Comamonas endophytica sp. nov., a novel indole acetic acid producing endophyte isolated from bamboo in China.

Two novel indole acetic acid-producing strains, 5MLIRT and D4N7, were isolated from Indosasa shibataeoides in Yongzhou, Hunan province, and Phyllostachys edulis in Hangzhou, Zhejiang province, respectively. Based on their 16S rRNA sequences, strains 5MLIRT and D4N7 were closely related to Comamonas antarcticus 16-35-5T (98.4 % sequence similarity), and the results of 92-core gene phylogenetic trees showed that strains 5MLIRT and D4N7 formed a phylogenetic lineage within the clade comprising Comamonas species. The complete genome size of strain 5MLIRT was 4.49 Mb including two plasmids, and the DNA G+C content was 66.5 mol%. The draft genome of strain D4N7 was 4.26 Mb with 66.7 mol% G+C content. The average nucleotide identity and digital DNA-DNA hybridization values among strain 5MLIRT and species in the genus Comamonas were all below the species delineation threshold. The colonies of strain 5MLIRT and D4N7 were circular with regular margins, convex, pale yellow and 1.0-2.0 mm in diameter when incubated at 30 °C for 3 days. Strains 5MLIRT and D4N7 grew optimally at 30 °C, pH 7.0 and 1.0 % NaCl. The respiratory isoprenoid quinone was ubiquinone-8. The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. Polyphasic analyses indicated that strains 5MLIRT and D4N7 could be distinguished from related validly named Comamonas species and represent a novel species of the genus Comamonas, for which the name Comamonas endophytica sp. nov. is proposed. The type strain is 5MLIRT (=ACCC 62069T=GDMCC 1.2958T=JCM 35331T).

Streptomyces herbicida sp. nov., a novel actinomycete with antibacterial and herbicidal activity isolated from soil.

A novel actinobacterial strain (NEAU-HV9T) showing antibacterial activity against Ralstonia solanacearum and herbicidal activity against Amaranthus retroflexus L. was isolated from soil sampled in Bama yao Autonomous County, Hechi City, Guangxi Zhuang Autonomous Region. The strain is aerobic and Gram-positive. Phylogenetic analysis based on 16S rRNA gene sequence indicated that strain NEAU-HV9T belonged to the genus Streptomyces and showed high 16S rRNA sequence similarity to Streptomyces panaciradicis 1MR-8T (98.90 %), Streptomyces sasae JR-39T (98.89 %) and Streptomyces barringtoniae JA03T (98.69 %) and less than 98.5 % similarity to other members of the genus Streptomyces. The cell wall of strain NEAU-HV9T contained ll-diaminopimelic acid and the whole-cell hydrolysates were galactose, mannose and ribose. The predominant menaquinones were composed of MK-9(H2) and MK-9(H8). The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and phosphatidylinositol. The major fatty acids were C16 : 0, iso-C16 : 0 and C17 : 1 ω8c. The genomic DNA G+C content of strain NEAU-HV9T was 70.6 mol%. Furthermore, the strain could be clearly distinguished from its closely related type strains by the combination of DNA-DNA hybridization results and some phenotypic characteristics. Meanwhile, strain NEAU-HV9T displayed herbicidal activity. Therefore, strain NEAU-HV9T represents a novel species within the genus Streptomyces, for which the name Streptomyces herbicida sp. nov. is proposed, with strain NEAU-HV9T (=CCTCC AA 2019088T=DSM 113364T) as the type strain.

Description of six new cyanobacterial species from soil biocrusts on San Nicolas Island, California, in three genera previously restricted to Brazil.

As the taxonomic knowledge of cyanobacteria from terrestrial environments increases, it remains important to analyze biodiversity in areas that have been understudied to fully understand global and endemic diversity. This study was completed as part of a larger algal biodiversity study of the soil biocrusts of San Nicholas Island, California, USA. Among the taxa isolated were several new species in three genera (Atlanticothrix, Pycnacronema, and Konicacronema) which were described from, and previously restricted to, Brazil. New taxa are described herein using a polyphasic approach to cyanobacterial taxonomy that considers morphological, molecular, ecological, and biogeographical factors. Morphological data corroborated by molecular analysis including sequencing of the 16S rRNA gene, and the associated 16S-23S ITS rRNA region was used to delineate three new species of Atlanticothrix, two species of Pycnacronema, and one species of Konicacronema. The overlap of genera from San Nicolas Island and Brazil suggests that cyanobacterial genera may be widely distributed across global hemispheres, whereas the presence of distinct lineages may indicate that this is not true at the species level. Our data suggest that based upon global wind patterns, cyanobacteria in both Northern and Southern hemispheres of the Americas may have a more recent common ancestor in Northern Africa, but this common ancestry is distant enough that speciation has occurred since transatlantic dispersal.

