Response of microbial diversity and function to the degradation of Barkol Saline Lake

Barkol Lake, a shrinking hypersaline lake situated in the northeast of Xinjiang, China, has experienced the exposure of its riverbed and the gradual drying up of its original sediment due to climate change and human activities, resulting in the formation of alkaline soils. These changes have correspondingly altered the physicochemical characteristics of the surrounding environment. Microorganisms play a crucial role, with special functioning involved in various nutrient cycling and energy transfer in saline lake environments. However, little is known about how the microbial community dynamics and metabolic functions in this shrinking saline lake relate to the degradation process. To address this knowledge gap, a cultivation-independent method of amplicon sequencing was used to identify and analyze the microbial community and its potential ecological functions in the sediment and degraded area. The microbial community diversity was found to be significantly lower in the degraded areas than in the sediment samples. The Pseudomonadota was dominant in Barkol Saline Lake. The abundance of Desulfobacterota and Bacillota in the degraded areas was lower than in the lake sediment, while Pseudomonadota, Acidobacteriota, and Actinobacteriota showed an opposite trend. The βNTI showed that microbial community assembly was primarily associated with deterministic processes in Barkol Saline Lake ecosystems and stochastic processes at the boundary between sediment and degraded areas. Functional predictions showed that sulfur metabolism, particularly sulfate respiration, was much higher in sediment samples than in the degraded areas. Overall, these findings provided a possible perspective for us to understand how microorganisms adapt to extreme environments and their role in saline lakes under environmental change.

Two Novel Alkaliphilic Species Isolated from Saline-Alkali Soil in China: Halalkalibacter flavus sp. nov., and Halalkalibacter lacteus sp. nov

The degradation of farmland in China underscores the need for developing and utilizing saline-alkali soil. Soil health relies on microbial activity, which aids in the restoration of the land's ecosystem, and hence it is important to understand microbial diversity. In the present study, two Gram-stain-positive strains HR 1-10T and J-A-003T were isolated from saline-alkali soil. Preliminary analysis suggested that these strains could be a novel species. Therefore, the taxonomic positions of these strains were evaluated using polyphasic analysis. Phylogenetic and 16S rRNA gene sequence analysis indicated that these strains should be assigned to the genus Halalkalibacter. Cell wall contained meso-2,6-diaminopimelic acid. The polar lipids present in both strains were diphosphatidyl-glycerol, phosphatidylglycerol, and an unidentified phospholipid. The major fatty acids (>10%) were anteiso-C15:0, C16:0 and iso-C15:0. Average nucleotide identity and digital DNA#x2013;DNA hybridization values were below the threshold values (95% and 70%, respectively) for species delineation. Based on the above results, the strains represent two novel species of the genus Halalkalibacter, for which the names Halalkalibacter flavus sp. nov., and Halalkalibacter lacteus sp. nov., are proposed. The type strains are HR 1-10T (=GDMCC 1.2946T = MCCC 1K08312T = JCM 36285T), and J-A-003T (=GDMCC 1.2949T = MCCC 1K08417T = JCM 36286T).

Chelativorans salis sp. nov., a slightly halophilic bacterium isolated from an enrichment system with saline lake sediment

A Gram-stain-negative, non-motile, and slightly halophilic alphaproteobacterium, designated strain EGI FJ00035T, was isolated from enrichment sediment samples of a saline lake in Xinjiang Uygur Autonomous Region, PR China. The taxonomic position of the isolate was determined using the polyphasic taxonomic and phylogenomic analyses. Phylogenetic analysis based on the 16S rRNA gene sequences indicated that strain EGI FJ00035T formed a distinct clade with 'Chelativorans alearense' UJN715 and 'Chelativorans xinjiangense' lm93 with sequence similarities of 98.44 and 98.22 %, respectively, while sharing less than 96.7 % with other valid type strains. The novel isolate could be distinguished from other species of the genus Chelativorans by its distinct phenotypic, physiological, and genotypic characteristics. Optimal growth of strain EGI FJ00035T occurred on marine agar 2216 at pH 7.0 and 30 °C. The major respiratory quinone was Q-10, while the major fatty acids (>5 %) were C19 : 0 cyclo ω8c, summed feature 8 (C17 : 1 ω6c and/or C17 : 1 ω7c), C16 : 0, C18 : 0, and iso-C17 : 0. The detected polar lipids included diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, unidentified aminophospholipids, unidentified glycolipids, and an unidentified lipid. Based on its genome sequence, the G+C content of strain EGI FJ00035T was 63.2 mol%. The average nucleotide identity, average amino acid identity, and digital DNA-DNA hybridization values of strain EGI FJ00035T against related members of the genus Chelativorans were below the thresholds for delineation of a novel species. According our polyphasic taxonomic data, strain EGI FJ00035T represents a new species of the genus Chelativorans, for which the name Chelativorans salis sp. nov. is proposed. The type strain of the proposed novel isolate is EGI FJ00035T (=KCTC 92251T=CGMCC 1.19480T).

Fundicoccus culcitae sp. nov., a novel potential bacteriocin producing bacterium isolated from a spoiled eye mask

A Gram-positive, facultatively anaerobic, oval beaded-shape, oxidase-negative, and non-motile bacterium designated DM20194951T was isolated from a spoiled eye mask obtained from Guangdong, China. Based on the 16S rRNA gene sequence, phylogenetic analysis indicated that strain DM20194951T showed the highest sequence similarity (95.8%) to Fundicoccus ignavus WS4937T. Meanwhile, strain DM20194951T could be distinguished from the type strains in the genus Fundicoccus by distinct phenotypic and genotypic traits. Strain DM20194951T grew variably with 1-2% (w/v) NaCl and tolerated pH 6.0-10.0. Growth was observed from 28 to 37 °C. The diagnostic diamino acids in the cell-wall peptidoglycan consisted of aspartic and glutamic acids as well as alanine. The predominant fatty acids were C18:1 ω9c, C16:0, and C16:1 ω9c. In the polar lipid profile, two glycolipids, three phospholipids, one phosphatidylglycerol, and one diphosphatidylglycerol were found. No respiratory quinones were detected. The DM20194951T genome is 3.2 Mb in size and contains a G + C content of 38.1%. A gene cluster for lactococcin 972 family bacteriocin production was found in the DM20194951T genome. Based on morphological, genotypic, and phylogenetic data, strain DM20194951T should be considered to represent a novel species in the genus Fundicoccus, for which the name Fundicoccus culcitae sp. nov. is proposed with the type strain DM20194951T (= KCTC 43472T = GDMCC 1.3614T).

Microbial Risks Caused by Livestock Excrement: Current Research Status and Prospects

Livestock excrement is a major pollutant yielded from husbandry and it has been constantly imported into various related environments. Livestock excrement comprises a variety of microorganisms including certain units with health risks and these microorganisms are transferred synchronically during the management and utilization processes of livestock excrement. The livestock excrement microbiome is extensively affecting the microbiome of humans and the relevant environments and it could be altered by related environmental factors as well. The zoonotic microorganisms, extremely zoonotic pathogens, and antibiotic-resistant microorganisms are posing threats to human health and environmental safety. In this review, we highlight the main feature of the microbiome of livestock excrement and elucidate the composition and structure of the repertoire of microbes, how these microbes transfer from different spots, and they then affect the microbiomes of related habitants as a whole. Overall, the environmental problems caused by the microbiome of livestock excrement and the potential risks it may cause are summarized from the microbial perspective and the strategies for prediction, prevention, and management are discussed so as to provide a reference for further studies regarding potential microbial risks of livestock excrement microbes.

Sediment prokaryotic microbial community and potential biogeochemical cycle from saline lakes shaped by habitat

The microbial diversity and ecological function in different saline lakes was reduced or disappeared as the influence of climate change and human activities even before they were known. However, reports about prokaryotic microbial of saline lakes from Xinjiang are very limited especially in large-scale investigations. In this study, a total of 6 saline lakes represented three different habitats, including hypersaline lake (HSL), arid saline lake (ASL), and light saltwater lake (LSL) were involved. The distribution pattern and potential functions of prokaryotes were investigated by using the cultivation-independent method of amplicon sequencing. The results showed that Proteobacteria was the predominant community and was widely distributed in all kinds of saline lakes, Desulfobacterota was the representative community in hypersaline lakes, Firmicutes and Acidobacteriota were mainly distributed in arid saline lake samples, and Chloroflexi was more abundant in light saltwater lakes. Specifically, the archaeal community was mainly distributed in the HSL and ASL samples, whereas it was very rare in the LSL lakes. The functional group showed that fermentation was the main metabolic process of microbes in all saline lakes and covered 8 phyla, including Actinobacteriota, Bacteroidota, Desulfobacterota, Firmicutes, Halanaerobiaeota, Proteobacteria, Spirochaetota, and Verrucomicrobiota. Among the 15 functional phyla, Proteobacteria was a distinctly important community in saline lakes, as it exhibited wide functions in the biogeochemical cycle. According to the correlation of environmental factors, SO₄^2-, Na⁺, CO₃^2-, and TN were significantly affected in the microbial community from saline lakes in this study. Overall, our study provided more detailed information about microbial community composition and distribution from three different habitats of saline lakes, especially the potential functions of carbon, nitrogen, and sulfur cycles, which provided new insight for understanding the complex microbiota adapt to the extreme environment and new perspectives on evaluating microbial contributions to degraded saline lakes under environmental change.

