ACIDIPHILIUM-MULTIVORUM SP-NOV, AN ACIDOPHILIC CHEMOORGANOTROPHIC BACTERIUM FROM PYRITIC ACID-MINE DRAINAGE

Six strains of acidophilic chemoorganotrophic bacteria from acid mine drainage were studied in their taxonomic aspects. They were gram negat ive, aerobic, mesophilic, oxidase negative, catalase positive, urease positive, nonsporeforming, and rod-shaped. Carotenoid and bacteriochlo rophyll a were formed. Two strains had a polar flagellum and other two strains fimbriae. They used a wide variety of organic compounds for g rowth, but did not use ferrous iron, elemental sulfur, and thiosulfate as the sole energy source. Acetate was inhibitory to growth. Growth w as enhanced by adding high concentrations of glucose or complex organi c compounds such as trypticase soy (BBL) and yeast extract. Methanol w as utilized as the sole source of carbon and energy. The major ubiquin one was Q-10. The major cellular fatty acid was straight-chain unsatur ated C18:1 acid. The hydroxy acid was 3-OH C14:0 acid. The DNA base co mposition was 66.2 to 68.1 mol% guanine plus cytosine. The isolates sh owed relatively low levels of genetic similarity to Acidiphilium crypt um and Acidiphilium organovorum. On the basis of the phenotypic, chemo taxonomic, and genotypic characters, we conclude the isolates as a new species, for which we propose Acidiphilium multivorum sp. nov. The ty pe strain is AIU 301 (JCM 8867).