16S rRNA Gene Sequence Analysis Research Articles

Lysobacter arvi sp. nov. Isolated from Farmland Soil.

A bacterial strain designated as UC was isolated from farmland soil. Strain UCT formed a pale yellow colony on nutrient agar. Cell morphology revealed it as the rod-shaped bacterium that stained Gram-negative. The 16S rRNA gene sequence analysis identified strain UCT as a member of the genus Lysobacter that showed high identity with L. soli DCY21T (99.5%), L. panacisoli CJ29T (98.7%), and L. tabacisoli C8-1T (97.9%). It formed a distinct cluster with these strains in the neighbor-joining phylogenetic tree. A similar tree topology was observed in TYGS-based phylogenomic analysis. However, genome sequence analyses of strain UCT showed 87.7% average nucleotide identity and 34.7% digital DNA-DNA hybridization similarity with the phylogenetically closest species, L. soli DCY21T. The similarity was much less with other closely related strains of the genus Lysobacter. The G + C content of strain UCT was 68.1%. Major cellular fatty acids observed were C14:0 iso (13.4%), C15:0 iso (13.6%), and C15:0 anteiso (14.8%). Quinone Q-8 was the major respiratory ubiquinone. Predominant polar lipids were phosphatidylethanolamine, diphosphatidylglycerol, and phosphatidylglycerol. Production of xanthomonadin pigment was observed. Based on phenotypic differences and phylogenomic analysis, strain UCT represents a novel species of the genus Lysobacter, for which the name Lysobacter arvi is proposed. The type strain of the novel species is UCT (= KCTC 92613T = JCM 23757T = MTCC 12824T).

Dietary Paenibacillus polymyxa AM20 as a new probiotic: Improving effects on IR broiler growth performance, hepatosomatic index, thyroid hormones, lipid profile, immune response, antioxidant parameters, and caecal microorganisms

The search for a natural antimicrobial agent is ongoing and critical because of the rise and rapid proliferation of antibiotic-resistant pathogenic bacteria. The current study aims to examine the effect of Paenibacillus polymyxa AM20 as an alternative antibiotic and feed additive on Indian river broiler performance, digestive enzymes, thyroid hormones, lipid profile, hepatosomatic index, immunological response, gut bacteria, and antioxidant parameters. The bacterial isolate AM20 was identified at the gene level by isolating DNA and using PCR to detect genes. Based on 16S rRNA gene sequence analysis, the bacterial isolate was identified as Paenibacillus polymyxa. One hundred twenty Indian river broilers (1-day old) were randomly divided into 4 groups of 10 chicks each, with 3 replicates. The control group was fed a basal diet only, while the other 3 were administered control diets supplemented with P. polymyxa at 3 concentrations: 0.5, 1, and 1.5 mg/kg. The findings revealed that all groups that received graded amounts of P. polymyxa increased all growth parameters throughout the study. P. polymyxa treatment at 1.5 mg/kg increased body gain by 9% compared to the control due to increased feed intake (P = 0.0001), growth rate (P = 0.0001), and decreased feed conversion ratio. Compared to the control group, P. polymyxa (1.5 mg/kg) enhanced kidney functions in chickens by reducing uric acid and creatinine levels (P = 0.0451). Compared to the control group, alanine aminotransferase and aspartate transaminase levels in the liver were significantly reduced at all P. polymyxa doses. Liver function values were highest for P. polymyxa at 1.5 mg/kg. Compared to the control group, those whose diets included P. polymyxa had significantly better blood cholesterol levels, high-density lipoprotein, low-density lipoprotein, immunological response, thyroid function, and gut microbiota. In general, broiler chickens' economic efficiency was improved by including P. polymyxa in their diet, which also improved their growth performance, carcass dressing, specific blood biochemical levels and enzymes, and the composition of the gut microbiota.

