Closest Type Strain Research Articles

Svornostia abyssi gen. nov., sp. nov. isolated from the world's deepest silver-uranium mine currently devoted to the extraction of radon-saturated water.

A Gram-stain-positive, rod-shaped, aerobic, motile bacterium, J379T, was isolated from radioactive water spring C1, located in a former silver-uranium mine in the Czech Republic. This slow-growing strain exhibited optimal growth at 24-28 °C on solid media with <1 % salt concentration and alkaline pH 8-10. The only respiratory quinone found in strain J379T was MK-7(H4). C18 : 1 ω9c (60.9 %), C18 : 0 (9.4 %), C16 : 0 and alcohol-C18 : 0 (both 6.2 %) were found to be the major fatty acids. The peptidoglycan contained directly cross-linked meso-diaminopimelic acid. Phylogenetic reconstruction based on the 16S rRNA gene sequences and the core-genome analysis revealed that strain J379T forms a separate phylogenetic lineage within the recently amended order Solirubrobacterales. A comparison of the 16S rRNA gene sequences between strain J379T and other members of the order Solirubrobacterales showed <96 % similarity. This analysis revealed that the closest type strains were Parviterribacter kavangonensis D16/0 /H6T (95.2 %), Capillimicrobium parvum 0166_1T (94.9 %) and Conexibacter arvalis KV-962T (94.5 %). Whole-genome analysis showed that the closest type strain was Baekduia soli BR7-21T with an average nucleotide identity of 78 %, average amino acid identity of 63.2 % and percentage of conserved proteins of 48.2 %. The G+C content of the J379T genomic DNA was 71.7 mol%. Based on the phylogenetic and phylogenomic data, as well as its physiological characteristics, strain J379T is proposed to represent a type strain (DSM 113746T=CCM 9300T) of Svornostia abyssi gen. nov. sp. nov. within the family Baekduiaceae.

Pseudomonas flavocrustae sp. nov., an endophyte with plant growth promoting traits isolated from Passiflora incarnata

A polyphasic approach was applied to characterize taxonomically a novel endophytic bacterial strain, designated as EP178T, which was previously isolated from Passiflora incarnata leaves and characterized as plant-growth promoter. The strain EP178T forms Gram stain-negative and rod-shaped cells, and circular and yellow-pigmented colonies. Its growth occurs at 10–37 °C, at pH 6.0–8.0, and tolerates up to 7% (w/v) NaCl. The major cellular fatty acids found were summed feature 8 (C18:1 ω7c), summed feature 3 (C16:1 ω6c /C16:1 ω7c), and C16:0, and the predominant ubiquinone was Q-9. The phylogenetic and nucleotide-similarity analysis with 16S rRNA gene sequences showed that strain EP178T belongs to Pseudomonas genus. The genomic-based G + C content was 65.5%. The average nucleotide identity and digital DNA-DNA hybridization values between strains EP178T and the closest type strain, P. oryzihabitans DSM 6835T, were 92.6% and 52.2%, respectively. Various genes associated with plant-growth promoting mechanisms were annotated from genome sequences. Based on the phenotypic, genomic, phylogeny and chemotaxonomic data, strain EP178T represents a new species of the genus Pseudomonas, for which the name Pseudomonas flavocrustae sp. nov. was proposed. The type strain is EP178T (= CBMAI 2609T = ICMP 24844T = MUM 23.01T).

Nocardioides agri sp. nov., isolated from garden soil.

