The Specificities of Lysophosphatidic Acid Acyltransferase and Fatty Acid Desaturase Determine the High Content of Myristic and Myristoleic Acids in sp. IPPAS B-1200.

The cyanobacterial strain sp. IPPAS B-1200 isolated from Lake Balkhash is characterized by high relative amounts of myristic (30%) and myristoleic (10%) acids. The remaining fatty acids (FAs) are represented mainly by palmitic (20%) and palmitoleic (40%) acids. We expressed the genes for lysophosphatidic acid acyltransferase (LPAAT; EC 2.3.1.51) and Δ9 fatty acid desaturase (FAD; EC 1.14.19.1) from sp. IPPAS B-1200 in PCC 7942, which synthesizes myristic and myristoleic acids at the level of 0.5-1% and produces mainly palmitic (~60%) and palmitoleic (35%) acids. cells that expressed foreign LPAAT synthesized myristic acid at 26%, but did not produce myristoleic acid, suggesting that Δ9-FAD of cannot desaturate FAs with chain lengths less than C16. cells that co-expressed LPAAT and Δ9-FAD of synthesized up to 45% palmitoleic and 9% myristoleic acid, suggesting that Δ9-FAD of is capable of desaturating saturated acyl chains of any length.