Dysbiosis of gut microbiota in patients with protein-losing enteropathy after the Fontan procedure

BackgroundThere is a lack of predictive biomarkers for the onset or activity of protein-losing enteropathy (PLE), a Fontan procedure-associated complication. Here, we aimed to identify the gut microbiota composition of patients with active PLE and investigate its relationship with PLE activity. MethodsThis multicenter case–control study involved patients who developed PLE (n = 16) after the Fontan procedure and those who did not (non-PLE; n = 20). Patients with PLE who maintained a serum albumin level of ≥3 g/dL for >1 year were included in the remissive-stage-PLE group (n = 9) and those who did not maintain this level were included in the active-PLE group (n = 7). 16S rRNA gene sequencing analysis of fecal samples was performed using QIIME2 pipeline. Alpha (Shannon and Faith's phylogenetic diversity indices) and beta diversity was assessed using principal coordinate analysis based on unweighted UniFrac distances. ResultsShannon and Faith's phylogenetic diversity indices were lower in the active-PLE group than in the remissive-stage- (q = 0.028 and 0.025, respectively) and non-PLE (q = 0.028 and 0.017, respectively) groups. Analysis of beta diversity revealed a difference in the microbiota composition between the active-PLE and the other two groups. Linear discriminant effect size analysis demonstrated differences in the relative abundance of Bifidobacterium and Granulicatella spp., and Ruminococcus torques between patients with active- and those with remissive-stage-PLE. ConclusionsGut microbiota dysbiosis was observed in patients with active PLE. Changes in the bacterial composition of the gut microbiota and decreased diversity may be associated with the severity of PLE.

Rheinheimera oceanensis sp. nov., a novel member of the genus Rheinheimera, isolated from the West Pacific Ocean.

Two Gram-stain-negative, aerobic, non-motile and short-rod-shaped bacteria, designated as strains GL-53T and GL-15-2-5, were isolated from the seamount area of the West Pacific Ocean and identified using a polyphasic taxonomic approach. The growth of strains GL-53ᵀ and GL-15-2-5 occurred at pH 5.5-10.0, 4-40 °C (optimum at 28 °C) and 0-10.0 % NaCl concentrations (optimum at 0-5.0 %). On the basis of 16S rRNA gene sequence analysis, strains GL-53ᵀ and GL-15-2-5 exhibited the highest similarity to Rheinheimera lutimaris YQF-2T (98.4 %), followed by Rheinheimera pacifica KMM 1406T (98.1 %), Rheinheimera nanhaiensis E407-8T (97.4 %), Rheinheimera aestuarii H29T (97.4 %), Rheinheimera hassiensis E48T (97.2 %) and Rheinheimera aquimaris SW-353T (97.2 %). Phylogenetic analysis revealed that the isolates were affiliated with the genus Rheinheimera and represented an independent lineage. The major fatty acids were summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c), C16 : 0 and summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c). The sole isoprenoid quinone was ubiquinone 8. The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol, one unidentified aminophospholipid (and one unidentified glycolipid. The DNA G+C content was 48.5 mol%. The average nucleotide identity, average amino acid identity and in silico DNA-DNA hybridization values among the genomes of strain GL-53ᵀ and the related strains in the genus Rheinheimera were 75.5-90.1 %, 67.5-93.9 % and 21.4-41.4 %, respectively. Based on their phenotypic, chemotaxonomic and genotypic properties, the two strains were identified as representing a novel species of the genus Rheinheimera, for which the name Rheinheimera oceanensis sp. nov. is proposed. The type strain is GL-53T (=KCTC 82651T=MCCC M20598T).

Human milk miRNAs associate to maternal dietary nutrients, milk microbiota, infant gut microbiota and growth

