Abstract: An engineered strain of the oleaginous yeast Yarrowia lipolytica capable of producing greater than 5.6% docosahexaenoic acid acid (DHA, an w-3 polyunsaturated fatty acid) in the total oil fraction is described. This strain comprises various chimeric genes expressing heterologous desaturases, elongases and acyltransferases and optionally comprises various native desaturase and acyltransferase knockouts to enable synthesis and high accumulation of DHA. Production host cells are claimed, as are methods for producing DHA within said host cells.

Abstract: Genes have been identified in the Methylomonas genome that are responsive to various metabolic and growth conditions. The identified responsiveness of these genes allows for the use of their promoters in regulated gene expression in C1 metabolizing bacteria. In particular, the hps promoter, which in its native state drives the expression of 3-hexulose-6-phosphate synthase (HPS), was found to be useful for directing expression of heterolgous coding regions (e.g., crtZ) in the obligate methanotroph Methylomonas sp. 16a.