Interferon-ß deficiency alters brain response to chronic HIV-1 envelope protein exposure in a transgenic model of NeuroHIV.

Human immunodeficiency virus-1 (HIV-1) infects the central nervous system (CNS) and causes HIV-associated neurocognitive disorders (HAND) in about half of the population living with the virus despite combination anti-retroviral therapy (cART). HIV-1 activates the innate immune system, including the production of type 1 interferons (IFNs) α and ß. Transgenic mice expressing HIV-1 envelope glycoprotein gp120 (HIVgp120tg) in the CNS develop memory impairment and share key neuropathological features and differential CNS gene expression with HIV patients, including the induction of IFN-stimulated genes (ISG). Here we show that knocking out IFNß (IFNßKO) in HIVgp120tg and non-tg control mice impairs recognition and spatial memory, but does not affect anxiety-like behavior, locomotion, or vision. The neuropathology of HIVgp120tg mice is only moderately affected by the KO of IFNß but in a sex-dependent fashion. Notably, in cerebral cortex of IFNßKO animals presynaptic terminals are reduced in males while neuronal dendrites are reduced in females. The IFNßKO results in the hippocampal CA1 region of both male and female HIVgp120tg mice in an ameliorated loss of neuronal presynaptic terminals but no protection of neuronal dendrites. Only female IFNß-deficient HIVgp120tg mice display diminished microglial activation in cortex and hippocampus and increased astrocytosis in hippocampus compared to their IFNß-expressing counterparts. RNA expression for some immune genes and ISGs is also affected in a sex-dependent way. The IFNßKO abrogates or diminishes the induction of MX1, DDX58, IRF7 and IRF9 in HIVgp120tg brains of both sexes. Expression analysis of neurotransmission related genes reveals an influence of IFNß on multiple components with more pronounced changes in IFNßKO females. In contrast, the effects of IFNßKO on MAPK activities are independent of sex with pronounced reduction of active ERK1/2 but also of active p38 in the HIVgp120tg brain. In summary, our findings show that the absence of IFNß impairs memory dependent behavior and modulates neuropathology in HIVgp120tg brains, indicating that its absence may facilitate development of HAND. Moreover, our data suggests that endogenous IFNß plays a vital role in maintaining neuronal homeostasis and memory function.

Plasmodium falciparum Cysteine-Rich Protective Antigen (CyRPA) Elicits Detectable Levels of Invasion-Inhibitory Antibodies during Natural Infection in Humans.

Plasmodium falciparum cysteine-rich protective antigen (CyRPA) is a conserved component of an essential erythrocyte invasion complex (RH5/Ripr/CyRPA) and a target of potent cross-strain parasite-neutralizing antibodies. While naturally acquired human RH5 antibodies have been functionally characterized, there are no similar reports on CyRPA. Thus, we analyzed the parasite-neutralizing activity of naturally acquired human CyRPA antibodies. In this regard, CyRPA human antibodies were measured and purified from malaria-infected plasma obtained from patients in central India and analyzed for their parasite neutralizing activity via in vitro growth inhibition assays (GIA). We report that, despite being susceptible to antibodies, CyRPA is a highly conserved antigen that does not appear to be under substantial immune selection pressure, as a very low acquisition rate for anti-CyRPA antibodies was reported in malaria-exposed Indians. We demonstrate for the first time that the small amounts of natural CyRPA antibodies exhibited functional parasite-neutralizing activity and that a CyRPA-based vaccine formulation induces highly potent antibodies in rabbits. Importantly, the vaccine-induced CyRPA antibodies exhibited a robust 50% inhibitory concentration (IC50) of 21.96 µg/ml, which is comparable to the IC50 of antibodies against the leading blood-stage vaccine candidate, reticulocyte-binding-like homologous protein 5 (RH5). Our data support CyRPA as a unique vaccine target that is highly susceptible to immune attack but is highly conserved compared to other leading candidates such as MSP-1 and AMA-1, further substantiating its promise as a leading blood-stage vaccine candidate.