Maternal diet influences the milk composition, yet little information is available on the impact of maternal diet on milk miRNAs expression. Further, the association of human milk miRNAs to maternal diet and milk microbiota is not explored. In addition, the role of milk miRNAs on the infant gut microbiota, infant growth and development has not been investigated. Milk samples were collected from 60 healthy lactating women at ≤15d post-partum, HTG transcriptome assay was performed to examine milk miRNA profile. Maternal clinical and dietary clusters information were available and infant anthropometric measures were followed up to one year of age. Milk and infant microbiota were analyzed by 16S rRNA gene sequencing and integrative multi-omics data analysis was performed to identify potential association between microRNA, maternal dietary nutrients and microbiota. Discriminant analysis revealed that the milk miRNAs were clustered into groups according to the maternal protein source. Interestingly, 31 miRNAs were differentially expressed (P adj<0.05) between maternal dietary clusters (Cluster 1: enriched in plant protein and fibers and Cluster 2: enriched in animal protein), with 30 miRNAs downregulated in the plant protein group relative to animal protein group. Pathway analysis revealed that the top enriched pathways (P adj<0.01) were involved in cell growth and proliferation processes. Furthermore, significant features contributing to the clustering were associated with maternal dietary nutrients and milk microbiota (r>0.70). Further, miR-378 and 320 family miRNAs involved in adipogenesis were positively correlated to the infant BMI-z-scores, weight, and weight for length-z-scores at 6 months of age. Maternal dietary source impacts the milk miRNA expression profile. Further, miRNAs were associated with maternal dietary nutrients, milk microbiota and to the infant gut microbiota and infant growth and development. The study is registered in ClinicalTrials.gov. The identification number is NCT03552939.

Parerythrobacter aestuarii sp. nov., Isolated from Seawater in the Tidal Region of Taizhou.

A yellow, Gram-stain-negative, aerobic, and rod-shaped strain, designated as C18T, was isolated from seawater in the tidal region of Taizhou. Growth of strain C18T occurs at 20-45 °C, at pH 5.5-8.0 and with 1.0-8.0% (w/v) NaCl. The 16S rRNA gene sequence analysis showed that strain C18T shared sequence identities with the genera Erythrobacter (< 98.4%), Qipengyuania (< 98.0%), Altererythrobacter (< 96.4%), Parerythrobacter (< 96.2%), Aurantiacibacter (< 96.2%), Tsuneonella (< 96.0%), Pelagerythrobacter (< 96.0%), Alteriqipengyuania (< 95.9%), and Parapontixanthobacter (< 95.7%) type strains. While the phylogenomic tree based on single-copy orthologous clusters revealed that strain C18T was stably clustered into the genus Parerythrobacter. Average nucleotide identity and digital DNA-DNA hybridization values of strain C18T and Parerythrobacter type strains were 73.5-75.2% and 18.5-19.4%, respectively, which were lower than the species delineation thresholds. The sole respiratory quinones were identified as ubiquinone-10. The major fatty acids (> 10%) were C17:1ω6c and summed feature 8 (C18:1ω7c and/or C18:1ω6c). Polar lipids included diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, sphingoglycolipid, an unidentified phospholipid, and an unidentified aminophospholipid. Based on the genetic, chemotaxonomic and phenotypic results, strain C18T is concluded to represent a novel species in the genus Parerythrobacter, for which the name Parerythrobacter aestuarii sp. nov. is proposed. The type strain is C18T (= KCTC 82594T = MCCC 1K05109T).

Utilization of Palm Oil Midrib Biochar as Soil Amendment with a Newly Isolated Bacillus sp. SM11 for Growth Enhancement and Nitrate Reduction in Romaine Lettuce (Lactuca sativa L. var. longifolia)

Biochar is a carbon-rich material that enhances nutrient availability, soil quality, and microbial activity, improving plant growth and crop productivity. In this study, the palm oil midrib biochar (POMB) was used as a soil conditioner to improve the growth of romaine lettuce (Lactuca sativa L. var. longifolia), together with a biofertilizer containing a newly isolated bacterial strain SM11. The newly isolated SM11 was closely related to Bacillus siamensis, with 99.77% similarity based on 16s rRNA gene sequence analysis. POMB treatment improved the fresh weight of romaine lettuce by up to 181.33 ± 1.15 g plant−1, which is equivalent to 160.27% growth enhancement compared to the control without POMB. By comparison, POMB treatment with a biofertilizer containing SM11 increased fresh weight to 275.67 ± 11.59 g plant−1 with a growth enhancement of 295.68%. The addition of SM11 biofertilizer also protected against disease during cultivation. The addition of POMB reduced nitrate accumulation in romaine lettuce from 631.38 ± 0.36 to 223.31 ± 0.20 mg kg−1 by 59.08% compared to the control. This study suggests a way to manage agricultural waste from local palm oil plantations, thereby reducing waste accumulation and adding value to palm oil waste by-products for agricultural benefit through a biotechnological process.

