Statistically unbiased prediction enables accurate denoising of voltage imaging data.

Here we report SUPPORT (statistically unbiased prediction utilizing spatiotemporal information in imaging data), a self-supervised learning method for removing Poisson-Gaussian noise in voltage imaging data. SUPPORT is based on the insight that a pixel value in voltage imaging data is highly dependent on its spatiotemporal neighboring pixels, even when its temporally adjacent frames alone do not provide useful information for statistical prediction. Such dependency is captured and used by a convolutional neural network with a spatiotemporal blind spot to accurately denoise voltage imaging data in which the existence of the action potential in a time frame cannot be inferred by the information in other frames. Through simulations and experiments, we show that SUPPORT enables precise denoising of voltage imaging data and other types of microscopy image while preserving the underlying dynamics within the scene.

L-type Ca2+ channels mediate regulation of glutamate release by subthreshold potential changes.

Subthreshold depolarization enhances neurotransmitter release evoked by action potentials and plays a key role in modulating synaptic transmission by combining analog and digital signals. This process is known to be Ca2+ dependent. However, the underlying mechanism of how small changes in basal Ca2+ caused by subthreshold depolarization can regulate transmitter release triggered by a large increase in local Ca2+ is not well understood. This study aimed to investigate the source and signaling mechanisms of Ca2+ that couple subthreshold depolarization with the enhancement of glutamate release in hippocampal cultures and CA3 pyramidal neurons. Subthreshold depolarization increased presynaptic Ca2+ levels, the frequency of spontaneous release, and the amplitude of evoked release, all of which were abolished by blocking L-type Ca2+ channels. A high concentration of intracellular Ca2+ buffer or blockade of calmodulin abolished depolarization-induced increases in transmitter release. Estimation of the readily releasable pool size using hypertonic sucrose showed depolarization-induced increases in readily releasable pool size, and this increase was abolished by the blockade of calmodulin. Our results provide mechanistic insights into the modulation of transmitter release by subthreshold potential change and highlight the role of L-type Ca2+ channels in coupling subthreshold depolarization to the activation of Ca2+-dependent signaling molecules that regulate transmitter release.

Potent Analgesic Action of 2-acetoxy-5-(2-4 (trifluoromethyl)-phenethylamino)-benzoic Acid (Flusalazine) in Experimental Mice.

Purpose: Nonsteroidal anti-inflammatory drugs (NSAIDs) and cyclooxygenase (COX)-2 selective inhibitors are the most widely used drugs to treat pain. Conventional NSAIDs and COX-2 selective inhibitors, however, cause several side effects such as gastric damage, kidney damage, and cardiovascular problems. Our previous study showed that 2-acetoxy-5-(2-4-(trifluoromethyl)-phenethylamino)-benzoic acid ie, flusalazine (also known as ND-07), which exerts dual actions by serving both as an anti-inflammatory agent and a free radical scavenger, is an effective and safe treatment for severe inflammatory diseases in mice. The goal of the present study was to examine the potential analgesic action and safety of flusalazine in mice models of pain. Methods and Results: Flusalazine showed a significant analgesic effect in an acetic acid-induced abdominal constriction model. Likewise, total paw licking was reduced significantly in neurogenic (early stage) and inflammatory (late stage) pain induced by formalin in flusalazine-treated mice. In the tail immersion test, flusalazine significantly increased tail withdrawal time at 2 h after its administration. Also, the formation of paw edema in the flusalazine-treated group was significantly inhibited in a carrageenan-induced inflammatory pain model. Gastric damage was not induced by flusalazine even up to 1000 mg/kg, while aspirin and indomethacin caused critical gastric bleeding. Conclusion: These findings suggest that flusalazine's safety profile and analgesic effects have high translational potential for the clinical treatment of patients experiencing pain.

DYRK3 phosphorylates SNAPIN to regulate axonal retrograde transport and neurotransmitter release.

