Yarrowia lipolytica SWJ-1b isolated from the marine fish gut was found to contain 47.6 g of crude protein per 100 g of cell dry weight and had potential use as single cell protein. When the gene encoding enhanced green fluorescent protein (EGFP) was inserted into the surface display plasmid pINA1317-YlCWP110 and expressed in uracil mutant Of Y. lipolytica SWJ-Ib, the corresponding protein was successfully displayed on the cell surface, and 100% of the yeast cells exhibited the anchored target proteins. We found that yeast cells displaying EGFP were similar to those of Y. lipolytica SWJ-1b. Furthermore, C-18:1 and C-18:3 fatty acids biosynthesis in the marine yeast cells displaying the heterologous EGFP was weakly enhanced compared with that in its wild-type. The results suggest that the marine-derived Y. lipolytica SWJ-1b can be armed with the heterologous protein by the genetic modification and further used as single cell protein. (c) 2009 American Institute of Chemical Engineers Biotechnol. Prog., 25: 1297-1303, 2009