Screening for endophytic bacteria from Ambon Banana (Musa paradisiaca) as biocontrol agent of anthracnose (Colletotrichum gloeosporioides) on bananas fruit

Abstract. Pangastuti A, Pratiwi H, Setyaningsih R. 2023. Screening for endophytic bacteria from Ambon Banana (Musa paradisiaca L.) as biocontrol agent of anthracnose (Colletotrichum gloeosporioides) on bananas fruit. Nusantara Bioscience 15: 238-244. Post-harvest Ambon Bananas (Musa paradisiaca L.) are sensitive to anthracnose disease, caused by Colletotrichum gloeosporioides, and causes the fruit to rot quickly. Thus, chemical fungicides are employed, damaging living organisms and the environment. One solution is biocontrol using endophytic microorganisms as antagonistic agents against the anthracnose fungus that causes anthracnose disease. This study aimed to obtain potential endophytic bacteria from the Ambon Banana plant that had inhibitory activity against the growth of the pathogenic fungus C. gloeosporioides that causes anthracnose in bananas. Endophytic bacteria were recovered from Ambon Banana roots by crushing plant components. Therefore, bacterial isolates were tested for antagonistic interactions with pathogenic fungi using the dual culture approach. The 16S rRNA gene sequence analysis was used to identify bacterial isolates with the most significant inhibitory potential. According to the findings of this study, seven isolates of endophytic bacteria, A2-1, A2-2, A5-2, A6-2, A6-3, A8-1, and A9-1, can limit the growth of the pathogenic fungus C. gloeosporioides. The strain A6-3, identified as Pseudomonas pseudoalcaligenes, exhibited the greatest potential as a biocontrol agent against the pathogenic fungus C. gloeosporioides. It achieved the highest inhibition rate of 43.59%, resulting in an extended fruit shelf life and reduced harm susceptibility.

Proposal of a novel subspecies: Alicyclobacillus hesperidum subspecies aegles.

Alicyclobacillus sp. DSM 11985T was isolated from geothermal soil but had not yet been classified at the species level. The strain produced guaiacol, which is of interest from the viewpoint of food spoilage in the food industry. 16S rRNA gene sequence analysis revealed that strain DSM 11985T was closely related (99.6 % similarity) to Alicyclobacillus hesperidum DSM 12489T. However, strains of A. hesperidum did not produce guaiacol; therefore, we performed the taxonomic characterization of strain DSM 11985T. The results showed that strain DSM 11985T and strains of A. hesperidum showed different phenotypic characteristics in biochemical/physiological tests including guaiacol production. Average nucleotide identity values between strain DSM 11985T and strain DSM 12489T were 95.4-95.9 %, and the in silico DNA-DNA hybridization value using the Genome-to-Genome Distance Calculator between strains DSM 11985T and DSM 12489T was 65.5 %. These values showed that strain DSM 11985T was genetically closely related but separated from strains of A. heparidum. From the above results, a novel subspecies of A. hesperidum, named Alicyclobacillus hesperidum subsp. aegles subsp. nov. is proposed. The type strain is DSM 11985T (=FR-12T=NBRC 113041T).

Early life stress induces irritable bowel syndrome from childhood to adulthood in mice.

