Zhengquan Gu

Massilia eurypsychrophila sp. nov. a facultatively psychrophilic bacteria isolated from ice core

Strain B528-3(T), a Gram-stain-negative, rod-shaped, aerobic, facultatively psychrophilic bacterium with polar flagella, was isolated from an ice core drilled from Muztagh Glacier, Xinjiang, China. The novel isolate was classified into the genus Massilia. The 16S rRNA gene sequence of the novel isolate shares a pairwise similarity of less than 97% with those of all the type strains of the genus Massilia. The major fatty acids of strain B528-3(T) were summed feature 3 (C16:1ω7c and/or iso-C15:0 2-OH) (57.31%), C16:0 (11.46%) and C18:1ω7c (14.72%). The predominant isoprenoid quinone was Q-8. The DNA G + C content was 62.2 mol% (Tm). The major polar lipids of this bacterium were phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. From the genotypic and phenotypic data, it is evident that strain B528-3(T) represents a novel species of the genus Massilia, for which the name Massilia eurypsychrophila sp. nov. is proposed. The type strain is B528-3(T) ( = JCM 30074(T) = CGMCC 1.12828(T)).

Hymenobacter glacieicola sp nov., isolated from glacier ice

A Gram-stain-negative, rod-shaped, non-motile and red-pink-pigmented bacterial strain, designated B1909T, was isolated from an ice core drilled from Muztagh Glacier on the Tibetan Plateau, China. A phylogenetic tree based on 16S rRNA gene sequences showed that strain B1909T formed a lineage within the genus Hymenobacter and was closely related to Hymenobacter xinjiangensis X2-1gT (96.16 % similarity) and Hymenobacter psychrotolerans Tibet-IIU11T (95.99 %). The predominant fatty acids were iso-C15 : 0, summed feature 3 (C16 : 1ω7c/C16 : 1ω6c), summed feature 4 (iso-C17 : 1ω6c I/anteiso B), C16 : 1ω5c, anteiso-C15 : 0 and iso-C17 : 0 3-OH. The major menaquinone was MK-7. The major polar lipid was phosphatidylethanolamine. The DNA G+C content was 59 mol%. On the basis of the phenotypic, phylogenetic and chemotaxonomic data presented, strain B1909T is considered to represent a novel species of the genus Hymenobacter, for which the name Hymenobacterglacieicola sp. nov. is proposed; the type strain is B1909T (=JCM 30596T=CGMCC 1.12990T).

Massilia psychrophila sp. nov., isolated from an ice core.

A Gram-stain-negative, aerobic, rod-shaped, motile bacterium, strain B1555-1T, was isolated from an ice core drilled from Ulugh Muztagh Glacier, China. The optimum growth temperature of strain B1555-1T was 15 °C and optimum pH was 7. The major fatty acids of strain B1555-1T were summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), C16 : 0 and summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c). The predominant respiratory quinone was Q-8. The major polar lipids were phosphatidylethanolamine and phosphatidylglycerol. The DNA G+C content of strain B1555-1T was 66.0 mol%. In 16S rRNA gene sequence comparisons, strain B1555-1T was affiliated to the genus Massilia and shared 98.30 and 97.13 % similarity with Massilia eurypsychrophila B528-3T and Massilia niabensis 5420S-26T, respectively. The results of DNA-DNA hybridization revealed that strain B1555-1T showed 49.8 % relatedness with M. eurypsychrophila B528-3T and 38.5 % with M. niabensis 5420S-26T. Based on the genotypic and phenotypic evidence presented in this study, strain B1555-1T represents a novel species of the genus Massilia, for which the name Massilia psychrophila sp. nov. is proposed. The type strain is B1555-1T (=CGMCC 1.15196T=JCM 30813T).

Polaromonas eurypsychrophila sp. nov., isolated from an ice core.

A Gram-stain-negative, aerobic, rod-shaped, beige bacterium, strain B717-2T, was isolated from an ice core drilled from Muztagh Glacier on the Tibetan Plateau, China. According to phylogenetic analyses based on 16S rRNA gene sequences, the novel strain was related most closely to Polaromonas vacuolataand shared 97.7 % similarity with the type strain of this species. It grew optimally at pH 7, at 15 °C and with 2 % (w/v) NaCl. Major polar lipids were phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. The major fatty acids were summed feature 3 (C16 : 1ω7c and/or iso-C15 : 0 2-OH), summed feature 8 (C18 : 1ω7c, C18 : 1ω6c) and C16 : 0. The sole respiratory quinone was Q-8. The DNA G+C content was 63.4 mol %. In DNA-DNA hybridization tests, strain B717-2T shared 37.0±1.9, 30.0±1.7, 26.0±0.9, 23.4±0.5 and 18.4±1.9 % DNA-DNA relatedness with Polaromonas jejuensisJS12-13T, P. vacuolata 34-PT, Polaromonas aquatica CCUG 39402T, Polaromonas glacialisCr4-12T and Polaromonas cryoconitiCr4-35T, respectively. Based on the phenotypic, phylogenetic and genetic characteristics, strain B717-2T represents a novel species of the genus Polaromonas, for which the name Polaromonaseurypsychrophila sp. nov. is proposed. The type strain is B717-2T (=CGMCC 1.15322T=JCM 31171T).

