Paracoccus onchidii sp. nov., a moderately halophilic bacterium isolated from a marine invertebrate from the South China Sea

A novel moderately halophilic bacterial strain, designated Z330^T, was isolated from the egg of a marine invertebrate of the genus Onchidium collected in the South China Sea. The 16S rRNA gene sequence of strain Z330^T exhibited the highest similarity value to that of the type strain Paracoccus fistulariae KCTC 22803^T (97.6%), Paracoccus seriniphilus NBRC 100798^T (97.6%) and Paracoccus aestuarii DSM 19484^T (97.6%). Phylogenomic and 16S rRNA phylogenetic analysis showed that strain Z330^T was most closely related to P. seriniphilus NBRC 100798^T and P. fistulariae KCTC 22803^T. Strain Z330^T grew optimally at 28-30 °C, pH 7.0-8.0 with the presence of 5.0-7.0% (w/v) NaCl. In addition, growth of strain Z330^T occurred at 0.5-16% NaCl, indicated strain Z330^T was a moderately halophilic and halotolerant bacterium of genus Paracoccus. The predominant respiratory quinone in strain Z330^T was identified as ubiquinone-10. The major polar lipids of strain Z330^T were phosphatidylcholine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylmonomethylethanolamine, glycolipid and six unidentified polar lipids. The major fatty acids of strain Z330^T was summed feature 8 (C_18:1 ω6c and/or C_18:1 ω7c). The draft genome sequence of strain Z330^T includes 4,084,570 bp in total (N50 = 174,985 bp) with a medium read coverage of 463.6 × and 83 scaffolds. The DNA G + C content of strain Z330^T was 60.5%. In silico DNA-DNA hybridization with the four type strains showed 20.5, 22.3, 20.1 and 20.1% relatedness to Paracoccus fistulariae KCTC 22803^T, Paracoccus seriniphilus NBRC 100798^T, Paracoccus aestuarii DSM 19484^T and Paracoccus denitrificans 1A10901^T, respectively. And the average nucleotide identity (ANIb) values between strain Z330^T and these four type strains were 76.2, 80.0, 75.8 and 73.8%, respectively, lower than the 95-96% threshold value for dividing prokaryotic species. On the basis of the phenotypic, phylogenetic, phylogenomic and chemotaxonomic properties, a novel species of the genus Paracoccus, Paracoccus onchidii sp. nov. is proposed with the type strain Z330^T (= KCTC 92727^T = MCCC 1K08325^T).

Paracoccus salsus sp. nov., a novel slightly halophilic bacterium isolated from saline lake sediment

A Gram-stain-negative, non-motile, slightly halophilic and non-endospore-forming alphaproteobacterium, designated strain EGI L200073T, was isolated from saline lake sediment sampled in Xinjiang Uygur Autonomous Region, China. The taxonomic position of the isolate was determined using the polyphasic taxonomic analysis and phylogenomic analysis. Phylogenetic analysis based on 16S rRNA gene sequence similarities indicated that strain EGI L200073T formed a distinct clade with Paracoccus seriniphilus DSM 14827T and shared sequence identity of 98.56 %. The novel isolate could be distinguished from other species of the genus Paracoccus by its distinct phenotypic, physiological and genotypic characteristics. Optimal growth of strain EGI L200073T occurred on marine agar 2216 at pH 8.0 and 30 °C. The major respiratory quinone was Q-10, while the major fatty acids (>10%) were summed feature 8 (C17 : 1  ω6c and/or C17 : 1  ω7c) and C18 : 0. The detected polar lipids included diphosphatidylglycerol, phosphatidylcholine and phosphatidylglycerol. Based on the genome sequence of strain EGI L200073T, the G+C content of the novel isolate was 65.7 mol%. The average nucleotide identity, amino acid identity and digital DNA–DNA hybridization values of strain EGI L200073T against related members in the genus Paracoccus were below the cut-off points proposed for delineation of a novel species. According our polyphasic taxonomic data, strain EGI L200073T represents a new species of the genus Paracoccus , for which the name Paracoccus salsus sp. nov. is proposed. The type strain of the proposed novel isolate is EGI L200073T (=KCTC 92045T=CGMCC 1.19242T).