Antibody Combinations Targeting the Essential Antigens CyRPA, RH5, and MSP-119 Potently Neutralize Plasmodium falciparum Clinical Isolates From India and Africa.

BACKGROUND: Targeting multiple key antigens that mediate distinct Plasmodium falciparum erythrocyte invasion pathways is an attractive approach for the development of blood-stage malaria vaccines. However, the challenge is to identify antigen cocktails that elicit potent strain-transcending parasite-neutralizing antibodies efficacious at low immunoglobulin G concentrations feasible to achieve through vaccination. Previous reports have screened inhibitory antibodies primarily against well adapted laboratory parasite clones. However, validation of the parasite-neutralizing efficacy against clinical isolates with minimal in vitro cultivation is equally significant to better ascertain their prospective in vivo potency. METHODS: We evaluated the parasite-neutralizing activity of different antibodies individually and in combinations against laboratory adapted clones and clinical isolates. Clinical isolates were collected from Central India and Mozambique, Africa, and characterized for their invasion properties and genetic diversity of invasion ligands. RESULTS: In our portfolio, we evaluated 25 triple antibody combinations and identified the MSP-Fu+CyRPA+RH5 antibody combination to elicit maximal parasite neutralization against P. falciparum clinical isolates with variable properties that underwent minimal in vitro cultivation. CONCLUSIONS: The MSP-Fu+CyRPA+RH5 combination exhibited highly robust parasite neutralization against P. falciparum clones and clinical isolates, thus substantiating them as promising candidate antigens and establishing a proof of principle for the development of a combinatorial P. falciparum blood-stage malaria vaccine.

A pivotal role for Interferon-α receptor-1 in neuronal injury induced by HIV-1.

BACKGROUND: HIV-1 infection remains a major public health concern despite effective combination antiretroviral therapy (cART). The virus enters the central nervous system (CNS) early in infection and continues to cause HIV-associated neurocognitive disorders (HAND). The pathogenic mechanisms of HIV-associated brain injury remain incompletely understood. Since HIV-1 activates the type I interferon system, which signals via interferon-α receptor (IFNAR) 1 and 2, this study investigated the potential role of IFNAR1 in HIV-induced neurotoxicity. METHODS: We cross-bred HIVgp120-transgenic (tg) and IFNAR1 knockout (IFNAR1KO) mice. At 11-14 months of age, we performed a behavioral assessment and subsequently analyzed neuropathological alterations using deconvolution and quantitative immunofluorescence microscopy, quantitative RT-PCR, and bioinformatics. Western blotting of brain lysates and an in vitro neurotoxicity assay were employed for analysis of cellular signaling pathways. RESULTS: We show that IFNAR1KO results in partial, sex-dependent protection from neuronal injury and behavioral deficits in a transgenic model of HIV-induced brain injury. The IFNAR1KO rescues spatial memory and ameliorates loss of presynaptic terminals preferentially in female HIVgp120tg mice. Similarly, expression of genes involved in neurotransmission reveals sex-dependent effects of IFNAR1KO and HIVgp120. In contrast, IFNAR1-deficiency, independent of sex, limits damage to neuronal dendrites, microgliosis, and activation of p38 MAPK and restores ERK activity in the HIVgp120tg brain. In vitro, inhibition of p38 MAPK abrogates neurotoxicity caused similarly by blockade of ERK kinase and HIVgp120. CONCLUSION: Our findings indicate that IFNAR1 plays a pivotal role in both sex-dependent and independent processes of neuronal injury and behavioral impairment triggered by HIV-1.

Naturally Acquired Human Antibodies Against Reticulocyte-Binding Domains of Plasmodium vivax Proteins, PvRBP2c and PvRBP1a, Exhibit Binding-Inhibitory Activity.

