ABSTRACT
DeLong and Yayanos (1985) were the first to test the responses to pressures from 30 to 50 MPa (at 2°C) by the gram-negative and facultative anaerobic bacterium CNPT3. Fatty acids detected in CNPT3 lipids include 0 4 :0 ,0 4 :1 ,0 6 :0 ,0 6 :1 ,0 8 :0 , and 0 8 :1 , with 0 6 :0 ,0 6 :1 , and 0 8 :1 being most abundant. The concentration of saturated fatty acids decreased from 34 to 25% with pressure (Fig. 7). More significantly, the concentration of unsaturated fatty acids increased from 45% to 75%. The authors concluded that the pressure-induced changes in fatty acid composition is comparable to those induced by temperature changes and that homeoviscous adaptation of membrane lipids occurs in piezophilic bacteria in response to pressure. Interestingly, the concentrations of short-chain fatty acids (0 4 :0 and 0 4 :1 ) decreased from 27.5% (0.1 MPa) to 15% (69 MPa). No polyunsaturated fatty acids were reported in this study.
