Paracoccus benzoatiresistens sp. nov., a benzoate resistance and selenite reduction bacterium isolated from wetland.

A Gram-stain-negative, aerobic, non-motile, catalase- and oxidase-positive, pale orange, rod-shaped strain EF6T, was isolated from a natural wetland reserve in Hebei province, China. The strain grew at 25-37 °C (optimum, 30 °C), pH 5-9 (optimum, pH 7), and in the presence of 1.0-4.0% (w/v) NaCl (optimum, 2%). A phylogenetic analysis based on 16S rRNA gene sequence revealed that strain EF6T belongs to the genus Paracoccus, and the closest members were Paracoccus shandongensis wg2T with 98.1% similarity, Paracoccus fontiphilus MVW-1 T (97.9%), Paracoccus everestensis S8-55 T (97.7%), Paracoccus subflavus GY0581T (97.6%), Paracoccus sediminis CMB17T (97.3%), Paracoccus caeni MJ17T (97.0%), and Paracoccus angustae E6T (97.0%). The genome size of strain EF6T was 4.88 Mb, and the DNA G + C content was 65.3%. The digital DNA-DNA hybridization, average nucleotide identity, and average amino acid identity values between strain EF6T and the reference strains were all below the threshold limit for species delineation (< 32.8%, < 88.0%, and < 86.7%, respectively). The major fatty acids (≥ 5.0%) were summed feature 8 (86.3%, C18:1 ω6c and/or C18:1 ω7c) and C18:1 (5.0%) and the only isoprenoid quinone was Q-10. The polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, two unidentified glycolipids, five unidentified phospholipids, and an unidentified aminolipid. Strain EF6T displays notable resistance to benzoate and selenite, with higher tolerance levels (25 g/L for benzoate and 150 mM for selenite) compared to the closely related species. Genomic analysis identified six benzoate resistance genes (acdA, pcaF, fadA, pcaC, purB, and catA) and twenty selenite resistance and reduction-related genes (iscR, ssuB, ssuD, selA, selD and so on). Additionally, EF6T possesses unique genes (catA, ssuB, and ssuC) absent in the closely related species for benzoate and selenite resistance. Its robust resistance to benzoate and selenite, coupled with its genomic makeup, make EF6T a promising candidate for the remediation of both organic and inorganic pollutants. It is worth noting that the specific resistance phenotypes described above were not reported in other novel species in Paracoccus. Based on the results of biochemical, physiological, phylogenetic, and chemotaxonomic analyses, combined with comparisons of the 16S rRNA gene sequence and the whole genome sequence, strain EF6T is considered to represent a novel species of the genus Paracoccus within the family Rhodobacteraceae, for which the name Paracoccus benzoatiresistens sp. nov. is proposed. The type strain is EF6T (= GDMCC 1.3400 T = JCM 35642 T = MCCC 1K08702T).

Paracoccus binzhouensis sp. nov., isolated from activated sludge.

A gram-stain-negative, non-motile and rod-shaped strain, designated wg1T, was isolated from activated sludge obtained from wastewater treatment plant in Binzhou (Shandong province, PR China). Growth of strain wg1T 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 wg1T belonged to the genus Paracoccus. The species with highest similarity to strain wg1T was Paracoccus communis VKM B-2787T (98.27%), followed by Paracoccus kondratievae VKM B-2222T (98.25%). The isoprenoid quinone was Q-10. Major cellular fatty acids were summed feature 8, C16:0 and C18:0. 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 wg1T contained 12 clusters, and the gene involved in primary metabolism showed differences in the comparison between wg1T and reference strains. The dDDH values of strain wg1T with P. communis VKM B-2787T, P. kondratievae VKM B-2222T and P. denitrificans DSM 413T were 45.30, 30.60 and 39.50%, respectively. Based on its physiological properties, chemotaxonomic characteristics and low ANI and dDDH results, strain wg1T is considered to represent a novel species for which the name Paracoccus binzhouensis sp. nov., is proposed. The type strain is wg1T (= KCTC 72861T = CCTCC AB 2019400T).

Paracoccus onubensis sp. nov., a novel alphaproteobacterium isolated from the wall of a show cave.