Salinibacterium sedimenticola sp. nov., Isolated from Tidal Flat Sediment

An actinobacterium, designated as SYSU T00001^T, was isolated from a tidal flat sediment sample from Guangdong province, China. Cells were Gram-stain-positive, aerobic, motile and short rod-shaped. Colonies on marine agar 2216 were smooth, yellow-pigmented, and circular with low convexity. The isolate was able to grow at the temperature range 4-37 °C (optimum 30 °C), at pH 4.0-10.0 (optimum 7.0) and in the presence of 0-10% (w/v) NaCl. The major menaquinones were MK-11 and MK-10. The cell wall contained alanine, glutamic acid, lysine and ornithine. The major fatty acids were C_19:0 cyclo ω8c (35.7%) and anteiso C_15:0 (26.0%). The polar lipids consisted of one diphosphatidyl glycerol, one unidentified glycolipid and one unknown lipid. Whole genome sequencing of strain SYSU T00001^T revealed 2,837,702 bp with a DNA G + C content of 67.8%. Phylogenetic analyses clearly demonstrated that strain SYSU T00001^T belonged to the genus Salinibacterium, and the highest 16S rRNA gene similarity to Salinibacterium hongtaonis 194^T (97.8%). The ANI and dDDH values of strain SYSU T00001^T relative to Salinibacterium hongtaonis 194^T were 74.5% and 19.5%, respectively. According to our data, strain SYSU T00001^T represents a novel species of the genus Salinibacterium, for which the name Salinibacterium sedimenticola sp. nov. is proposed, the type strain is SYSU T00001^T (= GDMCC 1.3283^T = KCTC 49758^T).

Aquiflexum gelatinilyticum sp. nov., isolated from river water

Two Gram-stain-negative, strictly aerobic, rod-shaped, non-motile and non-gliding bacteria, designated as XJ19-10^T and XJ19-11, were isolated from river water in Xinjiang Uygur Autonomous Region, PR China. Cells of these strains were catalase-, oxidase- and gelatinase-positive and contained carotenoids but no flexirubins. Growth occurred at 10-30 °C, pH 7.0-9.0 and with 0-2.5% (w/v) NaCl. On the basis of the results of 16S rRNA gene sequence and genome analyses, the two isolates represented members of the genus Aquiflexum, and the closest relative was Aquiflexum aquatile Z0201^T with 16S rRNA gene sequence pairwise similarities of 97.9-98.1%. Furthermore, the average nucleotide identities and digital DNA-DNA hybridization identities between the two isolates and other relatives were all less than 82.9 and 28.2 %, respectively, all below the species delineation thresholds. The results of pan-genomic analysis indicated that the type strain XJ19-10^T shared 2813 core gene clusters with other three type strains of members of the genus Aquiflexum, as well as having 623 strain-specific clusters. The major polar lipids were phosphatidylethanolamine, phosphatidylcholine, an unidentified aminolipid and unidentified lipids. The predominant fatty acids (>10% of the total contents) were iso-C_{15 : 0}, iso-C_{15 : 1}G, iso-C_{17 : 0} 3-OH and summed feature 9, and MK-7 was the respiratory quinone. On the basis of the results of phenotypic, physiological, chemotaxonomic and genotypic characterization, strains XJ19-10^T and XJ19-11 are considered to represent a novel species, for which the name Aquiflexum gelatinilyticum sp. nov. is proposed. The type strain is XJ19-10^T (=CGMCC 1.19385^T =KCTC 92266^T).

Culturomics- and metagenomics-based insights into the microbial community and function of rhizosphere soils in Sinai desert farming systems

BACKGROUND

The microbiome of the Sinai Desert farming system plays an important role in the adaptive strategy of growing crops in a harsh, poly-extreme, desert environment. However, the diversity and function of microbial communities under this unfavorable moisture and nutritional conditions have not yet been investigated. Based on culturomic and metagenomic methods, we analyzed the microbial diversity and function of a total of fourteen rhizosphere soil samples (collected from twelve plants in four farms of the Sinai desert), which may provide a valuable and meaningful guidance for the design of microbial inoculants.

RESULTS

The results revealed a wide range of microbial taxa, including a high proportion of novel undescribed lineages. The composition of the rhizosphere microbial communities differed according to the sampling sites, despite similarities or differences in floristics. Whereas, the functional features of rhizosphere microbiomes were significantly similar in different sampling sites, although the microbial communities and the plant hosts themselves were different. Importantly, microorganisms involved in ecosystem functions are different between the sampling sites, for example nitrogen fixation was prevalent in all sample sites while microorganisms responsible for this process were different.

CONCLUSION

Here, we provide the first characterization of microbial communities and functions of rhizosphere soil from the Sinai desert farming systems and highlight its unexpectedly high diversity. This study provides evidence that the key microorganisms involved in ecosystem functions are different between sampling sites with different environment conditions, emphasizing the importance of the functional microbiomes of rhizosphere microbial communities. Furthermore, we suggest that microbial inoculants to be used in future agricultural production should select microorganisms that can be involved in plant-microorganism interactions and are already adapted to a similar environmental setting.

Devosia ureilytica sp. nov., isolated from Kuche River in China

Two novel strains, designated XJ19-45^T and XJ19-1, were isolated from water of Kuche River in Xinjiang Uygur Autonomous Region, China. Their cells were Gram-stain-negative, aerobic and motile rods. The phylogenetic analyses based on 16S rRNA genes and genomes showed that the two isolates belonged to the genus Devosia and the closest relative was Devosia subaequoris HST3-14^T. The 16S rRNA genes sequences pairwise similarities, average nucleotide identities, digital DNA-DNA hybridizations and average amino acid identities between type strain XJ19-45^T and other relatives were all less than 98.3, 80.3, 23.6 and 85.7 %, respectively, all below the species delineation thresholds. Pan-genomic analysis indicated that the novel isolate XJ19-45^T shared 1594 core gene clusters with the 11 closely related type strains in Devosia, and the number of strain-specific clusters was 390. The major cellular fatty acids (>10 %) of the two isolates were summed feature 8, C_18 : 1 ω7c 11-methyl and C_16 : 0. Diphosphatidylglycerol, phosphatidylglycerol and glycolipids were the major polar lipids, and Q10 was the detected respiratory quinone. Based on the results of phenotypic, physiological, chemotaxonomic and genotypic characterizations, we propose that the isolates represent a novel species, for which the name Devosia ureilytica sp. nov. is proposed. The type strain is XJ19-45^T (=CGMCC 1.19388^T=KCTC 92263^T).

Viral community-wide auxiliary metabolic genes differ by lifestyles, habitats, and hosts

BACKGROUND

Viral-encoded auxiliary metabolic genes (AMGs) are important toolkits for modulating their hosts' metabolisms and the microbial-driven biogeochemical cycles. Although the functions of AMGs have been extensively reported in numerous environments, we still know little about the drivers that shape the viral community-wide AMG compositions in natural ecosystems. Exploring the drivers of viral community-wide AMG compositions is critical for a deeper understanding of the complex interplays among viruses, hosts, and the environments.

RESULTS

Here, we investigated the impact of viral lifestyles (i.e., lytic and lysogenic), habitats (i.e., water, particle, and sediment), and prokaryotic hosts on viral AMG profiles by utilizing metagenomic and metatranscriptomic techniques. We found that viral lifestyles were the most important drivers, followed by habitats and host identities. Specifically, irrespective of what habitats viruses came from, lytic viruses exhibited greater AMG diversity and tended to encode AMGs for chaperone biosynthesis, signaling proteins, and lipid metabolism, which could boost progeny reproduction, whereas temperate viruses were apt to encode AMGs for host survivability. Moreover, the lytic and temperate viral communities tended to mediate the microbial-driven biogeochemical cycles, especially nitrogen metabolism, in different manners via AMGs. When focusing on each lifestyle, we further found clear dissimilarity in AMG compositions between water and sediment, as well the divergent AMGs encoded by viruses infecting different host orders.

CONCLUSIONS

Overall, our study provides a first systematic characterization of the drivers of viral community-wide AMG compositions and further expands our knowledge of the distinct interactions of lytic and temperate viruses with their prokaryotic hosts from an AMG perspective, which is critical for understanding virus-host-environment interactions in natural conditions. Video Abstract.

