Pressure-induced alteration in fatty acid composition of barotolerant deep-sea bacterium

Barotolerant bacterium was isolated from sediment sample which was obtained from the depth of 4033 m in the Izu-Ogasawara Trench. The physiological property, growth characteristics and fatty acid composition were examined. The strain was a psychrotrophic and barotolerant bacterium, and was identified as species in the genus Alteromonas. The fatty acids of the strain were from C12 to C18. As the growth pressure increased, the portion of unsaturated fatty acid in membrane fraction increased due to an increase in the portion of C17:1 and C18:1, while the relative portion of C16:0 and C16:1 decreased. On the other hand, as the growth temperature decreased, the portion of unsaturated fatty acid increased due to the increase in the portion of C16:1 and C18:1.