Molecular ecology of extremely halophilic Archaea and Bacteria

Proteolytic enzymes from extremely halophilic bacteria.

Halobacterium strains produce a truly extracellular proteinase which degrades gelatine and casein. It has a pH optimum of about 8 and depends upon divalent cations and a high concentration of NaCl or KC1 for activity and stability. Proteolytic enzymes were also found in cell homogenates obtained by ultra sonic treatment. A caseinolytic enzyme, probably different from the extracellular one, is a...

Biodegradation of organic pollutants by halophilic bacteria and archaea.

Hypersaline environments are important for both surface extension and ecological significance. As all other ecosystems, they are impacted by pollution. However, little information is available on the biodegradation of organic pollutants by halophilic microorganisms in such environments. In addition, it is estimated that 5% of industrial effluents are saline and hypersaline. Conventional nonextr...

Comparative analysis of uranium bioassociation with halophilic bacteria and archaea

Rock salt represents a potential host rock formation for the final disposal of radioactive waste. The interactions between indigenous microorganisms and radionuclides, e.g. uranium, need to be investigated to better predict the influence of microorganisms on the safety assessment of the repository. Hence, the association process of uranium with two microorganisms isolated from rock salt was com...

Malate dehydrogenase isolated from extremely halophilic bacteria of the Dead Sea. 1. Purification and molecular characterization.

The complete purification of malate dehydrogenase (EC 1.1.1.37) from extremely halophilic bacteria of the Dead Sea is described. The purification procedure includes (a) precipitation by ammonium sulfate, (b) fractionation on Sepharose 4B using a decreasing concentration gradient of ammonium sulfate, (c) gel permeation chromatography on Sephadex G-100, (d) chromatography on hydroxylapatite, and ...

Salt-dependent properties of proteins from extremely halophilic bacteria.