Igniting taxonomic curiosity: The amazing story of Amazonocrinis with the description of a new genus Ahomia gen. nov. and novel species of Ahomia, Amazonocrinis, and Dendronalium from the biodiversity-rich northeast region of India.

Five cyanobacterial strains exhibiting Nostoc-like morphology were sampled from the biodiversity hotspots of the northeast region of India and characterized using a polyphasic approach. Molecular and phylogenetic analysis using the 16S rRNA gene indicated that the strains belonged to the genera Amazonocrinis and Dendronalium. In the present investigation, the 16S rRNA gene phylogeny clearly demarcated two separate clades of Amazonocrinis. The strain MEG8-PS clustered along with Amazonocrinis nigriterrae CENA67, which is the type strain of the genus. The other three strains ASM11-PS, RAN-4C-PS, and NP-KLS-5A-PS clustered in a different clade that was phylogenetically distinct from the Amazonocrinis sensu stricto clade. Interestingly, while the 16S rRNA gene phylogeny exhibited two separate clusters, the 16S-23S ITS region analysis did not provide strong support for the phylogenetic observation. Subsequent analyses raised questions regarding the resolving power of the 16S-23S ITS region at the genera level and the associated complexities in cyanobacterial taxonomy. Through this study, we describe a novel genus Ahomia to accommodate the members clustering outside the Amazonocrinis sensu stricto clade. In addition, we describe five novel species, Ahomia kamrupensis, Ahomia purpurea, Ahomia soli, Amazonocrinis meghalayensis, and Dendronalium spirale, in accordance with the International Code of Nomenclature for algae, fungi, and plants (ICN). Apart from further enriching the genera Amazonocrinis and Dendronalium, the current study helps to resolve the taxonomic complexities revolving around the genus Amazonocrinis and aims to attract researchers to the continued exploration of the tropical and subtropical cyanobacteria for interesting taxa and lineages.

Cyanobacterial Harmful Algal Mats (CyanoHAMs) in tropical rivers of central Mexico and their potential risks through toxin production.

Cyanobacteria inhabiting lotic environments have been poorly studied and characterized in Mexico, despite their potential risks from cyanotoxin production. This article aims to fill this knowledge gap by assessing the importance of benthic cyanobacteria as potential cyanotoxin producers in central Mexican rivers through: (i) the taxonomic identification of cyanobacteria found in these rivers, (ii) the environmental characterization of their habitats, and (iii) testing for the presence of toxin producing genes in the encountered taxa. Additionally, we introduce and discuss the use of the term "CyanoHAMs" for lotic water environments. Populations of cyanobacteria were collected from ten mountain rivers and identified using molecular techniques. Subsequently, these taxa were evaluated for genes producing anatoxins and microcystins via PCR. Through RDA analyses, the collected cyanobacteria were grouped into one of three categories based on their environmental preferences for the following: (1) waters with high ionic concentrations, (2) cold-temperate waters, or (3) waters with high nutrient enrichment. Populations from six locations were identified to genus level: Ancylothrix sp., Cyanoplacoma sp., and Oxynema sp. The latter was found to contain the gene that produces anatoxins and microcystins in siliceous rivers, while Oxynema tested positive for the gene that produces microcystins in calcareous rivers. Our results suggest that eutrophic environments are not necessarily required for toxin-producing cyanobacteria. Our records of Compactonostoc, Oxynema, and Ancylothrix represent the first for Mexico. Four taxa were identified to species level: Wilmottia aff. murrayi, Nostoc tlalocii, Nostoc montejanii, and Dichothrix aff. willei, with only the first testing positive using PCR for anatoxin and microcystin-producing genes in siliceous rivers. Due to the differences between benthic growths with respect to planktonic ones, we propose the adoption of the term Cyanobacterial Harmful Algal Mats (CyanoHAMs) as a more precise descriptor for future studies.