Pseudalkalibacillus salsuginis sp. nov., a novel salt-tolerant bacterium isolated from a saline lake sediment

A salt-tolerant bacterium, designated strain EGI L200015T, was isolated from saline lake sediment in Xinjiang Uygur Autonomous Region, PR China. The taxonomic position of the isolate was determined using polyphasic taxonomic analysis and phylogenomic analysis. Phylogenetic analysis and 16S rRNA gene sequence similarities indicated that EGI L200015T formed a distinct clade with Pseudalkalibacillus berkeleyi KCTC 12718T with sequence identity of 98.3%. The novel isolate could be distinguished from species of the genus Pseudalkalibacillus by its distinct phenotypic, physiological and genotypic characteristics. Cells of EGI L200015T were aerobic, Gram-stain-positive, non-motile and rod-shaped. Optimal growth conditions for EGI L200015T occurred on marine agar 2216 at pH 8.0 at 30 °C. The major respiratory quinone was MK-7, while the major fatty acids (> 10 %) were anteiso-C15 : 0, iso-C15 : 0, iso-C16 : 0 and anteiso-C17 : 0. The detected polar lipids of included diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. On the basis of the genome sequence data, the DNA G+C content of EGI L200015T was 41.6 %. On the basis of the phenotypic, physiological, genotypic and phylogenetic data, strain EGI L200015T represents a novel species of the genus Pseudalkalibacillus , for which the name Pseudalkalibacillus salsuginis sp. nov. is proposed. The type strain of the proposed novel isolate is EGI L200015T (= KCTC 43363T = CGMCC 1.19260T).

Functional differentiation determines the molecular basis of the symbiotic lifestyle of Ca. Nanohaloarchaeota

BACKGROUND

Candidatus Nanohaloarchaeota, an archaeal phylum within the DPANN superphylum, is characterized by limited metabolic capabilities and limited phylogenetic diversity and until recently has been considered to exclusively inhabit hypersaline environments due to an obligate association with Halobacteria. Aside from hypersaline environments, Ca. Nanohaloarchaeota can also have been discovered from deep-subsurface marine sediments.

RESULTS

Three metagenome-assembled genomes (MAGs) representing a new order within the Ca. Nanohaloarchaeota were reconstructed from a stratified salt crust and proposed to represent a novel order, Nucleotidisoterales. Genomic features reveal them to be anaerobes capable of catabolizing nucleotides by coupling nucleotide salvage pathways with lower glycolysis to yield free energy. Comparative genomics demonstrated that these and other Ca. Nanohaloarchaeota inhabiting saline habitats use a "salt-in" strategy to maintain osmotic pressure based on the high proportion of acidic amino acids. In contrast, previously described Ca. Nanohaloarchaeota MAGs from geothermal environments were enriched with basic amino acids to counter heat stress. Evolutionary history reconstruction revealed that functional differentiation of energy conservation strategies drove diversification within Ca. Nanohaloarchaeota, further leading to shifts in the catabolic strategy from nucleotide degradation within deeper lineages to polysaccharide degradation within shallow lineages.

CONCLUSIONS

This study provides deeper insight into the ecological functions and evolution of the expanded phylum Ca. Nanohaloarchaeota and further advances our understanding on the functional and genetic associations between potential symbionts and hosts. Video Abstract.

The Metabolic Potential of Endophytic Actinobacteria Associated with Medicinal Plant Thymus roseus as a Plant-Growth Stimulator

Bio-fertilizer practice considers not only economical but also environmentally friendly, sustainable agriculture. Endophytes can play important beneficiary roles in plant development, directly, indirectly, or synergistically. In this study, the majority of our endophytic actinobacteria were able to possess direct plant growth-promoting (PGP) traits, including auxin (88%), ammonia (96%), siderophore production (94%), and phosphate solubilization (24%), along with cell-wall degrading enzymes such as protease (75%), cellulase (81%), lipase (81%), and chitinase (18%). About 45% of tested strains have an inhibitory effect on the phytopathogen Fusarium oxysporum, followed by 26% for Verticillium dahlia. Overall, our results showed that strains XIEG63 and XIEG55 were the potent strains with various PGP traits that caused a higher significant increase (p ≤ 0.05) in length and biomass in the aerial part and roots of tomato and cotton, compared to the uninoculated plants. Our data showed that the greatest inhibition percentages of two phytopathogens were achieved due to treatment with strains XIEG05, XIEG07, XIEG45, and XIEG51. The GC-MS analysis showed that most of the compounds were mainly alkanes, fatty acid esters, phenols, alkenes, and aromatic chemicals and have been reported to have antifungal activity. Our investigation emphasizes that endophytic actinobacteria associated with medicinal plants might help reduce the use of chemical fertilization and potentially lead to increased agricultural productivity and sustainability.

Habitat-dependent prokaryotic microbial community, potential keystone species, and network complexity in a subtropical estuary

Microbes (e.g., bacteria and archaea) are indispensable components for the key biological processes of estuarine ecosystems and three main habitats (sediment, particle, and water) are harboring diverse estuarine microbes. However, we still know little about how the microbial community structures, potential keystone species, and network properties change among these three habitats in estuarine ecosystems. In this study, we collected size-fractioned water and sediment samples from the Pearl River Estuary to reveal their microbial diversity, community structures, network properties, and potential keystone taxa. We found that the sediment microbial community was remarkably more diverse than particle-attached (PA) and free-living (FL) communities, whereas its ecological network was less complex in terms of node distance and connectivity. TOC was determined as the main driver of sediment community, while the PA and FL communities were predominantly shaped by NO₂^-, non-ionic ammonia (NH) and pH. Among the bulk water, there were no significant differences between PA and FL communities in diversity, community structure, and network complexity. However, the PA community was more susceptible to metal elements, suggesting their higher level of involvement in physiological metabolism. Potential keystone taxa among community networks were taxonomically divergent in three habitats. Specifically, Synechococcales (Cyanobacteria) and Actinomarinales (Actinobacteria) exclusively served as the module-hubs in FL network, while members from phylum Proteobacteria and Bacteroidetes were the module-hubs and connectors in PA network. Potential keystone taxa in sediment network were more diverse and covered 9 phyla, including the only archaeal lineage Bathyarchaeia (Crenarchaeota). Overall, our study provided more detailed information about estuarine microbial communities in three habitats, especially the potential keystone species, which provided new perspectives on evaluating further effects of anthropogenic disturbances on estuarine microbes and facilitated the environment monitoring based on microbial community.

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

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

Agromyces cavernae sp. nov., a novel member of the genus Agromyces isolated from a karstic cave in Shaoguan

A novel actinobacterial strain, designated SYSU K20354T, was isolated from a soil sample collected from a karst cave in Shaoguan city, Guangdong province, southern China. The taxonomic position of the strain was investigated using a polyphasic approach. Cells of the strain were aerobic, Gram-stain-positive and non-motile. On the basis of 16S rRNA gene sequence similarities and phylogenetic analysis, strain SYSU K20354T was most closely related to Agromyces humatus JCM 14319T, and shared the highest sequence identity of 98.3 % based on NCBI database. In addition, 2,4-diaminobutyric acid was the diagnostic diamino acid in cell-wall peptidoglycan. The whole-cell sugars were galactose, glucose, mannose and ribose. The major isoprenoid quinone was MK-12, while the major fatty acids (>10 %) were iso-C16 : 0, anteiso-C15 : 0 and anteiso-C17 : 0. The polar lipids contained diphosphatidylglycerol, phosphatidylglycerol, three unknown glycolipids, three unknown phospholipids and two unknown lipids. The draft genome size of strain SYSU K20354T was 3.96 Mbp with G+C content of 69.7 mol%. Furthermore, the average nucleotide identity and digital DNA-DNA hybridization values between strain SYSU K20354T and A. humatus JCM 14319T were 90.3 and 55.6 %, respectively. On the basis of phenotypic, genotypic and phylogenetic data, strain SYSU K20354T represents a novel species of the genus Agromyces, for which the name Agromyces cavernae sp. nov. is proposed. The type strain is SYSU K20354T (=KCTC 49499T= CGMCC 4.7691T).

Thermomonas flagellata sp. nov. and Thermomonas alba sp. nov., two novel members of the phylum Pseudomonadota isolated from hot spring sediments

Two novel species, designated strains SYSU G04041T and SYSU G04536T, were isolated from hot spring sediments collected in Yunnan, PR China. Phenotypic and chemotaxonomic analyses, and whole-genome sequencing were used to determine the taxonomic positions of the candidate strains. Phylogenetic analysis using 16S rRNA gene sequence indicated that strain SYSU G04041T showed the highest sequence similarity to Thermomonas haemolytica A50-7-3T (97.5 %), and SYSU G04536T showed the highest sequence similarity to Thermomonas hydrothermalis SGM-6T (98.2 %). The strains could be differentiated from other species of the genus Thermomonas by their distinct phenotypic and genotypic characteristics. Cells of strains SYSU G04041T and SYSU G04536T were aerobic, motile and Gram-stain-negative. Growth both occurred optimally at 45 °C and pH 7.0 for SYSU G04041T and SYSU G04536T. In addition, the predominant respiratory quinone in both isolates was ubiquinone Q-8. The major fatty acids (>10 %) of strain SYSU G04041T were C16 : 0, iso-C15 : 0 and iso-C16 : 0, while the major fatty acids (>10 %) of strain SYSU G04536T were iso-C15 : 0 and iso-C16 : 0. The main detected polar lipids in strains SYSU G04041T and SYSU G04536T included phosphatidylethanolamine, diphosphatidylglycerol and phosphatidylglycerol. The G+C contents of the genomic DNA of strains SYSU G04041T and SYSU G04536T based on draft genomic sequences were 72.5 and 68.3 %, respectively. On the basis of phenotypic, genotypic and phylogenetic data, strains SYSU G04041T and SYSU G04536T represent two novel species of the genus Thermomonas , for which the names Thermomonas flagellata sp. nov. and Thermomonas alba sp. nov. are proposed, with the type strains SYSU G04041T (=CGMCC 1.19366T=KCTC 92228T) and SYSU G04536T (=CGMCC 1.19367T=KCTC 82839T), respectively.