Among the five members of the dual-specificity tyrosine-phosphorylation-regulated kinase (DYRK) family, the cellular functions of DYRK3 have not been fully elucidated. Some studies have indicated limited physiological roles and substrates of DYRK3, including promotion of glioblastoma, requirement in influenza virus replication, and coupling of stress granule condensation with mammalian target of rapamycin complex 1 signaling. Here, we demonstrate that serum deprivation causes a decrease in intracellular DYRK3 levels via the proteolytic autophagy pathway, as well as the suppression of DYRK3 gene expression. To further demonstrate how DYRK3 affects cell viability, especially in neurons, we used a yeast two-hybrid assay and identified multiple DYRK3-binding proteins, including SNAPIN, a SNARE-associated protein implicated in synaptic transmission. We also found that DYRK3 directly phosphorylates SNAPIN at the threonine (Thr) 14 residue, increasing the interaction of SNAPIN with other proteins such as dynein and synaptotagmin-1. In central nervous system neurons, SNAPIN is associated with and mediate the retrograde axonal transport of diverse cellular products from the distal axon terminal to the soma and the synaptic release of neurotransmitters, respectively. Moreover, phosphorylation of SNAPIN at Thr-14 was found to positively modulate mitochondrial retrograde transport in mouse cortical neurons and the recycling pool size of synaptic vesicles, contributing to neuronal viability. In conclusion, the present study demonstrates that DYRK3 phosphorylates SNAPIN, positively regulating the dynein-mediated retrograde transport of mitochondria and SNARE complex-mediated exocytosis of synaptic vesicles within the neurons. This finding further suggests that DYRK3 affects cell viability and provides a novel neuroprotective mechanism.

SCAMP5 mediates activity-dependent enhancement of NHE6 recruitment to synaptic vesicles during synaptic plasticity.

Na+(K+)/H+ exchanger 6 (NHE6) on synaptic vesicle (SV) is critical for the presynaptic regulation of quantal size at the glutamatergic synapses by converting the chemical gradient (ΔpH) into membrane potential (Δψ) across the SV membrane. We recently found that NHE6 directly interacts with secretory carrier membrane protein 5 (SCAMP5), and SCAMP5-dependent recruitment of NHE6 to SVs controls the strength of synaptic transmission by modulation of quantal size of glutamate release at rest. It is, however, unknown whether NHE6 recruitment by SCAMP5 plays a role during synaptic plasticity. Here, we found that the number of NHE6-positive presynaptic boutons was significantly increased by the chemical long-term potentiation (cLTP). Since cLTP involves new synapse formation, our results indicated that NHE6 was recruited not only to the existing presynaptic boutons but also to the newly formed presynaptic boutons. Knock down of SCAMP5 completely abrogated the enhancement of NHE6 recruitment by cLTP. Interestingly, despite an increase in the number of NHE6-positive boutons by cLTP, the quantal size of glutamate release at the presynaptic terminals remained unaltered. Together with our recent results, our findings indicate that SCAMP5-dependent recruitment of NHE6 plays a critical role in manifesting presynaptic efficacy not only at rest but also during synaptic plasticity. Since both are autism candidate genes, reduced presynaptic efficacy by interfering with their interaction may underlie the molecular mechanism of synaptic dysfunction observed in autism.

SCAMP5 plays a critical role in axonal trafficking and synaptic localization of NHE6 to adjust quantal size at glutamatergic synapses.

Glutamate uptake into synaptic vesicles (SVs) depends on cation/H+ exchange activity, which converts the chemical gradient (ΔpH) into membrane potential (Δψ) across the SV membrane at the presynaptic terminals. Thus, the proper recruitment of cation/H+ exchanger to SVs is important in determining glutamate quantal size, yet little is known about its localization mechanism. Here, we found that secretory carrier membrane protein 5 (SCAMP5) interacted with the cation/H+ exchanger NHE6, and this interaction regulated NHE6 recruitment to glutamatergic presynaptic terminals. Protein-protein interaction analysis with truncated constructs revealed that the 2/3 loop domain of SCAMP5 is directly associated with the C-terminal region of NHE6. The use of optical imaging and electrophysiological recording showed that small hairpin RNA-mediated knockdown (KD) of SCAMP5 or perturbation of SCAMP5/NHE6 interaction markedly inhibited axonal trafficking and the presynaptic localization of NHE6, leading to hyperacidification of SVs and a reduction in the quantal size of glutamate release. Knockout of NHE6 occluded the effect of SCAMP5 KD without causing additional defects. Together, our results reveal that as a key regulator of axonal trafficking and synaptic localization of NHE6, SCAMP5 could adjust presynaptic strength by regulating quantal size at glutamatergic synapses. Since both proteins are autism candidate genes, the reduced quantal size by interrupting their interaction may underscore synaptic dysfunction observed in autism.

