Pseudarthrobacter humi sp. nov., an actinobacterium isolated from soil

Abstract

A Gram-stain-positive, facultatively aerobic, rod-shaped and non-motile bacterial strain designated RMG13T was isolated from the soil near Gaetgol Eco Park and collected in Siheung-si, Republic of Korea. It was taxonomically characterized through polyphasic analysis. Phylogenetic analysis based on the 16S rRNA gene revealed that the novel isolate was most closely related to the type strains of species of the genus Pseudarthrobacter . RMG13T shared the highest similarities with Pseudarthrobacter sulfonivorans ALLT (99.2 %) and Pseudarthrobacter psychrotolerans YJ56T (99.0 %). In silico DNA–DNA hybridization values of RMG13T with P. sulfonivorans ALLT and P. psychrotolerans YJ56T were 28.1 and 41.8 %, respectively. The average nucleotide identities of RMG13T with P. sulfonivorans ALLT and P. psychrotolerans YJ56T were 84.2 and 70.3 %, respectively, whilst the average amino acid identities of RMG13T with P. sulfonivorans ALLT and P. psychrotolerans YJ56T were 90.5 and 74.6 %, respectively. Two-dimensional thin-layer chromatography showed that the major polar lipids of RMG13T were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylinositol, and its major cellular fatty acids were anteiso-C15 : 0, iso-C15 : 0 and anteiso-C17 : 0. MK-9 (H2) was the sole menaquinone. Cells grew at 4–37 °C (optimum 30 °C) and pH 5.0–12.0 (optimum pH 8.0) in Reasoner’s 2A (MB cell). The cells tolerated 0–5% NaCl (w/v) but not 6 % NaCl. The DNA G+C content of RMG13T was 65.0 %. The results of phenotypic, genotypic, chemotaxonomic and phylogenetic analyses indicated that RMG13T represents a novel member of the genus Pseudarthrobacter , and the proposed name is P. humi sp. nov. The type strain of P. humi is RMG13T (= KACC 22359T = TBRC 15115T).

Pseudomonas and Pseudarthrobacter are the key players in synergistic phenanthrene biodegradation at low temperatures

“…Members of the genus Pseudomonas are the dominant PAH-degrading bacteria and are cold-adapted indigenous bacteria in Antarctic soils 42 . These isolated species were previously reported as cold-tolerant species 41 , 43 – 45 . Several species, including P. silesiensis 12 and P. frederiksbergensis JAJ28 T 45 , have been reported to be capable of growing and degrading phenanthrene.…”

“…For example, Pseudarthrobacter albicanus NJ-Z5 T isolated from Antarctic soil has been shown to grow at temperatures ranging from 4 to 28 °C 40 . Similarly, Pseudarthrobacter humi RMG13 T isolated from soil exhibited a capacity to grow within a temperature range of 4–37 °C 41 . Under poor water availability, the bacterial communities in consortium C13 were also dominated by Pseudarthrobacter , similar to the observations reported above (Fig.…”

Cellulomonas alba sp. nov. and Cellulomonas edaphi sp. nov., isolated from wetland soils

“…For isolation, a portion of the soil sample was weighed (1.0 g) and diluted in 10 mL of 0.85 % (w/v) NaCl [14]. The quantified sample was rotated for 30 min at 200 rpm in a 50-mL conical tube [15]. Then, a 200 µL sample was serially diluted (10 −1 , 10 −2 , 10 −3 , 10 −4 and 10 −5 ), while an 80 µL sample was uniformly spread on Reasoner's 2A (R2A) agar plate.…”

Lysobacter stagni sp. nov. and Limnohabitans lacus sp. nov., isolated from a pond

“…The pH range for growth was estimated by cultivating the cells in R2A medium at different pH levels (pH 4.0-11.0, at 1.0 pH unit intervals) at 30 °C for a week. The pH was adjusted using different buffers, such as citrate-NaH 2 PO 4 buffer (pH 4.0-5.0), phosphate buffer (pH 6.0-8.0), Tris buffer (pH 9.0-10.0), Na 2 HPO 4 -NaOH buffer (pH 11.0), and KCl-NaOH buffer (pH 12.0-13.0) [44,45]. Catalase and oxidase activities were evaluated by assessing bubble production with 3 % (v/v) hydrogen peroxide solution and by using 1 % (w/v) tetramethyl-p-phenylenediamine (bioMérieux), respectively [46].…”