Unraveling microbe-mediated degradation of lignin and lignin-derived aromatic fragments in the Pearl River Estuary sediments

Estuaries are one of the most crucial areas for the transformation and burial of terrestrial organic carbon (TerrOC), playing an important role in the global carbon cycle. While the transformation and degradation of TerrOC are mainly driven by microorganisms, the specific taxa and degradation processes involved remain largely unknown in estuaries. We collected surface sediments from 14 stations along the longitudinal section of the Pearl River Estuary (PRE), P. R. China. By combining analytical chemistry, metagenomics, and bioinformatics methods, we analyzed composition, source and degradation pathways of lignin/lignin-derived aromatic fragments and their potential decomposers in these samples. A diversity of bacterial and archaeal taxa, mostly those from Proteobacteria (Deltaproteobacteria, Gammaproteobacteria etc.), including some lineages (e.g., Nitrospria, Polyangia, Tectomicrobia_uc) not previously implicated in lignin degradation, were identified as potential polymeric lignin or its aromatic fragments degraders. The abundance of lignin degradation pathways genes exhibited distinct spatial distribution patterns with the area adjacent to the outlet of Modaomen as a potential degradation hot zone and the Syringyl lignin fragments, 3,4-PDOG, and 4,5-PDOG pathways as the primary potential lignin aromatic fragments degradation processes. Notably, the abundance of ferulic acid metabolic pathway genes exhibited significant correlations with degree of lignin oxidation and demethylation/demethoxylization and vegetation source. Additionally, the abundance of 2,3-PDOG degradation pathways genes also showed a positive significant correlation with degree of lignin oxidation. Our study provides a meaningful insight into the microbial ecology of TerrOC degradation in the estuary.

Rhabdothermincola salaria sp. nov., a novel actinobacterium isolated from a saline lake sediment

An actinobacterium, designated strain EGI L10124T, was isolated from saline lake sediment collected in Xinjiang province, PR China. The taxonomic position of the isolate was determined based on polyphasic taxonomic and phylogenomic analyses. Phylogenetic analysis and 16S rRNA gene sequence similarities indicated that strain EGI L10124T formed a distinct clade with Rhabdothermincola sediminis SYSU G02662T, with a shared sequence identity of 95.2 %. The novel isolate could be distinguished from species in the genus Rhabdothermincola by its distinct phenotypic, physiological and genotypic characteristics. The cells of strain EGI L10124T were aerobic, Gram-stain-positive and short rod-shaped. Optimal growth conditions of strain EGI L10124T on marine agar 2216 were registered at pH 8.0 at 37 °C. In addition, meso-diaminopimelic acid was the diagnostic diamino acid in the cell-wall peptidoglycan. The major respiratory quinone was MK-9 (H8), while the major fatty acids were iso-C16 : 0, C17 : 0 and C16 : 0. The polar lipids included diphosphatidylglycerol, phosphatidylinositol mannoside and phosphatidylinositol. Based on the genome sequence of strain EGI L10124T, it appears that the G+C content of the novel isolate was 71.8 mol%. According to our data, strain EGI L10124T represents a new species of the genus Rhabdothermincola , for which the name Rhabdothermincola salaria sp. nov. is proposed. The type strain of the proposed novel isolate is EGI L10124T (=CGMCC 1.19113T=KCTC 49679T).

Synergistic Plant-Microbe Interactions between Endophytic Actinobacteria and Their Role in Plant Growth Promotion and Biological Control of Cotton under Salt Stress

Bacterial endophytes are well-acknowledged inoculants to promote plant growth and enhance their resistance toward various pathogens and environmental stresses. In the present study, 71 endophytic strains associated with the medicinal plant Thymus roseus were screened for their plant growth promotion (PGP), and the applicability of potent strains as bioinoculant has been evaluated. Regarding PGP traits, the percentage of strains were positive for the siderophore production (84%), auxin synthesis (69%), diazotrophs (76%), phosphate solubilization (79%), and production of lytic enzymes (i.e., cellulase (64%), lipase (62%), protease (61%), chitinase (34%), and displayed antagonistic activity against Verticillium dahliae (74%) in vitro. The inoculation of strain XIEG05 and XIEG12 enhanced plant tolerance to salt stress significantly (p < 0.05) through the promotion of shoot, root development, and reduced the activities of antioxidant enzymes (SOD, POD, and CAT), compared with uninoculated controls in vivo. Furthermore, inoculation of strain XIEG57 was capable of reducing cotton disease incidence (DI) symptoms caused by V. dahliae at all tested salt concentrations. The GC-MS analysis showed that many compounds are known to have antimicrobial and antifungal activity. Our findings provide valuable information for applying strains XIEG05 and XIEG12 as bioinoculant fertilizers and biological control agent of cotton under saline soil conditions.

Noviherbaspirillum aridicola sp. nov., isolated from an arid soil in Pakistan

Strain NCCP-691T was isolated from a soil sample collected from an arid soil in Karak, Khyber Pakhtunkhwa, Pakistan. Phenotypically, the cells were Gram-stain-negative, aerobic and motile rods. The organism was able to grow between 20-40 °C (optimum at 30-37 °C), at pH 5.5-8.0 (optimum at pH 7.0-7.2) and tolerated 0-1.5% NaCl (w/v) (optimum at 0-0.5). Based on 16S rRNA gene sequences, strain NCCP-691T formed a distinct phylogenetic clade with Noviherbaspirillum arenae, N. agri, N. denitrificans and N. autotrophicum (having sequence similarities of 99.0; 98.1; 98.0 and 97.7% respectively). Phylogenetic analyses based on the whole genome sequences confirmed that strain NCCP-691T should be affiliated to the genus Noviherbaspirillum. The average nucleotide identity values compared to other species of Noviherbaspirillum were below 95-96 % and digital DNA-DNA hybridization values were less than 70 %. Chemotaxonomic analyses showed that the strain had ubiquinone-8, as the only respiratory quinine. The major cellular fatty acids were summed feature 3 (C16 : 1 ω 7 c/C16 : 1 ω 6 c, 35.9 %), summed feature 8 (C18 : 1 ω 7 c/C18 : 1 ω 6 c, 26.9 %) and C16 : 0 (22.9 %) and the polar lipid profile was composed of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and phosphatidylcholine. The genomic DNA G+C content was 65.5 mol% (from draft genome). Genome analyses showed that strain NCCP-691T had terpene and arylpolyene biosynthetic genes clusters and genes related to resistance against heavy metals. Based on phylogenetic analyses, phenotypic features and genomic comparison, it is proposed that strain NCCP-691T is a novel species of the genus Noviherbaspirillum and the name Noviherbaspirillum aridicola sp. nov. is proposed. Type strain is NCCP-691T (=KCTC 52721T=CGMCC 1.13600T).

Agilicoccus flavus gen. nov., sp. nov., a novel member of the family Dermatophilaceae isolated from the Pearl River

A novel actinobacterium, designated strain SYSU M44304^T, was isolated from freshwater samples in the Pearl River Estuary. The isolate was Gram-stain-positive, aerobic, coccus-shaped, oxidase-positive and motile. The cell wall contained meso-diaminopimelic acid as its diagnostic diamino acid. The predominant menaquinone was MK-8. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, phosphatidylethanolamine and seven unidentified phospholipids. The major fatty acids were C_16 : 0 and C_16 : 1. The G+C content based on genomic DNA was 73.2 mol %. The nearest phylogenetic neighbours to the novel strain were Mobilicoccus pelagius NBRC 104925^T and Mobilicoccus caccae YIM 101593^T. On the basis of chemotaxonomic and physiological characteristics and phylogenetic analysis, strain SYSU M44304^T should be considered to represent a novel species of a new genus in the family Dermatophilaceae, for which we propose the name Agilicoccus flavus gen. nov., sp. nov. The type strain of Agilicoccus flavus is SYSU M44304^T (=NBRC 114808^T=CGMCC 1.18608^T).