Irritable bowel syndrome (IBS) is one of the most common functional gastrointestinal disorder. Traditionally, early life stress (ELS) is predisposed to IBS in adult. However, whether ELS induces IBS in early life remains unclear. Separated cohort studies were conducted in neonatal male pups of C57BL/6 mice by maternal separation (MS) model. MS and non-separation mice were scheduled to be evaluated for prime IBS-phenotypes, including visceral hypersensitivity, intestinal motility, intestinal permeability, and anxiety-like behavior. Ileal contents and fecal samples were collected and analyzed by 16S rRNA gene sequencing and bacterial community analyses. Subcellular structures of intestinal epithelial, such as epithelial tight junctions and mitochondria, were observed under transmission electron microscopy. MS induced visceral hypersensitivity and decreased total intestinal transit time from childhood to adulthood. In addition, MS induced intestinal hyperpermeability and anxiety-like behavior from adolescence to adulthood. Besides, MS affected intestinal microbial composition from childhood to adulthood. Moreover, MS disrupted intestinal mitochondrial structure from childhood to adulthood. The study showed for the first time that MS induced IBS from early life to adulthood in mice. The disrupted intestinal mitochondrial structure and the significant dysbiosis of intestinal microbiota in early life may contribute to the initiation and progress of IBS from early life to adulthood.

Human Tularemia Epididymo-Orchitis Caused by Francisella tularensis Subspecies holartica, Austria.

A previously healthy man in Austria had tularemia epididymo-orchitis develop, leading to unilateral orchiectomy. Francisella tularensis subspecies holartica was detected by 16S rRNA gene sequencing analysis of inflamed granulomatous testicular tissue. Clinicians should suspect F. tularensis as a rare etiologic microorganism in epididymo-orchitis patients with relevant risk factors.

Integrated 'omics analysis for the gut microbiota response to moxibustion in a rat model of chronic fatigue syndrome.

To observe the efficacy of moxibustion in the treatment of chronic fatigue syndrome (CFS) and explore the effects on gut microbiota and metabolic profiles. Forty-eight male Sprague-Dawley rats were randomly assigned to control group (Con), CFS model group (Mod, established by multiple chronic stress for 35 d), MoxA group (CFS model with moxibustion Shenque (CV8) and Guanyuan (CV4), 10 min/d, 28 d) and MoxB group (CFS model with moxibustion Zusanli (ST36), 10 min/d, 28 d). Open-field test (OFT) and Morris-water-maze test (MWMT) were determined for assessment the CFS model and the therapeutic effects of moxibustion.16S rRNA gene sequencing analysis based gut microbiota integrated untargeted liquid chromatograph-mass spectrometer (LC-MS) based fecal metabolomics were executed, as well as Spearman correlation analysis, was utilized to uncover the functional relevance between the potential metabolites and gut microbiota. The results of our behavioral tests showed that moxibustion improved the performance of CFS rats in the OFT and the MWMT. Microbiome profiling analysis revealed that the gut microbiomes of CFS rats were less diverse with altered composition, including increases in pro-inflammatory species (such as Proteobacteria) and decreases in anti-inflammatory species (such as Bacteroides, Lactobacillus, Ruminococcus, and Prevotella). Moxibustion partially normalized these changes in the gut microbiota. Furthermore, CFS was associated with metabolic disorders, which were effectively ameliorated by moxibustion. This was demonstrated by the normalization of 33 microbiota-related metabolites, including mannose (P = 0.001), aspartic acid (P = 0.009), alanine (P = 0.007), serine (P = 0.000), threonine (P = 0.027), methionine (P = 0.023), 5-hydroxytryptamine (P = 0.008), alpha-linolenic acid (P = 0.003), eicosapentaenoic acid (P = 0.006), hypoxanthine (P = 0.000), vitamin B6 (P = 0.000), cholic acid (P = 0.013), and taurocholate (P = 0.002). Correlation analysis showed a significant association between the perturbed fecal microbiota and metabolite levels, with a notable negative relationship between LCA and Bacteroides. In this study, we demonstrated that moxibustion has an antifatigue-like effect. The results from the 16S rRNA gene sequencing and metabolomics analysis suggest that the therapeutic effects of moxibustion on CFS are related to the regulation of gut microorganisms and their metabolites. The increase in Bacteroides and decrease in LCA may be key targets for the moxibustion treatment of CFS.

Evaluation and Genome Mining of Bacillus stercoris Isolate B.PNR1 as Potential Agent for Fusarium Wilt Control and Growth Promotion of Tomato.