Detection of Chilomastix mesnili in Common Marmoset (Callithrix jacchus) and Treatment with Metronidazole.

BACKGROUND: Recently, the use of common marmoset (Callithrix jacchus) has increased in biomedical research as an animal model. This study aimed to test fecal samples to monitor bacterial and parasite infections in common marmoset at the Laboratory Animal Center of Osong Medical Innovation Foundation in Korea. METHODS: To monitor bacteria and parasites in common marmoset, we tested 43 fecal samples of 43 common marmosets by culture and parasitological test in 2014. Infection by Chilomastix mesnili was determined by PCR method. RESULTS: We identified nonpathogenic bacteria such as Proteus mirabilis and Escherichia coli in feces of normal common marmosets. Interestingly, C. mesnili was isolated from a healthy common marmoset by fecal centrifugation concentration and PCR. The monkey infected with C. mesnili was treated with metronidazole. After the treatment, C. mesnili were not found in feces using fecal centrifugation concentration and PCR. CONCLUSION: This is the first case report of C. mesnili infection in common marmoset. Treatment with metronidazole is found to be highly effective in eradicating C. mesnili infection in common marmoset.

Erratum to: A murine colitis model developed using a combination of dextran sulfate sodium and Citrobacter rodentium.

In the article by Park et al. published in Journal of Microbiology 2018; 56, 272-279, the supplementary data Figs S1 and S2 should be corrected as below. The original article can be found online at https://doi.org/10.1007/s12275-018-7504-x .

A murine colitis model developed using a combination of dextran sulfate sodium and Citrobacter rodentium.

Adult mice were treated with dextran sulfate sodium (DSS) and infected with Citrobacter rodentium for developing a novel murine colitis model. C57BL/6N mice (7-week-old) were divided into four groups. Each group composed of control, dextran sodium sulfate-treated (DSS), C. rodentium-infected (CT), and DSS-treated and C. rodentium-infected (DSS-CT) mice. The DSS group was administered 1% DSS in drinking water for 7 days. The CT group was supplied with normal drinking water for 7 days and subsequently infected with C. rodentium via oral gavage. The DSS-CT group was supplied with 1% DSS in drinking water for 7 days and subsequently infected with C. rodentium via oral gavage. The mice were sacrificed 10 days after the induction of C. rodentium infection. The DSS-CT group displayed significantly shorter colon length, higher spleen to body weight ratio, and higher histopathological score compared to the other three groups. The mRNA expression levels of tumor necrosis factor (TNF)-α and interferon (INF)-γ were significantly upregulated; however, those of interleukin (IL)-6 and IL-10 were significantly downregulated in the DSS-CT group than in the control group. These results demonstrated that a combination of low DSS concentration (1%) and C. rodentium infection could effectively induce inflammatory bowel disease (IBD) in mice. This may potentially be used as a novel IBD model, in which colitis is induced in mice by the combination of a chemical and a pathogen.

Anti-obesity effect of robusta fermented with Leuconostoc mesenteroides in high-fat diet-induced obese mice.

