Effect of Anti-immunoglobulin Antisera on Homograft Rejection in Mice

HETEROLOGOUS antisera against immunoglobulins or their component protein chains have been shown to inhibit the immune response in a variety of systems. Antibodies against mouse immunoglobulins, for example, inhibit the response of mouse spleen cells cultured in vitro^1–3. Antibodies against the heavy chains of chicken IgM (anti-μ), administered during embryonation and again at hatching, have produced agamma-globulinaemia in bursectomized chickens⁴, apparently by plasma cell line elimination⁵. Graft-versus-host (GVH) and delayed hypersensitivity reactions have been suppressed in neonatal mice by in vitro pretreatment of injected lymphoid cells with antiserum against light chains⁶. Similar pretreatment with univalent fragments (Fab) of anti-immunoglobulin antibodies has diminished the GVH reaction in adult mice⁷.     

Macrophage Functional Heterogeneity in the <Emphasis Type="Italic">in vitro</Emphasis> Induced Immune Response

RNA from antigenically stimulated peritoneal macrophages is immunogenic in vitro^1–4. The studies of Fishman and Adler^5–6 suggest that the peritoneal macrophage population consists of at least three functionally distinct subpopulations. Although most peritoneal macrophages act as scavenger cells⁷, a second population—possibly less than one cell per 1,000—consists of cells that produce but do not necessarily secrete antibody^8,9 and respond to antigen by synthesizing informational RNA. On transfer to normal lymphoid cells, this RNA elicits IgM antibody with the allotypic specificity of the macrophage donor¹⁰. A third type of macrophage gives rise to the RNA-antigen complex responsible for the in vitro synthesis of IgG antibody with the allotypic specificity of the lymphocyte donor¹⁰.     

Chaperone Skp from <Emphasis Type="Italic">Yersinia pseudotuberculosis</Emphasis> exhibits immunoglobulin G binding ability

A low-molecular-weight cationic protein that can bind human and rabbit immunoglobulins G has been isolated from Yersinia pseudotuberculosis cells. This immunoglobulin binding protein (IBP) interacts with IgG Fc-fragment, the association constant of the resulting complex being 3.1 μM^?1. MALDI-TOF mass spectrometry analysis of IBP revealed its molecular mass of 16.1 kDa, and capillary isoelectrofocusing analysis showed pI value of 9.2. N-Terminal sequence determination by Edman degradation revealed the sequence of the 15 terminal amino acid residues (ADKIAIVNVSSIFQ). Tryptic hydrolysate of IBP was subjected to MALDI-TOF mass spectrometry for proteolytic peptide profiling. Based on the peptide fingerprint, molecular mass, pI, and N-terminal sequence and using bioinformatic resources, IBP was identified as Y. pseudotuberculosis periplasmic chaperone Skp. Using the method of comparative modeling a spatial model of Skp has been built. This model was then used for modeling of Skp complexes with human IgG1 Fc-fragment by means of molecular docking.     

Feeding habits of the whale shark (<Emphasis Type="Italic">Rhincodon typus</Emphasis>) inferred by fatty acid profiles in the northern Mexican Caribbean

Whale shark (Rhincodon typus, Smith, 1828) is an endangered species with anthropogenic pressures due to increasing demand of encounter tourism activities. Research efforts to identify management and conservation strategies for this species are needed. The Northern Mexican Caribbean is one of the most important feeding aggregation sites of whale sharks worldwide. In this study, Mexican Caribbean whale shark feeding habits are assessed by means of fatty acid (FA) signature analysis, a biochemical non-destructive technique widely applied in trophic ecology studies. Sub-dermal tissue biopsies of 68 whale sharks and samples of their potential prey (zooplankton) were collected during 2010 and 2011 in two areas with high R. typus abundance. Zooplankton samples (n?=?17) were divided in two categories: mixed zooplankton (several groups of zooplankton) and fish eggs (> 95% of sample components were fish eggs). FA profiles of whale shark tissue sampled between years showed significant variability; while there was no intraspecific differences in FA signature related to sex, size and location. FA profiles of whale sharks and their potential prey were dominated by saturated fatty acids (SFA). R. typus FA signature was significantly different from that of mixed zooplankton; on the other hand, whale shark and fish egg FA profiles formed groups with overlapping values and registered high levels of oleic acid. PUFA average ω3/ ω6 ratio on whale shark FA profiles for both years was below 1. Arachidonic acid (ARA) percentage was higher in whale shark biopsies (13.2% in 2010, 6.8% in 2011) compared to values observed in fish eggs (2.0%) and mixed zooplankton (1.4%). Similarity between FA profiles of whale sharks and fish eggs, low levels of bacterial FA found in R. typus biopsies, as well as whale shark feeding behavior observations in the study area, suggest that R. typus is feeding mainly on surface zooplankton in Mexican Caribbean; however, elevated ARA percentages in whale shark samples may indicate that this species has complementary feeding sources, such as demersal zooplankton, which has been reported in other aggregation sites. Results obtained contribute to the knowledge of the whale shark trophic ecology in the area, but are inconclusive. Further studies are recommended to evaluate whale shark FA profiles from different tissues (muscle or blood); also, broader information is needed about zooplankton FA signature in the study area.     