Sphingomicrobium sediminis sp. nov., isolated from marine sediment in the Republic of Korea.

A Gram-stain-negative, rod-shaped, bright-orange coloured bacterium without flagellum, designated as strain GRR-S6-50T, was isolated from a tidal flat of Garorim bay, Taean-gun, Chungcheongbuk-do, Republic of Korea. Cells grew aerobically at 20-37 °C (optimum, 30 °C), pH 7.0-10.0 (optimum, pH 7.0) and with 1-5 % (w/v) NaCl (optimum, 3 %). The 16S rRNA gene sequence analysis demonstrated that strain GRR-S6-50T was closely related to Sphingomicrobium aestuariivivum AH-M8T with a sequence similarity of 97.80 % followed by Sphingomicrobium astaxanthinifaciens CC-AMO-30BT (97.44 %), Sphingomicrobium marinum CC- AMZ-30MT (97.16 %), Sphingomicrobium arenosum CAU 1457T (96.37 %), Sphingomicrobium flavum CC-AMZ-30NT (95.31 %) and Sphingomicrobium lutaoense CC-TBT-3T (95.23 %). The average nucleotide identity and digital DNA-DNA hybridization values with related strains ranged from 74.5 to 77.3% and 21.1 to 35.0 %, respectively. The G+C content of strain GRR-S6-50T was 63.30 mol%. The strain has ubiquinone-10 as the predominant respiratory quinone and the major fatty acids were C18 : 3 ω6c (54.57 %) and C17 : 1 ω6c (10.58 %). The polar lipids consisted of phosphatidylethanolamine, phosphatidylglycerol, three unidentified lipids and one glycolipid. On the basis of the results of phylogenetic, phenotypic and chemotaxonomic studies, strain GRR-S6-50T is regarded to represent a novel species within the genus Sphingomicrobium, for which the name Sphingomicrobium sediminis sp. nov. (KACC 22562T=KCTC 92123T=JCM 35084T) is proposed.

Reclassification of Streptomyces griseostramineus as a synonym of Streptomyces griseomycini based on a polyphasic taxonomic approach.

In the present work, the taxonomic relationship between Streptomyces griseomycini and Streptomyces griseostramineus was reevaluated by a comprehensive comparison of phenotypic, chemotaxonomic and genomic characteristics, as well as phylogeny. Phylogenetic analysis based on 16S rRNA gene sequences and whole-genome sequences indicated that Streptomyces griseostramineus JCM 4385T was clustered together with Streptomyces griseomycini JCM 4382T, suggesting they were closely related to each other. However, the average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between their genomes were 99.7 and 97.5 %, respectively, much larger than the recommended threshold values of 96.7 % ANI and 70 % dDDH for Streptomyces species delineation. In addition, the morphological, cultural, physio-biochemical and chemotaxonomic features of these two species further demonstrated that they belonged to the same genome species. Based on the above data and the principle of priority in nomenclature, it is proposed that S. griseostramineus (Preobrazhenskaya et al. 1957) Pridham et al. 1958 (Approved Lists 1980) is a later heterotypic synonym of S. griseomycini (Preobrazhenskaya et al. 1957) Pridham et al. 1958 (Approved Lists 1980).

Description of Jidongwangia harbinensis gen. nov. sp. nov.

During our previous study, strain NEAU-J3T was classified as representing a novel genus 'Wangella' within the family Micromonosporaceae. Nevertheless, it is a great pity the name cannot be validated as the proposed genus name is illegitimate (Principle 2 of the ICNP). In this study, we describe Jidongwangia as a novel genus within the family Micromonosporaceae and a polyphasic approach was used to provide evidence to support the classification. The G+C content of the genomic DNA of the type strain is 71.6 %. Digital DNA-DNA hybridization and average nucleotide identity (ANI) values could be used to differentiate NEAU-J3T from its related type strains. The phenotypic, genetic and chemotaxonomic data also indicated that NEAU-J3T occupies a branch separated from those of known genera in the family Micromonosporaceae. Therefore, NEAU-J3T represents a novel species of a novel genus in the family Micromonosporaceae, for which the name Jidongwangia harbinensis gen. nov., sp. nov. is proposed. The type strain of Jidongwangia harbinensis is NEAU-J3T (= CGMCC 4.7039T = DSM 45747T).