Blastomonas aquatica sp. nov., a bacteriochlorophyll-containing bacterium isolated from lake water.

Yellow or orange-to-brown pigmented, ovoid or rod-shaped, Gram-negative staining, aerobic strains PE 4-5(T) and N5-10 m-1 were isolated from brackish water in Lake Peng Co and fresh to brackish water in Lake Namtso on the Tibetan Plateau, China. Bacteriochlorophyll a was produced by the isolates. The predominant cellular fatty acids were C16 : 1, C17 : 1 and C18 : 1 unsaturated fatty acids, C17 : 1ω6c (55.3%), C17 : 1ω8c (13.0%) and C18 : 1ω7c (10.4%) for PE 4-5(T) and C18 : 1ω7c (54.7%) and C16 : 1ω7c (18.0%) for N5-10 m-1. The polar lipid profiles of strains PE 4-5(T) and N5-10 m-1 were composed of diphosphatidylglycerol, phosphatidylcholine (not detected in N5-10 m-1), phosphatidyldimethylethanolamine, phosphatidylethanolamine, phosphatidylmonomethylethanolamine, phosphatidylglycerol, sphingoglycolipid and an unknown phospholipid. The predominant respiratory quinone was ubiquinone Q10 and the DNA G+C content was 66.0 mol% for both strains. The16S rRNA gene sequence of strain PE 4-5(T) shared 99.0% similarity with that of N5-10 m-1, and 97.56% similarity with those of Blastomonas natatoria LMG 17322(T) and Blastomonas ursincola DSM 9006(T), respectively. The DNA-DNA hybridization relatedness between strains PE 4-5(T) and N5-10 m-1 was 79.0 ± 1.0%, but below 70% with the type strains in the genus Blastomonas . Based on the variability of phylogenetic and phenotypic characteristics, the isolates should be classified as representatives of a novel species of the genus Blastomonas; the name Blastomonas aquatica sp. nov. is proposed. The type strain is PE 4-5(T) ( =JCM 30179(T) =CGMCC 1.12851(T)).

Hafnia psychrotolerans sp. nov., isolated from lake water

A psychrotolerant, Gram-stain-negative, motile, aerobic, peritrichous bacterium, strain DJC1-1(T), was isolated from Lake Dajiaco, Tibetan Plateau, China. The strain was negative for citrate utilization, lipase activity and α-glucosidase, but positive for the Voges-Proskauer reaction and N-acetyl-β-glucosaminidase. 16S rRNA gene sequence analysis indicated that Hafnia paralvei ATCC 29927(T), Hafnia alvei ATCC 13337(T), Serratia grimesii DSM 30063(T) and Serratia plymuthica DSM 4540(T) were the closest relatives of strain DJC1-1(T), with similarities of 97.76, 96.80, 97.71 and 97.58 %, respectively. The DNA G+C content of strain DJC1-1(T) was 53.9 mol%. The predominant fatty acids were C16 : 0 and C17 : 0 cyclo. Based on these characteristics, strain DJC1-1(T) can be assigned to the genus Hafnia. In DNA-DNA hybridization tests, strain DJC1-1(T) shared 50.6, 35.1, 36.5 and 18.1 % DNA-DNA relatedness with the type strains of H. paralvei, H. alvei, S. grimesii and S. plymuthica, respectively. The growth temperature ranged from 0 to 40 °C, with optimum growth at 15 °C. Physiological and biochemical tests differentiated strain DJC1-1(T) from the type strains of recognized species of the genus Hafnia. Therefore, strain DJC1-1(T) is identified as representing a novel species of the genus Hafnia, for which the name Hafnia psychrotolerans sp. nov. is proposed. The type strain is DJC1-1(T) ( = JCM 30077(T) = CGMCC1.12806(T)).

