Emticicia aquatilis sp. nov., isolated from a freshwater sample

Abstract

A Gram-stain-negative, facultatively anaerobic, non-motile, rod-shaped and yellow-pigmented bacterium, designated strain THG-DN6.14 T , was isolated from a freshwater sample near Donghaksa temple in Daejeon, South Korea. On the basis of the results of 16S rRNA gene sequence comparisons, THG-DN6.14 T was found to be most closely related to Emticicia sediminis JBR12 T (99.1 % sequence similarity), Emticicia oligotrophica DSM 17448 T (97.6 %), Emticicia aquatica HMF2925 T (96.5 %), andEmticicia ginsengisoli Gsoil 085 T (94.4 %). The DNA-DNA relatedness between THG-DN6.14 T and its phylogenetically closest neighbours was below 65.0 %. The DNA G+C content was 43.3 mol%. The major polar lipids were found to be phosphatidylethanolamine, an unidentified glycolipid and an unidentified aminoglycolipid. The major fatty acids were identified as C 16 : 0 , iso-C 15 : 0 , iso-C 17 : 0 3-OH, and summed feature 3 (C 16 : 1 !7c and/or C 16 : 1 !6c). The respiratory quinone was menaquinone MK-7. These data supported the affiliation of THG-DN6.14 T to the genus Emticicia. THG-DN6.14 T could be distinguished from related species of the genus Emticicia by physiological and biochemical tests. Therefore, the novel isolate represents a novel species, for which the name Emticicia aquatilis sp. nov. is proposed, with THG-DN6.14 T (=KACC 18540 . The purpose of this study was to determine the taxonomic position of strain THG-DN6.14 T by using a polyphasic approach.Strain THG-DN6.14 T was isolated from a freshwater sample near Donghaksa temple in Daejeon, Republic of Korea. A 1 ml aliquot of water sample was diluted in 9 ml sterile 0.85 % NaCl (w/v; saline solution). Serially diluted samples were plated onto nutrient agar plates (NA; Difco). The plates were incubated at 28 C for one week. Single colonies were purified, transferred to fresh NA plates and were incubated once again. One isolate, THG-DN6.14 T , was cultured routinely on NA at 28 C and preserved as a suspension in nutrient broth (NB; Difco) with glycerol (25 %, w/v) at À80 C.Extraction of the genomic DNA was achieved using a commercial genomic DNA extraction kit (Solgent). The 16S rRNA gene was amplified from the chromosomal DNA with two primer pairs (27F/1492R and 518F/805R) [5] and the purified PCR products were sequenced by Solgent (Daejeon, Republic of Korea). The 16S rRNA gene sequences of related taxa were obtained from the GenBank database and EzTaxone server [6]. The multiple alignments were performed by using the CLUSTAL_X program [7]. Gaps were edited in the BioEdit program [8]. The evolutionary distances were calculated using the Kimura two-parameter model [9]. The phylogenetic trees were reconstructed using the neighbour-joining method [10] and the maximum-likelihood method [11] in the MEGA 6 program, with bootstrap values based on 1000 replications [12].According to the EzTaxon-e server, 16S rRNA gene sequence similarity indicated that the closest relatives of THG-DN6.14 T were E. sediminis JBR12 T (99.1 % sequence similarity), E. oligotrophica DSM 17448 T (...

First report on Bacterial Diversity of Potable Spring water of Indian Himalayan Region

“…A number of significant members from the genera were identified in aquatic systems viz. Emticicia aquatica (Seo et al ., 2015), Emticicia aquatilis (Ngo et al ., 2017), and Emticicia fontis (Nam et al ., 2016). The bacterial genera Flavobacterium was found in all the other three districts except in the south.…”