Tumebacillus lacus sp. nov., isolated from lake water.

A Gram-stain-positive, aerobic, rod-shaped, endospore-forming and motile, by means of peritrichous flagella, bacterium, designated DT12T, was isolated from a lake water sample from Datun Lake of Yunnan Province, PR China. The results of phylogenetic analysis based on 16S rRNA gene sequence and the concatenated alignment of 120 ubiquitous single-copy proteins indicated that the novel strain represented a member of the genus Tumebacillus. The sole quinone was menaquinone-7 and the cell-wall peptidoglycan was type-A1γ. The major fatty acids (>10 %) of the novel strain were iso-C15 : 0 and anteiso-C15 : 0, while the major polar lipids were phosphatidylmonomethylethanolamine, phosphatidylethanolamine and phosphatidylglycerol. The results of phylogenetic analyses combined with phylogenetic, phenotypic and chemotaxonomic features, strongly supported the hypothesis that the strain should be classified as representing a novel species of the genus Tumebacillus, for which the name Tumebacillus lacus sp. nov. is proposed. The type strain is DT12T (=KCTC 33958T= MCCC 1H00320T). The genomic analysis revealed that DT12T has various biosynthetic gene clusters for secondary metabolites, and members of the genus Tumebacillus may represent a promising source of new natural products. Our study also showed that members of the genus Tumebacillus are widely distributed in a variety of habitats throughout the globe, particularly in soils, human-, animal- and plant-associated environments. Members of the genus Tumebacillus may have an important role in the growth and health of humans, plants and animals.

Marinicella marina sp. nov. and Marinicella gelatinilytica sp. nov., isolated from coastal sediment, and genome analysis and habitat distribution of the genus Marinicella.

Three Marinicella strains, X102, S1101T and S6413T, were isolated from sediment samples from different coasts of Weihai, PR China. All strains were Gram-stain-negative, rod-shaped and non-motile. The predominant fatty acids of all strains were iso-C15 : 0 and summed feature 3 (C16 : 1 ω7c/C16 : 1 ω6c) and the major polar lipids comprised phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. Strains X102 and S1101T shared 100 % 16S rRNA gene sequence similarity, and strains S1101T/X102 and S6413T had 95.4 % similarity. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between strains S1101T and X102 were 99.9 and 99.2 %, respectively. Strain S1101T had ANI values of 69.1-72.9% and dDDH values of 17.9-20.5 % to members of the genus Marinicella. Strain S6413T had ANI values of 69.1-77.5% and dDDH values of 17.6-21.5 % to members of the genus Marinicella. The results of phylogenetic and comparative genomic analysis showed that the three strains belong to two novel species in the genus Marinicella, and strains X102 and S1101T represented one novel species, and strain S6413T represented another novel species. The result of BOX-PCR and genomic analysis showed that X102 and S1101T were not the same strain. The phylogenetic analyses and genomic comparisons, combined with phylogenetic, phenotypic and chemotaxonomic features, strongly supported that the three strains should be classified as representing two novel species of the genus Marinicella, for which the names Marinicella marina sp. nov. and Marinicella gelatinilytica sp. nov. are proposed, respectively. The type strains of the two novel species are S1101T (=KCTC 92642T=MCCC 1H01359T) and S6413T (=KCTC 92641T=MCCC 1H01362T), respectively. In addition, all previously described isolates of Marinicella were isolated from marine environments, but our study showed that Marinicella is also distributed in non-/low-saline habitats (e.g. animal gut, soil and indoor surface), which broadened our perception of the environmental distribution of Marinicella.

An updated classification of cyanobacterial orders and families based on phylogenomic and polyphasic analysis.

