5. Importance of PUFAs in deep-sea piezophiles
Trevors et al. have extensively investigated structural and compositional
changes that occur in bacterial membranes exposed to varied environmental
factors including temperature, ions,pH, and chemicals, and
demonstrated various adaptive strategies employed by bacterial membranes
[34,35]. In response to these perturbations, bacterial cells potentially
alter their lipid acyl chain structure by changing the ratio of(i) saturation to unsaturation, (ii) cis to trans unsaturation, (iii) branched
to unbranched structure, and (iv) acyl chain length. These alterations
occur simultaneously in membranes to adjust the properties to fulfill
physiological functions in hostile environments. When cells of E. coli
and psychrophilic Vibrio sp. strain ABE-1 are grown at higher temperatures,
membrane fluidity remained constant by altering lipid composition
[14,36]. However, lipid composition is not always altered with
environmental changes. For example, Yersinia enterocolitica can change