Recently, strategies for controlling Fusarium oxysporum f. sp. lycopersici (Fol), the causal agent of Fusarium wilt of tomato, focus on using effective biocontrol agents. In this study, an analysis of the biocontrol and plant growth promoting (PGP) attributes of 11 isolates of loamy soil Bacillus spp. has been conducted. Among them, the isolates B.PNR1 and B.PNR2 inhibited the mycelial growth of Fol by inducing abnormal fungal cell wall structures and cell wall collapse. Moreover, broad-spectrum activity against four other plant pathogenic fungi, F. oxysporum f. sp. cubense race 1 (Foc), Sclerotium rolfsii, Colletotrichum musae, and C. gloeosporioides were noted for these isolates. These two Bacillus isolates produced indole acetic acid, phosphate solubilization enzymes, and amylolytic and cellulolytic enzymes. In the pot experiment, the culture filtrate from B.PNR1 showed greater inhibition of the fungal pathogens and significantly promoted the growth of tomato plants more than those of the other treatments. Isolate B.PNR1, the best biocontrol and PGP, was identified as Bacillus stercoris by its 16S rRNA gene sequence and whole genome sequencing analysis (WGS). The WGS, through genome mining, confirmed that the B.PNR1 genome contained genes/gene cluster of a nonribosomal peptide synthetase/polyketide synthase, such as fengycin, surfactin, bacillaene, subtilosin A, bacilysin, and bacillibactin, which are involved in antagonistic and PGP activities. Therefore, our finding demonstrates the effectiveness of B. stercoris strain B.PNR1 as an antagonist and for plant growth promotion, highlighting the use of this microorganism as a biocontrol agent against the Fusarium wilt pathogen and PGP abilities in tomatoes.

Atrazine Degradation by Bacillus safensis Strain BUK_BCH_BTE6 Isolated from Agricultural Land in Northwestern Nigeria

Atrazine herbicide is known to disrupt the endocrine system and is potentially carcinogenic. Consumption of which is devastating. This research aimed to isolate and characterize bacteria with atrazine degrading ability. An enrichment method was adopted to isolate the bacteria on mineral salt media following serial dilution. The isolate was identified molecularly and characterized based on effects of temperature, pH, substrate concentration, incubation time, inoculum size and heavy metals. GC-MS analysis was performed to identify the metabolites and degradation efficiency. The isolate was identified as Bacillus safensis strain BUKˍBCHˍBTE6 based on 16S rRNA gene sequence and molecular phylogenetic analysis. Growth and degradation of atrazine by this bacterium was optimal at 35 °C, pH of 7.5, 400 mgL-1, inoculum size 600 µL after 48 h. The growth of the isolate was inhibited by 2 ppm Hg, Cd, Cr, Pb, Ar and Ni. The degradation efficiency after 120 h was 88.85%. GC-MS analysis detected the formation of Desethyldeisopropylatrazine, Deisopropylatrazine, N-Ethylammelide and Cyanuric acid as metabolites. This isolate can be efficient atrazine degrader, hence may be beneficial for bioremediation of atrazine polluted sites.

Combination of galacto-oligosaccharides and wheat peptides synergistically relieved constipation via regulating water transport, gut barrier, inflammation and gut microbiota

Constipation is a common gastrointestinal problem. This study aimed to identify a combination of prebiotics and wheat peptides (WP) to promote intestinal peristalsis and explore the underlying mechanism. First, we screened four prebiotics (galacto-oligosaccharides (GOS), fructose oligosaccharides (FOS), inulin (IN), and resistant dextrin (RD)) using a zebrafish model and found that GOS was the most synergistic with WP. We then tested the GOS-WP combination in a mouse model of loperamide (Lop)-induced constipation and found that it significantly improved constipation symptoms. Specifically, GOS-WP shortened the first black stool time, increased the number of defecation particles, accelerated small intestinal propulsion rate, and increased fecal water content. GOS-WP also normalized the colonic water transport system by inhibiting colonic AQP4/8 expression. Additionally, GOS-WP reversed Lop-induced morphological damage in the ileum and colon, increased colonic barrier, and reduced inflammation in mice. Furthermore, 16S rRNA gene sequence analysis showed that GOS-WP reversed the gut microbiota structure changes induced by Lop. GOS-WP significantly increased butyric acid and decreased BCFA levels, indicating improved gut health. Our findings suggest that the GOS-WP combination has potential as a novel intervention for constipation relief. This study highlights the potential of combining prebiotics and WP as a therapeutic strategy for constipation.