A novel facultatively anaerobic, non-motile, Gram-stain-negative, non-endospore-forming alphaproteobacterium, strain 1011MAR3C25T, was isolated from a white biofilm colonizing the walls of the Andalusian show cave Gruta de las Maravillas (Huelva, Spain). Strain 1011MAR3C25T grew at 8-42 °C (optimum, 20-30 °C), at pH 5.0-9.0 (optimum, pH 5.0-6.0) and in the presence of 0-12 % (w/v) NaCl (optimum 3-5 %). Cells were catalase- and oxidase-positive. The strain grew heterotrophically with various carbon sources and chemoautotrophically with thiosulfate under aerobic conditions. Results of phylogenetic analysis showed that strain 1011MAR3C25T was related to Paracoccus saliphilus DSM 18447T and Paracoccus alkanivorans LMG 30882T (97.90 % and 97.32 % 16S rRNA sequence identity values, respectively). The major respiratory quinone was ubiquinone Q-10 and the predominant fatty acid was C18 : 1 ω7c. The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylcholine, phosphatidylglycerol, an unidentified aminolipid, an unidentified glycolipid and an unidentified polar lipid. The DNA G+C content was 60.3 mol%. Based on a polyphasic taxonomic study it is proposed that strain 1011MAR3C25T (=CECT 9092T=LMG 29414T) represents a novel species of the genus Paracoccus, for which the name Paracoccus onubensis sp. nov. is proposed.

Paracoccus bengalensis is a later heterotypic synonym of Paracoccus versutu.

The present study aimed to examine the taxonomic relationship between two species, Paracoccus bengalensis Ghosh et al. 2006 and Paracoccus versutus (Harrison 1983) Katayama et al. 1996. Comparison of 16S rRNA gene sequences revealed that P. bengalensis JJJT was highly similar (99.9 %) to P. versutus A2T. The results of phylogenetic analysis based on 16S rRNA gene sequences indicated that the two strains formed a tight cluster within the genus Paracoccus. Whole genomic comparison between the two strains showed a digital DNA-DNA hybridization estimate of 82. 0 % and an average nucleotide identity value of 98.2 %, clearly indicating that the two strains were members of the same species. Moreover, the type strains of both species shared similar physiological and biochemical properties and fatty acids profiles. Based on genotypic and phenotypic evidence, we conclude that Paracoccus bengalensis Ghosh et al. 2006 is a later heterotypic synonym of Paracoccus versutus (Harrison 1983) Katayama et al. 1996 according to the priority of publication and validation of the name.

Paracoccus xiamenensis sp. nov., isolated from seawater on the Xiamen.

Strain 12-3T was isolated from seawater of the Guanyinshan Coast, Xiamen, Fujian Province, PR China. The bacterium was Gram-stain-negative, rod-shaped, aerobic, oxidase-positive and catalase-negative. Growth of strain 12-3T occurred at 10-37 °C (optimum, 20-30 °C), at pH 5.0-11.0 (optimum, pH 7.0-8.0) and at a salinity range of 0-10 % (optimum, 3-5 %). The results of phylogenetic analysis based on its 16S rRNA gene sequence indicated that strain 12-3T belonged to the genus Paracoccus and had the highest sequence similarity to Paracoccus lutimaris HDM-25T (97.4 %), followed by Paracoccus isoporae SW-3T (96.9 %), Paracoccus caeni MJ17T (96.9 %), Paracoccus pacificus F14T (96.8 %) and other species in the genus Paracoccus (95.3-96.5 %). The average nucleotide identity (ANI) and DNA-DNA hybridization (DDH) values between strain 12-3T and P. lutimaris HDM-25T were 76.1 and 17.0 %, respectively. ANI and DDH values between strain 12-3T and P. isoporae SW-3T were 78.9 and 18.2 %, respectively. The principal fatty acid of strain 12-3T was summed feature 8 (C18 : 1 ω6c/ω7c) and C18 : 0. The respiratory quinone of strain 12-3T was Q10. The polar lipids included phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and an unidentified glycolipid. The G+C content of the chromosomal DNA was 63.9 mol%. The combination of the results of the phylogenetic, phenotypic and chemotaxonomic analyses, and its low ANI and DDH values indicate that strain 12-3T represents a novel species of the genus Paracoccus, for which the name Paracoccus xiamenensis sp. nov. is proposed. The type strain is 12-3T (=MCCC 1A16381T=KCTC 72687T).