Robusta beans cultivated with Monascus ruber (RMR) were successively fermented with Leuconostoc mesenteroides (LM) and the antiobesity effects were examined. To produce an obese mouse model to investigate the hypolipidemic effects, ICR mice were fed the same high-fat diet for 6 weeks. Treatment groups were given 10 or 20% RMR-LM. Body weight changes in the 20% RMR-LM group were lower compared with those in the control group. Visceral adipose tissue weight and adipose size were significantly lower in the 20% RMR-LM group compared with those in the control group. Significant improvement in glucose tolerance was observed in the 10 and 20% RMR-LM groups compared with the control group. The 20% RMR-LM group exhibited a significant reduction in serum glucose concentration. Hepatic mRNA levels of sterol regulatory element-binding protein 1, fas cell surface death receptor, and peroxisome proliferator-activated receptor γ, which are associated with lipid, and fatty acid metabolism, in the 20% RMR-LM group were significantly lower compared with those in the control group. The results of the present study demonstrated that 20% RMR-LM may be used to prevent obesity, and ameliorate diabetes and lipid metabolism imbalances.

Establishment of a mouse model of 70% lethal dose by total-body irradiation.

Whereas increasing concerns about radiation exposure to nuclear disasters or side effects of anticancer radiotherapy, relatively little research for radiation damages or remedy has been done. The purpose of this study was to establish level of LD70/30 (a lethal dose for 70% of mice within 30 days) by total-body γ irradiation (TBI) in a mouse model. For this purpose, at first, 8-week-old male ICR and C57BL/6N mice from A and B companies were received high dose (10, 11, 12 Gy) TBI. After irradiation, the body weight and survival rate were monitored for 30 days consecutively. In next experiment, 5-week-old male ICR and C57BL/6N mice from B company were received same dose irradiation. Results showed that survival rate and body weight change rate in inbred C57BL/6N mice were similar between A and B company. In ICR mice, however, survival rate and body weight change rate were completely different among the companies. Significant difference of survival rate both ICR and C57BL6N mice was not observed in between 5-week-old and 8-week-old groups receiving 10 or 12 Gy TBI. Our results indicate that the strain and age of mice, and even purchasing company (especially outbred), should be matched over experimental groups in TBI experiment. Based on our results, 8-week-old male ICR mice from B company subjected to 12 Gy of TBI showed LD70/30 and suitable as a mouse model for further development of new drug using the ideal total-body irradiation model.

The Probiotic Lactobacillus Prevents Citrobacter rodentium-Induced Murine Colitis in a TLR2-Dependent Manner.

The main objective of this study was to investigate whether Lactobacillus rhamnosus GG (LGG) ameliorated the effects of Citrobactor rodentium infection in Toll-like receptor 2 (TLR2) knockout (KO) and TLR4 KO mice, as well as in wild-type C57BL/6 (B6) mice. TLR2 KO, TLR4 KO, and B6 mice were divided into three groups per each strain. Each group had an uninfected control group (n = 5), C. rodentium-infected group (n = 8), and LGG-pretreated C. rodentium-infected group (n = 8). The survival rate of B6 mice infected with C. rodentium was higher when pretreated with LGG. Pretreatment with LGG ameliorated C. rodentium-induced mucosal hyperplasia in B6 and TLR4 KO mice. However, in C-rodentium-infected TLR2 KO mice, mucosal hyperplasia persisted, regardless of pretreatment with LGG. In addition, LGG-pretreated B6 and TLR4 KO mice showed a decrease in spleen weight and downregulation of tumor necrosis factor alpha, interferon gamma, and monocyte chemotactic protein 1 mRNA expression compared with the non-pretreated group. In contrast, such changes were not observed in TLR2 KO mice, regardless of pretreatment with LGG. From the above results, we conclude that pretreatment with LGG ameliorates C. rodentium-induced colitis in B6 and TLR4 KO mice, but not in TLR2 KO mice. Therefore, LGG protects mice from C. rodentium-induced colitis in a TLR2-dependent manner.

Sendai F/HN viroplexes for efficient transfection of leukemic T cells.