Bioactivity Features of Novel Actinobacteria Isolated from Lichen and Orchid Plant

A total of 10 actinobacterial strains were isolated from a lichen and an orchid species by employing a selective isolation procedure for actinobacteria. Antimicrobial activities of the isolates were evaluated against Aspergillus niger ATCC 16404, Candida albicans ATCC 10231, Enterococcus faecalis ATCC 29212, Bacillus subtilis ATCC 6633, Escherichia coli ATCC 25922, Klebsiella pneumoniae ATCC 700603, Pseudomonas aeroginosa ATCC 27853, Salmonella enterica ATCC 13311, Staphylococcus aureus ATCC 29213 and Listeria monocytogenes NCTC 5348. Out of the 10 isolates, eight showed antimicrobial activity against at least one pathogen. For molecular identification of the strains, 16S rRNA gene sequence analysis was performed. The pairwise comparison of the 16S rRNA gene sequences of the strains with the databases showed that the strains are members of the genus Streptomyces by sharing 98.9 – 100% gene sequence similarities. Phylogenetic relationships of the strains within the genus Streptomyces were revealed by maximum likelihood and maximum parsimony phylogenetic trees. The results revealed that unexplored environmental habitats like lichens and plant tissues may represent a potential reservoir for novel actinobacteria with promising bioactivity features.

Muricauda meishanensis sp. nov., a facultative anaerobic bacterium belonging to the family Flavobacteriaceae isolated from marine sediment in the East China Sea.

A facultative anaerobic, Gram-strain-negative, rod-shaped bacterium (strain NBU2970T) was isolated by using modified ichip in situ cultivation from a marine sediment sample collected from Meishan Island in the East China Sea. Strain NBU2970T grew optimally at 37 °C, with a NaCl concentration of 2.0 % (w/v) and at pH 7.0. The 16S rRNA gene sequence analyses revealed that strain NBU2970T represents a novel species with the genus Muricauda, sharing highest sequence identities with Muricauda beolgyonensis BB-My12T (96.1 %), Muricauda alvinocaridis SCR12T (96.0 %), Muricauda taeanensis 105T (96.0 %) and Muricauda ruestringensis B1T (95.6 %). Phylogenetic analyses also indicated that strain NBU2970T clustered with the genus Muricauda and was closely related to M. beolgyonensis BB-My12T and M. ruestringensis B1T. The draft genome sequence of strain NBU2970T was composed of six contigs with a size of 3.2 Mbp, containing 3045 protein-coding genes and 38 RNA genes. The DNA G+C content was 43.8 mol%. The average nucleotide identity and digital DNA-DNA hybridization values between strain NBU2970T and related species of the genus Muricauda were well below the threshold limit for prokaryotic species delineation. The major cellular fatty acids were iso-C15 : 0, iso-C15 : 1 G and iso-C17 : 0 3-OH. The only respiratory quinone was MK-6. The major polar lipid was phosphatidylethanolamine. Based on its phenotypic, chemotaxonomic and genotypic data, strain NBU2970T is considered to be a representative of a novel species in the genus Muricauda, for which the name Muricauda meishanensis sp. nov. is proposed. The type strain is NBU2970T (=KCTC 82915T=MCCC 1K06394T).

Immune Activation and Inflammatory Response Mediated by the NOD/Toll-like Receptor Signaling Pathway-The Potential Mechanism of Bullfrog (Lithobates catesbeiana) Meningitis Caused by Elizabethkingia miricola.