Paracoccus luteus sp. nov., isolated from the intestine of grass carp.

A novel Gram-negative bacterium, designated CFH 10530T, was isolated from the intestine of grass carp. The sample was collected from the aquaculture training base at the College of Fisheries, Henan Normal University, Xinxiang, PR China. Cells of strain CFH 10530T were coccoid, ovoid or short-rod-shaped, aerobic, non-spore-forming and non-motile. 16S rRNA gene sequence analysis demonstrated that strain CFH 10530T was closely related to Paracoccus endophyticus SYSUP0003T (97.7 % sequence similarity), Paracoccus halophilus HN-182T (96.5 %) and Paracoccus panacisoli DCY94T (96.1 %). The strain grew optimally at 25-28 °C, at pH 7.0 and with 0-2 % (w/v) NaCl. Cells were positive for catalase and oxidase, nitrate was reduced and H2S was not produced. The isoprenoid quinone was Q-10. Major cellular fatty acids were summed feature 8, C18 : 0 and C18 : 03-OH. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, one unidentified aminolipid and five unidentified polar lipids. The genome size was 3 331 229 bp with a G+C content of 69.6 mol%. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between CFH 10530T and the other species of the genus Paracoccus were found to be below the recommended levels for species delineation (ANIm <85, ANIb <80 and dDDH <24 %). Based on its physiological properties, chemotaxonomic characteristics and low ANI and dDDH results, strain CFH 10530T is considered to represent a novel species for which the name Paracoccus luteus sp. nov., is proposed. The type strain is CFH 10530T (=KCTC 62919T=CGMCC 1.16597T).

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).

Paracoccus liaowanqingii sp. nov., isolated from Tibetan antelope (Pantholops hodgsonii).

Two strains, designated 2251T and 3058, that were aerobic, Gram-stain-negative, non-motile, coccoid or short rod-shaped bacilli, have recently been isolated from Tibetan antelopes on the Qinghai-Tibet Plateau. The results of phylogenetic analyses of 16S rRNA gene sequences indicated that strains 2251T and 3058 represent a new species within the genus Paracoccus and are most similar to 'Paracoccus gahaiensis' CUG00006T (98.9 and 99.3 %), Paracoccus nototheniae I-41R45T (98.3 and 98.7 %) and Paracoccus hibiscisoli THG-T2.31T (97.6 and 97.8 %). Results of genomic sequence-based phylogenomic analysis agreed with those from 16S rRNA gene sequence analysis. Optimal growth was achieved at pH 7.0-7.5 and 28 °C with marine medium. Cells contained C18 : 1 ω7c as the major cellular fatty acid and ubiquinone-10 as the predominant menaquinone. The polar lipids comprised phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, phospholipid, glycolipid and an unidentified lipid. The cell-wall peptidoglycan amino acids were meso-2,6-diaminopimelic acid, alanine and glutamic acid; the major cell-wall sugar was galactose. The G+C content of strain 2251T was 66.5 mol%. Both strains (2251T and 3058) had DNA-DNA relatedness values less than 50 % with all available genomes of the genus Paracoccus in the ncbi database. Differential genotypic inferences, together with phenotypic and biochemical characteristics, demonstrated that strains 2251T and 3058 should be classified as a novel species of the genus Paracoccus, for which the name Paracoccus liaowanqingii sp. nov. is suggested. The type strain is 2251T (=CGMCC 1.16490T=DSM 106269T).

Paracoccus aurantiacus sp. nov., isolated from shallow-sea hydrothermal systems off Kueishantao Island.

