Characteristics of microbiome-derived metabolomics according to the progression of alcoholic liver disease

BACKGROUND AND AIM

The prevalence and severity of alcoholic liver disease (ALD) are increasing. The incidence of alcohol-related cirrhosis has risen up to 2.5%. This study aimed to identify novel metabolite mechanisms involved in the development of ALD in patients. The use of gut microbiome-derived metabolites is increasing in targeted therapies. Identifying metabolic compounds is challenging due to the complex patterns that have long-term effects on ALD. We investigated the specific metabolite signatures in ALD patients.

METHODS

This study included 247 patients (heathy control, HC: n = 62, alcoholic fatty liver, AFL; n = 25, alcoholic hepatitis, AH; n = 80, and alcoholic cirrhosis, AC, n = 80) identified, and stool samples were collected. 16S rRNA sequencing and metabolomics were performed with MiSeq sequencer and liquid chromatography coupled to time-of-flight-mass spectrometry (LC-TOF-MS), respectively. The untargeted metabolites in AFL, AH, and AC samples were evaluated by multivariate statistical analysis and metabolic pathotypic expression. Metabolic network classifiers were used to predict the pathway expression of the AFL, AH, and AC stages.

RESULTS

The relative abundance of Proteobacteria was increased and the abundance of Bacteroides was decreased in ALD samples (p = 0.001) compared with that in HC samples. Fusobacteria levels were higher in AH samples (p = 0.0001) than in HC samples. Untargeted metabolomics was applied to quantitatively screen 103 metabolites from each stool sample. Indole-3-propionic acid levels are significantly lower in AH and AC (vs. HC, p = 0.001). Indole-3-lactic acid (ILA: p = 0.04) levels were increased in AC samples. AC group showed an increase in indole-3-lactic acid (vs. HC, p = 0.040) level. Compared with that in HC samples, the levels of short-chain fatty acids (SCFAs: acetic acid, butyric acid, propionic acid, iso-butyric acid, and iso-valeric acid) and bile acids (lithocholic acids) were significantly decreased in AC. The pathways of linoleic acid metabolism, indole compounds, histidine metabolism, fatty acid degradation, and glutamate metabolism were closely associated with ALD metabolism.

CONCLUSIONS

This study identified that microbial metabolic dysbiosis is associated with ALD-related metabolic dysfunction. The SCFAs, bile acids, and indole compounds were depleted during ALD progression.

CLINICAL TRIAL

Clinicaltrials.gov, number NCT04339725.

Gut microbiota-derived indole compounds attenuate metabolic dysfunction-associated steatotic liver disease by improving fat metabolism and inflammation

Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most common chronic liver disease, and its prevalence has increased worldwide in recent years. Additionally, there is a close relationship between MASLD and gut microbiota-derived metabolites. However, the mechanisms of MASLD and its metabolites are still unclear. We demonstrated decreased indole-3-propionic acid (IPA) and indole-3-acetic acid (IAA) in the feces of patients with hepatic steatosis compared to healthy controls. Here, IPA and IAA administration ameliorated hepatic steatosis and inflammation in an animal model of WD-induced MASLD by suppressing the NF-κB signaling pathway through a reduction in endotoxin levels and inactivation of macrophages. Bifidobacterium bifidum metabolizes tryptophan to produce IAA, and B. bifidum effectively prevents hepatic steatosis and inflammation through the production of IAA. Our study demonstrates that IPA and IAA derived from the gut microbiota have novel preventive or therapeutic potential for MASLD treatment.

Gut-microbiota prompt activation of natural killer cell on alcoholic liver disease

The liver is rich in innate immune cells, such as natural killer (NK) cells, natural killer T cells, and Kupffer cells associated with the gut microbiome. These immune cells are dysfunctional owing to alcohol consumption. However, there is insufficient data on the association between immune cells and gut microbiome in alcoholic liver disease (ALD). Therefore, the purpose of this study was to evaluate the effects of probiotic strains on NK cells in ALD patients. In total, 125 human blood samples [control (n = 22), alcoholic hepatitis (n = 43), and alcoholic cirrhosis (n = 60]) were collected for flow cytometric analysis. C57BL/6J mice were divided into four groups (normal, EtOH-fed, and 2 EtOH+strain groups [Phocaeicola dorei and Lactobacillus helveticus]). Lymphocytes isolated from mouse livers were analyzed using flow cytometry. The frequency of NK cells increased in patients with alcoholic hepatitis and decreased in patients with alcoholic cirrhosis. The expression of NKp46, an NK cell-activating receptor, was decreased in patients with alcoholic hepatitis and increased in patients with alcoholic cirrhosis compared to that in the control group. The number of cytotoxic CD56dimCD16+ NK cells was significantly reduced in patients with alcoholic cirrhosis. We tested the effect of oral administration P. dorei and L. helveticus in EtOH-fed mice. P. dorei and L. helveticus improved liver inflammation and intestinal barrier damage caused by EtOH supply and increased NK cell activity. Therefore, these observations suggest that the gut microbiome may ameliorate ALD by regulating immune cells.

The seamless integration of dietary plant-derived natural flavonoids and gut microbiota may ameliorate non-alcoholic fatty liver disease: a network pharmacology analysis

We comprised metabolites of gut microbiota (GM; endogenous species) and dietary plant-derived natural flavonoids (DPDNFs; exogenous species) were known as potent effectors against non-alcoholic fatty liver disease (NAFLD) via network pharmacology (NP). The crucial targets against NAFLD were identified via GM and DPDNFs. The protein interaction (PPI), bubble chart and networks of GM or natural products- metabolites-targets-key signalling (GNMTK) pathway were described via R Package. Furthermore, the molecular docking test (MDT) to verify the affinity was performed between metabolite(s) and target(s) on a key signalling pathway. On the networks of GNMTK, Enterococcus sp. 45, Escherichia sp.12, Escherichia sp.33 and Bacterium MRG-PMF-1 as key microbiota; flavonoid-rich products as key natural resources; luteolin and myricetin as key metabolites (or dietary flavonoids); AKT Serine/Threonine Kinase 1 (AKT1), CF Transmembrane conductance Regulator (CFTR) and PhosphoInositide-3-Kinase, Regulatory subunit 1 (PIK3R1) as key targets are promising components to treat NAFLD, by suppressing cyclic Adenosine MonoPhosphate (cAMP) signalling pathway. This study shows that components (microbiota, metabolites, targets and a key signalling pathway) and DPDNFs can exert combinatorial pharmacological effects against NAFLD. Overall, the integrated pharmacological approach sheds light on the relationships between GM and DPDNFs.

New insight into gut microbiota-derived metabolites to enhance liver regeneration via network pharmacology study

We intended to identify favourable metabolite(s) and pharmacological mechanism(s) of gut microbiota (GM) for liver regeneration (LR) through network pharmacology. We utilized the gutMGene database to obtain metabolites of GM, and targets associated with metabolites as well as LR-related targets were identified using public databases. Furthermore, we performed a molecular docking assay on the active metabolite(s) and target(s) to verify the network pharmacological concept. We mined a total of 208 metabolites in the gutMGene database and selected 668 targets from the SEA (1,256 targets) and STP (947 targets) databases. Finally, 13 targets were identified between 61 targets and the gutMGene database (243 targets). Protein-protein interaction network analysis showed that AKT1 is a hub target correlated with 12 additional targets. In this study, we describe the potential microbe from the microbiota (E. coli), chemokine signalling pathway, AKT1 and myricetin that accelerate LR, providing scientific evidence for further clinical trials.

Screening of lactic acid bacteria with anti-adipogenic effect and potential probiotic properties from grains

A total of 187 lactic acid bacteria were isolated from four types of grains collected in South Korea. The bacterial strains were assigned as members of Levilactobacillus brevis, Latilactobacillus curvatus, Lactiplantibacillus plantarum, Lactococcus taiwanensis, Pediococcus pentosaceus, and Weissella paramesenteroides based on the closest similarity using 16S rRNA gene sequence analysis. The strains belonging to the same species were analyzed using RAPD-PCR, and one or two among strains showing the same band pattern were selected. Finally, 25 representative strains were selected for further functional study. Inhibitory effects of lipid accumulation were observed in the strains tested. Pediococcus pentosaceus K28, Levilactobacillus brevis RP21 and Lactiplantibacillus plantarum RP12 significantly reduced lipid accumulation and did not show cytotoxicity in C3H10T1/2 cells at treatment of 1-200 μg/mL. The three LAB strains decreased significantly expression of six adipogenic marker genes, PPARγ, C/EBPα, CD36, LPL, FAS and ACC, in C3H10T1/2 adipocytes. The three strains survived under strong acidity and bile salt conditions. The three strains showed adhesion to Caco-2 cells similar to a reference strain LGG. The resistance of the three strains to several antibiotics was also assessed. Strains RP12 and K28 were confirmed not to produce harmful enzymes based on API ZYM kit results. Based on these results, strains K28, RP21 and RP12 isolated from grains had the ability to inhibit adipogenesis in adipocytes and potentially be useful as probiotics.

