THE EFFECTS OF GROWTH TEMPERATURE ON THE METHYL STEROL AND PHOSPHOLIPID FATTY-ACID COMPOSITION OF METHYLOCOCCUS-CAPSULATUS (BATH)

Growth of Methylococcus capsulatus (Bath) at temperatures ranging from 30 to 50-degrees-C resulted in changes to the whole cell lipid constituents. As temperature was lowered, the overall proportion of hexadecenoic acid (C16:1) increased, and the relative proportions of the DELTA-9, DELTA-10 and DELTA-11 C16:1 double bond positional isomers changed. Methyl sterol content also increased as the growth temperature was lowered. The highest amounts of methyl sterol were found in 30-degrees-C cells and the lowest in 50-degrees-C cells (sterol-phospholipid ratios of 0.077 and 0.013, respectively). The data are consistent with a membrane modulating role for the sterol produced by this prokaryotic organism.