An orange-pigmented, short-rod-shaped, aerobic and non-motile bacterial strain, designated TK008T, was isolated from the shallow-sea hydrothermal systems off Kueishantao Island in Taiwan, China, and it was studied by using a polyphasic taxonomic approach. Cells were Gram-stain-negative, and catalase- and oxidase-positive. Strain TK008T exhibited highest 16S rRNA gene sequence similarity of 97.1 % to Paracoccus pacificus F14T. The phylogenetic trees based on 16S rRNA gene sequences showed that strain TK008T was a member of the genus Paracoccus. Digital DNA-DNA hybridization values between strain TK008T and two closely related species (Paracoccus zhejiangensis and Paracoccus tegillarcae) were 20.6 and 20.9 %. The average nucleotide identity values of strain TK008T compared with P. zhejiangensis and P. tegillarcae were 75.2 and 74.6 % respectively. The major isoprenoid quinone was ubiquinone-10. The predominant fatty acids (>10 %) were summed feature 8 (C18 : 1ω6c and/or C18 : 1ω7c). The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, three unidentified phospholipids, two unidentified lipids and an unidentified glycolipid. The DNA G+C content of strain TK008T from genomic sequence data was 62.54 mol%. On the basis of polyphasic analysis, strain TK008T represents a novel species, for which the name Paracoccus aurantiacus sp. nov. is proposed. The type strain is TK008T (=CGMCC 1.13898T=JCM 33630T).

Diversity of Methylotrophy Pathways in the Genus Paracoccus (Alphaproteobacteria).

Paracoccus denitrificans Pd 1222 is a model methylotrophic bacterium. Its methylotrophy is based on autotrophic growth (enabled by the Calvin cycle) supported by energy from the oxidation of methanol or methylamine. The growing availability of genome sequence data has made it possible to investigate methylotrophy in other Paracoccus species. The examination of a large number of Paracoccus spp. genomes reveals great variability in C1 metabolism, which have been shaped by different evolutionary mechanisms. Surprisingly, the methylotrophy schemes of many Paracoccus strains appear to have quite different genetic and biochemical bases. Besides the expected 'autotrophic methylotrophs', many strains of this genus possess another C1 assimilatory pathway, the serine cycle, which seems to have at least three independent origins. Analysis of the co-occurrence of different methylotrophic pathways indicates, on the one hand, evolutionary linkage between the Calvin cycle and the serine cycle, and, on the other hand, that genes encoding some C1 substrate-oxidizing enzymes occur more frequently in association with one or the other. This suggests that some genetic module combinations form more harmonious enzymatic sets, which act with greater efficiency in the methylotrophic process and thus undergo positive selection.

Paracoccus nototheniae sp. nov., isolated from a black rock cod fish (Notothenia coriiceps) from the Chilean Antarctic.

An orange-pigmented, oxidase-positive bacterial strain (I-41R45T), isolated from the kidney of a black rock cod fish sampled in the Chilean Antarctic was studied in a polyphasic taxonomic investigation. Cells of the isolate were coccoid and stained Gram-negative. A comparison of the 16S rRNA gene sequence of strain I-41R45T with sequences of type strains of most closely related Paracoccus species showed highest sequence similarities to Paracoccus hibiscisoli (98.4 %), Paracoccus marcusii (98.3 %), Paracoccus haeundaensis and Paracoccus carotinifaciens (both 98.2 %). 16S rRNA gene sequence similarities to all other Paracoccus species were below 97 %. The draft genome of strain I-41R45T had a size of 4.59 Mb with a DNA G+C content of 65.26 mol% and included the prediction and annotation of 4426 coding genes, 1973 protein-coding genes and 46 tRNAs. The fatty acid profile of strain I-41R45T consisted mainly of the major fatty acids C18 : 1 ω7c/ω9t/ω12t and C18:0, typical of the genus Paracoccus. DNA-DNA hybridizations between I-41R45T and type strains of P. hibiscisoli, P. marcusiiand P. haeundaensis resulted in similarity values of 45 % (reciprocal 26 %), 66 % (reciprocal 61 %), and 29 % (reciprocal 36 %), respectively. DNA-DNA hybridization results, together with the differentiating biochemical and chemotaxonomic properties, showed that strain I-41R45T represents a novel Paracoccus species, for which the name Paracoccus nototheniae sp. nov. (type strain I-41R45T=CCM 8875T=CIP 111632T), is proposed.

Paracoccus suum sp. nov., isolated from a pig farm dust collector.