Cyanobacterial taxonomy is facing a period of rapid changes thanks to the ease of 16S rRNA gene sequencing and established workflows for description of new taxa. Since the last comprehensive review of the cyanobacterial system in 2014 until 2021, at least 273 species in 140 genera were newly described. These taxa were mainly placed into previously defined orders and families although several new families were proposed. However, the classification of most taxa still relied on hierarchical relationships inherited from the classical morphological taxonomy. Similarly, the obviously polyphyletic orders such as Synechococcales and Oscillatoriales were left unchanged. In this study, the rising number of genomic sequences of cyanobacteria and well-described reference strains allowed us to reconstruct a robust phylogenomic tree for taxonomic purposes. A less robust but better sampled 16S rRNA gene phylogeny was mapped to the phylogenomic backbone. Based on both these phylogenies, a polyphasic classification throughout the whole phylum of Cyanobacteria was created, with ten new orders and fifteen new families. The proposed system of cyanobacterial orders and families relied on a phylogenomic tree but still employed phenotypic apomorphies where possible to make it useful for professionals in the field. It was, however, confirmed that morphological convergence of phylogenetically distant taxa was a frequent phenomenon in cyanobacteria. Moreover, the limited phylogenetic informativeness of the 16S rRNA gene, resulting in ambiguous phylogenies above the genus level, emphasized the integration of genomic data as a prerequisite for the conclusive taxonomic placement of a vast number of cyanobacterial genera in the future.

Description of four new filamentous cyanobacterial taxa from freshwater habitats in the Azores Archipelago.

Simple filamentous cyanobacteria comprise a diverse and polyphyletic group of species, primarily in the orders Leptolyngbyales and Oscillatoriales, that need more sampling to improve their taxonomy. Oceanic islands, such as the Azores archipelago, present unique habitats and biogeographic conditions that harbor an unknown range of diversity of microorganisms. Filamentous cyanobacteria isolated from aquatic habitats in the Azores and maintained in the BACA culture collection were described using morphology, both light and transmission electron microscopy, ecology, and genetic data of the 16S rRNA gene sequences and 16S-23S Internal Transcribed Spacer (ITS) rRNA region secondary structure. Our analyses revealed two new monophyletic genera: Tumidithrix elongata gen. sp. nov. (Pseudanabaenaceae) and Radiculonema aquaticum gen. sp. nov. (Leptolyngbyaceae). In addition, two new species Leptodesmis lacustris sp. nov. (Leptolyngbyaceae) and Pycnacronema lacustrum sp. nov. (Wilmottiaceae) are reported as the first aquatic species for these genera. The description of these new taxa and the genetic study of an isolate of Leptodesmis alaskaensis from the Azores followed the polyphasic approach, identifying diacritical features. Our results reinforce the need for taxonomic studies on cyanobacteria from less-studied habits and geographic regions, which have a potential for new taxa description.

Chlorophyll f production in two new subaerial cyanobacteria of the family Oculatellaceae.

Chlorophyll (Chl) f was recently identified in a few cyanobacteria as the fifth chlorophyll of oxygenic organisms. In this study, two Leptolyngbya-like strains of CCNU0012 and CCNU0013 were isolated from a dry ditch in Chongqing city and a brick wall in Mount Emei Scenic Area in China, respectively. These two strains were described as new species: Elainella chongqingensis sp. nov. (Oculatellaceae, Synechococcales) and Pegethrix sichuanica sp. nov. (Oculatellaceae, Synechococcales) by the polyphasic approach based on morphological features, phylogenetic analysis of 16S rRNA gene and secondary structure comparison of 16S-23S internal transcribed spacer domains. Both strains produced Chl a under white light (WL) but additionally induced Chl f synthesis under far-red light (FRL). Unexpectedly, the content of Chl f in P. sichuanica was nearly half that in most Chl f-producing cyanobacteria. Red-shifted phycobiliproteins were also induced in both strains under FRL conditions. Subsequently, additional absorption peak beyond 700 nm in the FRL spectral region appeared in these two strains. This is the first report of Chl f production induced by FRL in the family Oculatellaceae. This study not only extended the diversity of Chl f-producing cyanobacteria but also provided precious samples to elucidate the essential binding sites of Chl f within cyanobacterial photosystems.

Albertania and Egbenema gen. nov. from Nigeria and the United States, expanding biodiversity in the Oculatellaceae (cyanobacteria).

