Halobacterium

Abstract

Ha.lo.bac.te' ri.um . Gr. n. hals , halos the sea, salt; Gr. n. bakterion a small rod; M.L. neut. n. Halobacterium salt bacterium. Euryarchaeota / Halobacteria / Halobacteriales / Halobacteriaceae / Halobacterium Under optimum growth conditions cells are rod shaped (0.5–1.2 × 1.0–6.0 µm). Pleomorphic forms common (bent and swollen rods, flat ribbons, clubs, spheres). Cells divide by constriction. No known resting stages. Stain Gram‐negative but no outer membrane is present. Motile by tufts of polar flagella. Some strains have gas vacuoles. Most strains are strict aerobes, but some exhibit facultatively anaerobic growth. Oxidase and catalase positive. Extremely halophilic with growth occurring in media containing 3.0–5.2 M NaCl. Most strains grow best at 3.5–4.5 M NaCl. Optimum temperature: 35–50°C; maximum, 55°C; minimum, 15–20°C. pH range, 5.5–8.5. Chemoorganotrophic. Amino acids required for growth. Most strains are proteolytic. The mol % G + C of the DNA is : 67.1–71.2 (major component) and 57–60 (minor component). Type species : Halobacterium salinarum corrig. (Harrison and Kennedy 1922) Elazari‐Volcani 1957, 208; emend. Larsen 1 9 8 4, 262; emend. Larsen and Grant 1989, 2222; emend. Ventosa and Oren 1996, 347 ( Pseudomonas salinaria Harrison and Kennedy 1922, 120; Halobacterium halobium (Petter 1931) Elazari‐Volcani 1957, 210; Halobacterium cutirubrum (Lochhead 1934) Elazari‐Volcani 1957, 209.)

Comparative molecular analysis of the prokaryotic diversity of two salt mine soils in southwest China

“…Few archaeal sequences grouped with Crenarchaeota , consistent with previous studies of hypersaline environments where crenarchaeotes were rare or absent . Halobacteriales require at least 9% w/v NaCl for growth, with most growing best at salt concentrations between 20 and 26% NaCl . This could explain the presence of fewer Halobacteriales clones from the lower salinity YPL soil than from QH soil.…”