TAXONOMIC CHARACTERIZATION OF NOVEL AEROBIC BACTERIOCHLOROPHYLL-CONTAINING BACTERIA ISOLATED FROM SOIL

Aerobic bacteriochlorophyll (BChl) a-containing bacteria (designated a s strains NS89, NS102, and NS130) were isolated from soil samples in J apan and their taxonomic characteristics were investigated. These stra ins were obligately aerobic, Gram-negative, and non-motile cocci, and formed irregular colonies on agar media. The strains could not utilize methanol as a sole carbon and energy source and sulfate as a sole sul fur source. Strain NS130 required divalent cations (Ca2+ or Mg2+) for growth in liquid culture. The cations were not necessary for the growt h of strains NS89 and NS102 in liquid culture, however, the cations pr omoted growth. Light stimulated the growth of strains NS89 and NS 102, but not the growth of strain NS130. The absorption spectra of membran e fractions of strains NS89 and NS102 had a large peak at 856 nm that was derived from BChl a, while the spectrum of strain NS130 had a larg e peak at 872 nm. Membrane fractions of the three strains showed photo chemical activity. The guanine plus cytosine contents of DNA of strain s NS89, NS102, and NS130 were 70.3, 71.0, and 70.5 mol%, respectively. The ubiquinone system of the strains was Q-10, and the major cellular fatty acid was octadecenoic acid (C-18:1) (57-68%). The three strains contained 2-hydroxy and 3-hydroxy fatty acids, and 2-hydroxy-octadece noic acid (2-OH C-18:1) was 11-12%.