Background: Crucial gaps in our understanding of Plasmodium vivax reticulocyte invasion and protective immunity have hampered development of vivax vaccines. P. vivax exclusively invades reticulocytes that is mediated by the P. vivax reticulocyte-binding proteins (PvRBPs) specifically PvRBP2c and PvRBP1a. Vivax infections in Duffy-null individuals have suggested the evolution of alternate invasion pathways that may be mediated by the PvRBPs. Thus, PvRBPs appear as potential targets for efficacious P. vivax neutralization. However, there are limited data validating their vaccine efficacy. In the absence of vivax invasion assays, binding-inhibitory activity of antibodies has been reported to be associated with protection and a measure of vaccine potential. Methods: -based analysis was performed of the PvRBP reticulocyte-binding properties and binding-inhibitory activity of specific anti-PvRBP2c/PvRBP1a human antibodies. Results: PvRBP2c and PvRBP1a displayed a distinct reticulocyte-binding specificity, and their specific reticulocyte-binding domains were mapped within their N-terminal regions. Importantly, naturally acquired antibodies against the reticulocyte-binding domains efficaciously blocked reticulocyte binding of native PvRBPs, suggesting that the human immune system produced functional binding-inhibitory antibodies through exposure to vivax malaria. Conclusions: Reticulocyte-binding domains of PvRBP2c/PvRBP1a are targets of naturally acquired binding-inhibitory antibodies, substantiating their promise as candidate antigens against which vaccine-inducible immunity could potentially be boosted through natural infections.

Pedobacter panacis sp. nov., isolated from Panax ginseng soil.

A novel strain, DCY108T was isolated from soil of a Panax ginseng field, Yeoncheon province (38°04'N 126°57'E), Republic of Korea. Strain DCY108T is Gram-negative, non-motile, non-flagellate, rod-shaped, and aerobic. The bacterium grows optimally at 25-30 °C, pH 6.5-7.0 and 1 % NaCl. Phylogenetically, strain DCY108T is closely related to Pedobacter jejuensis JCM 18824T, Pedobacter aquatilis JCM 13454T, Pedobacter kyungheensis LMG 26577T and the type strain of the genus Pedobacter heparinus DSM 2366T. The DNA-DNA relatedness values between strain DCY108T and its close phylogenetic neighbors were below 30.0 %. The DNA G+C content of strain DCY108T was determined to be 45.1 mol%. The predominant quinone was menaquinone 7 (MK-7). The major polar lipids were identified as phosphatidylethanolamine and three unidentified aminolipids AL1, AL13 and AL17. Iso-C15:00, iso-C17:03OH and summed feature 3 (C16:1 ω7c/C16:1 ω6c) were identified as the major fatty acids present in strain DCY108T. The results of physiological and biochemical tests allowed strain DCY108T to be differentiated phenotypically from other recognized species belonging to the genus Pedobacter. Therefore, it is suggested that the newly isolated organism represents a novel species, for which the name Pedobacter panacis sp. nov is proposed with the type strain designated as DCY108T (=CCTCCAB 2015196T = KCTC 42748T).

Nocardioides flava sp. nov., isolated from rhizosphere of poppy plant, Republic of Korea.

Phylogenetic and taxonomic characterization was performed for bacterium, designated strain THG-DN5.4(T), isolated from the rhizosphere of poppy plant collected from Gyeryongsan, Republic of Korea. Strain THG-DN5.4(T) consists of Gram-stain-positive, aerobic, non-motile rods. The bacteria grow optimally at 18-30 °C, at pH 7.0 and in the presence of 0.5-1.0 % NaCl. Based on 16S rRNA gene sequence analysis, strain THG-DN5.4(T) was found to be most closely related to Nocardioides nitrophenolicus KCTC 047BP(T), followed by Nocardioides ginsengisoli KCTC 19135(T), Nocardioides kongjuensis KCTC 19054(T), Nocardioides simplex KACC 20620(T), Nocardioides aromaticivorans KACC 20613(T), Nocardioides daeguensis KCTC 19799(T) and Nocardioides caeni KCTC 19600(T). The DNA-DNA relatedness between strain THG-DN5.4(T) and closely related phylogenetic neighbors was below 45.0 %, and the DNA G+C content of strain THG-DN5.4(T) was 70.8 mol%. An isoprenoid quinone was identified as MK-8(H4). Strain THG-DN5.4(T) was characterized chemotaxonomically as having LL-diaminopimelic acid in the cell-wall peptidoglycan. The polar lipids were identified as diphosphatidylglycerol, phosphatidylglycerol, some unidentified aminolipids and some unidentified polar lipids. iso-C16:0 and C18:1 ω9c were identified as the major fatty acids present in THG-DN5.4(T). On the basis of a polyphasic taxonomic study, strain THG-DN5.4(T) is considered to represent a novel species of the genus Nocardioides, for which the name Nocardioides flava sp. nov. is proposed. The type strain is THG-DN5.4(T) (=KCTC 39606(T)=CCTCC AB 2015298(T)).