Roseomonas ponticola sp. nov., a novel bacterium isolated from Pearl River estuary

A novel species of the genus Roseomonas, designated SYSU M41301T, was isolated from water sample of the Pearl River estuary in Guangdong, China. Polyphasic, taxonomic and phylogenomic analyses were used to determine the taxonomy position of the strain. Phylogenetic analysis using 16S rRNA gene sequence indicated that strain SYSU M41301T showed the highest sequence similarity to Roseomonas stagni KCTC 22213T (97.9 %) and Roseomonas riguiloci KCTC 23339T (96.4 %). The novel species could be differentiated from other species of the genus Roseomonas by its distinct phenotypic and genotypic characteristics. The isolate was Gram-staining-negative, aerobic, short rod-shape, oxidase-positive and non-motile. The predominant respiratory quinone was ubiquinone 8 (Q-8). The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, and one unidentified polar lipid. The major fatty acids (>10 % of total) were 11-methyl C18 : 1  ω7c, summed feature 3 (C16 : 1  ω7c and/ or C16 : 1  ω6c) and summed feature 8 (C18:  :1  ω7c and/or C18 : 1  ω6c). The G+C content of the novel isolate based on genomic DNA was 72.0 mol%. On the basis of phenotypic, genotypic and phylogenetic data, strain SYSU M41301T should be considered to represent a novel species in the genus Roseomonas, for which the name Roseomonas ponticola sp. nov. is proposed with the type strain SYSU M41301T (=KCTC 72726T=CGMCC 1.18613T).

Insight into the function and evolution of the Wood-Ljungdahl pathway in Actinobacteria

Carbon fixation by chemoautotrophic microbes such as homoacetogens had a major impact on the transition from the inorganic to the organic world. Recent reports have shown the presence of genes for key enzymes associated with the Wood-Ljungdahl pathway (WLP) in the phylum Actinobacteria, which adds to the diversity of potential autotrophs. Here, we compiled 42 actinobacterial metagenome-assembled genomes (MAGs) from new and existing metagenomic datasets and propose three novel classes, Ca. Aquicultoria, Ca. Geothermincolia and Ca. Humimicrobiia. Most members of these classes contain genes coding for acetogenesis through the WLP, as well as a variety of hydrogenases (NiFe groups 1a and 3b-3d; FeFe group C; NiFe group 4-related hydrogenases). We show that the three classes acquired the hydrogenases independently, yet the carbon monoxide dehydrogenase/acetyl-CoA synthase complex (CODH/ACS) was apparently present in their last common ancestor and was inherited vertically. Furthermore, the Actinobacteria likely donated genes for CODH/ACS to multiple lineages within Nitrospirae, Deltaproteobacteria (Desulfobacterota), and Thermodesulfobacteria through multiple horizontal gene transfer events. Finally, we show the apparent growth of Ca. Geothermincolia and H2-dependent acetate production in hot spring enrichment cultures with or without the methanogenesis inhibitor 2-bromoethanesulfonate, which is consistent with the proposed homoacetogenic metabolism.

Complete genome sequencing and comparative genome analysis of the extremely halophilic archaea, Haloterrigena daqingensis

In the present study, we report the complete genome sequencing of Haloterrigena daqingensis species. The genome of H. daqingensis JX313^T consisted of a circular chromosome with three plasmids. The genome size and G+C content were estimated to be 3835796 bp and 61.7%, respectively. A total of 4158 genes were predicted with six rRNAs and 45 tRNAs. Metabolic pathway analysis suggests that H. daqingensis JX313^T codes for all the necessary genes responsible to sustain its life at saline environment. The pan-genome analysis suggests that the number of singleton-gene between H. daqingensis and other Haloterrigena species varied. The study not only helps us understand H. daqingensis strategy for dealing with high stress, but it also provides an overview of its genomic makeup.

Rhabdothermincola sediminis gen. nov., sp. nov., a new actinobacterium isolated from hot spring sediment, and emended description of the family Iamiaceae

One thermophilic bacterium, designated strain SYSU G02662^T, was isolated from hot spring sediment sampled in Tibet, PR China. Polyphasic taxonomic analyses and whole-genome sequencing were used to determine the taxonomy position of the strain. Phylogenetic analysis using 16S rRNA gene sequences indicated that strain SYSU G02662^T showed the highest sequence similarity to Actinomarinicola tropica SCSIO 58843^T (95.1 %). The strain could be differentiated from other species of the family Iamiaceae by its distinct phenotypic and genotypic characteristics. Cells of strain SYSU G02662^T were aerobic, Gram-staining-positive and short rodshaped. Growth occurred optimally at 45 °C and pH 7.0. In addition, meso-diaminopimelic acid was the diagnostic diamino acid in the cell-wall peptidoglycan. The respiratory quinone was MK-9 (H₈), while the major fatty acids (>10 %) were C_16 : 0, C_17 : 0, C_18 : 0 and iso-C_16 : 0. The detected polar lipids included diphosphatidylglycerol, phosphatidylinositol mannoside and phosphatidylinositol. The G+C content of the genomic DNA was 70.5 % based on the draft genomic sequence. On the basis of phenotypic, genotypic and phylogenetic data, strain SYSU G02662^T represents a novel species of a novel genus in the family Iamiaceae, for which the name Rhabdothermincola sediminis gen. nov., sp. nov. is proposed. The type strain of the proposed novel species is SYSU G02662^T (=CGMCC 4.7688^T=KCTC 49500^T).

Lunatibacter salilacus gen. nov., sp. nov., a member of the family Cyclobacteriaceae, isolated from a saline and alkaline lake sediment

A non-motile, Gram-staining negative, catalase- and oxidase-positive, crescent-rod shaped bacterium, designated strain CUG 91308^T, was isolated from a sediment sample of Qinghai Lake, Qinghai Province, China. Colonies on OSM agar were round, smooth, flat and pinkish-orange in colour. Strain CUG 91308^T could grow at 15-37 °C, pH 6-12 and in the presence of up to 7.0 % NaCl (w/v). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain CUG 91308^T belonged to the family Cyclobacteriaceae and formed a clade with the genus Lunatimonas in the phylogenetic tree, but separated from any species of the known genera within the family. The genomic DNA G+C content is about 42.1 %. The predominant fatty acids (>10 %) were iso-C_15 : 0 (21.1 %), summed feature 3 (C_16 : 1  ω7c / C_16 : 1  ω6c / iso-C_15 : 0 2OH) (14.3 %), iso-C_17 : 0 3OH (12.3 %) and summed feature 9 (iso-C_17 : 1  ω9c / C_16 : 0 10-methyl) (10.6 %). The polar lipids of strain CUG 91308^T were phosphatidylethanolamine (PE) and four unidentified polar lipids. Strain CUG 91308^T contained MK-7 as the major respiratory quinone. On the basis of phenotypic, genotypic and phylogenetic data, strain CUG 91308^T represents a novel species of a novel genus in the family Cyclobacteriaceae, for which the name Lunatibacter salilacus gen. nov., sp. nov. is proposed. The type strain of the proposed new isolate is CUG 91308^T (=KCTC 62636^T=CGMCC 1.13593^T).

Revealing the salinity adaptation mechanism in halotolerant bacterium Egicoccus halophilus EGI 80432T by physiological analysis and comparative transcriptomics

Egicoccus halophilus EGI 80432^T, a halotolerant bacterium isolated from a saline-alkaline soil, belongs to a member of the class Nitriliruptoria, which exhibits high adaptability to salt environments. At present, the detailed knowledge of the salinity adaptation strategies of Nitriliruptoria was limited except for one research by using comparative genomics analysis. Here, we investigated the salinity adaptation mechanism of E. halophilus EGI 80432^T by comparative physiological and transcriptomic analyses. The results of physiological analyses showed that trehalose and glutamate were accumulated by salt stress and showed the maximum at moderate salinity condition. Furthermore, the contents of histidine, threonine, proline, and ectoine were increased with increasing salt concentration. We found that both 0% and 9% NaCl conditions resulted in increased expressions of genes involved in carbohydrate and energy metabolisms, but negatively affected the Na⁺ efflux, iron, and molybdate transport. Moreover, the high salt condition led to enhancement of transcription of genes required for the synthesis of compatible solutes, e.g., glutamate, histidine, threonine, proline, and ectoine, which agree with the results of physiological analyses. The above results revealed that E. halophilus EGI 80432^T increased inorganic ions uptake and accumulated trehalose and glutamate in response to moderate salinity condition, while the salinity adaptation strategy was changed from a "salt-in-cytoplasm" strategy to a "compatible solute" strategy under high salinity condition. The findings in this study would promote further studies in salt tolerance molecular mechanism of Nitriliruptoria and provide a theoretical support for E. halophilus EGI 80432^T's application in ecological restoration.Key Points• Salt stress affected gene expressions responsible for carbohydrate and energy metabolisms of E. halophilus EGI 8042^T.• E. halophilus EGI 80432^T significantly accumulated compatible solutes under salt stress.• E. halophilus EGI 80432^T adopted a "compatible solute" strategy to withstand high salt stress.

