Hyperthermophilic bacteria

Figure 1.4 Hyperthermophile bacteria at Prismatic Lake in Yellowstone National Park. (A colour reproduction of this figure can be seen in the colour section). (Reproduced from a photo of Prismatic Lake by courtesy of National Park Service, Yellow Stone National Park)...

Table 2 Percentage of charged amino acids and (G - - C) content of 10 hyperthermophilic archaea (A), 2 hyperthermophilic bacteria (B), and mesophilic bacteria E. coli. A strong prevalence of lysine over arginine in proteomes of hyperthermophiles is obtained for nine organisms. A bold font marks the exception from the general trend...

On the basis of the 16S/18S rRNA sequence comparisons, the hyperthermophilic bacteria (optimal growth temperature higher than 80°C) are located nearer to origins of life in the phylogenetic tree (Stetter, 1994). Therefore, many researchers think that life might have originated at temperatures as high as 100°C, before the surface of the Earth had cooled to around 30° K)°C. 

Temperature and pressure extremes require different strategies. Cellular lipids, proteins and nucleic acids are sensitive to high temperatures. Hyperthermophile bacteria have ether lipids instead of the more hydrolysis sensitive ester lipids in mesophiles [13]. Enzymes from hyperthermophiles show an unusual thermostability in the laboratory, and an important aspect of protein chemistry research is to find out the stabilizing principles. Crude cell extracts of hyperthermophiles show the presence of heat inducible proteins, called chaperones, which assist in the folding of proteins during cellular synthesis. Molecular details for cold adaptation of enzymes have been reported but are less extensively studied [14]. 

These discoveries inspired from nature are mostly from the material sciences. Examples of bio-inspiration at the molecular level are rarer antifreeze proteins/fish of the Southern Ocean, enzymes/hyperthermophilic bacteria, and surgical glues yssus of mussels are some of them. 

---