Knowledge of the tropical terrestrial cyanobacterial flora from the African continent is still limited. Of 31 strains isolated from soil and subaerial samples collected in Lagos State, Nigeria, three were found to be in the Oculatellaceae, including two species in a new genus. Subsequently, isolates from microbial mats in White Sands National Park in New Mexico, United States, and from a rock near the ocean in Puerto Rico, United States, were found to belong to the new genus as well. Cyanobacterial isolates were characterized microscopically, sequenced for the 16S rRNA gene and associated ITS region, and phylogenetically analyzed. Egbenema gen. nov., with three new species, as well as two new species of Albertania were differentiated from all other Oculatellaceae. Both genera belong to a supported clade within the Oculatellaceae that includes Trichotorquatus and Komarkovaea. The two new species of Albertania, A. egbensis and A. latericola, were from the same sample, but were evolutionarily separate based on 16S rRNA gene phylogenies, percent identity below the 98.7% threshold, and ITS rRNA percent dissimilarity >7.0%. Egbenema aeruginosum gen. et sp. nov. was phylogenetically separated from Trichotorquatus and Albertania but was in a clade with other strains belonging to Egbenema. The two Egbenema strains from the United States are here named Egbenema epilithicum sp. nov. and Egbenema gypsiphilum sp. nov. Our results support the hypothesis that further species discoveries of novel cyanobacteria will likely be made in soils and subaerial habitats, as these habitats continue to be studied, both in tropical and temperate biomes.

Olsenella intestinalis sp. nov., isolated from cow feces.

A Gram-stain-negative, anaerobic, non-motile, rod-shaped bacterium, designated as BGYT1T, was isolated from the feces of a cow in Andong, Republic of Korea. It was studied using a polyphasic method to determine its taxonomic position. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain BGYT1T formed a lineage within the genus Olsenella and was most closely related to O. umbonate KCTC 15140T (98.2%). The complete genome sequence of strain BGYT1T was 2,476,083 bp long with a G + C content of 66.9 mol% and contained 1835 genes and 8 contigs. The N50 value was 604,117 bp. There were 50 tRNAs, 6 rRNAs (5S, 16S, 23S), 1778 CDSs and 2 BGCs and 1 tmRNA. The values for ANI (76.8%), AAI (67.3%), and dDDH (22.2%) compared to the closest related species were all below the threshold for bacterial species delineation. In addition, genes encoding the cell wall degrading enzymes such as chitinases, ß-1,3 glucanases, and proteases were also detected. The strain was able to grow at pH 6.0-8.0 (optimum, pH 7.0), in the presence of 0.5-1.5% NaCl (optimum, 0.5%, w/v) and at the temperature range of 35-40 °C (optimum, 35 °C). The predominant fatty acids were C16:0 DMA (20.2%), C16:0 (20.2%), C18:0 (10.5%) and C18:1 cis 9 (17.0%). The polar lipids consisted of an unidentified phospholipid, four unidentified glycolipids and three unidentified lipids. Based on its phenotypic analyses, phylogenetic and physiological characteristics, strain BGYT1T represented a novel species within the genus Olsenella, for which the name Olsenella intestinalis sp. nov. is proposed. The type strain is BGYT1T (= KCTC 25379T = GDMCC 1.3011T).

Aurantiacibacter sediminis sp. nov., a marine bacterium isolated from a tidal flat.

A yellow-coloured bacterium, designated as strain JGD-13T, was isolated from a tidal flat in the Republic of Korea. Cells were Gram-stain-negative, aerobic, non-flagellated and rod-shaped. Growth was observed at 4-42 °C (optimum, 30 °C), at pH 6.0-12.0 (pH 7.0-8.0) and at 1-7 % (w/v) NaCl concentration (3 %). The 16S rRNA gene sequence analysis indicated that strain JGD-13T was closely related to Aurantiacibacter gangjinensis K7-2T with a sequence similarity of 98.2 %, followed by Aurantiacibacter aquimixticola JSSK-14T (98.1 %), Aurantiacibacter atlanticus s21-N3T (97.6 %), Aurantiacibacter zhengii V18T (97.6 %) and Aurantiacibacter luteus KA37T (97.5 %). The average nucleotide identity and digital DNA-DNA hybridization values with related strains were 70.3-76.2 % and 18.5-20.3 %. The genomic DNA G+C content was 60.2 mol%. Phylogenetic analysis using the maximum-likelihood method showed that strain JGD-13T formed a clade with A. aquimixticola JSSK-14T and A. gangjinensis K7-2T. The major fatty acids were summed feature 8 (39.7 %) and C17 : 1 ω6c (14.4 %). The predominant respiratory quinone was ubiquinone-10. The polar lipids were phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, one sphingoglycolipid and three unidentified lipids. On the basis of phylogenetic, phenotypic and chemotaxonomic characteristics, strain JGD-13T represents a novel species within the genus Aurantiacibacter, for which the name Aurantiacibacter sediminis JGD-13Tsp. nov. is proposed. The type strain is JGD-13T (=KCTC 72892T=KACC 21676T=JCM 33995T).