Acinetobacter plantarum sp. nov. isolated from wheat seedlings plant.

Strain THG-SQM11(T), a Gram-negative, aerobic, non-motile, coccus-shaped bacterium, was isolated from wheat seedlings plant in P. R. China. Strain THG-SQM11(T) was closely related to members of the genus Acinetobacter and showed the highest 16S rRNA sequence similarities with Acinetobacter junii (97.9 %) and Acinetobacter kookii (96.1 %). DNA-DNA hybridization showed 41.3 ± 2.4 % DNA reassociation with A. junii KCTC 12416(T). Chemotaxonomic data revealed that strain THG-SQM11(T) possesses ubiquinone-9 as the predominant respiratory quinone, C18:1 ω9c, summed feature 3 (C16:1 ω7c and/or C16:1 ω6c), and C16:0 as the major fatty acids. The major polar lipids were found to be diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, and phosphatidylcholine. The DNA G+C content was 41.7 mol %. These data, together with phenotypic characterization, suggest that the isolate represents a novel species, for which the name Acinetobacter plantarum sp. nov. is proposed, with THG-SQM11(T) as the type strain (=CCTCC AB 2015123(T) =KCTC 42611(T)).

Brachybacterium horti sp. nov., isolated from garden soil.

A bacterial strain, THG-S15-4T, was isolated from garden soil taken from the Guro-gu district of Seoul, Republic of Korea. Strain THG-S15-4T was Gram-stain-positive, facultatively anaerobic, coccus-shaped and non-motile, forming white colonies. The strain grew optimally at 25-37 °C, at pH 7.0 and in the presence of 0-2.0 % (w/v) NaCl. Phylogenetic analysis, based on 16S rRNA gene sequences, showed that strain THG-S15-4T was affiliated to species of the genus Brachybacterium, and the most closely related species were Brachybacterium rhamnosum KCTC 9917 T (98.5 % sequence similarity) and Brachybacterium squillarum KCTC 19899T (96.9 % sequence similarity). The DNA-DNA relatedness between strain THG-S15-4T and B. rhamnosum KCTC 9917 T was found to be below 20.0 %. The DNA G+C content was determined to be 69.5 mol%. The major isoprenoid quinone detected was MK-7. Strain THG-S15-4T was characterized chemotaxonomically as having meso-diaminopimelic acid in the cell-wall peptidoglycan. The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylglycerol, unidentified glycolipids and an unidentified polar lipid. The major fatty acids were found to be iso-C16 : 0 and anteiso-C15 : 0. The results of physiological and biochemical tests enabled strain THG-S15-4T to be differentiated phenotypically from species of the genus Brachybacterium with validly published names. Therefore, it is suggested that this newly isolated organism represents a novel species, for which the name Brachybacterium horti sp. nov. is proposed. The type strain is THG-S15-4T ( = KCTC 39563T = CCTCC AB 2015116T).

Nocardioides albidus sp. nov., an actinobacterium isolated from garden soil.