PURPOSE: Most chemical transfection reagents are ineffective for the transfection of cells in suspension, such as leukemic cell and stem cell lineages. We developed two different types of viroplexes, cationic Sendai F/HN viroplexes (CSVs) and protamine sulfate-condensed cationic Sendai F/HN viroplexes (PCSVs) for the efficient transfection of T-leukemic cells. MATERIALS AND METHODS: The viroplex systems were prepared by reconstitution of fusogenic Sendai F/HN proteins in DMKE (O,O'-dimyristyl-N-lysyl glutamate) cationic liposomes. The viroplexes were further optimized for plasmid DNA and siRNA delivery to suspension cells. The particle size and surface charge of the viroplexes were analyzed with a ζ-sizer. Transfection of plasmid DNA (pDNA) and small interfering RNA (siRNA) by CSVs or PCSV was evaluated by measurement of transgene expression, confocal microscopy, FACS, and RT-PCR. RESULTS: The optimized CSVs and PCSVs exhibited enhanced gene and siRNA delivery in the tested suspension cell lines (Jurkat cells and CEM cells), compared with conventional cationic liposomes. In the case of pDNA transfection, the CSVs and PCSVs show at least 10-fold and 100-fold higher transgene expression compared with DMKE lipoplexes (or lipofectamine 2000), respectively. The CSVs showed more effective siRNA delivery to the suspension cells than cationic liposomes, as assessed by confocal microscopy, FACS, and RT-PCR. The effective transfection by the CSVs and PCSVs is presumably due to fusogenic activity of F/HN proteins resulting in facilitated internalization of pDNA and siRNA. CONCLUSION: This study suggests that Sendai F/HN viroplexes can be widely applicable for the transfection of pDNA and siRNA to suspension cell lines.

Flavobacterium resistens sp. nov., isolated from stream sediment.

An aerobic, yellow-pigmented, Gram-negative bacterium, designated strain BD-b365(T), was isolated from sediment of the Hakjang stream in Busan, South Korea. Growth was observed at 15-40 degrees C (optimum 20-30 degrees C) and at pH 6.0-9.5 (optimum pH 7.0-8.0). Cells were non-spore-forming rods that showed gliding motility and contained branched and hydroxy fatty acids. The G+C content of the genomic DNA was 35.4 mol%. The major respiratory quinone was menaquinone-6 (MK-6). The major polar lipid of strain BD-b365(T) was phosphatidylethanolamine. Comparative 16S rRNA gene sequence analysis showed that strain BD-b365(T) formed a distinct phyletic line within the genus Flavobacterium. Based on levels of 16S rRNA gene sequence similarity, the novel strain was related most closely to Flavobacterium aquidurense WB 1.1-56(T), but the level of DNA-DNA relatedness between these two strains was only 9.6 %. On the basis of phenotypic and genotypic data, it is clear that strain BD-b365(T) represents a novel species of the genus Flavobacterium, for which the name Flavobacterium resistens sp. nov. is proposed. The type strain is BD-b365(T) (=KCTC 22078(T) =DSM 19382(T)).

Rheinheimera soli sp. nov., a gammaproteobacterium isolated from soil in Korea.

A Gram-negative, non-spore-forming bacterium, designated strain BD-d46(T), was isolated from a playground soil sample in Jinju, South Korea. Cells were straight or curved rods and showed catalase- and oxidase-positive reactions. Growth of strain BD-d46(T) was observed between 15 and 35 degrees C (optimum 25-30 degrees C) and between pH 6.5 and 8.0 (optimum pH 7.0-7.5). The predominant fatty acids were summed feature 3 (C(16 : 1)omega7c and/or iso-C(15 : 0) 2-OH), C(12 : 0) 3-OH and C(16 : 0). Strain BD-d46(T) contained phosphatidylethanolamine and phosphatidylglycerol as major polar lipids. Isoprenoid quinones were Q-8 (75 %) and MK-7 (25 %). The G+C content of the genomic DNA was 49.2 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain BD-d46(T) formed a distinct lineage with Rheinheimera chironomi K19414(T) within the genus Rheinheimera. Levels of 16S rRNA gene sequence similarity between strain BD-d46(T) and the type strains of recognized Rheinheimera species ranged from 94.4 to 96.9 %. On the basis of chemotaxonomic data and molecular properties, strain BD-d46(T) is considered to represent a novel species of the genus Rheinheimera, for which the name Rheinheimera soli sp. nov. is proposed. The type strain is BD-d46(T) (=KCTC 22077(T) =DSM 19413(T)).