A novel bacterial strain, designated as MAH-18T, was isolated from soil sampled in a flower garden. Cells of strain MAH-18T were Gram-stain-positive, aerobic, motile, and rod-shaped. The colonies were beige in colour, smooth, and spherical when grown on Reasoner's 2A agar medium. Strain MAH-18T grew at 20-40 °C, pH 6.0-8.0, and 0-1.0 % NaCl. Cells were able to hydrolyse aesculin, gelatin, and Tween 20. According to the 16S rRNA gene sequence comparisons, the isolate was determined to be a member of the genus Nocardioides and most closely related to Nocardioides pyridinolyticus OS4T (97.9 %), Nocardioides hankookensis DS-30T (97.9 %), Nocardioides aquiterrae GW-9T (97.6 %), Nocardioides soli mbc-2T (97.5 %), Nocardioides conyzicola HWE 2-02T (97.4 %), and Nocardioides mangrovi GBK3QG-3T (96.3 %). Strain MAH-18T has a draft genome size of 4 788 325 bp (eight contigs), 4572 protein-coding genes, 46 tRNA, and three rRNA genes. The average nucleotide identity and digital DNA-DNA hybridization values between strain MAH-18T and the closest type strains were 81.5-83.4 % and 24.4-25.8 %, respectively. In silico genome mining revealed several biosynthetic gene clusters in the genome of the novel strain MAH-18T. The G+C content of the genomic DNA of strain was 72.2 mol% and the predominant isoprenoid quinone was MK-8 (H4). The main polar lipids were phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, and unknown phospholipids. The major cellular fatty acids were determined to be C16:0 iso and C17 : 1 ω6c. The DNA-DNA hybridization results and phenotypic, genotypic, and chemotaxonomic data demonstrated that strain MAH-18T represents a novel species, for which the name Nocardioides agri sp. nov. is proposed, with MAH-18T as the type strain (=KACC 19744T=CGMCC 1.13656T).

Curtobacterium salicis sp. nov., isolated from willow tree stems in Washington state.

Curtobacterium sp. strain WW7 is a Gram-positive, non-motile, orange rod-shaped bacterium isolated from branches of wild willow (Salix sitchensis) trees. The WW7T strain has optimum growth in the temperature range between 25 and 30°C, a pH range of 6-7.7, and tolerates up to 5.5% (w/v) of NaCl. The genome sequencing of strain WW7T revealed a genome size of approximately 3.8 Mbp and a G + C content of 71.3mol%. The phylogenomic analyses support the WW7T affiliation to a novel Curtobacterium lineage, with Curtobacterium herbarum being the closest type-strain. Chemotaxonomic analysis indicates that the carbon sources assimilation profile of strain WW7T was similar to the type strains, i.e. Curtobacterium luteum, Curtobacterium albidum, and Curtobacterium flaccumfaciens, while no assimilation of the organic acids succinate, alpha-ketobutyrate, mono methyl-succinate, and lactate was observed. Finally, fatty acid methyl ester analysis identifies anteiso-C15:0 and anteiso-C17:0 as major cellular fatty acids which is a common feature for members of the Curtobacterium genus. Based on the results of phylogenomic and chemotaxonomic analyses, strain WW7T represents a novel Curtobacterium lineage, for which the name Curtobacterium salicis sp. nov. is proposed. The type strain is WW7T (DSM 34805T-NRRL B-68078T).

Description of Streptomyces naphthomycinicus sp. nov., an endophytic actinobacterium producing naphthomycin A and its genome insight for discovering bioactive compounds.

Endophytic actinobacteria are a group of bacteria living inside plant tissue without harmful effects, and benefit the host plant. Many can inhibit plant pathogens and promote plant growth. This study aimed to identify a strain of Streptomyces as a novel species and study its antibiotics production. An endophytic actinobacterium, strain TML10T was isolated from a surface-sterilized leaf of a Thai medicinal plant (Terminalia mucronata Craib and Hutch). As a result of a polyphasic taxonomy study, strain TML10T was identified as a member of the genus Streptomyces. Strain TML10T was an aerobic actinobacterium with well-developed substrate mycelia with loop spore chains and spiny surface. Chemotaxonomic data, including cell wall components, major menaquinones, and major fatty acids, confirmed the affiliation of strain TML10T to the genus Streptomyces. The results of the phylogenetic analysis, including physiological and biochemical studies in combination with a genome comparison study, allowed the genotypic and phenotypic differentiation of strain TML10T and the closest related type strains. The digital DNA-DNA hybridization (dDDH), Average nucleotide identity Blast (ANIb), and ANIMummer (ANIm) values between strain TML10T and the closest type strain, Streptomyces musisoli CH5-8T were 38.8%, 88.5%, and 90.8%, respectively. The name proposed for the new species is Streptomyces naphthomycinicus sp. nov. (TML10T = TBRC 15050T = NRRL B-65638T). Strain TML10T was further studied for liquid and solid-state fermentation of antibiotic production. Solid-state fermentation with cooked rice provided the best conditions for antibiotic production against methicillin-resistant Staphylococcus aureus. The elucidation of the chemical structures from this strain revealed a known antimicrobial agent, naphthomycin A. Mining the genome data of strain TML10T suggested its potential as a producer of antbiotics and other valuable compounds such as ε-Poly-L-lysine (ε-PL) and arginine deiminase. Strain TML10T contains the arcA gene encoding arginine deiminase and could degrade arginine in vitro.

