- Volume 71, Issue 4, 2021

A bacterial strain designated RZ02T was isolated from surface seawater collected from the Yellow Sea in PR China and characterized by polyphasic taxonomy. Cells of strain RZ02T were Gram-stain-negative, aerobic, non-motile, catalase- and oxidase-positive rods forming ochre-pigmented colonies. Growth occurred at 7–36 °C (optimum, 30 °C), at pH 6.0–9.0 (optimum, pH 7.0) and with 1–5 % (optimum, 2 %) NaCl. The major cellular fatty acids (>10 %) of strain RZ02T were summed feature 8 (C18 : 1  ω6c and/or C18 : 1  ω7c), summed feature 3 (C16 : 1  ω7c and/or C16 : 1  ω6c) and C16 : 0. The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, diphosphatidylglycerol and sphingoglycolipid. The genome size of strain RZ02T was 2.79 Mbp with a G+C content of 55.5 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain RZ02T was mostly related to Pontixanthobacter luteolus SW-109T and Pontixanthobacter aestiaquae HDW-31T (97.3 and 97.1% sequence similarity, respectively), and formed a phyletic lineage with members of the genus Pontixanthobacter . The phylogenetic analysis based on the up-to-date bacterial core gene sequences confirmed that strain RZ02T clustered within the genus Pontixanthobacter . The average nucleotide identity and in silico DNA–DNA hybridization values between strain RZ02T and P. luteolus SW-109T and P. aestiaquae HDW-31T were 72.8 and 72.9 % and 18.7 and 18.5%, respectively. Based on these evidences, strain RZ02T is proposed to represent a novel species of the genus Pontixanthobacter under the name Pontixanthobacter rizhaonensis sp. nov. The type strain is RZ02T (=KCTC 62828T=MCCC 1K04521T). In addition, based on the results of whole genome analyses, proposals of Pseudopontixanthobacter gen. nov., Pseudopontixanthobacter confluentis comb. nov. and Pseudopontixanthobacter sediminis comb. nov. are also included.

A Gram-stain-negative, ovoid-shaped, motile and strictly aerobic bacterium, designated ZQ172T, was isolated from marine sediment sampled on Zhoushan Island located in the East China Sea. Strain ZQ172T grew optimally at temperatures of 25–30 °C, at NaCl concentration of 2.0 % (w/v) and at pH 7.0–8.5. Catalase and oxidase activities, urease, and nitrate reduction were positive. Indole production, methyl red reaction, H2S production and hydrolysis of gelatin, starch, casein and Tweens 20, 40, 60 and 80 were negative. The major cellular fatty acid was summed feature 8 (C18 : 1  ω7c and/or C18 : 1  ω6c). The only respiratory quinone was ubiquinone-10. The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and phosphatidylcholine. Comparative analysis of the 16S rRNA gene sequence showed highest similarities to Shimia aestuarii JC2049T (97.5 %), Shimia abyssi JAMH 043T (97.5 %) and Shimia thalassica CECT 7735T (97.3 %). Phylogenetic analyses indicated that strain ZQ172T clustered with the genus Shimia and was closely related to Shimia thalassica CECT 7735T. The average nucleotide identity and digital DNA–DNA hybridization values between strain ZQ172T and related species of the genus Shimia were well below the threshold limit for prokaryotic species delineation. The DNA G+C content was 59.6 mol%. Based on its phenotypic, chemotaxonomic and genotypic data, strain ZQ172T is considered to be a representative of a novel species in the genus Shimia , for which the name Shimia sediminis sp. nov. is proposed. The type strain is ZQ172T (=KCTC 62578T=MCCC 1K03531T).

A novel Gram-negative, facultatively anaerobic, non-spore-forming and rod-shaped bacterial strain (KUDC3025T) was isolated from rhizospheric soil of Artemisia japonica subsp. littoricola collected from the Dokdo Islands, Republic of Korea and bacterial strain MYb239 was isolated from compost from Kiel, Germany. Phylogenetic analysis based on 16S rRNA gene sequences, multilocus genes (atpD, gyrB, infB and rpoB), and whole-genome sequences indicated that both strains belonged to the genus Serratia and were most closely related to Serratia rubidaea KCTC 2927T. The average nucleotide identity values based on blast and MUMmer, tetranucleotide usage pattern and genome-based digital DNA–DNA hybridization values were all below the 95.0 %/95.0 %/0.998/70 % cutoff points. The genome G+C content was 58.0 mol%. The cellular quinone content contained ubiquinone-8 and the major components in the fatty acid profile were C16 : 0, C17 : 0 cyclo and C14 : 0. The polar lipid profile included diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, four unknown amino lipids, two unknown phospholipids and an unknown lipid. Based on phenotypic, chemotaxonomic and genotypic data, strain KUDC3025T (DSM 106578T=CGMCC 1.18473T) and MYb239 represents a novel species, for which the name Serratia rhizosphaerae sp. nov. is proposed. Furthermore, strain KUDC3025T was able to suppress disease symptoms by priming the plant defence system components, including the salicylic acid and ethylene pathways, furthering our understanding of Serratia as potential plant growth promoting bacteria.