Pseudoxanthomonas sacheonensis sp. nov., isolated from BTEX-contaminated soil in Korea, transfer of Stenotrophomonas dokdonensis Yoon et al. 2006 to the genus Pseudoxanthomonas as Pseudoxanthomonas dokdonensis comb. nov. and emended description of the genus Pseudoxanthomonas.

A Gram-negative, strictly aerobic, rod-shaped bacterium, designated strain BD-c54(T), was isolated from BTEX (benzene, toluene, ethylbenzene and xylenes)-contaminated soil in Sacheon, Korea. Growth of strain BD-c54(T) was observed at 15-35 degrees C (optimum 25-30 degrees C) and pH 6.0-9.5 (optimum pH 7.0-8.0). The predominant fatty acids were iso-C(15:0), iso-C(17:1)omega9c, iso-C(11:0) 3-OH, iso-C(16:0), iso-C(11:0) and iso-C(17:0). The strain contained large amounts of phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol and a small amount of an unknown amino-group-containing polar lipid as polar lipids. The major quinone was ubiquinone-8 (Q-8) and the G+C content of the genomic DNA was 67.5 mol%. A phylogenetic analysis based on 16S rRNA gene sequences showed that strain BD-c54(T) formed a tight phylogenetic lineage with Pseudoxanthomonas yeongjuensis GR12-1(T) within the genus Pseudoxanthomonas and was most closely related to P. yeongjuensis GR12-1(T) and [Stenotrophomonas] dokdonensis DS-16(T), with 98.3 and 96.6% 16S rRNA gene sequence similarity, respectively. The DNA-DNA relatedness between strain BD-c54(T) and P. yeongjuensis GR12-1(T) was 24.5%. On the basis of chemotaxonomic data and molecular properties, strain BD-c54(T) represents a novel species within the genus Pseudoxanthomonas, for which the name Pseudoxanthomonas sacheonensis sp. nov. is proposed. The type strain is BD-c54(T) (=KCTC 22080(T) =DSM 19373(T)). In addition, the transfer of Stenotrophomonas dokdonensis to Pseudoxanthomonas as Pseudoxanthomonas dokdonensis comb. nov. and an emended description of the genus Pseudoxanthomonas are proposed.

Caenimonas koreensis gen. nov., sp. nov., isolated from activated sludge.

A Gram-negative, rod-shaped bacterium, designated strain EMB320T, was isolated from activated sludge performing enhanced biological phosphorus removal in a sequencing batch reactor. The isolate was strictly aerobic and non-motile. Growth was observed between 10 and 35 degrees C (optimum 30 degrees C) and between pH 6.0 and 9.0 (optimum pH 7.0-8.0). The predominant cellular fatty acids of strain EMB320T were C16 : 0, C18 : 1omega7c and summed feature 3 (C16 : 1omega7c and/or iso-C15 : 0 2-OH). The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. Strain EMB320T contained ubiquinone-8 (Q-8) as the major respiratory quinone system and 2-hydroxyputrescine and putrescine as the major polyamines, which suggests that it belongs to the Betaproteobacteria. The G+C content of the genomic DNA was 62.7 mol%. Comparative 16S rRNA gene sequence analysis showed that strain EMB320T formed a phyletic lineage distinct from other genera within the family Comamonadaceae. On the basis of chemotaxonomic data and molecular properties, strain EMB320T represents a novel genus and species within the family Comamonadaceae, for which the name Caenimonas koreensis sp. nov. is proposed. The type strain of Caenimonas koreensis is EMB320T (=KCTC 12616T =DSM 17982T).

Devosia geojensis sp. nov., isolated from diesel-contaminated soil in Korea.

