Adaptation to low temperature and regulation of gene expression in antarctic psychrotrophic bacteria
- 316 Downloads
Exposure to extremes of temperatures cause stresses which are sometimes lethal to living cells. Microorganisms in nature, however, are extremely diverse and some of them can live happily in the freezing cold of Antarctica. Among the cold adapted psychrotrophs and psychrophiles, the psychrotrophic bacteria are the predominant forms in the continental Antarctica. In spite of living in permanently cold area, the antarctic bacteria exhibit, similar to mesophiles, ‘cold-shock’ response albeit at a much lower temperatures, e.g., at 0–5°C. However, because of permanently cold condition and the long isolation of the continent, the microorganisms have acquired new adaptive features in the membranes, enzymes and macromolecular synthesis. Only recently these adaptive modifications are coming into light due to the efforts of various laboratories around the world. However, a lot more is known about adaptive response to low temperature in mesophilic bacteria than in antarctic bacteria. Combined knowledge from the two systems is providing useful clues to the understanding of basic biology of low temperature growing organisms. This article will provide an overview of this area of research with a special reference to sensing of temperature and regulation of gene expression at lower temperature.
KeywordsAntarctic bacteria cold adaptation cold-shock proteins temperature sensing cold induced gene expression
Unable to display preview. Download preview PDF.
- Bowman J P, McCammon S A, Nichols D S, Skerrat J H, Rea S M, Nichols P D and McMeekin T A 1997Schewanella gelidimarina sp. nov. andSchewanella frigidimarina sp. nov., novel antarctic species with ability to produce eicosapentaenoic acid (20∶5 ε3) and grow anaerobically by dissimilatory Fe (III) reduction;Int. J. Syst. Bacteriol. 47 1040–1047PubMedCrossRefGoogle Scholar
- Cossins A N 1994 Homeoviscous adaptation of biological membranes and its functional significance; inTemperature adaptation of biological membrane (ed.) A R Cossin (London: Portland Press) pp 63–76Google Scholar
- Davail S, Feller G, Narinx E and Gerday C 1995 Cold adaptation of proteins. Purification, characterization and sequence of the heat labile subtilisin from the antarctic psychrophileBacillus TA 47;J. Biol. Chem. 269 17448–17453Google Scholar
- Herbert R A 1986 The ecology and physiology of psychrophilic microorganisms; inMicrobes in extreme environments (eds) R A Herbert and G A Cod (London: Academic Press) pp 1–23Google Scholar
- Marshall C J 1997 Cold adapted enzyme;TIB TECH. 15 359–364Google Scholar
- Okuyama H, Okajima N, Sasaki S, Higashi S and Murata N 1991 Thecis/trans-isomerization of the double bond of a fattyacid as a strategy for adaptation to changes in ambient temperature in the psychrophilic bacterium,Vibrio sp. strain ABE-1;Biochim. Biophys. Acta 1084 13–20PubMedCrossRefGoogle Scholar
- Shivaji S and Ray M K 1995 Survival strategies of psychrotrophic bacteria and yeasts of Antarctica;Indian J. Microbiol. 35 263–281Google Scholar
- Wynn-Williams D D 1990 Ecological aspects of Antarctic microbiology;Adv. Microbiol. 11 71–146Google Scholar