Paracoccus binzhouensis sp. nov., isolated from activated sludge

A gram-stain-negative, non-motile and rod-shaped strain, designated wg1^T, was isolated from activated sludge obtained from wastewater treatment plant in Binzhou (Shandong province, PR China). Growth of strain wg1^T occurred at 25-45 °C (optimum, 37 °C), at pH 7.0-9.0 (optimum growth at pH 8.0) and at a salinity range of 0-4% (optimum, 1%). The chemotaxonomic, phenotypic and genomic traits were investigated. The 16S rRNA gene sequence analysis showed that strain wg1^T belonged to the genus Paracoccus. The species with highest similarity to strain wg1^T was Paracoccus communis VKM B-2787^T (98.27%), followed by Paracoccus kondratievae VKM B-2222^T (98.25%). The isoprenoid quinone was Q-10. Major cellular fatty acids were summed feature 8, C_16:0 and C_18:0. The major polar lipids were diphosphatidylglycerol (DPG), phosphatidylethanolamine (PE), aminoglycolipid (AGL), phosphatidylglycerol (PG), phosphatidylcholine (PC), aminolipid (AL), one unidentified lipid (L) and one unidentified phospholipid (PL). The genome size was 4,834,448 bp with a G+C content of 67.67 mol%. The prediction result of secondary metabolites based on genome has shown that the strain wg1^T contained 12 clusters, and the gene involved in primary metabolism showed differences in the comparison between wg1^T and reference strains. The dDDH values of strain wg1^T with P. communis VKM B-2787^T, P. kondratievae VKM B-2222^T and P. denitrificans DSM 413^T were 45.30, 30.60 and 39.50%, respectively. Based on its physiological properties, chemotaxonomic characteristics and low ANI and dDDH results, strain wg1^T is considered to represent a novel species for which the name Paracoccus binzhouensis sp. nov., is proposed. The type strain is wg1^T (= KCTC 72861^T = CCTCC AB 2019400^T).

Isolation and diversity of sediment bacteria in the hypersaline aiding lake, China

Halophiles are relatively unexplored as potential sources of novel species. However, little is known about the culturable bacterial diversity thrive in hypersaline lakes. In this work, a total of 343 bacteria from sediment samples of Aiding Lake, China, were isolated using nine different media supplemented with 5% or 15% (w/v) NaCl. The number of species and genera of bacteria recovered from the different media varied, indicating the need to optimize the isolation conditions. The results showed an unexpected level of bacterial diversity, with four phyla (Actinobacteria, Firmicutes, Proteobacteria, and Rhodothermaeota), fourteen orders (Actinopolysporales, Alteromonadales, Bacillales, Balneolales, Chromatiales, Glycomycetales, Jiangellales, Micrococcales, Micromonosporales, Oceanospirillales, Pseudonocardiales, Rhizobiales, Streptomycetales, and Streptosporangiales), including 17 families, 43 genera (including two novel genera), and 71 species (including four novel species). The predominant phyla included Actinobacteria and Firmicutes and the predominant genera included Actinopolyspora, Gracilibacillus, Halomonas, Nocardiopsis, and Streptomyces. To our knowledge, this is the first time that members of phylum Rhodothermaeota were identified in sediment samples from a salt lake.

Cyclobacterium salsum sp. nov. and Cyclobacterium roseum sp. nov., isolated from a saline lake