The convergent application of metabolites from Avena sativa and gut microbiota to ameliorate non-alcoholic fatty liver disease: a network pharmacology study

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is a serious public health issue globally, currently, the treatment of NAFLD lies still in the labyrinth. In the inchoate stage, the combinatorial application of food regimen and favorable gut microbiota (GM) are considered as an alternative therapeutic. Accordingly, we integrated secondary metabolites (SMs) from GM and Avena sativa (AS) known as potent dietary grain to identify the combinatorial efficacy through network pharmacology.

METHODS

We browsed the SMs of AS via Natural Product Activity & Species Source (NPASS) database and SMs of GM were retrieved by gutMGene database. Then, specific intersecting targets were identified from targets related to SMs of AS and GM. The final targets were selected on NAFLD-related targets, which was considered as crucial targets. The protein-protein interaction (PPI) networks and bubble chart analysis to identify a hub target and a key signaling pathway were conducted, respectively. In parallel, we analyzed the relationship of GM or AS─a key signaling pathway─targets─SMs (GASTM) by merging the five components via RPackage. We identified key SMs on a key signaling pathway via molecular docking assay (MDA). Finally, the identified key SMs were verified the physicochemical properties and toxicity in silico platform.

RESULTS

The final 16 targets were regarded as critical proteins against NAFLD, and Vascular Endothelial Growth Factor A (VEGFA) was a key target in PPI network analysis. The PI3K-Akt signaling pathway was the uppermost mechanism associated with VEGFA as an antagonistic mode. GASTM networks represented 122 nodes (60 GM, AS, PI3K-Akt signaling pathway, 4 targets, and 56 SMs) and 154 edges. The VEGFA-myricetin, or quercetin, GSK3B-myricetin, IL2-diosgenin complexes formed the most stable conformation, the three ligands were derived from GM. Conversely, NR4A1-vestitol formed stable conformation with the highest affinity, and the vestitol was obtained from AS. The given four SMs were no hurdles to develop into drugs devoid of its toxicity.

CONCLUSION

In conclusion, we show that combinatorial application of AS and GM might be exerted to the potent synergistic effects against NAFLD, dampening PI3K-Akt signaling pathway. This work provides the importance of dietary strategy and beneficial GM on NAFLD, a data mining basis for further explicating the SMs and pharmacological mechanisms of combinatorial application (AS and GM) against NAFLD.

A metabolomics approach to the validation of predictive metabolites and phenotypic expression in non-alcoholic fatty liver disease

AIMS

Nonalcoholic fatty liver disease (NAFLD) is becoming more common and severe. Individuals with NAFLD have an altered composition of gut- microbial metabolites. We used metabolomics profiling to identify microbial metabolites that could indicate gut-liver metabolic severity. Noninvasive biomarkers are required for NAFLD, especially for patients at high risk of disease progression.

MAIN METHODS

We compared the stool metabolomes, untargeted metabolomics, and clinical data of 80 patients. Patients with nonalcoholic fatty liver (NAFL: n = 16), nonalcoholic steatohepatitis (NASH: n = 26), and cirrhosis (n = 19) and healthy control individuals (HC: n = 19) were enrolled. The identified metabolites in NAFLD were evaluated by multivariate statistical analysis and metabolic pathotypic expression. Gas chromatography-mass spectrometry (GC-MS) and liquid chromatography coupled to time-of-flight-mass spectrometry (LC-TOF-MS) were used to analyze metabolites.

KEY FINDINGS

Untargeted metabolomics was used to identify and quantify 103 metabolites. Principal component analysis (PCA) was used to assess the metabolic discrimination of NAFL, NASH, and cirrhosis. Short-chain fatty acids (SCFA) levels were significantly lower in NAFLD patients, including those of acetate (p = 0.03), butyrate (p = 0.0008), and propionate. The stool cholic acid (p = 0.001) level was significantly increased in NAFLD patients. Palmitoylcarnitine and l-carnitine levels were significantly increased in NASH and cirrhosis patients. The phenotypic expression of these metabolites was linked to β-oxidation.

SIGNIFICANCE

We demonstrated a distinct metabolome profile in NAFLD patients with NAFL, NASH, and cirrhosis. We also discovered that the expression of certain metabolites and metabolic pathways was linked to NAFLD.

Bifidobacterium-derived short-chain fatty acids and indole compounds attenuate nonalcoholic fatty liver disease by modulating gut-liver axis

Emerging evidences about gut-microbial modulation have been accumulated in the treatment of nonalcoholic fatty liver disease (NAFLD). We evaluated the effect of Bifidobacterium breve and Bifidobacterium longum on the NAFLD pathology and explore the molecular mechanisms based on multi-omics approaches. Human stool analysis [healthy subjects (n = 25) and NAFLD patients (n = 32)] was performed to select NAFLD-associated microbiota. Six-week-old male C57BL/6 J mice were fed a normal chow diet (NC), Western diet (WD), and WD with B. breve (BB) or B. longum (BL; 109 CFU/g) for 8 weeks. Liver/body weight ratio, histopathology, serum/tool analysis, 16S rRNA-sequencing, and metabolites were examined and compared. The BB and BL groups showed improved liver histology and function based on liver/body ratios (WD 7.07 ± 0.75, BB 5.27 ± 0.47, and BL 4.86 ± 0.57) and NAFLD activity scores (WD 5.00 ± 0.10, BB 1.89 ± 1.45, and BL 1.90 ± 0.99; p < 0.05). Strain treatment showed ameliorative effects on gut barrier function. Metagenomic analysis showed treatment-specific changes in taxonomic composition. The community was mainly characterized by the significantly higher composition of the Bacteroidetes phylum among the NC and probiotic-feeding groups. Similarly, the gut metabolome was modulated by probiotics treatment. In particular, short-chain fatty acids and tryptophan metabolites were reverted to normal levels by probiotics, whereas bile acids were partially normalized to those of the NC group. The analysis of gene expression related to lipid and glucose metabolism as well as the immune response indicated the coordinative regulation of β-oxidation, lipogenesis, and systemic inflammation by probiotic treatment. BB and BL attenuate NAFLD by improving microbiome-associated factors of the gut-liver axis.

The Link between Gut Microbiota and Hepatic Encephalopathy

Hepatic encephalopathy (HE) is a serious complication of cirrhosis that causes neuropsychiatric problems, such as cognitive dysfunction and movement disorders. The link between the microbiota and the host plays a key role in the pathogenesis of HE. The link between the gut microbiome and disease can be positively utilized not only in the diagnosis area of HE but also in the treatment area. Probiotics and prebiotics aim to resolve gut dysbiosis and increase beneficial microbial taxa, while fecal microbiota transplantation aims to address gut dysbiosis through transplantation (FMT) of the gut microbiome from healthy donors. Antibiotics, such as rifaximin, aim to improve cognitive function and hyperammonemia by targeting harmful taxa. Current treatment regimens for HE have achieved some success in treatment by targeting the gut microbiota, however, are still accompanied by limitations and problems. A focused approach should be placed on the establishment of personalized trial designs and therapies for the improvement of future care. This narrative review identifies factors negatively influencing the gut–hepatic–brain axis leading to HE in cirrhosis and explores their relationship with the gut microbiome. We also focused on the evaluation of reported clinical studies on the management and improvement of HE patients with a particular focus on microbiome-targeted therapy.

Identification of Gut Microbiome Metabolites via Network Pharmacology Analysis in Treating Alcoholic Liver Disease

Alcoholic liver disease (ALD) is linked to a broad spectrum of diseases, including diabetes, hypertension, atherosclerosis, and even liver carcinoma. The ALD spectrum includes alcoholic fatty liver disease (AFLD), alcoholic hepatitis, and cirrhosis. Most recently, some reports demonstrated that the pathogenesis of ALD is strongly associated with metabolites of human microbiota. AFLD was the onset of disease among ALDs, the initial cause of which is alcohol consumption. Thus, we analyzed the significant metabolites of microbiota against AFLD via the network pharmacology concept. The metabolites from microbiota were retrieved by the gutMGene database; sequentially, AFLD targets were identified by public databases (DisGeNET, OMIM). The final targets were utilized for protein–protein interaction (PPI) networks and signaling pathway analyses. Then, we performed a molecular docking test (MDT) to verify the affinity between metabolite(s) and target(s) utilizing the Autodock 1.5.6 tool. From a holistic viewpoint, we integrated the relationships of microbiota-signaling pathways-targets-metabolites (MSTM) using the R Package. We identified the uppermost six key targets (TLR4, RELA, IL6, PPARG, COX-2, and CYP1A2) against AFLD. The PPI network analysis revealed that TLR4, RELA, IL6, PPARG, and COX-2 had equivalent degrees of value (4); however, CYP1A2 had no associations with the other targets. The bubble chart showed that the PI3K-Akt signaling pathway in nine signaling pathways might be the most significant mechanism with antagonistic functions in the treatment of AFLD. The MDT confirmed that Icaritin is a promising agent to bind stably to RELA (known as NF-Κb). In parallel, Bacterium MRG-PMF-1, the PI3K-Akt signaling pathway, RELA, and Icaritin were the most significant components against AFLD in MSTM networks. In conclusion, we showed that the Icaritin–RELA complex on the PI3K-Akt signaling pathway by bacterial MRG-PMF-1 might have promising therapeutic effects against AFLD, providing crucial evidence for further research.