A novel Gram-stain-negative, facultatively anaerobic, rod-shaped bacterium, designated as D167-6-1T, was isolated from deep-sea sediment collected from the Pacific Ocean. The cells were catalase- and oxidase-positive, and motile by means of peritrichous flagella. Growth occurred at NaCl concentrations ranging from 0 to 19 % (optimum, 2–8 %, w/v), from pH 6 to 11 (optimum, 7–8) and at temperatures between 4 and 45 °C (optimum, 33 °C). Phylogenetic analysis based on 16S rRNA, gyrB and rpoD gene sequences and its genome sequence revealed that strain D167-6-1T formed a monophyletic branch within the genus Halomonas and was most closely related to Halomonas saliphila , Halomonas pellis , Halomonas kenyensis , Halomonas daqingensis , Halomonas desiderata and Halomonas lactosivorans (with 98.5, 98.5, 98.4, 98.1, 97.5 and 97.8 % 16S rRNA sequence similarity, respectively). The complete genome size of strain D167-6-1T was 4.49 Mb, with a DNA G+C content of 62.8 mol%. The estimated averagenucleotide identity and DNA–DNA hybridization values between strain D167-6-1T and other closely related species were 77.59–85.35 % and 22.0–30.6 %, respectively. The principal cellular fatty acids (>5 %) were C18 : 1  ω7c, C16 : 0, C19 : 0 cyclo ω8c, summed feature 3 (C16 : 1  ω7c/C16 : 1  ω6c) and C17 : 0 cyclo. The polar lipids were identified as diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, an unidentified aminolipid, aminophospholipid and two unidentified phospholipids. The predominant respiratory quinones were Q-9 and Q-8. The combined genotypic and phenotypic data show that strain D167-6-1T represents a novel species of the genus Halomonas , for which the name Halomonas diversa sp. nov. is proposed, with the type strain D167-6-1T (=MCCC 1A13316T=KCTC 72441T).

A Gram-stain-negative, aerobic, flagellated, non-spore-forming, rod-shaped bacterium, named B2R-29T, was isolated from water collected from a crater lake on Da Hinggan mountain, PR China. Strain B2R-29T was oxidase- and catalase-positive. On the basis of the results of 16S rRNA gene sequence analyses, strain B2R-29T clearly belonged to the family Oxalobacteraceae , class Betaproteobacteria and showed the highest similarity to Undibacterium oligocarboniphilum EM1T (97.4 %) and to the other species of Undibacterium (less than 96.8 %). In the phylogenetic tree, strain B2R-29T formed a clade with U. oligocarboniphilum EM1T and Undibacterium squillarum CMJ-9T, indicating that is a member of the genus Undibacterium . Digital DNA–DNA hybridization and average nucleotide identity analyses were performed and the values between strain B2R-29T and its closely related Undibacterium species were less than 75.1 % and 16.9 %, respectively. The chemotaxonomic data of B2R-29T were as follows: major uniquinone, Q-8; predominant polar lipids, phosphatidylethanolamine, diphosphatidylglycerol and phosphatidylglycerol; major fatty acids, C16 : 0 and summed feature 3 (C16 : 1  ω7c / C16 : 1  ω6c); predominant polyamines, putrescine, 2-hydroxyputrescine and spermidine. The DNA G+C content was 51.7 mol% from the genomic sequencing data. In accordance with the phenotypic, physiological and chemotaxonomic properties mentioned above, strain B2R-29T represents a novel species of the genus Undibacterium for which the name Undibacterium crateris sp. nov. is proposed. The type strain is B2R-29T (=CGMCC 1.13792T=KCTC 72018T).

Two isolates from Canada and the USA (UAMH 7122 and UAMH 7211, respectively) previously identified as Stachybotrys eucylindrosporus were studied by morphology and six-locus phylogeny (cmdA, ITS, LSU, rpb2, tef1α and tub2). UAMH 7122 and UAMH 7211 are morphologically related but phylogenetically distinct from Striatibotrys eucylindrosporus (≡Stachybotrys eucylindrosporus) and Str. rhabdosporus. Hence, UAMH 7122 and UAMH 7211 are described as a new species, Striatibotrys neoeucylindrosporus sp. nov. with UAMH 7211 as the holotype. The characters of this species include some phialides proliferating by holoblastic extension of phialides and conidia clavate, subcylindrical or cylindrical ellipsoid, or dumbbell-shaped, dark brown to olivaceous grey when mature, longitudinally striate, 10.3–12.3×3–3.8 µm. A key to the species of Striatibotrys is provided.

During an investigation of the yeast communities associated with wild fruit shrubs in Dagestan (Caucasus, Russia), four fermenting ascospore-producing yeast strains were isolated from leaves of the Georgian honeysuckle (Lonicera iberica M. Bieb.) and from soil underneath this plant. Phylogenetic analyses based on concatenated sequences of the ITS region and D1/D2 domains of the large subunit rRNA gene and concatenated sequences of the ribosomal DNA cystron, RPB2 and TEF1 genes showed that the isolated strains represented a new species of the genus Zygotorulaspora. The new species was placed in the basal position to other species of the clade and close to Zygotorulaspora mrakii. Based on the results of phylogenetic analyses and the phenotypic characteristics of the four studied strains, a novel species is described, for which the name Zygotorulaspora dagestanica sp. nov. is proposed. The holotype is KBP Y-4591T, three metabolically inactive cryopreserved isotype cultures are DSM 100088, VKM Y-3060 and VKPM Y-4318. The MycoBank number is MB 838285.