Two novel strains, designated SYSU L10167^T and SYSU L10180^T, were isolated from sediment sampled at Dabancheng saline lake in Xinjiang, PR China. A polyphasic approach was used to clarify the taxonomic positions of the two strains. Cells of the isolates were curved ring-like, horseshoe-shaped or rod-shaped, non-motile and non-spore-forming. Cells were Gram-stain-negative, aerobic, heterotrophic and rose-pigmented. The phylogenetic trees based on 16S rRNA gene sequences showed that strains SYSU L10167^T and SYSU L10180^T formed a distinct lineage within the genus Cyclobacterium. Strains SYSU L10167^T and SYSU L10180^T showed highest similarities to Cyclobacterium jeungdonense KCTC 23150^T (98.0 and 97.4%, respectively). Results of genomic analyses (including average nucleotide identity, digital DNA-DNA hybridization and the marker gene tree) and pan-genome analysis further confirmed that strains SYSU L10167^T and SYSU L10180^T were separate from each other and other species of the genus Cyclobacterium. The draft genomes of the isolates had sizes of 5.5-5.7 Mb and reflected their major physiological capabilities. Based on phenotypic, physiological, chemotaxonomic and genotypic characterization, we propose that the isolates represent two novel species, for which the names Cyclobacterium salsum sp. nov. and Cyclobacterium roseum sp. nov. are proposed. The type strains of the species are SYSU L10167^T (=KCTC 72390^T=CGMCC 1.17521^T) and SYSU L10180^T (=KCTC 72391^T=CGMCC 1.17278^T).

Paracoccus alkanivorans sp. nov., isolated from a deep well with oil reservoir water

A Gram-stain-negative, non-motile and ovoid bacterial strain, designated 4-2T, was isolated from oil-contaminated water which was collected from Xinjiang Province, north-west PR China. The 16S rRNA gene sequence analysis showed that strain 4-2T belonged to the genus Paracoccus . The species with highest similarity to strain 4-2T was Paracoccus saliphilus YIM 90738T (97.83 %), followed by ‘ Paracoccus siganidrum ’ M26 (97.83 %) and Paracoccus endophyticus SYSUP0003T (97.25 %). The average nucleotide identity values between 4-2T and three type strains were 84.69, 77.88 and 74.07 %, respectively. The genomic DNA G+C content of strain 4-2T was 61.4 mol%. Chemotaxonomical characteristic results showed that the respiratory quinone was ubiquinone Q-10 and the major fatty acids were summed feature 8 (C18 : 1 ω7c or C18 : 1 ω6c) and C19 : 0 cyclo ω8c. The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, unidentified phospholipids, an unidentified aminolipid and an unidentified polar lipid. The predominant polyamines were putrescine, cadaverine and spermidine. On the basis of phenotypic, chemotaxonomic and phylogenetic inferences, strain 4-2T represents a novel species of the genus Paracoccus , for which the name Paracoccus alkanivorans sp. nov. is proposed. The type strain is 4-2T (=CGMCC 1.13669T=LMG 30882T).

Paracoccus aeridis sp. nov., an indole-producing bacterium isolated from the rhizosphere of an orchid, Aerides maculosa

A Gram-stain-negative, non-motile, coccoid-shaped, catalase- and oxidase-positive, non-denitrifying, neutrophilic bacterium designated as strain JC501T was isolated from an epiphytic rhizosphere of an orchid, Aerides maculosa, growing in the Western Ghats of India. Phylogenetic analyses based on the 16S rRNA gene sequence indicated that strain JC501T belonged to the genus Paracoccus and had the highest levels of sequence identity with Paracoccus marinus KKL-A5T (98.9 %), Paracoccus contaminans WPAn02T (97.3 %) and other members of the genus Paracoccus (<97.3 %). Strain JC501T produced indole-3 acetic acid and other indole derivatives from tryptophan. The dominant respiratory quinone was Q-10 and the major fatty acid was C18 : 1ω7c/C18 : 1ω6c, with significant quantities of C18 : 1ω9c, C17 : 0 and C16 : 0. The polar lipids of strain JC501T comprised phosphatidylglycerol, phosphatidylcholine, diphosphatidylglycerol, an unidentified glycolipid, two unidentified aminolipids, two unidentified lipids and four unidentified phospholipids. The genome of strain JC501T was 3.3 Mbp with G+C content of 69.4 mol%. For the resolution of the phylogenetic congruence of the novel strain, the phylogeny was also reconstructed with the sequences of eight housekeeping genes. Based on the results of phylogenetic analyses, low (<85.9 %) average nucleotide identity, digital DNA–DNA hybridization (<29.8 %), chemotaxonomic analysis and physiological properties, strain JC501T could not be classified into any of the recognized species of the genus Paracoccus . Strain JC501T represents a novel species, for which the name Paracoccus aeridis sp. nov. is proposed. The type strain is JC501T (=LMG 30532T=NBRC 113644T).