Silvimonas soli sp. nov., a new member of Chromobacteriaceae isolated from soil in Norrbyskär island, Sweden.

A novel bacterial species is described that was isolated from the soil of Norrbyskär island (Sweden). This Gram-negative, facultatively anaerobic and motile rod, designated 17-6T, was classified in the family Chromobacteriaceae, class Betaproteobacteria, and further characterized by a polyphasic approach. Comparative 16S rRNA gene analysis revealed the potential species novelty of the strain, with Silvimonas terrae (98.20 % similarity) and Silvimonas amylolytica (98.13 %) being its closest type strains. The phylogenetic novelty of the isolate at the level of species was confirmed using phylogenetic analyses based on the whole genome: average nucleotide identity values ranged from 79 to 81 %, average amino acid identity values from 75 to 81 % and percentage of conserved proteins values from 69-81 % with the members of genera Silvimonas and Amantichitinum. On the basis of phenotypic, phylogenetic, functional and genotypic analyses, we propose the isolate as the type strain of a novel species within the genus Silvimonas with the designation Silvimonas soli 17-6T (=DSM 115342T=CCM 9308T).

Selenobaculum gbiensis gen. nov. sp. nov., a new bacterium isolated from the gut microbiota of a patient with Crohn’s disease

The human gut microbiota is a complex ecology comprising approximately 10 to 100 trillion microbial cells. Most of the bacteria detected by 16s rRNA sequencing have yet to be cultured, but intensive attempts to isolate the novel bacteria have improved our knowledge of the gut microbiome composition and its roles within human host. In our culturomics study, a novel gram-negative, motile, obligately anaerobic, rod-shaped bacteria, designated as strain ICN-92133T, was isolated from a fecal sample of a 26-year-old patient with Crohn’s disease. Based on the 16s rRNA sequence of strain ICN-92133T, the phylogeny analysis placed the strain into the family Selenomonadaceae, showing 93.91% similarity with the closely related Massilibacillus massiliensis strain DSM 102838T. Strain ICN-92133T exhibited a genome size of 2,679,003 bp with a GC content of 35.5% which was predicted to contain 26 potential virulence factors and five antimicrobial resistance genes. In comparative genomic analysis, strain ICN-92133T showed digital DNA–DNA Hybridization and OrthoANI values lower than 21.9% and 71.9% with the closest type strains, respectively. In addition, comparing phenotypic, biochemical, and cellular fatty acids with those of closely related strains revealed the distinctiveness of strain ICN-92133T. Based on the taxonogenomic results, strain ICN-92133T is proposed as a novel species belonging to a new genus. Therefore, we suggest the name of the new genus Selenobaculum gen. nov. within the family Selenomonadaceae and strain ICN-92133T (= KCTC 25622T = JCM 36070T) as a type strain of new species Selenobaculum gbiensis sp. nov.

Bradyrhizobium xenonodulans sp. nov. isolated from nodules of Australian Acacia species invasive to South Africa

A genealogical concordance approach was used to delineate strains isolated from Acacia dealbata and Acacia mearnsii root nodules in South Africa. These isolates form part of Bradyrhizobium based on 16S rRNA sequence similarity. Phylogenetic analysis of six housekeeping genes (atpD, dnaK, glnII, gyrB, recA and rpoB) confirmed that these isolates represent a novel species, while pairwise average nucleotide identity (ANIb) calculations with the closest type strains (B. cosmicum 58S1T, B. betae PL7HG1T, B. ganzhouense CCBAU 51670 T, B. cytisi CTAW11T and B. rifense CTAW71T) resulted in values well below 95–96%. We further performed phenotypic tests which revealed that there are high levels of intraspecies variation, while an additional analysis of the nodA and nifD loci indicated that the symbiotic loci of the strains are closely related to those of Bradyrhizobium isolates with an Australian origin. Strain 14ABT (=LMG 31415 T = SARCC-753 T) is designated as the type strain of the novel species for which we propose the name Bradyrhizobium xenonodulans sp. nov.