Juvenile Greenland sharks <Emphasis Type="Italic">Somniosus microcephalus</Emphasis> (Bloch &amp; Schneider, 1801) in the Canadian Arctic

Life-stage-based management of marine fishes requires information on juvenile habitat preferences to ensure sustainable population demographics. This is especially important in the Arctic region given very little is known about the life histories of many native species, yet exploitation by developing commercial and artisanal fisheries is increasing as the ice extent decreases. Through scientific surveys and bycatch data from gillnet fisheries, we document captures of rarely reported juvenile Greenland sharks (Somniosus microcephalus; ≤200 cm total length [TL]) during the ice-free period in the Canadian Arctic. A total of 22 juvenile animals (42 % of total catch; n = 54), including the smallest reliably measured individual of 117 cm TL, were caught on scientific longlines and bottom trawls in Scott Inlet and Sam Ford Trough over three consecutive years. Molecular genetic nuclear markers confirmed species identity for 44 of these sharks sampled; however, two sharks including a juvenile of 150 cm TL were identified as carrying a Pacific sleeper shark (Somniosus pacificus) mitochondrial cytochrome b (cyt b) haplotype. This represents the first record of a Pacific sleeper shark genetic signature in Greenland sharks in Eastern Arctic waters. Juvenile sharks caught as bycatch in gillnet fisheries were only observed offshore in Baffin Bay surrounding a fishery closure area, while larger subadult and mature Greenland sharks (>200 cm TL) were caught in all fishing locations, including areas where juveniles were observed. The repeatable occurrence of juvenile Greenland sharks in a fjord and their presence at two offshore sites indicates that these smaller animals either reside in nurseries or have defined home ranges in both coastal and offshore regions or undertake large-scale inshore–offshore movements.     

Gas exchanges of an endangered species <Emphasis Type="Italic">Syringa pinnatifolia</Emphasis> and a widespread congener <Emphasis Type="Italic">S. oblata</Emphasis>

Net photosynthetic rate (P_N), transpiration rate (E), water use efficiency (WUE), stomatal conductance (g_s), and stomatal limitation (L_s) were investigated in two Syringa species. The saturation irradiance (SI) was 400 µmol m^-2s^-1 for S. pinnatifolia and 1 700 µmol m^-2s^-1 for S. oblata. Compared with S. oblata, S. pinnatifolia had extremely low g _s . Unlike S. oblata, the maximal photosynthetic rate (P_max) in S. pinnatifoliaoccurred around 08:00 and then fell down, indicating this species was sensitive to higher temperature and high photosynthetic photon flux density. However, such phenomenon was interrupted by the leaf development rhythms before summer. A relatively lower P_N together with a lower leaf area and shoot growth showed the capacity for carbon assimilation was poorer in S. pinnatifolia.     

Post-release fishing mortality of blue (<Emphasis Type="Italic">Prionace glauca</Emphasis>) and silky shark (<Emphasis Type="Italic">Carcharhinus falciformes</Emphasis>) from a Palauan-based commercial longline fishery

Accounting for components of fishing mortality, including post-release mortality (F_r), is necessary for robust assessments of the effects of fishing. Forty-eight blue (Prionace glauca) and 35 silky sharks (Carcharhinus falciformes) were tagged with pop-up satellite archival tags to monitor F_r rates from pelagic longline vessels in the western tropical Pacific Ocean. There is a paucity of F_r studies at low latitudes and identifying factors that significantly explain F_r is critical for understanding fishing mortality. Mean F_r rates were 0.17 [95% CI 0.09–0.30] for blue shark and 0.20 [95% CI 0.10–0.36] for silky shark. When it occurred, F_r was acute with 87% of mortalities within 2 days of release. Several prognostic operational, environmental, biological and handling variables were evaluated to assess their influence on survival outcomes. Using Kaplan–Meier survival curves, logistic regression, accelerated failure time and Cox proportional hazards models to screen variables, the only significant prognostic or risk variable was health condition at haulback. There was close correspondence (~?83% accuracy) between condition at capture and survival outcomes. Reliable methods to classify at-vessel condition represent an inexpensive and simple metric for estimating both F_r and at-vessel (F_c) mortality rates. Examining F_c rates in detail in longline fisheries using capture information on depth, temperature and dissolved oxygen that may act in synergy with condition code and hooking duration is a research priority. Results suggest that a large proportion of shark survive following release and that F_r rates can be increased by improving the haulback condition of captured sharks.     