Insights into the phylogenetic inconsistencies of the genus Amazonocrinis and description of epilithic Amazonocrinis malviyae sp. nov. (Cyanobacteria, Nostocales) from Jammu and Kashmir, India.

A dark-coloured thin film of cyanobacteria growing on the bottom of a submerged stone was isolated from Basantgarh village in Udhampur district, Jammu and Kashmir, India. The isolated strain (designated 19C-PST) was characterized using a polyphasic approach. The strain exhibited typical Nostoc-like morphology with a characteristic feature of having heterocytes in series. The 16S rRNA gene phylogeny placed the strain at a well-supported and distinct node. Notably, the recently described genus, Amazonocrinis, on the addition of more 16S rRNA gene sequences, reflected a critical split, which proved to be stable and well supported in all phylogenetic analyses of the 16S rRNA gene. Interestingly, Amazonocrinis nigriterrae CENA67T (type species of the genus) clustered together with our strain 19C-PST in the 16S rRNA gene phylogenetic analysis while the rest of the members of the genus Amazonocrinis were placed at a separate and distant node. This clearly indicated that strain 19C-PST is a member of Amazonocrinis sensu stricto. However, the results of phylogenetic analysis of ITS sequences only, in strains purported to belong to Amazonocrinis did not agree with the 16S rRNA gene results and placed our strain 19C-PST in a sister clade to three strains that have not yet been speciated, UHCC 0702, NIES-4103 and SA22, with A. nigriterrae falling into a separate clade. Further, folded secondary structures of the D1-D1', V2, BoxB and V3 helices of strain 19C-PST were found to be significantly different from those of all the phylogenetically related taxa. The study revealed an interesting case where low taxon sampling and phylogenomic interpretations came across as points of attention in cyanobacterial taxonomy. Based on the morphological, phylogenetic, 16S-23S ITS secondary structure analyses, we describe our strain as Amazonocrinis malviyae sp. nov. in accordance with the International Code of Nomenclature for algae, fungi and plants. This work also illuminates the need for further research to resolve the taxonomic discrepancies among Amazonocrinis strains.

Catellatospora tritici sp. nov., a novel cellulase-producing actinobacterium isolated from rhizosphere soil of wheat (Triticum aestivum L.) and emended description of the genus Catellatospora.

A Gram-positive, cellulose-degrading actinobacterium, designed strain NEAU-YM18T, was isolated from rhizosphere soil of wheat (Triticum aestivum L.) sampled in Langfang, Hebei Province, PR China. The novel strain was characterized using a polyphasic approach. Morphological and chemotaxonomic characteristics confirmed that strain NEAU-YM18T belonged to the genus Catellatospora. Cells of strain NEAU-YM18T were observed to contain meso- and 3-hydroxy-diaminopimelic acids as diagnostic cell-wall amino acids. The acyl type of the cell-wall muramic acid was glycolyl. The whole-cell hydrolysates were xylose, glucose and ribose. The phospholipids consisted of diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylinositol. The major fatty acids were iso-C15 : 0, iso-C16 : 0, C18 : 1 ω9c and summed feature 5 (anteiso-C18 : 0/C18 : 2 ω6,9c). The menaquinones were MK-9(H4), MK-9(H6) and MK-9(H2). The DNA G+C content was 71.1 %. The results of 16S rRNA gene sequence and phylogenetic analyses indicated that strain NEAU-YM18T was closely related to Catellatospora chokoriensis 2-25(1)T (98.4 % 16S rRNA gene sequence similarity), Catellatospora vulcania NEAU-JM1T (98.3%) and Catellatospora sichuanensis H14505T (98.3 %) and formed a branch with C. sichuanensis H14505T. Furthermore, the whole genome phylogeny of strain NEAU-YM18T showed that the strain formed an independent clade. The digital DNA-DNA hybridization results between NEAU-YM18T and C. chokoriensis 2-25(1)T, C. vulcania NEAU-JM1T and C. sichuanensis H14505T were 25.0, 24.7 and 24.7 %, respectively, and the whole-genome average nucleotide identity values between them were 81.5, 81.4 and 81.4 %, respectively. These genetic results and some phenotypic characteristics could distinguish strain NEAU-YM18T from its reference strains. In addition, genomic analysis confirmed that strain NEAU-YM18T had the potential to decompose cellulose and produce bioactive compounds. Therefore, strain NEAU-YM18T represents a novel species of the genus Catellatospora, for which the name Catellatospora tritici sp. nov. is proposed. The type strain is NEAU-YM18T (=CCTCC AA 2020040T=JCM 33977T).

