Anaerosalibacter bizertensis gen. nov., sp. nov., a new halotolerant bacterium isolated from sludge.
Résumé
A strictly anaerobic, halotolerant and thermotolerant strain designated C5BELT was isolated from storage tanks holding wastes generated by the recycling of discarded motor oils located in north Tunisia. Cells of strain C5BELT stained Gram-positive, were motile by laterally inserted flagella, straight, and spore-forming. Their two major fatty acids were iso-C15:0 (60.1 %) and iso-C15:0 dimethyl acetal (22.0 %). Growth was observed at temperatures ranging from 25 to 55 °C (optimum 40 °C) and at pH 6 to 9 (optimum 7.5). The salinity range for growth was 0-100 g l-1 of NaCl (optimum 5 g l-1). Yeast extract is required for growth. Strain C5BELT was heterotrophic, able to use glucose, pyruvate, succinate, yeast extract, bio-trypcase and peptone, but was unable to grow on casamino acids. Sulfate, thiosulfate, sulfite, elemental sulfur, fumarate, nitrate and nitrite were not reduced. The DNA G + C content was 31.1 mol%. 16S rRNA gene sequence analysis indicated that strain C5BELT was a member of the family Clostridiaceae, class Clostridia, phylum Firmicutes and was most closely related to Sporanaerobacter acetigenes DSM 13106T (92.4 % similarity). On the basis of 16S rRNA gene sequence comparisons and physiological characteristics, strain C5BELT can be classified as a new species of a new genus, for which the name Anaerosalibacter bizertensis gen. nov., sp. nov. is hereby proposed. The type strain is C5BELT (= DSM 23801 = JCM 17239).