The Lactobacillus as a Probiotic: Focusing on Liver Diseases

Over the past decade, scientific evidence for the properties, functions, and beneficial effects of probiotics for humans has continued to accumulate. Interest in the use of probiotics for humans has increased tremendously. Among various microorganisms, probiotics using bacteria have been widely studied and commercialized, and, among them, Lactobacillus is representative. This genus contains about 300 species of bacteria (recently differentiated into 23 genera) and countless strains have been reported. They improved a wide range of diseases including liver disease, gastrointestinal diseases, respiratory diseases, and autoimmune diseases. Here, we intend to discuss in depth the genus Lactobacillus as a representative probiotic for chronic liver diseases.

Oral Administration of Latilactobacillus sakei ADM14 Improves Lipid Metabolism and Fecal Microbiota Profile Associated With Metabolic Dysfunction in a High-Fat Diet Mouse Model

Effects of Latilactobacillus sakei ADM14 on changes in lipid metabolism and fecal microbiota composition were studied in high-fat diet (HFD) mouse model. The mice were divided into three groups: normal diet (ND), high-fat diet (HD), and HFD plus L. sakei ADM14 (HDA). Oral administration of L. sakei ADM14 daily for 10weeks decreased body weight gain, fat tissue mass, and liver weight in mice and reduced the size of histologically stained liver adipocytes. In addition, serum total cholesterol, triglycerides, and blood glucose decreased significantly. Latilactobacillus sakei ADM14 regulated the expression of genes related to lipid metabolism in epididymal adipose tissue and liver and induced changes in the composition of fecal microbiota, thereby improving energy harvests and changing metabolic disorder-related taxa. A significant decrease (p<0.05) in the Firmicutes to Bacteroidetes ratio was found in the HDA group compared to the HD group, particularly due to the difference in the relative abundance of the Bacteroidetes between the two groups over 10weeks. Differences in proportions of some taxa reported to have correlation with obesity were also found between HD and HDA groups. These results suggest that L. sakei ADM14 can have a positive effect on metabolic disorders such as obesity and fatty liver through effective regulation of host lipid metabolism and gut microbiota.

Gut Microbiota-Related Cellular and Molecular Mechanisms in the Progression of Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is one of the most common and increasing liver diseases worldwide. NAFLD is a term that involves a variety of conditions such as fatty liver, steatohepatitis, or fibrosis. Gut microbiota and its products have been extensively studied because of a close relation between NAFLD and microbiota in pathogenesis. In the progression of NAFLD, various microbiota-related molecular and cellular mechanisms, including dysbiosis, leaky bowel, endotoxin, bile acids enterohepatic circulation, metabolites, or alcohol-producing microbiota, are involved. Currently, diagnosis and treatment techniques using these mechanisms are being developed. In this review, we will introduce the microbiota-related mechanisms in the progression of NAFLD and future directions will be discussed.

Characterization of a novel carboxylesterase belonging to family VIII hydrolyzing β-lactam antibiotics from a compost metagenomic library

A novel esterase, EstCS3, was isolated from a metagenomic library constructed from a compost. The EstCS3, which consists of 409 amino acids with an anticipated molecular mass of 44 kDa, showed high amino acid sequence identities to predicted esterases, serine hydrolases and β-lactamases from uncultured and cultured bacteria. Phylogenetic analysis suggested that EstCS3 belongs to family VIII of lipolytic enzymes. EstCS3 had catalytic Ser78 residue in the consensus tetrapeptide motif SXXK, which is characteristic of family VIII esterases. Two conserved YXX and W(H or K)XG motifs in an oxyanion hole of family VIII esterases were also present in EstCS3. EstCS3 demonstrated the highest activity toward p-nitrophenyl butyrate (C4) and was stable up to 70 °C with optimal activity at 55 °C. EstCS3 had optimal activity at pH 8 and maintained its stability within pH range of 7-10. EstCS3 had over 70% activity in the presence of 20% (v/v) methanol and DMSO and hydrolyzed sterically hindered tertiary alcohol esters of t-butyl acetate and linalyl acetate. EstCS3 hydrolyzed ampicillin, cephalothin and cefepime. The properties of EstCS3, including moderate thermostability, stability against organic solvents and activity toward esters of tertiary alcohols, indicated that it has the potential to be used in industrial applications.

Characterization of a Novel Moderately Thermophilic Solvent-Tolerant Esterase Isolated From a Compost Metagenome Library

A novel esterase, EstCS1, was isolated from a compost metagenomics library. The EstCS1 protein, which consists of 309 amino acid residues with an anticipated molecular mass of 34 kDa, showed high amino acid sequence identities to predicted esterases and alpha/beta hydrolases (59%) from some cultured bacteria and to predicted lipases/esterases from uncultured bacteria. The phylogenetic analysis suggested that the EstCS1 belongs to the hormone-sensitive lipase family of lipolytic enzyme classification and contains a catalytic triad including Ser155–Asp255–His285. The Ser155 residue of the catalytic triad in the EstCS1 was located in the consensus active-site motif, GXSXG. Besides, a conserved HGGG motif placed in an oxyanion hole of the hormone-sensitive lipase family was discovered, too. The EstCS1 demonstrated the highest activity toward p-nitrophenyl propionate (C3) and caproate (C6) and was normally stable up to 60°C with optimal activity at 50°C. In addition, an optimal activity was observed at pH 8, and the EstCS1 possessed its stability within the pH range between 5 and 10. Interestingly, EstCS1 had an outstanding stability in up to 30% (v/v) organic solvents and activity over 50% in the presence of 50% (v/v) acetone, ethanol, dimethyl sulfoxide (DMSO), and N,N-dimethylformamide. The EstCS1 hydrolyzed sterically hindered tertiary alcohol esters of t-butyl acetate and linalyl acetate. Considering the properties, such as the moderate thermostability, stability against organic solvents, and activity toward esters of tertiary alcohols, the EstCS1 will be worthwhile to be used for organic synthesis and related industrial applications.

Aliishimia ponticola gen. nov., sp. nov., isolated from seawater

A Gram-stain-negative, aerobic, non-motile and coccoid, ovoid or rod-shaped bacterial strain, designated MYP11^T, was isolated from seawater around Jeju island, Republic of Korea and identified by polyphasic taxonomic study. A neighbour-joining phylogenetic tree of 16S rRNA gene sequences showed that strain MYP11^T joined the cluster comprising the type strains of Shimiaabyssi, Shimiaaestuarii and Shimiaaquaeponti, showing 16S rRNA gene sequence similarities of 96.3-96.8 %. Strain MYP11^T exhibited 16S rRNA gene sequence similarity values of 94.2-94.9 % to the type strains of other Shimia species. In the upgma dendrogram based on the average nucleotide identity values of genomic sequences, strain MYP11^T formed an evolutionary lineage independent of those of Shimia species and other taxa. Strain MYP11^T contained Q-10 as the predominant ubiquinone and C_18 : 1  ω7c and cyclo C_19 : 0  ω8c as the major fatty acids. The major polar lipids of strain MYP11^T were phosphatidylcholine, phosphatidylglycerol, two unidentified lipids and one unidentified aminolipid. The DNA G+C content of strain MYP11^T was 63.1 or 61.5 mol%. The differences in the fatty acid and polar lipid profiles and DNA G+C contents made it reasonable to distinguish strain MYP11^T from the type strains of S. abyssi, S. aestuarii and S. aquaeponti and those of other Shimia species. On the basis of the polyphasic data presented here, strain MYP11^T is considered to constitute a new genus and species within the class Alphaproteobacteria, for which the name Aliishimia ponticola gen. nov., sp. nov. is proposed. The type strain is MYP11^T (=KCTC 62899^T=NBRC 113544^T).