A novel bacterial strain, designated THG-S11.7T, was isolated from garden soil in Incheon, South Korea. Cells of the strain were Gram-stain-positive, aerobic, non-motile cocci, and were catalase- and oxidase-positive. Colonies of the strain were white. Strain THG-S11.7T grew optimally at 28 °C, at pH 7.0 and in the presence of 2.0 % NaCl. 16S rRNA gene sequence analysis indicated that the strain was a member of the genus Nocardioides. Strain THG-S11.7T showed a 16S rRNA gene sequence similarity of 98.2 % to Nocardioides kongjuensis KCTC 19054T, 98.0 % to Nocardioides caeni KCTC 19600T, 97.9 % to Nocardioides daeguensis KCTC 19799T, 97.8 % to Nocardioides nitrophenolicus KCTC 047BPT, 97.6 % to Nocardioides aromaticivorans KACC 20613T, 97.5 % to Nocardioides simplex KACC 20620T and 97.0 % to Nocardioides ginsengisoli KCTC 19135T. DNA-DNA relatedness values between strain THG-S11.7T and the closest phylogenetic neighbours were below 45.0 % and the DNA G+C content of strain THG-S11.7T was 72.2 mol%. Strain THG-S11.7T was characterized chemotaxonomically as having ll-diaminopimelic acid in the cell-wall peptidoglycan and menaquinone MK-8(H4) as the predominant isoprenoid quinone. The major phospholipid was determined to be diphosphatidylglycerol. The major cellular fatty acids of strain THG-S11.7T were iso-C15 : 0, C16 : 0 and iso-C16 : 0. Based on the phenotypic, genotypic and phylogenetic analyses, it is proposed that the isolate represents a novel species of the genus Nocardioides, for which the name Nocardioides albidus sp. nov. is proposed. The type strain is THG-S11.7T ( = KCTC 39607T = CCTCC AB 2015297T).

Devosia humi sp. nov., isolated from soil of a Korean pine (Pinus koraiensis) garden.

A bacterial isolate, designated strain THG-MM1T, was isolated from soil in Yongin region, Republic of Korea. Strain THG-MM1T was Gram-stain-negative, aerobic, non-motile and rod-shaped. Based on 16S rRNA gene sequence comparisons, strain THG-MM1T was most closely related to Devosia insulae DS-56T (96.5 % 16S rRNA gene sequence similarity), followed by Devosia yakushimensis Yak96BT (95.7 %) and Devosia albogilva IPL15T (95.2 %). The G+C content of the genomic DNA was 63.7 mol%. The major cellular fatty acids were C16 : 0, summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c) and C18 : 0. The predominant isoprenoid quinone was ubiquinone-10 (Q-10). The major polar lipids were phosphatidylglycerol and an unidentified lipid. The combined phenotypic, chemotaxonomic and phylogenetic data showed that strain THG-MM1T represents a novel species of the genus Devosia, for which the name Devosia humi sp. nov. is proposed, with strain THG-MM1T ( = KACC 18281T = CCTCC AB 2015121T) as the type strain.

Antibacterial, anti-biofilm and anticancer potentials of green synthesized silver nanoparticles using benzoin gum (Styrax benzoin) extract.

This study described a simple and green approach for the synthesis of silver nanoparticles (AgNPs) employing benzoin gum water extract as a reducing and capping agent and their applications. The AgNPs were characterized by ultraviolet-visible spectrophotometer, X-ray diffraction pattern, field emission transmission electron microscopy, dynamic light scattering, zeta potential and fourier transform infrared spectroscopy. The AgNPs showed promising antimicrobial activity against various pathogens (Gram-negative, Gram-positive and fungus) and possessed high free radical scavenging activity (104.5 ± 7.21 % at 1 mg/ml). In addition, the AgNPs exhibited strong cytotoxicity towards human cervical cancer and human lung cancer cells as compared to the normal mouse macrophage cells. Moreover, the AgNPs possessed anti-biofilm activity against Escherichia coli, and compatibility to human keratinocyte HaCaT cells, which suggests the use of dressing with the AgNPs in chronic wound treatment. Therefore, AgNPs synthesized by benzoin gum extract are comparatively green and may have broad spectrum potential application in biomedicine.

Pedobacter edaphicus sp. nov. isolated from forest soil in South Korea.