Thermaurantiacus tibetensis gen. nov., sp. nov., a novel moderately thermophilic bacterium isolated from hot spring microbial mat in Tibet

Two bacterial strains SYSU G02173^T and SYSU G03142 were isolated from hot springs in Tibet, China. Based on the results of nearly full-length 16S rRNA gene sequences and phylogenetic analyses, strains SYSU G02173^T and SYSU G03142 were assigned to the family Sphingosinicellaceae, and were closest to Sandaracinobacter sibiricus RB16-17 ^T (96.04% and 96.12% similarity, respectively). Cells of the both new strains were observed to be motile rod-shape, Gram-staining negative. Growth occurred at pH 6-8 (optimal: pH 7.0) and 37-55 °C (optimal: 45 °C) with 0-1.0% (w/v) NaCl in T4 broth. The cells were found to be positive for oxidase and catalase activities. The major respiratory ubiquinone was Q-8. The major fatty acids were identified as summed feature 8 (C_18:1 ω7c and/or C_18:1 ω6c), C_16:0, C_14:0 2-OH. The major polar lipids were found to consist of sphingoglycolipid, phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, one unidentified phospholipid, one unidentified glycolipid, three unidentified aminolipids and two unidentified polar lipids. The DNA G + C contents of strains SYSU G02173^T and SYSU G03142 were 71.8%. The average nucleotide identity (ANI) value between strain SYSU G02173^T and SYSU G03142 was 99.98%. The amino acid identity (AAI) values between them and their closely related species were below 66.14%. The isolates are characterized by aerobic growth, a yellow endocellular pigment and a higher optimum growth temperature. The results showed that strains SYSU G02173^T and SYSU G03142 represent a novel species of a novel genus in the family Sphingomonadaceae, and thus the name Thermaurantiacus tibetensis (type strain SYSU G02173^T = KCTC 72052 ^T = CGMCC 1.16680 ^T) is proposed.

Seramator thermalis gen. nov., sp. nov., a novel cellulose- and xylan-degrading member of the family Dysgonamonadaceae isolated from a hot spring

Two anaerobic bacteria, designated strains SYSU GA16112^T and SYSU GA16107, were isolated from a hot spring in Tengchong County, Yunnan Province, south-west PR China. Phylogenetic analyses based on 16S rRNA gene sequences showed that strains SYSU GA16112^T and SYSU GA16107 belong to the family Dysgonamonadaceae. Cells of strains SYSU GA16112^T and SYSU GA16107 were Gram-stain-negative, rod-shaped and non-motile. The major fatty acids (>10 %) of strains SYSU GA16112^T and SYSU GA16107 were identified as anteiso-C_15 : 0 and anteiso-C_17 : 0 3OH. The polar lipid profile of strain SYSU GA16112^T was found to consist of phosphatidylethanolamine, two unidentified aminophospholipids, two unidentified phosphoglycolipids, two unidentified aminolipids and one unidentified polar lipid, while that of strain SYSU GA16107 consisted of phosphatidylethanolamine, two unidentified polar lipids, three unidentified aminophospholipids, two unidentified phosphoglycolipids and one unidentified aminolipid. The genomic DNA G+C contents of strains SYSU GA16112^T and SYSU GA16107 were determined to be 41.90 and 41.89 %, respectively, and the average nucleotide identity value between them was 99.99 %. Based on their morphological and physiological properties, and results of phylogenetic analyses, strains SYSU GA16112^T and SYSU GA16107 are considered to represent a novel species of a novel genus, for which the name Seramator thermalis gen. nov., sp. nov. (type strain SYSU GA16112^T=CGMCC 1.5281^T=KCTC 15753^T) is proposed.

Nesterenkonia haasae sp. nov., an alkaliphilic actinobacterium isolated from a degraded pasture in Songnen Plain

An alkaliphilic actinobacterial strain, designated Hz 6-5^T, was isolated from saline-alkaline soil from Songnen Plain in north-eastern China. The isolate formed light yellow-colored colonies and its cells were Gram-staining positive, non-motile, and non-spore-forming short rods. The strain was aerobic with optimal growth at 33 °C, pH 9.0, and in the presence of 0.5% (w/v) NaCl or 3% (w/v) KCl. It was catalase-positive and oxidase-negative. The isolate had highest 16S rRNA gene sequence similarities to the type strains of the species Nesternkonia natronophila M8^T (98.2%), N. salmonea GY074^T (98.1%), and N. sphaerica GY239^T (97.4%), and the isolate formed a subclade with the type strains of these species in the neighbor-joining tree based on the 16S rRNA gene sequences. The phylogenetic tree based on the phylogenomic analysis also showed the same results. The DNA‒DNA relatedness (DDH) values of isolate Hz 6-5^T with N. natronophila M8^T, N. halophila DSM 16378^T, and N. halobia CGMCC 1.2323^T were 21.2%, 36.5%, and 32.0%, respectively. The characteristic diamino acid of strain Hz 6-5^T was found to be lysine. The respiratory quinones were MK-9, MK-8, MK-7(H₄), MK-7(H₂) and MK-7 and the major cellular fatty acids (> 10%) were anteiso-C_15:0, anteiso-C_17:0 and iso-C_16:0. The polar lipids detected for strain Hz 6-5^T were diphosphatidylglycerol, phosphatidylcholine, phosphatidylglycerol, phosphatidylinositol, an unidentified glycolipid, and two unidentified phospholipids. The DNA G + C content of isolate Hz 6-5^T was 60.8%. Based on the results of phylogenetic analysis supported by morphological, physiological, chemotaxonomic, and other differentiating phenotypic evidence, strain Hz 6-5^T is considered to represent a novel species of the genus Nesterenkonia, for which the name Nesterenkonia haasae sp. nov. is proposed. The type strain is Hz 6-5^T (=CPCC 205100^T=NBRC 113521^T).

Isolation of Clostridium from Yunnan-Tibet hot springs and description of Clostridium thermarum sp. nov. with lignocellulosic ethanol production

Lignocellulose is considered a major source of renewable energy that serve as an alternative to the fossil fuels. Members of the genus Clostridium are some of the many microorganisms that have the ability to degrade lignocellulose efficiently to sugar, which can be further converted to biofuel. In this study, we isolated twelve Clostridium strains from hot spring samples of Yunnan and Tibet, of which isolates SYSU GA15002^T and SYSU GA17076 showed low 16S rRNA gene sequence identity profiles to any of the validly named Clostridium strains (<94.0%). Studies using a polyphasic taxonomy approach concluded that the two isolates represent one novel species of the genus Clostridium, for which we propose the name Clostridium thermarum sp. nov., with SYSU GA15002^T as the type strain of the species. Isolate SYSU GA15002^T has an optimum growth temperature at 45°C. Fermentation of the substrates cellobiose, cellulose, xylan and untreated straw powder by this strain results in the production of ethanol, along with acetate and formate. The complete pathways for the conversion of cellulose and xylan to ethanol is also predicted from the genome of isolate SYSU GA15002^T, which revealed a single step conversion of lignocellulosic biomass through consolidated bioprocessing. This paper is a comprehensive study encompassing isolation, polyphasic taxonomy, lignocellulose biodegradation and the genomic information of Clostridium in Yunnan-Tibet hot springs.

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

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

Microvirga arsenatis sp. nov., an arsenate reduction bacterium isolated from Tibet hot spring sediments

Two novel Gram-stain negative, moderately thermophilic, aerobic, rod-shaped strains, designated 3D203^T and 3D207, were isolated from hot spring sediment samples collected from Tibet, western China. Phylogenetic analyses based on 16S rRNA gene sequence similarities showed that two isolates belonged to the genus Microvirga and were most closely related to Microvirga makkahensis SV1470^T (98.5% and 98.4%, respectively) and two strains had 99.8% similarity to each other. The average nucleotide identity (ANI) based on whole genome sequences of two strains and M. makkahensis SV1470^T was 80.8% and 80.78%, respectively. Optimum growth was observed at 45 °C, pH 7.0 and 0.5% NaCl. They both could tolerate to high concentration arsenic. Ubiquinone 10 (Q10) was their predominant quinone. The differences of strains 3D203^T and 3D207 were phosphatidyl dimethyl ethanolamine, phosphatidyl-N-methylethanolamine, phosphatidylglycerol, unidentified glycolipids and unidentified lipids. The major fatty acids (> 5%) were identified C_18:1ω7c and/or C_18:1ω6c, C_18:0 and C_16:0. The genomic DNA G + C contents of strain 3D203^T and 3D207 based on whole genome sequences were 64.8% and 64.7%, respectively. Phenotypic, chemotaxonomic, phylogenetic and genomic analyses suggested that two strains represent a novel species of the genus Microvirga, for which the name Microvirga arsenatis sp. nov. is proposed. The type strain is 3D203^T (= CGMCC 1.17691^T = KCTC 72653^T).