Aestuariibius insulae gen. nov., sp. nov., isolated from a tidal flat sediment

A Gram-stain-negative, non-motile and ovoid or rod-shaped bacterial strain, DBTF-13^T, which was isolated from a tidal flat sediment of the Yellow Sea in South Korea, was characterized taxonomically. Strain DBTF-13^T grew optimally at 25-30 °C and pH 7.0-8.0, and in the presence of 2.0 % (w/v) NaCl. The phylogenetic trees based on 16S rRNA gene sequences revealed that strain DBTF-13^T formed an evolutionary lineage independent of other genera, including the genera Pseudooctadecabacter and Octadecabacter. Strain DBTF-13^T exhibited 16S rRNA gene sequence similarity values of 96.9 % to the type strain of Pseudooctadecabacter jejudonensis, and of 95.8-96.5 % to the type strains of Octadecabacter species. Strain DBTF-13^T contained Q-10 as the predominant ubiquinone and C18 : 1ω7c and C16 : 0 as the major fatty acids. The major polar lipids of strain DBTF-13^T were phosphatidylcholine, phosphatidylglycerol, one unidentified aminolipid and one unidentified lipid. The DNA G+C content of strain DBTF-13^T was 61.6 mol%. The chemotaxonomic data and other differential phenotypic properties made it reasonable to differentiate strain DBTF-13^T from the genera Pseudooctadecabacter and Octadecabacter. On the basis of the data presented, strain DBTF-13^T constitutes a new genus and species within the class Alphaproteobacteria, for which the name Aestuariibius insulae gen. nov., sp. nov. is proposed. The type strain is DBTF-13^T (=KACC 19432^T=NBRC 113038^T).

Thalassotalea insulae sp. nov., isolated from tidal flat sediment

A Gram-stain-negative, aerobic, motile and rod-shaped or ovoid bacterial strain, designated JDTF-40^T, was isolated from a tidal flat in Jindo, an island of the Republic of South Korea. Strain JDTF-40^T grew optimally at pH 7.0-8.0, at 30 °C and in the presence of 2 % (w/v) NaCl. The neighbour-joining phylogenetic tree based on 16S rRNA gene sequences showed that strain JDTF-40^T fell within the cluster comprising the type strains of Thalassotalea species. Strain JDTF-40^T exhibited 16S rRNA gene sequence similarity values of 93.8-95.7 % to the type strains of Thalassotalea species. Strain JDTF-40^T contained Q-8 as the predominant ubiquinone and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and C16 : 0 as the major fatty acids. The major polar lipids of strain JDTF-40^T were phosphatidylglycerol, phosphatidylethanolamine, one unidentified aminolipid, one unidentified glycolipid and three unidentified lipids. The DNA G+C content of strain JDTF-40^T was 41.3 mol%. Differential phenotypic properties, together with the phylogenetic distinctiveness, demonstrated that strain JDTF-40^T is distinct from recognized species of the genus Thalassotalea. On the basis of the data presented here, strain JDTF-40^T is considered to represent a novel species of the genus Thalassotalea, for which the name Thalassotalea insulae sp. nov. is proposed. The type strain is JDTF-40^T (=KACC 19433^T=KCTC 62186^T=NBRC 113040^T).

Paracoccus alimentarius sp. nov., isolated from a Korean foodstuff, salted pollack

A Gram-stain-negative, aerobic, non-motile and coccoid or ovoid bacterial strain, designated LB2^T, was isolated from a Korean foodstuff, salted pollack. Strain LB2^T grew optimally at 25-30 °C, at pH 7.0-8.0 and in the presence of 0-2.0 % (w/v) NaCl. Phylogenetic trees based on 16S rRNA gene sequences showed that strain LB2^T belonged to the genus Paracoccus, coherently clustering with the type strain of Paracoccus sulfuroxidans. Strain LB2^T exhibited 16S rRNA gene sequence similarity values of 98.0 and 97.0 % to the type strains of P. sulfuroxidans and Paracoccus halophilus, respectively, and of less than 96.9 % to the type strains of other Paracoccus species. Strain LB2^T contained Q-10 as the predominant ubiquinone. Major fatty acids of strain LB2^T were cyclo C19 : 0ω8c, C18 : 1ω7c and C16 : 0 (when grown on MA) or C18 : 1ω7c and C16 : 0 (on TSA). The major polar lipids detected in strain LB2^T were phosphatidylcholine, phosphatidylglycerol, diphosphatidylglycerol, one unidentified aminolipid and one unidentified glycolipid. The DNA G+C content of strain LB2^T was 61.4 mol% and its DNA-DNA relatedness values with the type strains of P. sulfuroxidans and P. halophilus were 26 and 18 %, respectively. Differential phenotypic properties, together with its phylogenetic and genetic distinctiveness, revealed that strain LB2^T is separated from recognized Paracoccus species. On the basis of the data presented, strain LB2^T is considered to represent a novel species of the genus Paracoccus, for which the name Paracoccus alimentarius sp. nov. is proposed. The type strain is LB2^T (=KCTC 62138^T=NBRC 113023^T).

Tenacibaculum aestuariivivum sp. nov., isolated from a tidal flat

A Gram-stain-negative, aerobic, non-motile, non-spore-forming bacterial strain, designated JDTF-79^T, was isolated from a tidal flat in Jindo, an island of South Korea, and subjected to a taxonomic study using a polyphasic approach. Strain JDTF-79^T grew optimally at 25 °C and in the presence of 2.0 % (w/v) NaCl. Phylogenetic trees based on 16S rRNA gene sequences showed that strain JDTF-79^T fell within the clade comprising the type strains of species of the genus Tenacibaculum, clustering with the type strains of Tenacibaculum dicentrarchi, Tenacibaculum ovolyticum, 'Tenacibaculum haliotis' and Tenacibaculum soleae. The novel strain exhibited highest 16S rRNA gene sequence similarity (98.3 %) to the type strain of T. dicentrarchi and sequence similarities of 93.5-96.9 % to the type strains of the other species of the genus Tenacibaculum. Strain JDTF-79^T contained MK-6 as the predominant menaquinone and anteiso-C15 : 0, iso-C15 : 0 3-OH and iso-C15 : 0 as the major fatty acids. The major polar lipids of strain JDTF-79^T were phosphatidylethanolamine, one unidentified lipid and one unidentified aminophospholipid. The DNA G+C content of strain JDTF-79^T was 30.3 mol%. Strain JDTF-79^T had a mean DNA-DNA relatedness value of 19 % with the type strain of T. dicentrarchi. The differential phenotypic properties, together with the phylogenetic and genetic data, revealed that strain JDTF-79^T is separated from other recognized species of the genus Tenacibaculum. On the basis of the data presented, strain JDTF-79^T is considered to represent a novel species of the genus Tenacibaculum, for which the name Tenacibaculum aestuariivivum sp. nov. is proposed. The type strain is JDTF-79^T (=KCTC 52980^T=NBRC 112903^T).

Loktanella acticola sp. nov., isolated from seawater

A Gram-stain-negative, aerobic, non-motile and coccoid, ovoid or rod-shaped bacterial strain, designated OISW-6^T, was isolated from seawater near Oido, a South Korean island, and subjected to a polyphasic taxonomic study. Strain OISW-6^T grew optimally at 25 °C, at pH 7.0-8.0 and in the presence of 2.0-3.0 % (w/v) NaCl. The phylogenetic trees based on 16S rRNA gene sequences showed that strain OISW-6^T fell within the clade comprising the type strains of Loktanella species. Strain OISW-6^T exhibited 16S rRNA gene sequence similarity values of 97.0-98.9 % to Loktanellamaricola, Loktanellatamlensis, Loktanellarosea, Loktanellamaritima, Loktanellasediminilitoris and Loktanellalitorea, and of 94.0-96.3 % to the type strains of the other Loktanella species. Strain OISW-6^T contained Q-10 as the predominant ubiquinone and C18 : 1ω7c as the major fatty acid. The major polar lipids detected in strain OISW-6^T were phosphatidylcholine, phosphatidylglycerol and one unidentified aminolipid. The DNA G+C content of strain OISW-6^T was 57.3 mol% and its DNA-DNA relatedness values with the type strains of the six phylogenetically closely related Loktanella species were 8-25 %. Differential phenotypic properties, together with its phylogenetic and genetic distinctiveness, revealed that strain OISW-6^T is separated from recognized species of the genus Loktanella. On the basis of the data presented, strain OISW-6^T is considered to represent a novel species of the genus Loktanella, for which the name Loktanellaacticola sp. nov. is proposed. The type strain is OISW-6^T (=KCTC 52837^T=NBRC 112781^T).

