Genetic Modification of Mucor circinelloides to Construct Stearidonic Acid Producing Cell Factory.

Stearidonic acid (SDA; 18:4, n-3) is the delta 15-desaturase product of gamma linolenic acid (GLA; 18:3, n-6) and delta 6-desaturase product of alpha linolenic acid (ALA; 18:3, n-3). Construction of engineered oleaginous microbes have been attracting significant interest in producing SDA because of its nutritional value and pharmaceutical applications. Mucor circinelloides is a GLA producing filamentous fungus, which can be a useful tool to produce SDA. This study has, therefore, overexpressed the delta-15 desaturase (D15D) gene from Mortierella alpina in this fungus to construct a SDA-producing cell factory. To produce SDA in M. circinelloides, the homologous overexpression of D15D gene was analyzed. When the gene was overexpressed in M. circinelloides CBS 277.49, up to 5.0% SDA was accumulated in this strain. According to current knowledge, this is the first study describing the construction of a SDA-producing cell factory by overexpression of D15D gene in oleaginous fungus M. circinelloides. A new scope for further research has been established by this work to improve SDA production in this fungus, specifically in its high lipid-producing strain, WJ11.