Nocardiopsis suaedae sp. nov. and Nocardiopsis endophytica sp. nov., two novel halophilic actinobacteria isolated from halophytes.

A polyphasic approach was used to describe two halophilic actinobacterial strains, designated LSu2-4T and RSe5-2T, which were isolated from halophytes [Suaeda maritima (L.) Dum. and Sesuvium portulacastrum (L.) L.] collected from Prachuap Khiri Khan province, Thailand. Comparative analysis of 16S rRNA gene sequences showed that strains LSu2-4T and RSe5-2T were assigned to the genus Nocardiopsis, with Nocardiopsis chromatogenes YIM 90109T(99.2 and 99.2 % similarities, respectively) and Nocardiopsis halophila DSM 44494T(99.0 and 98.8 % similarities, respectively) being their closely related strains. Whereas the 16S rRNA gene sequence similarity between LSu2-4T and RSe5-2T was 99.4 %. Phylogenetic and phylogenomic analyses based on 16S rRNA gene and whole-genome sequences revealed that both strains clustered with N. chromatogenes YIM 90109T and N. halophila DSM 44494T. The average nucleotide identity (ANI) based on blast, ANI based on MUMmer and digital DNA-DNA hybridization (dDDH) relatedness values between the two strains and their closest type strains were below the threshold values for identifying a novel species. Morphological characteristics and chemotaxonomic features of both strains were typical for the genus Nocardiopsis by formed well-developed substrate mycelia and aerial mycelia which fragmented into rod-shaped spores. Whole-cell hydrolysates contained meso-diaminopimelic acid as the diagnostic diamino acid. The predominant menaquinones were variously hydrogenated with 10 isoprene units and contained phosphatidylcholine in their polar lipid profiles. Major fatty acids were iso-C16:0 and 10-methyl C18:0. In silico analysis predicted that the genomes of LSu2-4T and RSe5-2T contained genes associated with stress responses and biosynthetic gene clusters encoding diverse bioactive metabolites. Characterization based on chemotaxonomic, phenotypic, genotypic and phylogenetic evidence demonstrated that strains LSu2-4T and RSe5-2T represents two novel species of the genus Nocardiopsis, for which the names Nocardiopsis suaedae sp. nov. (type strain LSu2-4T=TBRC 16415T=NBRC 115855T) and Nocardiopsis endophytica sp. nov. (type strain RSe5-2T=TBRC 16416T=NBRC 115856T) are proposed.

Streptomyces zingiberis sp. nov., an endophytic actinobacterium isolated from the root tissue of Zingiber montanum.

An endophytic actinobacterium, designated strain PLAI 1-29T, was isolated from the root tissue of Zingiber montanum collected from Pathum Thani province, Thailand. Strain PLAI 1-29T was characterized using a polyphasic taxonomic approach. It typically exhibited morphological and chemotaxonomic properties of the genus Streptomyces. Strain PLAI 1-29T produced a spiral spore chain on aerial mycelium and grew at 15-40 °C, pH 6-10 on International Streptomyces Project 2 agar. The maximum NaCl concentration for growth was 9 % (w/v). Cells of strain PLAI 1-29T presented ll-diaminopimelic acid, arabinose, galactose and ribose. The detected phospholipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol and phosphatidylinositol mannoside. The major menaquinones were MK-9(H6) and MK-9(H8). The major cellular fatty acids were iso-C16 : 0, anteiso-C15 : 0 and anteiso-C17 : 0. The genome-based taxonomic details revealed the assignment of strain PLAI 1-29T to the genus Streptomyces and exhibited low threshold values for the delineation of a novel species by average nucleotide identity-blast (84.0%), average amino acid identity (80.0%) and digital DNA-DNA hybridization (27.6%) with its closest type strain, Streptomyces xinghaiensis S187T. Furthermore, several differential physiological and biochemical characteristics were detected between strain PLAI 1-29T and the closest type strain. Based on the combined phenotypic and genomic features, strain PLAI 1-29T (=TBRC 7645T=NBRC 113170T) is considered to represent a new Streptomyces species, for which we propose the name Streptomyces zingiberis sp. nov.

