RT Journal Article SR Electronic(1) A1 Takai, Ken A1 Inoue, Akira A1 Horikoshi, KokiYR 1999 T1 Thermaerobacter marianensis gen. nov., sp. nov., an aerobic extremely thermophilic marine bacterium from the 11000 m deep Mariana Trench JF International Journal of Systematic and Evolutionary Microbiology, VO 49 IS 2 SP 619 OP 628 DO https://doi.org/10.1099/00207713-49-2-619 PB Microbiology Society, SN 1466-5034, AB A novel extremely thermophilic bacterium was isolated from the world's deepest sea-floor, the Mariana Trench Challenger Deep at a depth of 10897 m. Cells were Gram-reaction variable, non-spore-forming and non-motile rods without flagella. Growth was observed between 50 and 80 °C (optimum: 74–76 C; 90 min doubling time), pH 5·4 and 9·5 (optimum: pH 7·0–7·5) and 0·5 and 5% sea salts (optimum: 2 % sea salts). The isolate was a strictly aerobic heterotroph capable of utilizing as sole energy and carbon source: yeast extract, peptone, cellulose, starch, chitin, casein, Casamino acids, a variety of sugars, carboxylic acids and amino acids. The G+C content of the genomic DNA was 72·5 mol%. Phylogenetic analysis based on 16S rRNA sequences placed this aerobic, high-G+C-content bacterium among the members of the Gram-positive, low-G+C-content anaerobic thermophilic bacteria within the Bacillus-Clostridium subphylum. On the basis of the physiological and molecular properties of the new isolate, the name Thermaerobacter marianensis gen. nov., sp. nov. (type strain 7p75aT = JCM 10246T) is proposed., UL https://www.microbiologyresearch.org/content/journal/ijsem/10.1099/00207713-49-2-619