Roseibium aestuarii sp. nov., isolated from Pearl River Estuary

A novel bacterium, designated strain SYSU M00256-3T, was isolated from a water sample collected from Pearl River Estuary at Guangzhou, PR China. Its taxonomic position was determined by using a polyphasic approach. Cells of the strain were Gram-staining-negative, motile, aerobic and rod-shaped with peritrichous flagella. It could grow at 15–45 °C, pH 4.0–10.0 and in the presence of 0–7.5 % (w/v) NaCl. The chemotaxonomic features of strain SYSU M00256-3T included ubiquinone-10 (Q-10) as the sole respiratory quinone; phosphatidylcholine, phosphatidylmethylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine and an unidentified phospholipid as major polar lipids; summed feature 8 (C18 : 1  ω7c and C18 : 1  ω6c) as the predominant fatty acids (>70 %). On the basis of 16S rRNA gene sequence analysis, strain SYSU M00256-3T was most closely related to the type strains of Roseibium hamelinense CGMCC 1.12584T (97.7 %) and R. aquae CGMCC 1.12426T (97.2 %), R. sediminis KCTC 52373T (96.7 %), R. denhamense CGMCC 1.12583T (96.4 %). The average nucleotide identity (ANI) values between R. aestuarii SYSU M00256-3T and R. hamelinense CGMCC 1.12584T, R. aquae CGMCC 1.12426T, R. denhamense CGMCC 1.12583T and R. sediminis KCTC 52373T were 78.0, 78.2, 77.7 and 78.8, and the dDDH value is 20.0, 20.8, 20.1 and 20.6 correspondingly. Based on the analyses of the phenotypic, genotypic and phylogenetic characteristics, strain SYSU M00256-3T is characterized to represent a novel species of the genus Roseibium , for which the name Roseibium aestuarii sp. nov. is proposed. The type strain is SYSU M00256-3T (=NBRC 112946T=CGMCC 1.16156T).

Streptomyces cavernae sp. nov., a novel actinobacterium isolated from a karst cave sediment sample

A novel actinobacterial strain, designated SYSU K10008^T, was isolated from a soil sample collected from a karst cave in Xingyi County, Guizhou Province, south-western PR China. The taxonomic position of the strain was investigated by using a polyphasic approach. Cells of the strain were aerobic, Gram-stain-positive and non-motile. On the basis of 16S rRNA gene sequence similarities and the results of phylogenetic analysis, strain SYSU K10008^T was most closely related to Streptomyces cyaneus CGMCC 4.1671^T, and shared the highest sequence identity of 98.3 % based on the NCBI database. In addition, ll-diaminopimelic acid was the diagnostic diamino acid in cell-wall peptidoglycan. The whole-cell sugars were glucose and rhamnose. The major isoprenoid quinone was MK-9(H₆), while the major fatty acids (>10 %) were C_16 : 0, iso-C_16 : 0, anteiso-C_15 : 0 and summed feature 3 (C_16 : 1 ω7c/C_{16  : 1} ω6c). The polar lipids contained diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol mannoside and one unidentified lipid. The genomic DNA G+C content of strain SYSU K10008^T was 70.5 mol%. On the basis of phenotypic, genotypic and phylogenetic data, strain SYSU K10008^T represents a novel species of the genus Streptomyces, for which the name Streptomyces cavernae sp. nov. is proposed. The type strain is SYSU K10008^T (=KCTC 39850^T=DSM 104115^T).

Antribacter gilvus gen. nov., sp. nov., a new member of the family Promicromonosporaceae from a karstic cavern

A novel actinobacterium, designated strain CFH 30434^T, was isolated from a soil sample collected from a karst cave in Luoyang, Henan Province, PR China. The taxonomic position of the strain was investigated by using a polyphasic approach. Cells of the strain were aerobic, Gram-stain-positive, non-motile and coccoid or short rods. The strain was found to be oxidase-positive and weakly catalase-positive. Strain CFH 30434^T grew optimally at 28 °C, pH 7.0-9.0 and in the presence of up to 0-1.5 % NaCl (w/v). The whole-cell sugars were glucose, mannose and rhamnose. The major isoprenoid quinone was MK-9(H₈) and the major fatty acids (>10 % of the total fatty acids compositions) were anteiso-C_15 : 0, iso-C_15:0 and iso-C_14 : 0. The polar lipids detected were diphosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannoside, an unidentified phosphoglycolipid, an unidentified phospholipid and an unidentified glycolipid. The genomic DNA G+C content was determined to be 72.3 mol%. The results of phylogenetic analysis of 16S rRNA gene sequences indicated that CFH 30434^T clustered within the family Promicromonosporaceae, and closely with the type strains of Xylanimicrobium pachnodae DSM 12657^T, Myceligenerans crystallogenes DSM 17134^T and Promicromonospora xylanilytica CCTCC AA 208046^T (97.3 %, 96.2 and 95.9 % sequence similarities, respectively). Phylogenetic analysis showed that strain CFH 30434^T formed a separate evolutionary branch, and was parallel to other related genera of Promicromonosporaceae. Its phylogenetic distinctiveness and distinguishing phenotypic characteristics supported that strain CFH 30434^T represents a novel genus of the family Promicromonosporaceae, for which the name Antribacter gilvus gen. nov., sp. nov. is proposed. The type strain is CFH 30434^T (=CGMCC 1.13856^T=KCTC 49093^T).

Pseudorivibacter rhizosphaerae gen. nov., sp. nov., isolated from rhizosphere soil of Camellia sinensis (L.) O. Ktze and emended description of the genus Rivibacter

A Gram-stain-negative, facultative anaerobic, motile and straight rod-shaped bacterium, designated strain C1-9^T, was isolated from rhizosphere soil of Camellia sinensis (L.) O. Ktze collected from a tea garden in Huize, south-western PR China. Cells were oxidase-positive and catalase-negative. Growth occurred at 20-40 °C and pH 6.0-10.0, with an optimal growth at 30 °C and pH 7.0. The respiratory quinone was detected as ubiquinone-8 (Q-8). The major fatty acids were identified as summed feature 3 (C_16 : 1ω7c and/or C_16 : 1ω6c), C_16 : 0 and summed feature 8 (C_18 : 1ω7c or C_18 : 1ω6c). The cellular polar lipids contained phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, three unidentified phospholipids, two unidentified lipids, one unidentified aminophospholipid and one unidentified aminolipid. The polyamine types were detected as 1,8-diaminooctane and 2-hydroxyputrescine. The genomic DNA G+C content was 68.6 mol%. Based on the results of 16S rRNA gene sequence analysis, strain C1-9^T (MF687442) showed highest sequence similarity to Rivibacter subsaxonicus DSM 19570^T (97.1 %). The phylogenetic tree based on 16S rRNA gene sequences showed that strain C1-9^T clustered close to R. subsaxonicus DSM 19570^T, Methylibium petroleiphilum CCTCC AB 2014193^T and species belonging to the genera Rhizobacter and Piscinibacter. The phylogenomic tree indicated that strain C1-9^T formed a clade with R. subsaxonicus. The average nucleotide identity value was 76.0 % between strain C1-9^T and R. subsaxonicus DSM 19570^T, which is lower than the prokaryotic species delineation threshold of 95.0-96.0 %. The polyphasic taxonomic characteristics indicated that strain C1-9^T represents a novel species of a new genus within the order Burkholderiales, for which the name Pseudorivibacter rhizosphaerae gen. nov., sp. nov. (type strain C1-9^T = KCTC 62325^T=CGMCC 1.13864^T) is proposed.

Dyella tabacisoli sp. nov., a bacterium isolated from an arable soil sample of Nicotiana tabacum L

A Gram-stain-negative, aerobic, non-motile and rod-shaped bacterium, designated strain L4-6T, was isolated from an arable soil sample of tobacco in Huize, south-western China and subjected to polyphasic taxonomic characterization. The cells showed oxidase-positive and catalase-positive reactions. Growth occurred at 20-35 °C, at pH 5.0-8.0 and with 0-2 % (w/v) NaCl, optimally at 30 °C, pH 6.0-7.0 and 0-1 % (w/v) NaCl. The major respiratory lipoquinone was ubiquinone-8. The predominant cellular fatty acids (>10.0 %) were identified as summed feature 9 (iso-C17 : 1ω9c or C16 : 0 10-methyl), iso-C15 : 0 and iso-C17 : 0. The polar lipid profile contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, two unidentified phospholipids, two unidentified aminophospholipids and five unidentified aminolipids. The genomic DNA G+C content was 60.8 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain L4-6T should be affiliated to the genus Dyella and formed a clade with the most closely related organism Dyella soli JS12-10T. 16S rRNA gene sequences similarity analysis showed that strain L4-6T was mostly closely related to D. soli JS12-10T (98.73 %) and Dyella lipolytica DHOB07T (98.02 %). DNA-DNA hybridization data indicated that strain L4-6T represented a novel genomic species belonging to the genus Dyella. The polyphasic taxonomic characteristics indicated that the strain L4-6T represents a novel species of the genus Dyella, for which the name Dyellatabacisoli sp. nov. (type strain L4-6T=CGMCC 1.16273T=KCTC 62035T) is proposed.