A Gram-stain-negative, strictly aerobic, non-motile, non-spore-forming, coccoid- or short rod-shaped bacterial strain, designated SC2-6T, was isolated from a dust collector of a pig farm located in Wanju-gun, Jeollabuk-do, Republic of Korea. Strain SC2-6T grew within the ranges of 10-37 °C (28-30 °C, optimally), pH 6.0-10.0 (pH 7.0-8.0, optimally) and 0-3% NaCl (w/v). The 16S rRNA gene sequence similarity of strain SC2-6T showed the highest values to Paracoccus kondratievae GBT (96.3%), Paracoccus denitrificans DSM 413T (96.3%) and Paracoccus sanguinis 5503T (96.1%). The phylogenetic tree based on the 16S rRNA gene sequences revealed that strain SC2-6T belonged to the genus Paracoccus and clustered with Paracoccus pacificus F14T. The phylogenetic tree based on the rpoD gene sequences also demonstrated that strain SC2-6T fell into the clade of the genus Paracoccus. The DNA G+C content was 66.9 mol%. The major respiratory quinone was ubiquinone-10 and the major fatty acids (> 10% of the total fatty acids) were summed feature 8 (comprising C18 : 1 ω6c and/or C18 : 1 ω7c). The polar lipids were composed of diphosphatidylglycerol, phosphatidylcholine, an unidentified glycolipid, two unidentified aminolipids and two unidentified lipids. On the basis of phenotypic, phylogenetic and genomic data, strain SC2-6T was classified in the genus Paracoccus as a member of a novel species, for which the name Paracoccus suum sp. nov. is proposed. The type strain is SC2-6T (=KACC 19328T=NBRC 113110T).

Paracoccus subflavus sp. nov., isolated from Pacific Ocean sediment.

A Gram-stain-negative, short rod-shaped, non-motile, catalase- and oxidase-positive, aerobic bacterium, designated GY0581T, was isolated from marine sediment sampled from the Western Pacific Ocean. Phylogenetic analyses based on 16S rRNA gene sequences indicated that strain GY0581T belonged to the genus Paracoccus and had the highest levels of sequence similarity to Paracoccus sediminis JCM 18467T (98.2 %). Levels of similarity between strain GY0581T and other Paracoccus species were lower than 97.0 %. The average nucleotide identity and the DNA-DNA hybridization values between strain GY0581T and P. sediminis JCM 18467T were 83.9 and 27 %, respectively, which are below the respective thresholds for species differentiation. The major cellular fatty acid was C18 : 1ω7c (79.5 %). The only isoprenoid quinone was Q-10. The polar lipid pattern indicated the presence of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, three unidentified phospholipids, three unidentified aminolipids, one unidentified glycolipid and two unidentified lipids. The DNA G+C content of strain GY0581T was 65.6 mol%. On the basis of polyphasic characterization, it is concluded that strain GY0581T represents a novel species of the genus Paracoccus, for which the name Paracoccus subflavus sp. nov. is proposed. The type strain is GY0581T (=KCTC 42710T=MCCC 1A10575T).

Paracoccus haematequi sp. nov., isolated from horse blood.

Two slightly orange-pigmented, oxidase-positive bacterial strains (M1-83T and M2-116), isolated from horse blood collected during slaughter in Giessen, Germany, were studied in a polyphasic taxonomic approach. Cells of the isolates were coccoid and stained Gram-negative. The two strains shared identical 16S rRNA gene sequences but their genomic fingerprint patterns differed, indicating the genetic distinctiveness of the two strains. A comparison of the 16S rRNA gene sequence of strain M1-83T with sequences of the type strains of the most closely related Paracoccus species showed highest sequence similarities to Paracoccus acridae (98.2 %) and Paracoccus aerius (98.1 %). 16S rRNA gene sequence similarities to all other Paracoccus species were below 97.6 %. The fatty acid profile of the two strains consisted mainly of the major fatty acids C18 : 1 ω7c and C18:0, which is typical for the genus Paracoccus. The polyamine patterns of strain M1-83T contained major amounts of putrescine and spermidine. The major quinone was ubiquinone Q-10. The diamino acid of the peptidoglycan was meso-diaminopimelic acid. The polar lipid profile was characterized by the major lipids diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, an unidentified aminolipid and an unidentified glycolipid. DNA-DNA hybridization experiments between M1-83T and the type strains of P. acridae and P. aerius resulted in similarity values of 17 % (reciprocal, 60 %) and 23 % (reciprocal 30 %), respectively. DNA-DNA hybridization results together with the differentiating biochemical and chemotaxonomic properties showed that strain M1-83T represents a novel Paracoccusspecies, for which the name Paracoccus haematequi sp. nov. (type strain M1-83T=LMG 30633T=CIP 111624T=CCM 8857T), is proposed.