A Gram-negative, strictly aerobic, non-spore-forming bacterium, designated strain BD-c194(T), was isolated from diesel-contaminated soil in Geoje, Korea. The cells were short, motile rods with single polar flagella. Growth of strain BD-c194(T) was observed between 15 and 45 degrees C (optimally at 30-35 degrees C) and between pH 6.0 and 9.5 (optimally at pH 7.5-9.0). The predominant fatty acids were 11-methyl C(18 : 1)omega7c, C(16 : 0), C(18 : 1)omega7c, C(18 : 0) and an unknown fatty acid (equivalent chain-length 18.814); a large amount of phosphatidylglycerol and a small amount of diphosphatidylglycerol were present as polar lipids. The G+C content of the genomic DNA was 60.8 mol% and the major isoprenoid quinone was Q-10. A comparative 16S rRNA gene sequence analysis showed that strain BD-c194(T) formed a well-defined phyletic lineage within the genus Devosia (with 100 % bootstrap support). The levels of 16S rRNA gene sequence similarity with respect to the type strains of other Devosia species ranged from 95.0 to 96.1 %. On the basis of chemotaxonomic data and molecular properties, strain BD-c194(T) represents a novel species within the genus Devosia, for which the name Devosia geojensis sp. nov. is proposed. The type strain is BD-c194(T) (=KCTC 22082(T) =DSM 19414(T)).

Hydrogenophaga bisanensis sp. nov., isolated from wastewater of a textile dye works.

A Gram-negative, non-spore-forming, rod-shaped, Hydrogenophaga-like bacterial strain, K102(T), was isolated from wastewater collected from a textile dye works in Korea and subjected to a polyphasic taxonomic study. Strain K102(T) grew optimally at pH 7.0-8.0 and 30-37 degrees C in the presence of 0.5 % (w/v) NaCl. It contained Q-8 as the predominant ubiquinone and C(16 : 0), C(16 : 1)omega7c and/or iso-C(15 : 0) 2-OH and C(18 : 1)omega7c as the major fatty acids. The DNA G+C content was 64.8 mol%. A neighbour-joining phylogenetic tree based on 16S rRNA gene sequences showed that strain K102(T) fell within the radiation of the cluster comprising species of the genus Hydrogenophaga. Strain K102(T) exhibited 16S rRNA gene sequence similarity values of 95.9-98.9 % to the type strains of recognized Hydrogenophaga species. Levels of DNA-DNA relatedness between strain K102(T) and the type strains of its four phylogenetically most closely related species, together with differential phenotypic properties, revealed that strain K102(T) could be distinguished from all recognized species of the genus Hydrogenophaga. On the basis of phenotypic, phylogenetic and genetic data, strain K102(T) is considered to represent a novel species of the genus Hydrogenophaga, for which the name Hydrogenophaga bisanensis sp. nov. is proposed. The type strain is K102(T) (=KCTC 12980(T) =CCUG 54518(T)).

Runella defluvii sp. nov., isolated from a domestic wastewater treatment plant.

A long, Gram-negative, rod-shaped bacterium, designated strain EMB13T, was isolated from a wastewater treatment plant in Korea. The isolate was strictly aerobic and non-motile. The strain grew optimally at 30-35 degrees C and pH 7.5-8.0, and the predominant fatty acids were iso-C15:0, summed feature 3 (C16:1omega7c and/or iso-C15:0 2-OH), C16:1omega5c and iso-C17:0 3-OH. The strain contained a large amount of phosphatidylethanolamine and small amounts of phosphatidylcholine and an unknown phospholipid as the polar lipids. The G+C content of the genomic DNA was 40.1 mol% and the major isoprenoid quinone was menaquinone-7. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain EMB13T belonged to the genus Runella and was most closely related to Runella limosa EMB111T, with a 16S rRNA gene sequence similarity of 97.1%. DNA-DNA relatedness between strain EMB13T and R. limosa EMB111T was approximately 25%. On the basis of phenotypic, chemotaxonomic and molecular data, it is clear that strain EMB13T represents a novel species within the genus Runella, for which the name Runella defluvii sp. nov. is proposed. The type strain is EMB13T (=KCTC 12614T=DSM 17976T).