Demequina litorisediminis sp. nov., isolated from a tidal flat, and emended description of the genus Demequina

A Gram-stain-positive, facultatively anaerobic, non-spore-forming, non-flagellated and rod-shaped or ovoid bacterial strain, GHD-1T, was isolated from a tidal flat sediment on the Yellow Sea, South Korea. It grew optimally at 30 °C, at pH 6.5-8.0 and in the presence of 1.0-2.0 % (w/v) NaCl. A neighbour-joining phylogenetic tree based on 16S rRNA gene sequences revealed that strain GHD-1T fell within the cluster comprising the type strains of species of the genus Demequina. Strain GHD-1T exhibited 16S rRNA gene sequence similarity values of 97.0-98.8 % to the type strains of Demequinaglobuliformis, D. salsinemoris, D. flava, D. sediminicola and D. activiva, and of 95.5-96.9 % to the type strains of the other species of the genus Demequina. The peptidoglycan type of strain GHD-1T is A4β based on l-Orn-l-Ser-l-Asp. It contained DMK-9(H4) and DMK-8(H4) as the major menaquinones and anteiso-C15 : 0, C16 : 0, iso-C16 : 0 and anteiso-C17 : 0 as the major fatty acids. The major polar lipids were phosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannoside and one unidentified glycolipid. The DNA G+C content of strain GHD-1T was 68.7 mol%, and its DNA-DNA relatedness values with the type strains of five phylogenetically related species of the genus Demequina were 13-29 %. The differential phenotypic properties, together with the phylogenetic and genetic distinctiveness, revealed that strain GHD-1T is separated from other recognized species of the genus Demequina. On the basis of the data presented, strain GHD-1T is considered to represent a novel species of the genus Demequina, for which the name Demequina litorisediminis sp. nov. is proposed. The type strain is GHD-1T (=KCTC 52260T=NBRC 112299T).

Paracoccus aestuariivivens sp. nov., isolated from a tidal flat

A Gram-stain-negative, non-spore-forming, non-motile and coccoid, ovoid or short-rod-shaped bacterial strain, designated GHD-30T, was isolated from a tidal flat on the Yellow Sea in South Korea, and subjected to a polyphasic taxonomic study. Strain GHD-30T grew optimally at 30 °C, at pH 6.5-7.5 and in the presence of 2.0 % (w/v) NaCl. The phylogenetic trees based on 16S rRNA gene sequences showed that strain GHD-30Trepresented a member of the genus Paracoccus. Strain GHD-30T exhibited 16S rRNA gene sequence similarity values of 97.10-97.33 % to the type strains of Paracoccus lutimaris, Paracoccus limosus and Paracoccus halophilus and of 94.35-96.97 % to the type strains of the other species of the genus Paracoccus. Strain GHD-30T contained Q-10 as the predominant ubiquinone and C18 : 1ω7c as the major fatty acid. The major polar lipids detected in strain GHD-30T were phosphatidylcholine, phosphatidylglycerol, diphosphatidylglycerol, one unidentified glycolipid and one unidentified aminolipid. The DNA G+C content of strain GHD-30T was 62.0 mol% and its mean DNA-DNA relatedness values with the type strains of P. lutimaris, P. limosus, and P. halophilus were 11-19 %. Differential phenotypic properties, together with its phylogenetic and genetic distinctiveness, revealed that strain GHD-30T is separated from recognized species of the genus Paracoccus. On the basis of the data presented, strain GHD-30T is considered to represent a novel species of the genus Paracoccus, for which the name Paracoccus aestuariivivens sp. nov. is proposed. The type strain is GHD-30T (=KCTC 52214T =NBRC 111993T).

Gramella sediminilitoris sp. nov., isolated from a tidal flat

A Gram-stain-negative, aerobic, non-spore-forming, motile by gliding and coccoid, ovoid or rod-shaped bacterial strain, designated GHTF-27^T, was isolated from a tidal flat at Goheung, South Korea, and subjected to a taxonomic study using a polyphasic approach. The novel strain grew optimally at 30 °C, at pH 7.0-8.0 and in the presence of 2.0-5.0 % (w/v) NaCl. Phylogenetic trees based on 16S rRNA gene sequences revealed that strain GHTF-27^T belongs to the genus Gramella. It exhibited 16S rRNA gene sequence similarity values of 97.6-98.3 % to the type strains of Gramella aestuariivivens, Gramella echinicola, Gramella gaetbulicola, Gramella aquimixticola, Gramella aestuarii and Gramella portivictoriae, respectively, and of 93.8-96.7 % to the type strains of the other species of the genus Gramellawith validly published names. Strain GHTF-27^T contained MK-6 as the predominant menaquinone and iso-C15 : 0 and iso-C17 : 0 3-OH as the major fatty acids. The major polar lipids of strain GHTF-27^T were phosphatidylethanolamine and one unidentified lipid. The DNA G+C content of strain GHTF-27^T was 39.7 mol% and DNA-DNA relatedness values with the type strains of the six phylogenetically closely related species of the genus Gramellawere 12-28 %. The differential phenotypic properties, together with its phylogenetic and genetic distinctiveness, revealed that strain GHTF-27^T is separated from other species of the genus Gramella. On the basis of the data presented, strain GHTF-27^T is considered to represent a novel species of the genus Gramella, for which the name Gramella sediminilitorissp. nov. is proposed. The type strain is GHTF-27^T (=KCTC 52208^T =NBRC 111992^T).

Primorskyibacter insulae sp. nov., isolated from the junction between the ocean and a freshwater spring

A Gram-stain-negative, aerobic, non-spore-forming, non-flagellated and rod-shaped bacterial strain, designated SSK3-2T, was isolated from the locality where the ocean and a freshwater spring meet at Jeju island, South Korea, and subjected to a polyphasic taxonomic study. Strain SSK3-2T grew optimally at 30 °C, at pH 7.0–8.0 and in the presence of 2.0 % (w/v) NaCl. Neighbour-joining, maximum-likelihood and maximum-parsimony phylogenetic trees based on 16S rRNA gene sequences revealed that strain SSK3-2T clustered with the type strain of Primorskyibacter sedentarius, with which it exhibited 97.3 % sequence similarity. Strain SSK3-2T contained Q-10 as the predominant ubiquinone and C18 : 1ω7c as the major fatty acid. The major polar lipids detected in strain SSK3-2T were phosphatidylcholine, phosphatidylglycerol, one unidentified lipid and one unidentified aminolipid. The DNA G+C content of strain SSK3-2T was 60.6 mol% and its mean DNA–DNA relatedness value with P. sedentarius JCM 16874T was 19 %. Differential phenotypic properties, together with phylogenetic and genetic distinctiveness, revealed that strain SSK3-2T is separated from P. sedentarius. On the basis of the data presented, strain SSK3-2T is considered to represent a novel species of the genus Primorskyibacter, for which the name Primorskyibacter insulae sp. nov. is proposed. The type strain is SSK3-2T ( = KCTC 42602T = CECT 8871T).

Pedobacter lignilitoris sp. nov., isolated from wood falls

A Gram-stain-negative, aerobic, non-motile and rod-shaped bacterial strain, designated W-WS13T, was isolated from wood falls collected around Wando, an island in the South Sea of South Korea, and subjected to a polyphasic taxonomic study. Strain W-WS13T grew optimally at 30 °C, at pH 7.5 and in the presence of 0.5 % NaCl. A neighbour-joining phylogenetic tree based on 16S rRNA gene sequences showed that strain W-WS13T belonged to the genus Pedobacter, clustering robustly with the type strain of Pedobacter arcticus, sharing 95.9 % sequence similarity. Strain W-WS13T exhibited 16S rRNA gene sequence similarity of 90.1–95.6 % to the type strains of the other species of the genus Pedobacter. Strain W-WS13T contained MK-7 as the predominant menaquinone and iso-C15 : 0, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and iso-C17 : 0 3-OH as the major fatty acids. The major polar lipid detected in strain W-WS13T was phosphatidylethanolamine. The DNA G+C content of strain W-WS13T was 36.9 mol%. Phylogenetic distinctiveness and differential phenotypic properties of strain W-WS13T revealed that the novel strain is separated from recognized species of the genus Pedobacter. On the basis of the data presented, strain W-WS13T is considered to represent a novel species of the genus Pedobacter, for which the name Pedobacter lignilitoris sp. nov. is proposed. The type strain is W-WS13T ( = KCTC 42500T = CECT 8725T).

Maribacter confluentis sp. nov., isolated from the junction between the ocean and a freshwater spring

A Gram-stain-negative, aerobic, non-spore-forming, non-flagellated, non-gliding and rod-shaped bacterial strain, SSK2-2(T), was isolated from the place where the ocean and a freshwater spring meet at Jeju island, South Korea. Strain SSK2-2(T) grew optimally at 30 °C, at pH 7.0-8.0 and in the presence of 2.0-3.0% (w/v) NaCl. The neighbour-joining phylogenetic tree based on 16S rRNA gene sequences revealed that strain SSK2-2(T) fell within the clade comprising the type strains of species of the genus Maribacter, joining the type strain of Maribacter sedimenticola with which it shared 99.4% similarity. Sequence similarities to the type strains of other Maribacter species were 94.6-98.2%. Strain SSK2-2(T) contained MK-6 as the predominant menaquinone and iso-C17 : 0 3-OH, iso-C15 : 0, iso-C15 : 1 G, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and summed feature 9 (iso-C17 : 1ω9c and/or 10-methyl C16 : 0) as the major fatty acids. The major polar lipids of strain SSK2-2(T) were phosphatidylethanolamine and one unidentified lipid. The DNA G+C content of strain SSK2-2(T) was 38.2 mol% and mean levels of DNA-DNA relatedness with the type strains of four phylogenetically related species of the genus Maribacter were 11-24%. Differential phenotypic properties, together with phylogenetic and genetic distinctiveness, revealed that strain SSK2-2(T) is separate from other Maribacter species. On the basis of the data presented, strain SSK2-2(T) is considered to represent a novel species of the genus Maribacter, for which the name Maribacter confluentis sp. nov. is proposed. The type strain is SSK2-2(T) ( = KCTC 42604(T) = CECT 8869(T)).

