Fusibacter ferrireducens sp. nov., an anaerobic, Fe(Ⅲ)- and sulphur-reducing bacterium isolated from mangrove sediment

Abstract

An anaerobic, alkaliphilic, halotolerant, Gram-stain-positive and rod-shaped bacterium, designated Q10-2T, was isolated from mangrove sediment sampled at the Jiulong river estuary, PR China. The cells of strain Q10-2T were motile and 0.5×2–4 µm in size. Strain Q10-2T grew at 8–45 °C (optimum, 32 °C), at pH 7.0–10.5 (optimum, pH 8.5) and in the presence of 0–6 % (w/v) NaCl (optimum, 3 %). It could use complex organic compounds and carbohydrates including d-fructose, d-galactose, d-glucose, d-mannitol, d-xylose, trehalose, lactose, maltose, sucrose and starch as carbon sources and electron donors. It could reduce sulphate, thiosulphate and elemental sulphur to sulphide, but not sulphite. Fe (Ⅲ) citrate, ferrihydrite, haematite and goethite in the presence of glucose as the electron donor were also reduced. Acetate, butyrate, ethanol, CO2 and H2 were end products of glucose fermentation. The predominant cellular fatty acids were composed of C14 : 0, C16 : 0 and summed features containing C16 : 1 ω7c and/or iso-C15 : 0 2-OH and iso-C17 : 1 and/or anteiso-C17 : 1 B. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the novel strain was most closely related to Fusibacter paucivorans DSM 12116T (95.5 % sequence similarity). The genome size of strain Q10-2T was 5.0 Mb, with a G+C content of 37.4 mol%. The average nucleotide identity and digital DNA–DNA hybridization values between strain Q10-2T and F. paucivorans DSM 12116T were 69.1 and 21.8 %, respectively. The combined genotypic and phenotypic data showed that strain Q10-2T represents a novel species of the genus Fusibacter , for which the name Fusibacter ferrireducens sp. nov. is proposed. The type strain is Q10-2T (=MCCC 1A16257T=KCTC 15906T).

Looking for the mechanism of arsenate respiration in an arsenate-dependent growing culture ofFusibactersp. strain 3D3, independent of ArrAB

“…bizertensis, and F. ferrireducens can not utilize lactate [77][78][79]81]. The genetic evidence agrees with the observed physiology on the culture conditions tested (Table 3).…”

“…Fas can be differentiated from F. paucivorans, F. tunisiensis, F. fontis, F. bizertensis and F. ferrireducens by its use of lactate as substrate, of sulfate as electron acceptor, the NaCl concentration for growth, its genomic DNA G+C content (Table 1) and its phylogeny [78]. Resistance to As was not reported for other isolated members of the genus.…”

“…• All the previously reported strains inside the Fusibacter genus are fermentative bacteria [77][78][79][80][81].…”

“…• Furthermore, all the reported Fusibacter species have the ability to reduce sulfured nutriments [77][78][79][80][81].…”

“…T[77]; 2: F. tunisiensis strain BELH1 T[79]; 3: F. fontis strain KhalAKB1 T[80]; 4: F. bizertensis strain LTF Kr01 T[81], and 5: F. ferrireducens strain Q10-2 T[78]. n.a.…”