Anianabacter salinae gen. nov., sp. nov. ASV31T, a Facultative Alkaliphilic and Extremely Halotolerant Bacterium Isolated from Brine of a Millennial Continental Saltern

During a prokaryotic diversity study in Añana Salt Valley, a new Rhodobacteraceae member, designated ASV31T, was isolated from Santa Engracia spring water. It was extremely halotolerant, tolerating up to 23% NaCl, and facultatively alkaliphilic, growing at pH 6.5–9.5 (optimum at 7.0–9.5). The isolate was a Gram-negative, rod-shaped, aerobic and non-motile bacterium that formed beige-to-pink colonies on marine agar. According to a 16S rRNA gene-based phylogenetic analysis, strain ASV31T forms a distinct branch of the family Rhodobacteraceae, with Thioclava pacifica DSM 10166T being its closest type strain (95.3%). This was confirmed with a phylogenomic tree and the values of ANI (73.9%), dDDH (19.3%), AAI (63.5%) and POCP (56.0%), which were below the genus/species level boundary. Additionally, an ability to degrade aromatic compounds and biosynthesise secondary metabolites was suggested by the genome of strain ASV31T. Distinguishing fatty acid profiles and polar lipid content were also observed. The genome size was 3.6 Mbp, with a DNA G+C content of 65.7%. Based on the data obtained, it was considered that strain ASV31T (=CECT 30309T = LMG 32242T) represents a new species of a new genus in the family Rhodobacteraceae, for which the name Anianabacter salinae gen. nov., sp. nov. is proposed.

Genetic diversity of rhizobial strains isolated from the relict legumes &lt;em&gt;Gueldenstaedtia monophylla&lt;/em&gt; and &lt;em&gt;G. verna&lt;/em&gt; growing in the republics of Altai and Buryatia (Russia)

For the first time, bacteria were isolated and identified from the root nodules of relict legumes Gueldenstaedtia monophylla Fisch. and G. verna (Georgi) Boriss. growing in the republics of Altai and Buryatia. The taxonomic position of the 29 obtained isolates was determined by sequencing the 16S rRNA gene (rrs). Showing a significant biodiversity, the isolates from G. monophylla and G. verna belonged to five genera of the order Rhizobiales: Mesorhizobium and Phyllobacterium (family Phyllobacteriaceae), Rhizobium (family Rhizobiaceae), Bosea (family Boseaceae), Bradyrhizobium (family Bradyrhizobiaceae). Three isolates which belonged to the species Bradyrhizobium valentinum and Rhizobium alamii showed 100 % of rrs-similarity with the type strains B. valentinum LmjM3T and R. alamii GBV016T, respectively. Six isolates of the genera Bosea and Rhizobium had a low level of rrs-similarity with the closest type strains (less than 99.5 %), which indicates that they may be assigned to new species. The data obtained can be used to itemise taxonomy within the order Rhizobiales, as well as to reveal the mechanisms of the formation of specific plant-microbial relationships during the evolution of symbiosis by studying the intermediate link between the extinct and modern rhizobia-legume symbiotic systems.

Rhodopirellula aestuarii sp. nov., a novel member of the genus Rhodopirellula isolated from brackish sediments collected in the Tagus River estuary, Portugal

Bacteria within the phylum Planctomycetota are biologically relevant due to unique characteristics among prokaryotes. Members of the genus Rhodopirellula can be abundant in marine habitats, however, only six species are currently validly described. In this study, we expand the explored genus diversity by formally describing a novel species. The pink-coloured strain ICT_H3.1T was isolated from brackish sediments collected in the Tagus estuary (Portugal) and a 16S rRNA gene sequence-based analysis placed this strain into the genus Rhodopirellula (family Pirellulaceae). The closest type strain is Rhodopirellula rubra LF2T, suggested by a similarity of 98.4% of the 16S rRNA gene sequence. Strain ICT_H3.1T is heterotrophic, aerobic and able to grow under microaerobic conditions. The strain grows between 15 and 37 °C, over a range of pH 6.5 to 11.0 and from 1 to 8% (w/v) NaCl. Several nitrogen and carbon sources were utilized by the novel isolate. Cells have an elongated pear-shape with 2.0 ± 0.3 × 0.9 ± 0.2 µm in size. Cells of strain ICT_H3.1T cluster in rosettes through a holdfast structure and divide by budding. Younger cells are motile. Ultrathin cell sections show cytoplasmic membrane invaginations and polar fimbriae. The genome size is 9,072,081 base pairs with a DNA G + C content of 56.1 mol%. Genomic, physiological and morphological comparison of strain ICT_H3.1T with its relatives suggest that it belongs to a novel species within the genus Rhodopirellula. Hence, we propose the name Rhodopirellula aestuarii sp. nov., represented by ICT_H3.1T (=CECT30431T = LMG32464T) as the type strain of this novel species.16S rRNA gene accession number: GenBank = OK001858.Genome accession number: The Whole Genome Shotgun project has been deposited at DDBJ/ENA/GenBank under the accession JAMQBK000000000. The version described in this paper is version JAMQBK010000000.