A Gram-negative, yellow-colored, rod-shaped, strictly aerobic, motile bacterium was isolated from forest soil in Gyeongsang Province, South Korea. The strain was designated as THG-DA2.1(T). Cells of strain THG-DA2.1(T) grew optimally at pH 7.0, at temperature 28 °C and in the presence of 0.5 % NaCl. Based on 16S rRNA gene sequence, strain THG-DA2.1(T) was shown to belong to the genus Pedobacter and shares highest sequence similarity with Pedobacter ginsengisoli KCTC 12576(T). The DNA G+C content was determined to be 42.3 mol %. The predominant isoprenoid quinone was identified as menaquinone MK-7. The major cellular fatty acids of strain THG-DA2.1(T) were iso-C15:0 and C16:1 ω6c and/or C16:1 ω7c (summed feature 3*). Strain THG-DA2.1(T) contains phosphatidylethanolamine as major polar lipid, but an unidentified aminolipid, two unidentified phospholipids and two unidentified lipids were also detected. On the basis of the data obtained from polyphasic taxonomy in this study, strain THG-DA2.1(T) is considered to represent a novel species of the genus Pedobacter, for which the name Pedobacter edaphicus sp. nov. is proposed. The type strain is THG-DA2.1(T) (=KCTC 42232(T) =JCM 30351(T)).

Sphingomonas flavus sp. nov. isolated from road soil.

A yellow-colored, Gram-negative, strictly aerobic, non-motile, rod-shaped bacterium, designated THG-MM5(T), was isolated from road soil in Yongin-si, Gyeonggi-do, Republic of Korea. Based on 16S rRNA gene sequence, strain THG-MM5(T) was moderately related to Sphingomonas sediminicola KACC 15039(T) (96.1%), Sphingomonas ginsengisoli KACC 16858(T) (96.1%) and Sphingomonas jaspsi KACC 13230(T) (96.0%). Chemotaxonomic data revealed that strain THG-MM5(T) possesses ubiquinone-10 as the only respiratory quinone, sym-homospermidine as the major polyamine and summed feature 3 (C16:1 ω7c and/or C16:1 ω6c), C18:1 ω7c and C16:0 as the major fatty acids. The polar lipid profile included sphingoglycolipid. The DNA G + C content was 60.7 mol%. These data, together with phenotypic characterization, corroborated the affiliation of strain THG-MM5(T) to the genus Sphingomonas. Thus, the isolate represents a novel species, for which the name Sphingomonas flavus sp. nov. is proposed, with THG-MM5(T) as the type strain (=KACC 18277(T) = CCTCC AB 2014320(T)).

Chryseobacterium formosus sp. nov., a bacterium isolated from an ancient tree trunk.

A Gram-reaction-negative, non-motile and rod-shaped bacterium, designated as THG-DN3.6(T), was isolated from an ancient tree trunk from Republic of Korea. On the basis of 16S rRNA gene sequence analysis, strain THG-DN3.6(T) was shown to belong to the genus Chryseobacterium and the highest similarity to Chryseobacterium indoltheticum LMG 4025(T) (97.2%) and the closest phylogenetic relatives were Chryseobacterium scophthalmum (96.8%), Chryseobacterium piscium (96.7%) and Chryseobacterium balustinum KCTC 2903(T) (96.3%). The DNA G + C content of the isolate was 33.2 mol%. The predominant isoprenoid quinone was menaquinone-6. The major fatty acids were iso-C15:0, summed feature 3 (C16:1 ω7c and/or C16:1 ω7t and/or iso-C15:0 2-OH), iso-C17:1 ω9c and iso-C17:0 3-OH. The major polar lipids of strain THG-DN3.6(T) were phosphatidylethanolamine. The mean DNA-DNA relatedness of strain THG-DN3.6(T) to C. indoltheticum LMG 4025(T) was 52 ± 0.5%. Based on the results of polyphasic characterization, strain THG-DN3.6(T) represented a novel species within the genus Chryseobacterium, for which the name Chryseobacterium formosus sp. nov. is proposed. The type strain is THG-DN3.6(T) (=KCTC 42606 = CCTCC AB 2015118). The NCBI GenBank accession number for the 16S rRNA gene sequence of strain THG-DN3.6(T) is KM035938.