Lutibacter crassostreae sp. nov., isolated from oyster

A Gram-stain-negative, aerobic, non-spore-forming, non-flagellated, non-gliding and ovoid or rod-shaped bacterial strain, designated TYO-8T, was isolated from an oyster collected from the South Sea in South Korea. Strain TYO-8T grew optimally at 25 °C, at pH 7.0-8.0 and in the presence of 2.0-3.0% (w/v) NaCl. A neighbour-joining phylogenetic tree, based on 16S rRNA gene sequences, revealed that strain TYO-8T fell within the clade comprising the type strains of species of the genus Lutibacter, clustering coherently with the type strain of Lutibacter litoralis with a sequence similarity of 99.3%. Strain TYO-8T exhibited 16S rRNA gene sequence similarity values of 95.3-97.5% to the type strains of other species of the genus Lutibacter and of less than 92.9% to the type strains of other species with validly published names. Strain TYO-8T contained MK-6 as the predominant menaquinone and iso-C15 : 0, iso-C15 : 0 3-OH and iso-C15 : 1 G as the major fatty acids. The major polar lipids of strain TYO-8T were phosphatidylethanolamine and two unidentified lipids. The DNA G+C content of strain TYO-8T was 33.8 mol% and its DNA-DNA relatedness values with the type strains of L. litoralis, Lutibacter aestuarii and Lutibacter flavus were 13-27%. The differential phenotypic properties, together with the phylogenetic and genetic distinctiveness, revealed that strain TYO-8T is distinct from other species of the genus Lutibacter. On the basis of the data presented, strain TYO-8T is considered to represent a novel species of the genus Lutibacter, for which the name Lutibacter crassostreae sp. nov. is proposed. The type strain is TYO-8T ( = KCTC 42461T = NBRC 110923T).

Sphingomicrobium aestuariivivum sp. nov., isolated from a tidal flat

A Gram-stain-negative, aerobic, non-spore-forming, non-flagellated and coccoid, ovoid or rod-shaped bacterial strain, designated AH-M8T, was isolated from a tidal flat sediment collected from Aphae Island in the south-western sea, South Korea. Strain AH-M8T grew optimally at 35 °C, at pH 7.0-8.0 and in the presence of 2.0-3.0% (w/v) NaCl. A neighbour-joining phylogenetic tree based on 16S rRNA gene sequences revealed that strain AH-M8T belonged to the genus Sphingomicrobium, clustering with the type strain of Sphingomicrobium astaxanthinifaciens, with which it shared 99.0% 16S rRNA gene sequence similarity. Sequence similarities to the type strains of other species of the genus Sphingomicrobium were 95.4-96.0%. Strain AH-M8T contained Q-10 as the predominant ubiquinone and C18 : 1ω7c, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and C16 : 0 as the major fatty acids. The major polar lipids of strain AH-M8T were phosphatidylglycerol, phosphatidylethanolamine, sphingoglycolipid and one unidentified glycolipid. The major polyamine is triamine sym-homospermidine. The DNA G+C content of strain AH-M8T was 66.7 mol% and its mean DNA-DNA relatedness value with S. astaxanthinifaciens JCM 18551T was 21%. The differential phenotypic properties, together with the phylogenetic and genetic distinctiveness, revealed that strain AH-M8T is separated from other species of the genus Sphingomicrobium. On the basis of the data presented, strain AH-M8T is considered to represent a novel species of the genus Sphingomicrobium, for which the name Sphingomicrobium aestuariivivum sp. nov. is proposed. The type strain is AH-M8T ( = KCTC 42286T = NBRC 110678T).

Sulfitobacter undariae sp. nov., isolated from a brown algae reservoir

A Gram-stain-negative, aerobic, non-spore-forming, non-flagellated and coccoid, ovoid or rod-shaped bacterial strain, W-BA2(T), was isolated from a brown algae reservoir in Wando of South Korea. Strain W-BA2(T) grew optimally at 25 °C, at pH 7.0-8.0 and in the presence of approximately 2.0-3.0% (w/v) NaCl. Phylogenetic trees based on 16S rRNA gene sequences revealed that strain W-BA2(T) fell within the clade comprising the type strains of species of the genus Sulfitobacter , clustering coherently with the type strains of Sulfitobacter donghicola and Sulfitobacter guttiformis showing sequence similarity values of 98.0-98.1%. Sequence similarities to the type strains of the other species of the genus Sulfitobacter were 96.0-97.4%. Strain W-BA2(T) contained Q-10 as the predominant ubiquinone and C18 : 1ω7c as the major fatty acid. The major polar lipids of strain W-BA2(T) were phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine, one unidentified aminolipid and one unidentified lipid. The DNA G+C content of strain W-BA2(T) was 55.0 mol% and its DNA-DNA relatedness values with the type strains of Sulfitobacter donghicola , Sulfitobacter guttiformis and Sulfitobacter mediterraneus were 16-23%. The differential phenotypic properties, together with the phylogenetic and genetic distinctiveness, revealed that strain W-BA2(T) is separated from other species of the genus Sulfitobacter . On the basis of the data presented, strain W-BA2(T) is considered to represent a novel species of the genus Sulfitobacter, for which the name Sulfitobacter undariae sp. nov. is proposed. The type strain is W-BA2(T) ( = KCTC 42200(T) = NBRC 110523(T)).

Pseudohalocynthiibacter aestuariivivens gen. nov., sp. nov., isolated from a tidal flat

A Gram-stain-negative, non-motile, aerobic and coccoid, ovoid or rod-shaped bacterial strain, designated BS-W9T, was isolated from a tidal flat of the South Sea, South Korea. Strain BS-W9T grew optimally at 25–30 °C, at pH 7.0–8.0 and in the presence of approximately 2.0 % (w/v) NaCl. Phylogenetic trees, based on 16S rRNA gene sequences, revealed that strain BS-W9T clustered with the type strain of Halocynthiibacter namhaensis , showing a highest sequence similarity of 97.3 %. It exhibited sequence similarity values of less than 95.6 % to the type strains of other species with validly published names. Strain BS-W9T contained Q-10 as the predominant ubiquinone and C18 : 1ω7c as the predominant fatty acid. The major polar lipids of strain BS-W9T were phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, one unidentified lipid and one unidentified aminolipid. The fatty acid and polar lipid profiles of strain BS-W9T were distinguished from those of the type strains of H. namhaensis and other phylogenetically related genera. The DNA G+C content of strain BS-W9T was 53.2 mol% and its mean DNA–DNA relatedness value with H. namhaensis RA2-3T was 14 %. On the basis of the phylogenetic, chemotaxonomic and other phenotypic properties, strain BS-W9T is considered to represent a novel genus and species within the family Rhodobacteraceae , for which the name Pseudohalocyntiibacter aestuariivivens gen. nov., sp. nov. is proposed. The type strain of Pseudohalocyntiibacter aestuariivivens is BS-W9T ( = KCTC 42348T = CECT 8726T).

Gramella aestuariivivens sp. nov., isolated from a tidal flat

A Gram-stain-negative, aerobic, non-spore-forming, non-flagellated and rod-shaped or ovoid bacterial strain, designated BG-MY13T, was isolated from a tidal flat sediment on the South Sea, South Korea. Strain BG-MY13T grew optimally at 30–35 °C, at pH 7.0–8.0 and in the presence of 2.0–3.0 % (w/v) NaCl. Phylogenetic trees based on 16S rRNA gene sequences revealed that strain BG-MY13T falls within the cluster comprising the type strains of species of the genus Gramella . Strain BG-MY13T exhibited 16S rRNA gene sequ4ence similarity values of 96.9–97.8 % to the type strains of Gramella echinicola , Gramella gaetbulicola , Gramella portivictoriae and Gramella marina and of 94.6–96.5 % to the type strains of other species of the genus Gramella with validly published names. Strain BG-MY13T contained MK-6 as the predominant menaquinone and iso-C15 : 0 and iso-C17 : 0 3-OH as the major fatty acids. The major polar lipids were phosphatidylethanolamine and one unidentified lipid. The DNA G+C content of strain BG-MY13T was 38.9 mol% and DNA–DNA relatedness values with the type strains of G. echinicola , G. gaetbulicola , G. portivictoriae and G. marina were 12–23 %. The differential phenotypic properties, together with phylogenetic and genetic distinctiveness, revealed that strain BG-MY13T is separated from other species of the genus Gramella . On the basis of the data presented, strain BG-MY13T is considered to represent a novel species of the genus Gramella , for which the name Gramella aestuariivivens sp. nov. is proposed. The type strain is BG-MY13T ( = KCTC 42285T = NBRC 110677T).

