increasing the triacylglycerol content of a cell by increasing the activity of a type 1 diacylglycerol acyltransferase (i.e., DGA2) and increasing the activity of a type 2 diacylglycerol acyltransferase (i.e., DGA1). In some embodiments, the triacylglycerol content of a cell is also modified by decreasing the activity of a triacylglycerol lipase in the same cell. Also disclosed are methods and compositions for increasing the triacylglycerol content of a cell by increasing the activity of a type 1 diacylglycerol acyltransferase (i.e., DGA2), or by increasing the activity of a type 3 diacylglycerol acyltransferase (i.e., DGA3).
1. A transformed Arxula or Yarrowia cell, comprising a nucleic acid molecule encoding a heterologous type 1 diacylglycerol acyltransferase protein from Claviceps ; and
a nucleic acid molecule encoding a heterologous type 2 diacylglycerol acyltransferase protein from Rhodosporidium,
wherein the transformed Arxula or Yarrowia cell does not express a triacylglycerol lipase protein and wherein the transformed Arxula or Yarrowia cell has a higher lipid content than a non-transformed cell of the same species.
2. The transformed cell of claim 1 , wherein said heterologous type 1 diacylglycerol acyltransferase protein is from Claviceps purpurea.
3. The transformed cell of claim 1 , wherein said heterologous type 2 diacylglycerol acyltransferase protein is from Rhodosporidium toruloides.
4. The transformed cell of claim 1 , wherein said triacylglycerol lipase is encoded by an endogenous TGL3 gene.
5. The transformed cell of claim 1 , wherein said cell is Yarrowia lipolytica and said triacylglycerol lipase comprises SEQ ID NO:41, or said triacylglycerol lipase is encoded by a nucleotide sequence comprising SEQ ID NO:42.
6. The transformed cell of claim 1 , wherein said cell is selected from the group consisting of Arxula adeninivorans and Yarrowia lipolytica.
7. The cell of claim 4 , wherein the transformed Yarrowia cell does not express a triacylglycerol lipase protein due to a deletion of a TGL3 gene.