Phylogenetic relationships among Bradyrhizobium species nodulating groundnut (Arachis hypogea L.), jack bean (Canavalia ensiformis L.) and soybean (Glycine max Merr.) in Eswatini

This study assessed the genetic diversity and phylogenetic relationships of rhizobial isolates obtained from root nodules of groundnut, jack bean and soybean planted in different locations within Eswatini. Seventy-six rhizobial isolates were studied using ERIC-PCR (enterobacterial repetitive intergenic consensus) fingerprinting and PCR amplification of 16S rRNA, housekeeping genes (atpD, dnaK, glnll and rpoB) and symbiotic genes (nifH and nodC). The dendrogram generated from the ERIC-PCR banding patterns grouped the test rhizobial isolates into 16 major clusters (Cluster I–XVI), with three isolates, namely TUTAHeS60, TUTGMeS3 and TUTAHeS127, forming outgroups of Clusters IV, VI and IX, respectively. Furthermore, the 76 test isolates were grouped into 56 ERIC-PCR types at 70% similarity level. The phylogenetic analysis of the 16S rRNA gene and multilocus sequence analysis of four housekeeping (atpD, dnaK, glnII and rpoB) and two symbiotic (nifH and nodC) genes showed that all three legumes (groundnut, jack bean and soybean) were nodulated by bacterial symbionts belonging to the genus Bradyrhizobium, with some isolates exhibiting high divergence from the known reference type strains. The results also showed that B. arachidis, B. iriomotense and B. canariense were the closest type strains to the groundnut isolates, while B. pachyrhizi and B. elkanii were the closest relatives to the bacterial symbionts associated with the nodulation of both jack bean and soybean. This study is the first report to describe of the bacterial symbionts nodulating jack bean in African soils.

Genomic architecture of three newly isolated unclassified Butyrivibrio species elucidate their potential role in the rumen ecosystem.

One cellulose-degrading strain CB08 and two xylan-degrading strains XB500-5 and X503 were isolated from buffalo rumen. All the strains were designated as putative novel species of Butyrivibrio based on phylogeny, phylogenomy, digital DNA-DNA hybridization, and average nucleotide identity with their closest type strains. The draft genome length of CB08 was ~3.54Mb, while X503 and XB500-5 genome sizes were ~3.24 Mb and ~3.27 Mb, respectively. Only 68.28% of total orthologous clusters were shared among three genomes, and 40-44% of genes were identified as hypothetical proteins. The presence of genes encoding diverse carbohydrate-active enzymes (CAZymes) exhibited the lignocellulolytic potential of these strains. Further, the genome annotations revealed the metabolic pathways for monosaccharide fermentation to acetate, butyrate, lactate, ethanol, and hydrogen. The presence of genes for chemotaxis, antibiotic resistance, antimicrobial activity, synthesis of vitamins, and essential fatty acid suggested the versatile metabolic nature of these Butyrivibrio strains in the rumen environment.

Pacificimonas pallium sp. nov., an Isolated Bacterium from the Mantle of Pacific Oyster Crassostrea gigas in Germany, and Prediction of One-Carbon Metabolism