Elizabethkingia miricola is an emerging opportunistic pathogen that is highly pathogenic in both immunocompromised humans and animals. Once the disease occurs, treatment can be very difficult. Therefore, a deep understanding of the pathological mechanism of Elizabethkingia miricola is the key to the prevention and control of the disease. In this study, we isolated the pathogenic bacteria from bullfrogs with dark skin color, weak limbs, wryneck, and cataracts. Via subsequent morphological observations and a 16S rRNA gene sequence analysis, the pathogen was identified as Elizabethkingia miricola. The histopathological and transmission electron microscopy analysis revealed that the brain was the main target organ. Therefore, brain samples from diseased and healthy bullfrogs were used for the RNA-Seq analysis. The comparative transcriptome analysis revealed that the diseased bullfrog brain was characterized by the immune activation and inflammatory response, which were mediated by the "NOD-like receptor signaling pathway" and the "Toll-like receptor signaling pathway". We also performed qRT-PCR to examine the expression profile of inflammation-related genes, which further verified the reliability of our transcriptome data. Based on the above results, it was concluded that the NOD/Toll-like receptor-related networks that dominate the immune activation and inflammatory response were activated in the brain of Elizabethkingia miricola-infected bullfrogs. This study contributes to the search for therapeutic targets for bullfrog meningitis and provides basic information for establishing effective measures to prevent and control bullfrog meningitis.

Streptomyces cynarae sp. nov., a novel actinomycete isolated from the leaves of Cynara scolymus L.

Strain HUAS 13-4T, a novel endophytic actinobacterium, was isolated from the leaves of Cynara scolymus L. collected from Changde City in China and characterized using a polyphasic approach. Based on 16S rRNA gene sequence analysis, strain HUAS 13-4T shared the highest sequence similarities to Streptomyces leeuwenhoekii C34T (98.90%), Streptomyces harenosi PRKS01-65T (98.83%) and Streptomyces glomeratus LMG 19903T (98.76%). Phylogenetic analysis of 16S rRNA gene sequence indicated that strain HUAS 13-4T was clustered together with Streptomyces bluensis ISP 5564T and Streptomyces cavernae SYSU K10008T. Phylogenomic analysis revealed that strain HUAS 13-4T was most closely related to S. glomeratus JCM 9091T. However, the average nucleotide identity and the digital DNA-DNA hybridization values between them were less than 96.7% and 70% cut-off points recommended for delineating species. Based on a comprehensive comparison of the genome sequences and phenotypic characteristics between strain HUAS 13-4T and its relative, strain HUAS 13-4T (= MCCC 1K08364T = JCM 35919T) should evidently represent a novel Streptomyces species, and the name Streptomyces cynarae sp. nov. is proposed.

Novosphingobium cyanobacteriorum sp. nov., isolated from a eutrophic reservoir during the Microcystis bloom period.

A novel Gram-stain-negative, aerobic and rod-shaped bacterial strain, HBC54T, was isolated from periphyton during a Microcystis bloom. Based on the results of the 16S rRNA gene sequence analysis, strain HBC54T was closely related to Novosphingobium aerophilum 4Y4T (98.36 %), Novosphingobium aromaticivorans DSM 12444T (98.08 %), Novosphingobium huizhouense c7T (97.94 %), Novosphingobium percolationis c1T (97.65 %), Novosphingobium subterraneum DSM 12447T (97.58 %), Novosphingobium olei TW-4T (97.58 %) and Novosphingobium flavum UCT-28T (97.37 %). The average nucleotide identity and digital DNA-DNA hybridization values between HBC54T and its related type stains were below 78.97 and 23.7 %, which are lower than the threshold values for species delineation. The major fatty acids (>10.0 %) were identified as C14 : 0 2-OH, summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c) and summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c) and the respiratory quinone was ubiquinone Q-10. The main polar lipids detected in the strain were phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, diphosphatidylglycerol and three unidentified phospholipids. The genomic DNA G+C content was 64.8 mol%. Strain HBC54T is considered to represent a novel species within the genus Novosphingobium, for which the name Novosphingobium cyanobacteriorum sp. nov. is proposed. The type strain is HBC54T (=KCTC 92033T=LMG 32427T).