Pseudoclavibacter terrae sp. nov. isolated from rhizosphere soil of Ophiopogon japonicus.

Strain THG-MD12T, a Gram-reaction-positive, aerobic, non-motile, rod-shaped bacterium was isolated from rhizosphere soil of Ophiopogon japonicus in PR China. THG-MD12T was closely related to members of the genus Pseudoclavibacter and showed the highest 16S rRNA gene sequence similarities with Pseudoclavibacter helvolus KCTC 19531T (98.8 %) and Pseudoclavibacter chungangensis KCTC 22691T (96.9 %). DNA-DNA hybridization showed 41.9 ± 2.1 % and 12.4 ± 0.9 % DNA reassociation with P. helvolus KCTC 19531T and P. chungangensis KCTC 22691T, respectively. Chemotaxonomic analyses revealed that strain THG-MD12T possesses menaquinone-9 as the predominant respiratory quinone, 2,4-diaminobutyric acid as the diamino acid in the peptidoglycan and anteiso-C15 : 0, iso-C16 : 0, C16 : 0 and anteiso-C17 : 0 as the major fatty acids. The polar lipid profile was found to consist of diphosphatidylglycerol, phosphatidylglycerol, two unknown glycolipids and two unknown lipids. These data corroborated the affiliation of THG-MD12T to the genus Pseudoclavibacter. Thus, the isolate represents a novel species, for which the name Pseudoclavibacter terrae sp. nov. is proposed, with THG-MD12T as the type strain ( = CCTCC AB 2015124T = KCTC 39562T).

Undibacterium aquatile sp. nov., isolated from a waterfall.

A Gram-stain-negative, aerobic, motile and rod-shaped strain, THG-DN7.3T, was isolated from a waterfall. Strain THG-DN7.3T grew well at 18-28 °C and at pH 6.0-7.5 on Reasoner's 2A agar. Based on 16S rRNA gene sequence comparisons, strain THG-DN7.3T was most closely related to Undibacterium jejuense JS4-4T (97.3 % 16S rRNA gene sequence similarity) and Undibacterium seohonense SHS5-24T (96.5 %). The G+C content of the genomic DNA was 57.4 mol%. The mean DNA-DNA relatedness of strain THG-DN7.3T with U. jejuense KACC 12607T was 40 ± 1 % (reciprocal 50 ± 2.1 %). The major cellular fatty acids of strain THG-DN7.3T were summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) (47.4 %), C16 : 0 (30.4 %), summed feature 8 (C18 : 1ω6c and/or C18 : 1ω7c) (6.8 %) and C12 : 0 (6.2 %). The predominant isoprenoid quinone was ubiquinone-8. The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. The results of the DNA-DNA hybridization and genotypic analysis, in combination with chemotaxonomic and physiological data, demonstrated that strain THG-DN7.3T represents a novel species of the genus Undibacterium, for which the name Undibacterium aquatile sp. nov. is proposed. The type strain is THG-DN7.3T ( = KCTC 42243T = CCTCC AB 2015119T).

Massilia arvi sp. nov., isolated from fallow-land soil previously cultivated with Brassica oleracea, and emended description of the genus Massilia.