Hymenobacter frigidus sp nov., isolated from a glacier ice core

A psychrophilic, Gram-stain-negative, rod-shaped, red-pigmented bacterium, designated strain B1789T, was isolated from an ice core of Muztagh Glacier on the Tibetan Plateau in China. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain B1789T was related to members of the genus Hymenobacter and had highest sequence similarity with Hymenobacter antarcticus JCM 17217T (97.9 %). The major menaquinone was MK-7 and the major polar lipid was phosphatidylethanolamine. The predominant fatty acids were iso-C15 : 0, anteiso-C15 : 0 and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c). The DNA G+C content was 59.4 mol%. In DNA-DNA hybridization tests, strain B1789T shared 42 % relatedness with H. antarcticus JCM 17217T. Based on the results of phenotypic and chemotaxonomic tests, strain B1789T was considered as representing a novel species of the genus Hymenobacter, for which the name Hymenobacter frigidus sp. nov. is proposed. The type strain is B1789T (=JCM 30595T=CGMCC 1.14966T).

Sphingomonas prati sp. nov., isolated from alpine meadow soil.

A Gram-staining-negative, non-motile, orange-coloured and rod-shaped aerobic bacterium, designated W18RDT, was isolated from the alpine meadow soil of the Tibetan plateau. Phylogenetic analysis based on 16S rRNA gene sequences positioned strain W18RDT as a representative of a novel species under the genus Sphingomonas which was most closely related to Sphingomonas fennica DSM 13665T with a sequence similarity level of 97.14 %. Meanwhile, it also had a high level of sequence similarity with Sphingomonas laterariae DSM 25432T (96.51 %), Sphingomonas haloaromaticamans CGMCC 1.10206T (96.43 %) and Sphingomonas formosensis DSM 24164T (96.26 %). The G+C content of the genomic DNA of the type strain W18RDT was 66.4mol%. DNA-DNA relatedness for the type strain W18RDT with respect to its closest phylogenetic relative Sphingomonas. fennica DSM 13665Twas 21.54±1.2 %. Major cellular fatty acids in strain W18RDT were C16 : 1ω7c and/or C16 : 1ω6c (48.12 %), C18 : 1ω7c and/or C18 : 1ω6c (21.98 %) and C14 : 0 2-OH (14.93 %), with ubiquinone-10 (Q-10) as the predominant respiratory quinone. The polar lipid profile of the strain consisted of phosphatidylethanolamine, phosphatidylglycerol, sphingoglycolipid, phosphatidylcholine, diphosphatidylglycerol and two unknown lipids. Based on the evidence from a combination of phenotypic, taxonomic and phylogenetic analyses, strain W18RDT represents a novel species of the genus Sphingomonas, for which the name Sphingomonas prati sp. nov. is proposed. The type strain is W18RDT (=CGMCC 1.15645T=DSM 103336T).

Aureimonas glaciei sp. nov., isolated from an ice core

A bacterial strain, B5-2T, was isolated from an ice core drilled from Muztagh Glacier, China. Strain B5-2T was a Gram-stain-negative, short rod-shaped, motile by polar flagella, aerobic bacterium. The major fatty acids of strain B5-2T were summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c) and iso-C13 : 0. The G+C content of the DNA from strain B5-2T was 69.3 mol%. The predominant isoprenoid quinone of strain B5-2T was Q-10. The major polar lipids were phosphatidylglycerol, phosphatidylethanolamine, phosphatidylmonomethylethanolamine, phosphatidyldimethylethanolamine, phosphatidylcholine, an unidentified phospholipid and sulfoquinovosyldiacylglycerol. Comparative 16S rRNA gene sequence analysis revealed that the novel strain B5-2T shared highest similarity (96.7 %) with Aureimonas altamirensis S21BT. On the basis of the results of this polyphasic study, strain B5-2T represents a novel species of the genus Aureimonas, for which the name Aureimonas glaciei sp. nov. is proposed. The type strain is B5-2T (=CGMCC 1.15493T=KCTC 52395T).

Massilia glaciei sp. nov., isolated from the Muztagh Glacier

A Gram-stain-negative, rod-shaped, bacterial strain, B448-2T, was isolated from an ice core from the Muztagh Glacier, on the Tibetan Plateau. B448-2T grew optimally at pH 7.0 and 20 °C in the presence of 0-1.0 % (w/v) NaCl. The results of 16S rRNA gene sequence similarity analysis indicated that B448-2T was closely related to Massilia eurypsychrophila CGMCC 1.12828T, Rugamonas rubra CCM3730T and Duganella zoogloeoides JCM20729T at levels of 97.8, 97.7  and 97.3 %, respectively. The predominant fatty acids of B448-2T were summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and C16 : 0. The predominant isoprenoid quinone was Q-8. The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. The genomic DNA G+C content of the strain was 66.1 mol%. In DNA-DNA hybridization tests, B448-2T shared 37.6 % DNA-DNA relatedness with Massilia eurypsychrophila CGMCC 1.12828T. On the basis of the results for phenotypic and chemotaxonomic characteristics, B448-2T was considered to represent a novel species of the genus Massilia, for which the name Massiliaglaciei sp. nov. is proposed. The type strain is B448-2T (=JCM 30271T=CGMCC 1.12920T).