Metabolism and Physiology of Halobacteria

Abstract

Halophiles (lat. “salt-loving”) is the taxonomic group of extreme aerobic microorganisms that live in conditions of high salinity – in the seas, salt lakes, saline soils etc. These microorganisms are known to reddish patina on products, preserved with using large quantities of salt (NaCl). Halophiles were isolated for the first time at the beginning of the XX century from the marine flora estuary mud, but their systematic study was started only at the end of the second decade of the XX century. The internal environment of the human body is not suitable for existence of halobacteria, since none of them are known to have pathogenic forms. Halobacteria have great practical potential for using in molecular bioelectronics and bio-nanotechnology due to their unique ability to convert the energy of sunlight into electrochemical energy of protons H⁺ due to the presence in their cells a special photo transforming retinal containing integral protein – bacteriorhodopsin, the mechanism of action of which has been currently studied in detail. This article describes the characteristics of the metabolism and physiology of halophilic bacteria, as well as a method of biosynthesis and preparation of bacteriorhodopsin from purple membranes of cells of the extreme photoorganotrophic halobacterium Halobacterium halobium.

Key words: halobacteria, bacteriorhodopsin, purple membranes, biosynthesis.