In
taxonomy, Natrialba is a
genus of the
Natrialbaceae.[4] The genus consists of many diverse species that can survive extreme environmental niches, especially they are capable to live in the waters saturated or nearly saturated with salt (
halophiles).[5][6] They have certain adaptations to live within their salty environments. For example, their cellular machinery is adapted to high salt concentrations by having charged
amino acids on their surfaces, allowing the cell to keep its water molecules around these components. The osmotic pressure and these amino acids help to control the amount of salt within the
cell.[7]
For instance, N. magadii is an
aerobic chemoorganotrophic, dual
extremophile requiring alkaline conditions and hypersalinity for optimal growth. Those harsh conditions resulted in changed composition of charged amino acids in the
proteins (average
isoelectric point is only 4.64, whereas other organisms average is 6.5) with almost all proteins being highly acidic.[8] The
genome of N. magadii consists of four
replicons with a total sequence of 4,443,643 bp and encodes 4,212 putative proteins. The genome analysis identified multiple
genes coding putative proteins involved in adaptation to hypersalinity, stress response,
glycosylation, and
polysaccharide biosynthesis. Additionally, proton-driven
ATP synthase and a variety of putative
cytochromes and other proteins required for
aerobic respiration and
electron transfer had been found. The genome encodes a number of putative
proteases/peptidases.[9]
Their resistance to salt allows for the use of some members of the genus in biotechnological processes.[10]
^Kamekura, M.; Seno, Y.; Dyall-Smith, M. (1996-05-23). "Halolysin R4, a serine proteinase from the halophilic archaeon Haloferax mediterranei; gene cloning, expression and structural studies". Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology. 1294 (2): 159–167.
doi:
10.1016/0167-4838(96)00016-7.
ISSN0006-3002.
PMID8645734.
Gibbons, NE (1974). "Family V. Halobacteriaceae fam. nov.". In RE Buchanan; NE Gibbons (eds.). Bergey's Manual of Determinative Bacteriology (8th ed.). Baltimore: The Williams & Wilkins Co.