A yellow bacterium from marine agar, strain WHA3T, was isolated from the mantel of the Pacific oysters Crassostrea gigas in the Wilhelmshaven Sea in northern Germany. Based on the 16S rRNA gene sequence, strain WHA3T had a high similarity to Pacificimonas flava JLT2015T (95.80%) and 94.79% to Pacificimonas aurantium JLT2012T. Furthermore, the dDDH and ANI value analysis between WHA3T and other closest type strains were lower than 70% and 95%, respectively. The percentage of conserved proteins (POCP) and the average amino acid identity (AAI) value against Pacificimonas flava JLT2015T and Pacificimonas aurantium JLT2012T represented in the ranges of higher than 50% and 60%, respectively. Strain WHA3T contained ubiquinone-10 (Q-10) as the predominant quinone, and the major fatty acids were C16:1 ω7c and C18:1 ω7c. Granules of polyhydroxyalkanoates (PHAs) were absent. The main polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, several sphingoglycolipids, an unknown phospholipid, an unknown glycolipid, and an unknown polar lipid. The polyamines contained spermidine and spermine. The DNA G + C content of strain WHA3T was 61.69%. An analysis of the whole-genome sequence in the frame of genome mining strain WHA3T predicted the presence of genomes for one-carbon metabolism, TonB-dependent transporters, vitamin B12 transporter, iron siderophore receptor protein, and other genes, some of which play important roles against restricted nutrient sources. The extract of strain WHA3T moderately inhibited the growth of Candida albicans DSM 1665. The polyphasic taxonomic analysis results suggested that strain WHA3T could be separated from its closest type strains. Strain WHA3T represents a novel species in the genus Pacificimonas, for which we propose the name Pacificimonaspallium sp. nov., with the type strain WHA3T (= DSM 111825T = NCCB 100832T).

Amycolatopsis aidingensis sp. nov., a Halotolerant Actinobacterium, Produces New Secondary Metabolites.

A novel actinobacterium, strain YIM 96748T, was isolated from a saline soil sample collected from the south bank of Aiding Lake in Xinjiang Province, Northwest China. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain YIM 96748T is closely related to Amycolatopsis cihanbeyliensis BNT52T (98.9%) and Amycolatopsis jiangsuensis KLBMP 1262T (97.2%). The DNA–DNA relatedness between strain YIM 96748T and its closest type strain A. cihanbeyliensis BNT52T was 59.6%. The average nucleotide identity between strain YIM 96748T and its neighbor strain was 88.97%. Based on the genotypic and phenotypic characteristics, it is concluded that strain YIM 96748T represents a novel species of the genus Amycolatopsis, whose name was proposed as Amycolatopsis aidingensis sp. nov. The type strain is YIM 96748T. To investigate the biosynthetic potential of producing secondary metabolites, the complete genome of YIM 96748T was sequenced and analyzed. The complete genome sequence of YIM 96748T consists of a 7,657,695-bp circular chromosome, comprising 7,162 predicted genes with a DNA G + C content of 70.21 mol%. Fifty-one putative biosynthetic gene clusters of secondary metabolites were found, including the antibacterial/antitumor agent TLN-05220, the antibacterial agent nocardicin A, the antifungal agent nystatin A1, and the osmolyte ectoine. The investigation of the secondary metabolites of A. aidingensis YIM96748T led to the discovery of two new phenylpropyl acetate enantiomers, amycoletates A (1) and B (2), and five known compounds: 4-hydroxy phenethyl acetate (3), 2-p-acetoxyphenylethanol (4), (S)-ethyl indole-3-lactate (5), (R)-ethyl indole-3-lactate (6), and p-hydroxybenzoic acid (7). One of the gene clusters 14, 36, and 43, which contain a single module of polyketide synthase, might be responsible for the biosynthesis of compounds 1 and 2 from compound 7 as a precursor. Further studies, including the one strain many compounds approach (OSMAC) and genetic modification, are needed to explore novel compounds from this talented halophilic Amycolatopsis strain.

Penaeicolahalotolerans gen. nov., sp. nov., a novel bacterium of the family Cyclobacteriaceae isolated from a shrimp pond.