Transcriptomic analysis of two endophytes involved in enhancing salt stress ability of Arabidopsis thaliana

Soil salinity is one of the serious environmental issues worldwide. In the present study, we made an attempt to isolate endophytic actinobacteria from halophyte and evaluate their growth promoting ability in Arabidopsis thaliana under salt stress through transcriptomic analysis. Two endophytic strains SYSU 333322 and SYSU 333140 were isolated and 16S rRNA gene sequence analysis suggests that these strains belong to Arthrobacter endophyticus and Nocardiopsis alba, respectively. To evaluate the growth promoting ability of two strains in Arabidopsis thaliana four experimental set up were designed. Set up designated s322 and s140 includes strains SYSU 333322 and SYSU 333140, respectively inoculated with A. thaliana under salt stress; set up designated MS322 and MS140 includes strains SYSU 333322 and SYSU 333140, respectively inoculated with A. thaliana without salt stress; MS includes seedlings without bacterial strains and salt stress; C150 includes seedlings grown in 150 mmol L^-1NaCl. A. endophyticus strain SYSU 333322 and N. alba strain SYSU 333140 were efficient to promote A. thaliana growth under salt stress A. endophyticus strain SYSU 333322 was more efficient than N. alba strain SYSU 333140 for growth promotion. Although A. endophyticus strain SYSU 333322 and N. alba strain SYSU 333140 were isolated from the same host, their mechanism of growth promotion in A. thaliana under salt stress was different. Gene encoding for chlorophyll a reductase, peptide-methionine (R)-S-oxide reductase, and potassium ion uptake were up-regulated when A. thaliana inoculated with strain SYSU 333322 and SYSU 333140 under salt stress. Pathways such as carotenoid biosynthesis, phenylalanine metabolism, phenylpropanoid biosynthesis, glycerolipid metabolism, and nitrogen metabolism played a crucial role in enhancing the salt stress tolerance of A. thaliana. Our results suggest that different bacteria have a different mechanism to promote plant growth under salt stress and hence it is necessary to understand the mechanism to overcome soil salinity problem.

Thermus caldilimi sp. nov., a thermophilic bacterium isolated from a geothermal area

A Gram-stain negative, aerobic bacterium, designated strain YIM 78456^T, was isolated from a hot spring sediment, Ngamring county, Tibet, south-west China. The taxonomic position of the isolate was investigated by a polyphasic approach. The novel isolate was found to be aerobic and rod-shaped. Colonies were observed to be pale yellow and circular. The strain was found to grow at pH 7.0-8.0 (optimum, pH 7.0), 45-65 °C (optimum, 55 °C) and in the presence of up to 1.5% NaCl. Comparison of the 16S rRNA gene sequence of strain YIM 78456^T and other members of the genus Thermus showed sequence similarities ranging from 90.3 to 97.3%, with strain YIM 78456^T showing close sequence similarity to Thermus caliditerrae YIM 77925^T (97.3%). The phylogenetic trees based on 16S rRNA gene sequences showed that strain YIM 78456^T forms a distinct clade with T. caliditerrae YIM 77925^T. The predominant menaquinone was identified as MK-8 and the DNA G+C content was determined to be 65.1 mol%. The major cellular fatty acids (> 10%) were identified as iso-C_15:0, anteiso-C_15:0 and iso-C_17:0. The polar lipids were found to consist of an aminophospholipid, a phospholipid and glycolipids. On the basis of the morphological and chemotaxonomic characteristics, as well as genotypic data, it is proposed that strain YIM 78456^T represents a novel species of the genus Thermus, for which the name Thermus caldilimi sp. nov. is proposed. The type strain is YIM 78456^T (= KCTC 52948^T = NBRC 113036^T).

Marinitenerispora sediminis gen. nov., sp. nov., a member of the family Nocardiopsaceae isolated from marine sediment

Three novel actinobacterial strains, designated as TPS16^T, TPS81 and TPS83, were isolated from a sample of marine sediment collected from Tioman Island, Malaysia. The strains formed abundant branched substrate mycelia without fragmentation along with production of blue spores and blue diffusible pigment on soybean meal agar. The strains could grow at pH ranging from pH 6 to 12 and in 0-8 % (w/v) NaCl. Cell-wall hydrolysis showed the presence of meso-diaminopimelic acid. The strains were closely related to Marinactinospora thermotolerans SCSIO 00652^T (97.60 %) and Marinactinospora endophytica YIM 690053^T (96.87 %) based on phylogenetic analysis of 16S rRNA gene sequences. Multilocus sequence analysis including gyrB, recA and rpoB genes further confirmed that strain TPS16^T represented a distinct branch within the family Nocardiopsaceae. The predominant menaquinones were MK-11(H₂), MK-10(H₂), MK-11(H₄) and MK-10(H₄), while the major fatty acids were found to be iso-C_16 : 0, anteiso-C_17 : 0, iso-C_15 : 0 and C_18 : 1ω9c. Genome sequencing revealed genome sizes of approximately 6 Mb and G+C contents of 73.8 mol%. A new genus, Marinitenerispora gen. nov., is proposed within the family Nocardiopsaceae based on polyphasic data and the type species is Marinitenerispora sediminis gen. nov., sp. nov. The type strain is TPS16^T (=DSM 46825^T=TBRC 5138^T).

Croceibacterium gen. nov., with description of Croceibacterium ferulae sp. nov., an endophytic bacterium isolated from Ferula sinkiangensis K. M. Shen and reclassification of Porphyrobacter mercurialis as Croceibacterium mercuriale comb. nov

A novel endophytic bacterium, designated strain SX2RGS8^T, was isolated from the surface-sterilized roots of an endangered medicinal plant (Ferula sinkiangensis K. M. Shen) collected from Xinjiang, north-western PR China. The taxonomic position of the candidate was investigated using a polyphasic approach. Strain SX2RGS8^T was found to be aerobic, Gram-stain-negative, oxidase-negative, catalase-positive and axiolitic-shaped. Strain SX2RGS8^T grew at 4-45 °C (optimum, 28 °C), pH 4.0-10.0 (pH 7.0) and in the presence of 0-5 % (w/v) NaCl. The polar lipids detected for strain SX2RGS8^T were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, phosphatidylinositol, unidentified phosphoglycolipids, an unidentified phospholipid and unidentified lipids. The major respiratory quinone of strain SX2RGS8^T was ubiquinone 10 and the major fatty acid was summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c). The DNA G+C content was determined to be 66.5 mol%. Phylogenetic analyses based on 16S rRNA gene sequences indicated that the isolate belonged to the family Erythrobacteraceae and showed 99.2 % (Porphyrobacter mercurialis), 95.5 % (Porphyrobacter donghaensisi) and 95.4 % (Porphyrobacter colymbi) similarities to its closest relatives. The isolate contained carotenoids, but no bacteriochlorophyll a. On the basis of phenotypic, genotypic and phylogenetic data, strain SX2RGS8^T represents a novel species of a novel genus in the family Erythrobacteraceae, for which the name Croceibacterium ferulae gen. nov., sp. nov. is proposed. The type strain is SX2RGS8^T (=CGMCC 1.16402^T=KCTC 62090^T). In addition, Porphyrobacter mercurialis Coil et al. 2016 is proposed to be transferred to this new genus as Croceibacterium mercuriale comb. nov.

Nocardioides ferulae sp. nov., isolated from root of an endangered medicinal plant Ferula songorica Pall. ex Spreng

A novel endophytic bacterium, designated strain SZ4R5S7^T, was isolated from surface-sterilized root of an endangered medicinal plant (Ferula songorica Pall. ex Spreng) collected from Xinjiang, north-west China. The taxonomic position of the strain was investigated by using a polyphasic approach. The strain was found to be aerobic, Gram-stain-positive, oxidase-negative and catalase-positive, short rods and non-motile. Strain SZ4R5S7^T grew at 4-37 °C (optimum, 28 °C), pH 5.0-9.0 (pH 6.0-8.0) and in the presence of 0-4 % (w/v) NaCl. The polar lipids detected for strain SZ4R5S7^T were phosphatidylglycerol, diphosphatidylglycerol, phosphatidylinositol and two unidentified lipids. The predominant menaquinone of strain SZ4R5S7^T was MK-8(H4), and the major fatty acids were iso-C16 : 0 and anteiso-C14 : 0. The DNA G+C content was determined to be 72.4 mol%. Phylogenetic analysis based on the 16S rRNA gene sequence indicated that strain SZ4R5S7^T belongs to the genus Nocardioides and showed highest levels of 16S rRNA gene sequence similarity to members of the strain Nocardioideskribbensis KSL-2^T (97.8 %). On the basis of phenotypic, genotypic and phylogenetic data, strain SZ4R5S7^T represents a novel species in the genus Nocardioides, for which the name Nocardioides ferulae sp. nov. is proposed and the type strain is SZ4R5S7^T (=CGMCC 4.7456^T=KCTC 39994^T).