Nonomuraea aurantiaca sp. nov., a novel cellulase-producing actinobacterium isolated from soil.

A novel cellulase-producing actinobacterium, designated strain NEAU-L178T, was isolated from soil sample collected from Qiqihaer, Heilongjiang Province, PR China. A polyphasic study was carried out to determine the taxonomic status of the strain. On the basis of 16S rRNA gene sequence analysis, strain NEAU-L178T should be classified into the genus Nonomuraea and is closely related to Nonomuraea cavernae SYSU K10005T (99.31 % 16S rRNA gene sequence similarity), Nonomuraea glycinis NEAU-BB2C19T (98.75 %), Nonomuraea guangzhouensis NEAU-ZJ3T (98.75 %) and 'Nonomuraea rhizosphaerae' NEAU-mq18T (98.34 %). The digital DNA-DNA hybridization values between them are 27.1, 26.1, 42.0 and 30.9 %, and the whole-genome average nucleotide identity values between them are 83.1, 82.3, 90.3 and 85.8 %, respectively. The whole-cell hydrolysates contained glucose, ribose, arabinose and madurose. The menaquinones were identified as MK-9(H0), MK-9(H4) and MK-9(H2). The major fatty acids were C16 : 0, iso-C17 : 0 and C17 : 0 10-methyl. The detected polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, hydroxy-phosphatidylethanolamine, phosphatidylinositol and three unidentified phospholipids. The genomic DNA G+C content was 69.7 mol%. In addition, whole-genome analysis indicated that strain NEAU-L178T had the potential to degrade cellulose. Based on the phenotypic, genotypic, chemotaxonomic and phylogenetic data, strain NEAU-L178T can be differentiated from its close phylogenetic relatives and represents a novel species of the genus Nonomuraea, for which the name Nonomuraea aurantiaca sp. nov. is proposed. The type strain is NEAU-L178T (=JCM 34799T=CGMCC 4.7741T).

Nucisporomicrobium flavum gen. nov., sp. nov., a new member of the family Micromonosporaceae isolated from saline-alkali soil.

A Gram-stain-positive, aerobic actinobacterium, designated strain NEAU-24T, was isolated from saline-alkali soil collected from Daqing City, Heilongjiang Province, PR China. Strain NEAU-24T was found to produce abundant substrate mycelia but no aerial hyphae. The substrate mycelia formed irregular pseudosporangia consisting of nuciform spores, and the surface of the spores was smooth. 16S rRNA gene sequence analysis showed that strain NEAU-24T clustered with Pseudosporangium ferrugineum 3-44-a(19)T, Couchioplanes caeruleus subsp. azureus DSM 44103T and C. caeruleus subsp. caeruleus DSM 43634T within the family Micromonosporaceae and was most closely related to P. ferrugineum 3-44-a(19)T (99.17 %). The strain contained meso-diaminopimelic acid as the cell-wall diamino acid and MK-9(H6) as the menaquinone. The whole cell sugar profile consisted of glucose, galactose, xylose and arabinose. The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, an unidentified phospholipid, phosphatidylinositol and an unidentified lipid. The major fatty acids were summarized as C16 : 0, C15 : 0, C17 : 0, iso-C16 : 0 and iso-C17 : 0. The low digital DNA-DNA hybridization and average nucleotide identity values could differentiate strain NEAU-24T from its related type strains. The phenotypic, genetic and chemotaxonomic data also indicated that strain NEAU-24T occupied a branch separated from those of known genera in the family Micromonosporaceae. In addition, genomic analysis confirmed that strain NEAU-24T had the potential to produce chitinase. Therefore, strain NEAU-24T represents a novel species of a new genus and species in the family Micromonosporaceae, for which the name Nucisporomicrobium flavum gen. nov., sp. nov. is proposed. The type strain of Nucisporomicrobium flavum is NEAU-24T (=CCTCC AA 2020016T=JCM 33973T).