Demequina activiva sp. nov., isolated from a tidal flat

A Gram-stain-positive, facultatively anaerobic, non-spore-forming, non-flagellated and rod-shaped or ovoid bacterial strain, designated BS-12M(T), was isolated from a tidal flat sediment on the South Sea, South Korea. Strain BS-12M(T) grew optimally at 35 °C, at pH 7.0-8.0 and in the presence of 2.0% (w/v) NaCl. The neighbour-joining phylogenetic tree based on 16S rRNA gene sequences revealed that strain BS-12M(T) fell within the cluster comprising the type strains of species of the genus Demequina, joining the type strain of Demequina aestuarii with which it shared the highest sequence similarity (98.6%). It exhibited 16S rRNA gene sequence similarity of 96.1-97.9% to the type strains of other species of the genus Demequina. The peptidoglycan type of strain BS-12M(T) was A4β based on L-Orn -L-Ser -D-Glu. Strain BS-12M(T) contained demethylmenaquinone-9(H4) as the major menaquinone and anteiso-C15:0 and C16:0 as the major fatty acids. The major polar lipids of strain BS-12M(T) were phosphatidylinositol and phosphatidylinositolmannoside. The DNA G+C content of strain BS-12M(T) was 70.7 mol% and its DNA-DNA relatedness values with the type strains of five phylogenetically related species of the genus Demequina were 15-34%. Differential phenotypic properties, together with phylogenetic and genetic distinctiveness, revealed that strain BS-12M(T) is separate from other species of the genus Demequina. On the basis of the data presented, strain BS-12M(T) is considered to represent a novel species of the genus Demequina, for which the name Demequina activiva sp. nov. is proposed. The type strain is BS-12M(T) ( =KCTC 29674(T) = NBRC 110675T).

Amphritea ceti sp. nov., isolated from faeces of Beluga whale (Delphinapterus leucas)

A Gram-stain-negative, aerobic, non-spore-forming, non-flagellated and rod-shaped or ovoid bacterial strain, designated RA1T, was isolated from faeces collected from Beluga whale (Delphinapterus leucas) in Yeosu aquarium, South Korea. Strain RA1T grew optimally at 25 °C, at pH 7.0–8.0 and in the presence of 2.0 % (w/v) NaCl. Neighbour-joining, maximum-likelihood and maximum-parsimony phylogenetic trees based on 16S rRNA gene sequences revealed that strain RA1T joins the cluster comprising the type strains of three species of the genus Amphritea , with which it exhibited 95.8–96.0 % sequence similarity. Sequence similarities to the type strains of other recognized species were less than 94.3 %. Strain RA1T contained Q-8 as the predominant ubiquinone and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), C18 : 1ω7c and C16 : 0 as the major fatty acids. The major polar lipids of strain RA1T were phosphatidylethanolamine, phosphatidylglycerol, two unidentified lipids and one unidentified aminolipid. The DNA G+C content of strain RA1T was 47.4 mol%. The differential phenotypic properties, together with the phylogenetic distinctiveness, revealed that strain RA1T is separated from other species of the genus Amphritea . On the basis of the data presented, strain RA1T is considered to represent a novel species of the genus Amphritea , for which the name Amphritea ceti sp. nov. is proposed. The type strain is RA1T ( = KCTC 42154T = NBRC 110551T).

Rheinheimera arenilitoris sp. nov., isolated from seashore sand

A Gram-stain-negative, non-flagellated, aerobic and ovoid or rod-shaped bacterium, designated J-MS1T, was isolated from seashore sand in the South Sea, South Korea, and subjected to a polyphasic taxonomic study. Strain J-MS1T was found to grow optimally at 30 °C and pH 7.0–8.0. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain J-MS1T belonged to the genus Rheinheimera , clustering coherently with the type strain of Rheinheimera chironomi and sharing 98.34 % sequence similarity. Strain J-MS1T exhibited 16S rRNA gene sequence similarity of 94.26–96.98 % to the type strains of the other species of the genus Rheinheimera . In the phylogenetic trees based on gyrB sequences, strain J-MS1T clustered with the type strain of R. chironomi , with which it shared the highest sequence similarity (86.97 %). Strain J-MS1T contained Q-8 as the predominant ubiquinone and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), C16 : 0 and C18 : 1ω7c as the major fatty acids. The major polar lipids detected in strain J-MS1T and in the type strain of R. chironomi were phosphatidylglycerol and phosphatidylethanolamine. The DNA G+C content of strain J-MS1T was 49.8 mol% and its mean DNA–DNA relatedness value with R. chironomi LMG 23818T was 12 %. Differential phenotypic properties, together with its phylogenetic and genetic distinctiveness, revealed that strain J-MS1T is separated from recognized species of the genus Rheinheimera . On the basis of the data presented, strain J-MS1T is considered to represent a novel species of the genus Rheinheimera , for which the name Rheinheimera arenilitoris sp. nov. is proposed. The type strain is J-MS1T ( = KCTC 42112T = CECT 8623T).

Granulosicoccus undariae sp. nov., a member of the family Granulosicoccaceae isolated from a brown algae reservoir and emended description of the genus Granulosicoccus

A Gram-stain-negative, aerobic, non-flagellated and coccoid bacterial strain, W-BA3(T), which was isolated from a brown algae reservoir in Wando of South Korea, was characterized taxonomically. Strain W-BA3(T) was found to grow optimally at 30 °C, at pH 7.0-8.0 and in presence of 2.0 % (w/v) NaCl. In the neighbour-joining phylogenetic tree based on 16S rRNA gene sequences, strain W-BA3(T) clustered with the type strains of Granulosicoccus antarcticus and Granulosicoccus coccoides, with which it exhibited sequence similarity values of 98.4-99.3 %. Sequence similarity values of strain W-BA3(T) to the type strains of the other recognized species were less than 90.2 %. Strain W-BA3(T) was found to contain Q-8 as the predominant ubiquinone and summed feature 3 (C16:1 ω7c and/or C16:1 ω6c), C18:1 ω7c and C16:0 as the major fatty acids. The major polar lipids of strain W-BA3(T), which were identified as phosphatidylethanolamine and phosphatidylglycerol, were similar to those of the type strains of G. antarcticus and G. coccoides. The DNA G+C content of strain W-BA3(T) was 56.0 mol % and its mean DNA-DNA relatedness values with the type strains of G. coccoides and G. antarcticus were 27 and 17 %, respectively. Differential phenotypic properties, together with the phylogenetic and genetic distinctiveness, demonstrated that strain W-BA3(T) is separated from the two Granulosicoccus species. On the basis of the data presented, strain W-BA3(T) is considered to represent a novel species of the genus Granulosicoccus, for which the name Granulosicoccus undariae sp. nov. is proposed. The type strain is W-BA3(T) (=KCTC 42134(T) = NBRC 110411(T)). An emended description of the genus Granulosicoccus is also proposed.

Aestuariivita boseongensis gen. nov., sp. nov., isolated from a tidal flat sediment

A Gram-stain-negative, aerobic, non-motile and coccoid, ovoid or rod-shaped bacterial strain, BS-B2T, which was isolated from a tidal flat sediment at Boseong in South Korea, was characterized taxonomically. Strain BS-B2T grew optimally at 30 °C, at pH 7.0–8.0 and in the presence of 2.0 % (w/v) NaCl. The novel strain exhibited highest 16S rRNA gene sequence similarity (97.4 %) to Marivita geojedonensis DPG-138T. Neighbour-joining, maximum-likelihood and maximum-parsimony phylogenetic trees based on 16S rRNA gene sequences revealed that strain BS-B2T is closely related to Primorskyibacter sedentarius KMM 9018T, showing 96.5 % sequence similarity. Strain BS-B2T contained Q-10 as the predominant ubiquinone and C18 : 1ω7c as the predominant fatty acid. The polar lipid profile of strain BS-B2T comprised phosphatidylcholine, phosphatidylglycerol, one unidentified aminolipid and one unidentified lipid as major components, and differentiated it from the type strains of P. sedentarius and M. geojedonensis . The DNA G+C content of strain BS-B2T was 62.2 mol%. Differential phenotypic properties, together with the phylogenetic and chemotaxonomic data, demonstrated that strain BS-B2T can be distinguished from phylogenetically related genera as well as P. sedentarius and M. geojedonensis . On the basis of the data presented, strain BS-B2T is considered to represent a novel species of a new genus, for which the name Aestuariivita boseongensis gen. nov., sp. nov. is proposed. The type strain of Aestuariivita boseongensis is BS-B2T ( = KCTC 42052T = CECT 8532T).