A Gram-stain-negative, non-motile, rod-shaped, aerobic bacterium (designated as LMIT005T) was isolated from shrimp ponds in Shantou, China. The new isolate was characterized taxonomically using a polyphasic approach. Based on 16S rRNA gene sequence analysis, strain LMIT005T was found to be affiliated with the family Cyclobacteriaceae of the order Cytophagales while appearing as a distinct lineage. The 16S rRNA gene sequence similarity between strain LMIT005T and Algoriphagus yeomjeoni KCTC 12309T, the closest type strain in the family, was 91.3 %. Strain LMIT005T grew optimally at 25 °C, pH 7 and in the presence of 2.0 % (w/v) NaCl. The DNA G+C content (data from genome sequence) was 40.5 mol%. Compared with reference strain A. yeomjeoni KCTC 12309T, the average nucleotide identity (ANI) of LMIT005T was 70 %. The sole respiratory quinone of LMIT005T was menaquinone (MK-7), and the major fatty acids were summed feature 3 (C16 : 1 ω6c / C16 : 1 ω7c). The polar lipids of strain LMIT005T were mainly composed of phosphatidylethanolamine, phosphatidylcholine, two unidentified amino lipids, two unidentified lipids, one unidentified glycolipid and one unidentified phospholipid. The draft genome of strain LMIT005T comprised 3 089 781 bp (3.09 Mb) nucleotides and 2773 genes. Antimicrobial resistant-related genes (blal, mexA, and mexb) were annotated in the genome of strain LMIT005T, which indicated that it might be able to resist β-lactam antibiotics. This was further verified by antimicrobial resistant test. Given its distinct genomic, morphological, and physiological differences from previously described type strains, strain LMIT005T is proposed as a representative of a novel genus of the family Cyclobacteriaceae, with the name Penaeicola halotolerans gen. nov., sp. nov. The type strain is LMIT005T (=KCTC 82616T=CICC 25047T).

Bioactivities of endophytic actinobacteria inhabiting Artemisia herba-alba emphasizing differences from free-living strains.

The endophytic actinobacteria associated with Artemisia herba-alba (synonym: Seriphidium herba-alba) are highly diverse. This study aimed to illustrate the extent of their differences from the free-living actinobacteria in the surrounding environment. A selection of eighteen actinobacteria inhabiting A. herba-alba were compared with twenty and ten actinobatceria isolates from the surrounding desert and groundwater, respectively, representing six genera. Antagonistic and enzymatic activities, plant growth-promoting traits, and the occurrence of biosynthetic genes were compared among the isolates. Data were analyzed statistically using principal component analysis (PCA) and were visualized using heat map. Endophytic strains showed higher antimicrobial activity and production of plant growth promoters compared to desert and groundwater strains. Polyketide synthase and non-ribosomal peptide synthetase gene clusters were detected at higher frequencies in the endophytic strains (8 and 11 strains, respectively) than the desert strains (1 and 2 strains, respectively). In contrast, both gene clusters were not detected in the groundwater strains. The PCA revealed unique metabolic characteristics of the endophytes. The heatmap clustered the endophytic strains apart from the free-living strains, indicating distinctive qualitative and quantitative bioactivities. Analysis of 16S rRNA genes confirmed the chemotaxonomic identity of all but two strains, with > 94.5% similarity. Six endophytes displayed < 99.5% similarity with their closest type strains, which might indicate species novelty. This study provides an evidence of functional differences and possible species novelty of the endophytic actinobacteria inhabiting A. herba-alba, compared with the free-living species.

Flavobacterium erciyesense sp. nov., a putative non-pathogenic fish symbiont.

During a study aiming at isolation and genomic characterization of non-pathogenic fish symbionts, strain F-328T was isolated from skin mucus of healthy-seeming rainbow trout (Oncorhynchus mykiss) and subjected to polyphasic characterization, including a comprehensive genome analysis. Strain F-328T was Gram stain negative, none-gliding, strictly aerobic, and rod shaped. The 16S rRNA gene sequence of strain F-328T exhibited the highest level of identity (98.9%) with F. turcicum F-339T. The major fatty acids were iso-C15:0, C15:1 ω6c, and summed feature 3 (C16:1 ω7c, C16:1 ω6c). The polar lipid profile consisted mainly of phosphatidylethanolamine and aminolipids, while the predominant menaquinone was MK-6. The DNA G + C content and genome size of the strain were 35.3% and 3.4Mb, respectively. Strain F-328T shows 93.8% average nucleotide identity and 53% digital DNA-DNA hybridization identity with the closest type strain F. turcicum F-339T. In addition, strain F-328T was found to carry antimicrobial resistance genes, which confer resistance to several antimicrobials, including aminoglycoside, macrolides, and streptogramin. Differential phenotypic properties, together with the phylogenetic inference, demonstrate that strain F-328T should be classified as a novel species of the genus Flavobacterium for which the name Flavobacterium erciyesense sp. nov. is proposed, with F-328T as the type strain (= JCM 34201T = KCTC 82261T).