Description of Paracoccus endophyticus sp. nov., isolated from Gastrodia elata Blume.

A Gram-stain-negative, strictly aerobic, non-motile strain, SYSUP0003T, was isolated from tubers of Gastrodia elata Blume. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain SYSUP0003T belonged to the genus Paracoccus, with the highest sequence similarity to the type strain of Paracoccus sediminis (97.5 %). Strain SYSUP0003T grew at pH 6.0-8.0 and 4-30 °C with optimum growth at pH 7.0 and 28 °C. Strain SYSUP0003T could tolerate up to 1 % (w/v) NaCl and grew optimally in the absence of NaCl. The isoprenoid quinone of strain SYSUP0003T was Q-10. The major fatty acids were C18 : 0, C16 : 0, C10 : 0 3-OH and summed feature 7. The polar lipids were diphosphatidylglycerol (DPG), aminophospholipids (AL), phosphatidylglycerol (PG), phosphatidylcholine (PC) and four unidentified polar lipids (L). The genome size was 3 204 685 bp, with a DNA G+C content of 69.7 mol%. The average nucleotide identity values between strain SYSUP0003T and P. sediminis DSM 26170T (ANIm 84.2 %, ANIb 75.6 %), Paracoccus solventivorans DSM 6637T (ANIm 84.5 %, ANIb 76.9 %) and Paracoccus alkenifer DSM 11593T (ANIm 84.3 %, ANIb 77.3 %) were below the cut-off level (95-96 %) for species delineation. Based on phenotypic, chemotaxonomic and molecular characterizations, strain SYSUP0003T represents a novel species of the genus Paracoccus, for which the name Paracoccus endophyticus sp. nov. is proposed. The type strain is SYSUP0003T (=KCTC 62180T=CGMCC 1.16545T).

Paracoccus sediminilitoris sp. nov., isolated from a tidal flat sediment.

A novel marine Gram-stain-negative, non-spore-forming, motile, aerobic, coccoid or ovoid bacterium, designated as strain DSL-16T, was isolated from a tidal flat sediment on the East China Sea and characterized phylogenetically and phenotypically. Optimal growth of the strain occurred at 35 °C (range 4-40 °C), at pH 6 (range 5-11) and with 4 % (w/v) NaCl (range 1-14 %). The nearest phylogenetic neighbour was Paracoccusseriniphilus DSM 14827T (98.2 % 16S rRNA gene sequence similarity). The digital DNA-DNA hybridization value between strain DSL-16T and P. seriniphilus DSM 14827T was 19.5±2.2 %. The average nucleotide identity value between strain DSL-16T and P. seriniphilus DSM 14827T was 83.6 %. The sole respiratory ubiquinone was Q-10. The major polar lipids were phosphatidylmonomethylethanolamine (PME), phosphatidylglycerol (PG), phosphatidylcholine (PC), phosphatidylethanolamine (PE), diphosphatidyglycerol (DPG) and glycolipid (GL). The predominant cellular fatty acids of strain DSL-16T were C18 : 1ω7c, C18 : 0 and 11-methyl C18 : 1ω7c. The G+C content of the genomic DNA was 64.5 mol%. The combined genotypic and phenotypic data indicated that strain DSL-16T represents a novel species of the genus Paracoccus, for which the name Paracoccus sediminilitoris sp. nov. is proposed. The type strain is DSL-16T (=KCTC 62644T=MCCC 1K03534T).

Paracoccus halotolerans sp. nov., isolated from a salt lake.