A novel bacterial strain, designated THG-RS2OT, was isolated from fallow-land soil previously cultivated with Brassica oleracea in Yongin, South Korea. Cells were Gram-stain-negative, aerobic, non-motile rods, catalase- and oxidase-positive. Strain THG-RS2OT grew optimally at 25­37 °C, at pH 7.0 and in the absence of NaCl. 16S rRNA gene sequence analysis demonstrated that strain THG-RS2OT shows highest sequence similarity with Massilia kyonggiensis KACC 17471T followed by Massilia aerilata KACC 12505T, Massilia niastensis KACC 12599T, Massilia tieshanensis KACC 14940T and Massilia haematophila KCTC 32001T. Levels of DNA­DNA relatedness between strain THG-RS2OT and the closest phylogenetic neighbours were below 55.0 % and the DNA G+C content of strain THG-RS2OT was 63.2 mol%. Major fatty acids were C16 : 0, cyclo-C17 : 0 and summed feature 3 (C16 : 1ω6c and/or C16 : 1ω7c). The major respiratory quinone was identified as ubiquonone-8 and predominant polar lipids were determined to be diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol. Characterization by 16S rRNA gene sequence analysis, DNA­DNA hybridization, ubiquinone, polar lipid, fatty acid composition, and physiological and biochemical parameters revealed that strain THG-RS2OT represents a novel species of the genus Massilia. Hence, the present study describes a novel species for which the name Massilia arvi sp. nov. is proposed. The type strain is THG-RS2OT ( = KCTC 42609T = CCTCC AB 2015115T).

Phycicoccus soli sp. nov., isolated from soil.

A Gram-stain-positive, non-motile, coccus-shaped bacterium, strain THG-a14T, was isolated from soil of Gyeyang mountain in Incheon, Republic of Korea. The isolate grew optimally at 28 °C, at pH 6.5-7.5 and with 0-3 % (w/v) NaCl. Based on 16S rRNA gene sequence comparisons, strain THG-a14T was closely related to Phycicoccus aerophilus 5516T-20T (97.7 %), P. ginsenosidimutans BXN5-13T (97.6 %), 'P. ochangensis' L1b-b9 (97.4 %) and P. bigeumensis MSL-03 (97.2 %). The DNA G+C content of strain THG-a14T was 71.6 mol%. In DNA-DNA hybridization, the DNA-DNA relatedness between strain THG-a14T and its closest phylogenetically neighbours was below 50.0 %. Strain THG-a14T was characterized chemotaxonomically as having meso-diaminopimelic acid in the cell-wall peptidoglycan. Strain THG-a14T contained glucose and ribose as whole-cell-wall sugars and menaquinone MK-8(H4) as the major isoprenoid quinone. Polar lipids in strain THG-a14T consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, phosphoaminoglycolipids, unidentified phospholipids and unidentified lipids. The major fatty acids were iso-C16:0, iso-C15:0 and C17:1ω8c. On the basis of our polyphasic taxonomy study, strain THG-a14T represents a novel species within the genus Phycicoccus, for which the name Phycicoccussoli sp. nov. is proposed. The type strain is THG-a14T ( = KACC 17892T = JCM 19837T).

Lysobacter novalis sp. nov., isolated from fallow farmland soil.

A novel bacterial strain, designated THG-PC7(T), was isolated from fallow farmland soil in Yongin, South Korea. Cells of strain THG-PC7(T) were Gram-stain-negative, dark yellow, aerobic, rod-shaped and had gliding motility. Strain THG-PC7(T) grew optimally at 25-35 °C, at pH 7 and in the absence of NaCl. Comparative 16S rRNA gene sequence analysis identified strain THG-PC7(T) as belonging to the genus Lysobacter, exhibiting highest sequence similarity with Lysobacter ximonensis KCTC 22336(T) (98.7%) followed by Lysobacter niastensis KACC 11588(T) (95.7%). In DNA-DNA hybridization tests, DNA relatedness between strain THG-PC7(T) and its closest phylogenetic neighbour L. ximonensis was below 25%. The DNA G+C content of the novel isolate was determined to be 62.5 mol%. Flexirubin-type pigments were found to be present. The major cellular fatty acids were determined to be iso-C15 : 0, iso-C16 : 0, anteiso-C15 : 0 and iso-C17 : 1ω9c. The major respiratory quinone was identified as ubiquonone-8 (Q8). The predominant polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and an unidentified aminophospolipid. On the basis of results from DNA-DNA hybridization and the polyphasic data, strain THG-PC7(T) represents a novel species of the genus Lysobacter, for which the name Lysobacter novalis sp. nov. is proposed. The type strain is THG-PC7(T)( = KACC 18276(T) = CCTCC AB 2014319(T)).