Production of docosahexaenoic acid by marine bacteria isolated from deep sea fish

Abstract

Five bacterial strains isolated from the intestine of deep sea fish were shown to produce docosahexaenoic acid (22:6n-3; DHA) at a level of 6.4 to 11.6% of total fatty acids when incubated in DHA-free medium. In all of the strains examined, other polyunsaturated fatty acids were barely detectable, except for eicosapentaenoic acid (20:5n-3). A typical strain, such as T3615, produced DHA at a concentration of about 0.8 mg/L within six days of aerobic incubation at 5 degrees C and under atmospheric pressure. The T3615 strain, belonging to the genus Vibrio, is rod-shaped, Gram-negative, motile and facultatively anaerobic.