A novel Gram-stain-negative, aerobic, non-motile, coccus-shaped bacterium, designated CFH 90064T, was isolated from a salt lake sediment sample collected from Yuncheng city, Shanxi province, PR China. 16S rRNA gene sequence comparisons and phylogenetic analyses showed that the strain belonged to the genus Paracoccus and clustered with Paracoccus zeaxanthinifaciens R-1512T (98.2 % similarity), Paracoccus homiensis DD-R11T (97.6 % similarity) and Paracoccus fistulariae 22-5T (96.5 % similarity), respectively. Growth of strain CFH 90064T was observed at 10-37 °C, pH 6.0-9.0 and with NaCl concentrations of up to 6.0 % (w/v). Strain CFH 90064T contained Q-10 as the only isoprenoid quinone, and the major fatty acid was C18 : 1ω7c. Polar lipids of strain CFH 90064T comprised diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, an unidentified glycolipid, an unidentified aminolipid and an unidentified phospholipid. The genome of strain CFH 90008T was 3.75 Mbp with a DNA G+C content of 65.1 %. Based on the phylogenetic analyses, low average nucleotide identity results, chemotaxonomic characteristics and differential physiological properties, strain CFH 90064T could not be classified into any recognized species of the genus Paracoccus, suggesting that this strain represents a novel species, for which the name Paracoccushalotolerans sp. nov. is proposed. The type strain is CFH 90064T (=CCTCC AB 2016131T=DSM 103234T).

Paracoccus tegillarcae sp. nov., isolated from the gastrointestinal tract of a blood cockle (Tegillarca granosa).

A novel bacterial isolate, designated as strain BM15T, was isolated from the gastrointestinal tract of a blood cockle, Tegillarca granosa, which was collected from the foreshore of Beolgyo-eup, Republic of Korea. Strain BM15T was Gram-stain-negative, non-motile, strictly aerobic and short-rod-shaped. Optimum growth of the isolate occurred at 20 °C, in the presence of 4 % (w/v) NaCl and at pH 6. The 16S rRNA gene sequence analysis showed that strain BM15T belonged to the genus Paracoccus and had more than 97 % 16S rRNA gene sequence similarity to 'Paracoccus zhejiangensis' J6 (97.40 % similarity) and Paracoccus lutimaris HDM-25T (97.04 %). The polar lipid profile of strain BM15T comprised phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, an unidentified glycolipid and two unidentified lipids. The predominant respiratory quinone was ubiquinone-10. The major cellular fatty acid (>20 %) was summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c). The complete genome sequence of strain BM15T comprised 3,759,866 bp with 62.2 mol% G+C content. The results of the phylogenetic, phenotypic and genotypic analyses indicated that strain BM15T represents a novel species in the genus Paracoccus, for which the name Paracoccus tegillarcae is proposed. The type strain is BM15T (=KCTC 72032T=JCM 33289T).

Paracoccus indicus sp. nov., isolated from surface seawater in the Indian Ocean.

Strain IO390502T, isolated from surface seawater in the Indian Ocean, was characterised using a polyphasic taxonomy approach. Phylogenetic analyses based on 16S rRNA gene sequences indicated that strain IO390502T belongs to the genus Paracoccus and is closely related to Paracoccus seriniphilus DSM 14827T (97.6%), followed by P. zeaxanthinifaciens JCM 21774T (97.5%), P. homiensis DSM 17862T (97.3%), P. marcusii DSM 11574T (97.2%), P. haeundaensis BC 74171T (97.0%) and P. carotinifaciens E-396T (97.0%). Cells are Gram-negative, aerobic, poly-ß-hydroxybutyrate-accumulating, motile, rod-shaped, and forms creamy-white colonies. Optimal growth occurred at 25-30 °C, pH 5-8, and in the presence of 3-8% NaCl. The genome of strain IO390502T has a G+C content of 64.9 mol% and a 3.5 Mb chromosome. The in silico DNA-DNA hybridisation and average nucleotide identity values between strain IO390502T and the three closely related taxa, P. seriniphilus DSM 14827T, P. zeaxanthinifaciens JCM 21774T and P. homiensis DSM 17862T, are 19.6%, 21.9% and 20.6%, and 76.0%, 79.9% and 77.8%, respectively. Phosphatidylglycerol is the major lipid present, ubiquinone-10 (Q-10) is the sole isoprenoid quinone, and the major cellular fatty acid is C18:1ω7c. Based on data from phenotypic tests and genotypic differences between strain IO390502T and its close phylogenetic relatives, strain IO390502T represents a new species belonging to the genus Paracoccus, for which the name Paracoccus indicus sp. nov. is proposed. The type strain is IO390502T (= JCM 32637T = CCTCC AB 2018071T).