Moorella humiferrea sp. nov., a thermophilic, anaerobic bacterium capable of growth via electron shuttling between humic acid and Fe(III) Nepomnyashchaya, Y. N. and Slobodkina, G. B. and Baslerov, R. V. and Chernyh, N. A. and Bonch-Osmolovskaya, E. A. and Netrusov, A. I. and Slobodkin, A. I.,, 62, 613-617 (2012), doi = https://doi.org/10.1099/ijs.0.029009-0, publicationName = Microbiology Society, issn = 1466-5026, abstract= An anaerobic, thermophilic, spore-forming bacterium (strain 64-FGQT) was isolated from a terrestrial hydrothermal spring from the Kamchatka peninsula, Russia. This strain utilized lactate as an electron donor, insoluble poorly crystalline Fe(III) oxide incorporated into alginate beads as a potential electron acceptor and 9,10-anthraquinone-2,6-disulfonate (AQDS) as an electron-shuttling compound. Vegetative cells of strain 64-FGQT were Gram-stain-positive, peritrichously flagellated, motile, straight rods, 0.3–0.5 µm in diameter and 2.0–5.0 µm long, growing singly or forming short chains. Cells formed round refractive endospores in terminal swollen sporangia. The temperature range for growth was 46–70 °C, with an optimum at 65 °C. The pH range for growth was 5.5–8.5, with an optimum at pH 7.0. The substrates utilized by strain 64-FGQT in the presence of AQDS as an electron acceptor included lactate, malate, succinate, glycerol and yeast extract. The strain fermented galactose, fructose, maltose, sucrose, pyruvate and peptone. Strain 64-FGQT used AQDS, humic acid, thiosulfate, nitrate and perchlorate as electron acceptors for growth. Fe(III) was not directly reduced, but strain 64-FGQT was able to grow and reduce Fe(III) oxide in the presence of small amounts of AQDS or humic acid as electron-shuttling compounds. The G+C content of the DNA of strain 64-FGQT was 51 mol%. 16S rRNA gene sequence analysis placed the isolate in the genus Moorella, with the type strain of Moorella glycerini as its closest relative (97.2 % similarity). Based on phylogenetic analysis and physiological characteristics, strain 64-FGQT is considered to represent a novel species of the genus Moorella, for which the name Moorella humiferrea sp. nov. is proposed; the type strain is 64-FGQT ( = DSM 23265T = VKM B-2603T)., language=, type=