Pseudoruegeria sabulilitoris sp. nov., isolated from seashore sand

A Gram-stain-negative, aerobic, non-spore-forming, non-flagellated and ovoid or rod-shaped bacterial strain, GJMS-35(T), was isolated from seashore sand at Geoje Island, South Korea. Strain GJMS-35(T) grew optimally at 28-30 °C, at pH 7.0-8.0 and in the presence of 2.0 % (w/v) NaCl. Phylogenetic trees based on 16S rRNA gene sequences revealed that strain GJMS-35(T) clustered with type strains of species of the genus Pseudoruegeria, with which it exhibited 96.97-98.42 % 16S rRNA gene sequence similarity. Sequence similarities to the type strains of other recognized species were less than 96.39 %. Strain GJMS-35(T) contained Q-10 as the predominant ubiquinone and C18 : 1ω7c as the major fatty acid. The major polar lipids of strain GJMS-35(T) were phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine, one unidentified glycolipid, one unidentified aminolipid and one unidentified lipid. The DNA G+C content of strain GJMS-35(T) was 64.1 mol% and its mean DNA-DNA relatedness values with type strains of three species of the genus Pseudoruegeria were 11-21 %. Its differential phenotypic properties, together with its phylogenetic and genetic distinctiveness, revealed that strain GJMS-35(T) is set apart from other species of the genus Pseudoruegeria. On the basis of the data presented, strain GJMS-35(T) is considered to represent a novel species of the genus Pseudoruegeria, for which the name Pseudoruegeria sabulilitoris sp. nov. is proposed. The type strain is GJMS-35(T) ( = KCTC 42111(T) = NBRC 110380(T)).

Seonamhaeicola aphaedonensis gen. nov., sp. nov., a member of the family Flavobacteriaceae isolated from a tidal flat sediment

A Gram-stain-negative, non-motile, rod-shaped bacterial strain, AH-M5T, which was isolated from a tidal flat sediment at Aphae Island in South Korea, was characterized taxonomically. Strain AH-M5T grew optimally at 25 °C, at pH 7.0–8.0 and in presence of 2.0 % (w/v) NaCl. Phylogenetic trees based on 16S rRNA gene sequences revealed that strain AH-M5T clustered coherently with the type strains of Mangrovimonas yunxiaonensis and Meridianimaribacter flavus , showing 93.4–94.3 % sequence similarity. The novel strain exhibited 16S rRNA gene sequence similarity values of less than 93.4 % to the type strains of other recognized species. Strain AH-M5T contained MK-6 as the predominant menaquinone and iso-C15 : 1 G, iso-C15 : 0, iso-C17 : 0 3-OH and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) as the major fatty acids. The polar lipid profile of strain AH-M5T containing phosphatidylethanolamine and one unidentified lipid as major components was differentiated from those of the type strains of Mangrovimonas yunxiaonensis and Meridianimaribacter flavus . The DNA G+C content of strain AH-M5T was 34.8 mol%. Differential phenotypic properties, together with the phylogenetic and chemotaxonomic data, demonstrated that strain AH-M5T is distinguished from Mangrovimonas yunxiaonensis and Meridianimaribacter flavus . On the basis of the data presented, strain AH-M5T is considered to represent a novel genus and species within the family Flavobacteriaceae , for which the name Seonamhaeicola aphaedonensis gen. nov., sp. nov. is proposed. The type strain of the type species is AH-M5T ( = KCTC 32578T = CECT 8487T).

Winogradskyella wandonensis sp. nov., isolated from a tidal flat

A Gram-stain-negative, non-flagellated, non-gliding, aerobic, rod-shaped bacterium, designated WD-2-2T, was isolated from a tidal flat of Wando, an island of South Korea, and subjected to a polyphasic taxonomic analysis. Strain WD-2-2T grew optimally at 30 °C, at pH 7.0–8.0 and in the presence of 2.0 % (w/v) NaCl. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain WD-2-2T belonged to the genus Winogradskyella , clustering coherently with the type strain of Winogradskyella litorisediminis . Strain WD-2-2T exhibited 16S rRNA gene sequence similarity of 97.4 % to W. litorisediminis DPS-8T and 94.5–96.6 % to the type strains of the other species of the genus Winogradskyella . Strain WD-2-2T contained MK-6 as the predominant menaquinone and iso-C15 : 1 G, iso-C17 : 0 3-OH and iso-C15 : 0 as the major fatty acids. The major polar lipids detected in strain WD-2-2T were phosphatidylethanolamine, one unidentified lipid and one unidentified aminolipid. The DNA G+C content was 36.4 mol%, and DNA–DNA relatedness with W. litorisediminis DPS-8T was 13 %. Differential phenotypic properties, together with its phylogenetic and genetic distinctiveness, revealed that strain WD-2-2T is separate from recognized species of the genus Winogradskyella . On the basis of the data presented, strain WD-2-2T is considered to represent a novel species of the genus Winogradskyella , for which the name Winogradskyella wandonensis sp. nov. is proposed. The type strain is WD-2-2T ( = KCTC 32579T = CECT 8445T).

Piperine effects on the expression of P4502E1, P4502B and P4501A in rat

1. Treatment of rat with piperine (PIP) (1.4 mmol/kg, 3 days ip injections) resulted in an approximate two-fold increase in total liver microsomal P450 content relative to that in uninduced animals. 2. 4-Nitrophenol and aniline hyroxylase activities in the hepatic microsomes prepared from rat treated with PIP decreased by 30 and 28% respectively as compared with control. Immunoblot analyses also revealed decreased P4502E1 levels in hepatic microsomes from PIP-treated animals. 3. In contrast with P4502E1 suppression, hepatic 2B1 and 2B2 levels were significantly increased in PIP-induced animals, as evidence by both metabolic activity and immunoblot analysis of the liver microsomal fractions. The rate of hexobarbital hydroxylase activity in microsomes from PIP-treated animals was markedly elevated and was inhibited by approximately 62% in the presence of monoclonal anti-P4502B IgG. Immunoblot analyses demonstrated that P4502B1 and 2B2 levels in hepatic microsomes from PIP-treated animals were comparable with those from phenobarbital-treated animals. 4. 7-Ethoxycoumarin deethylase activity was elevated approximately two-fold in PIP-induced animals and was 17% of that derived from 3-methylcholanthrene-induced animals. 7-ethoxycoumarin deethylase activity in PIP-induced hepatic microsomes was inhibited 63% in the presence of monoclonal anti-P4501A antibody. Immunoblot analysis confirmed the increase in P4501A levels by PIP, which was 15% of that in hepatic microsomes from 3-methylcholanthrene-induced animals. 5. PIP treatment failed to affect microsomal epoxide hydrolase (mEH) and glutathione S-transferases (GST) expression, as indicated by immunoblot analyses using polyclonal antibodies toward mEH and GST subunits Ya, Yb1, Yb2 and Yc. 6. These results demonstrate that PIP treatment suppressed P4502E1 expression and enhanced 2B and 1A expression, whereas this agent failed to affect hepatic mEH and GST expression.

Phenytoin induction of cytochrome P4502B in mice: effects on hexobarbital hydroxylase activity

1. Treatment of ICR and C57BL/6 mice with phenytoin (50 mg/kg, i.p., 3 days) resulted in approximately 33 and 43% increases in hepatic cytochrome P450 levels relative to uninduced microsomes, respectively. Phenytoin treatment caused a 63% decrease in hexobarbital sleeping time in ICR mice (19 versus 52 min). 2. Both Western immunoblot analysis and solid phase radioimmunoassay using monoclonal anti-rat P4502B antibody showed that P4502B was increased significantly in phenytoin-induced mouse microsomes compared with uninduced mice. P4502B9 was the predominantly induced form whereas 2B10 was elevated marginally. Phenytoin was as efficacious as phenobarbital in increasing P4502B. 3. Phenytoin treatment resulted in an approximately 8-fold increase in hexobarbital hydroxylase activity whereas phenobarbital treatment caused an approximately 13-fold increase. Addition of anti-P4502B antibody produced complete inhibition of hexobarbital oxidation in phenytoin-induced microsomes, indicating that raised P4502B in phenytoin-induced microsomes is associated with the increased hexobarbital hydroxylase activity. 4. Phenytoin failed to increase P4501A in either C57BL/6 or ICR mice, as assessed by both immunoblot analysis and metabolic activities. Although both aryl hydrocarbon hydroxylase and 7-ethoxycoumarin deethylase activities were raised approximately two-fold following phenytoin treatment, the metabolic activities were not inhibited by anti-P4501A antibody. 5. These results provide evidence that phenytoin induces P4502B in mice with pronounced increase in hexobarbital hydroxylase activity, and fails to induce P4501A in either C57BL/6 or ICR mice.