Fine-scale movement and activity patterns of Caribbean reef sharks (<Emphasis Type="Italic">Carcharhinus perezi</Emphasis>) in the Bahamas

Knowledge of the spatial ecology and movement of animals contributes to our understanding of intra- and inter-specific interactions and ecosystem dynamics, and can inform conservation actions. Here we assessed the space use and activity levels of a marine predator, the Caribbean reef shark (Carcharhinus perezi), in coastal regions of Eleuthera, The Bahamas over a 60-day period using acoustic telemetry. Of the 14 adult sharks (eight males, six females) tagged with acoustic transmitters (equipped with accelerometer sensor), nine were detected in a 14 km² gridded receiver array. Male sharks were significantly less likely to be detected over time relative to females. Given post-release survival is typically high in C. perezi, this finding may indicate that males have larger home ranges and may exhibit lower site fidelity compared to females. Patterns of space use indicated C. perezi primarily occupied the outer reef shelf and were rarely detected on the interior of the reef. Shark activity levels (inferred from acceleration profiles) were highest in close proximity to the reef shelf. Our findings indicate C. perezi individuals frequently occupy deeper water habitats, but make forays into reef shelf habitats where high activity levels are likely related to foraging.     

New insights into whale shark <Emphasis Type="Italic">Rhincodon typus</Emphasis> diet in Brazil: an observation of ram filter-feeding on crab larvae and analysis of stomach contents from the first stranding in Bahia state

We describe the first record of a whale shark, Rhincodon typus, feeding in Brazilian coastal waters, and the first stranding record in the state of Bahia, Northeast Brazil. In April 2008, an individual of R. typus was observed surface feeding on Dromiidae crab larvae in the continental shelf off the coast of Bahia, near a gas platform. Other fishes were observed foraging in association with the whale shark. We also document the first stranding of R. typus on the coast of Bahia in October 2013. Biometric data confirmed that the stranded whale shark was a juvenile. Stomach content analysis revealed the ingestion of Geryonidae crab larvae. Plastic debris were also found in the gastric lumen of the stranded juvenile whale shark, and we speculate that it could have been a contributing factor to the stranding, and subsequent death of the whale shark. Crab larvae were observed in both of our records and likely to consist as relevant prey items for R. typus in Brazilian continental shelf. Our study provided a contribution on the diet and feeding behaviour of whale sharks in tropical oligotrophic waters and highlights the risks of marine pollution for the species conservation.     

Increase in Salt Tolerance of <Emphasis Type="Italic">Arabidopsis thaliana</Emphasis> by <Emphasis Type="Italic">TaDi19</Emphasis>

The gene expression profile chip of salt-resistant wheat mutant RH8706-49 under salt stress was investigated. The overall length of the cDNA sequence of the probe was obtained using electronic cloning and RT-PCR. An unknown gene induced by salt was obtained, cloned, and named TaDi19 (Triticum aestivum drought-induced protein). No related report or research on the protein is available. qPCR analysis showed that gene expression was induced by many stresses, such as salt. Arabidopsis thaliana was genetically transferred using the overexpressing gene, which increased its salt tolerance. After salt stress, the transgenic plant demonstrated better physiological indicators (higher Ca²⁺ and lower Na⁺) than those of the wild-type plant. Results of non-invasive micro-test technology indicate that TaDi19-overexpressing A. thaliana significantly effluxed Na⁺ after salt treatment, whereas the wild-type plant influxed Na⁺. Chelating extracellular Ca²⁺ resulted in insignificant differences in salt tolerance between overexpressing and wild-type A. thaliana. Subcellular localization showed that the gene encoding protein was mainly located in the cell membrane and nucleus. TaDi19 was overexpressed in wild-type A. thaliana, and the transgenic lines were more salt-tolerant than the control A. thaliana. Thus, the wheat gene TaDi19 could increase the salt tolerance of A. thaliana.     

<Emphasis Type="Italic">Candida krusei</Emphasis> isolated from fruit juices ultrafiltration membranes promotes colonization of <Emphasis Type="Italic">Escherichia coli</Emphasis> O157:H7 and <Emphasis Type="Italic">Salmonella enterica</Emphasis> on stainless steel surfaces

To clarify the interactions between a common food spoilage yeast and two pathogenic bacteria involved in outbreaks associated with fruit juices, the present paper studies the effect of the interplay of Candida krusei, collected from UF membranes, with Escherichia coli O157:H7 and Salmonella enterica in the overall process of adhesion and colonization of abiotic surfaces. Two different cases were tested: a) co-adhesion by pathogenic bacteria and yeasts, and b) incorporation of bacteria to pre-adhered C. krusei cells. Cultures were made on stainless steel at 25°C using apple juice as culture medium. After 24 h of co-adhesion with C. krusei, both E. coli O157:H7 and S. enterica increased their counts 1.05 and 1.11 log CFU cm², respectively. Similar increases were obtained when incorporating bacteria to pre-adhered cells of Candida. Nevertheless C. krusei counts decreased in both experimental conditions, in a) 0.40 log CFU cm² and 0.55 log CFU cm² when exposed to E. coli O157:H7 and S. enterica and in b) 0.18 and 0.68 log CFU cm², respectively. This suggests that C. krusei, E. coli O157:H7, and S. enterica have a complex relationship involving physical and chemical interactions on food contact surfaces. This study supports the possibility that pathogen interactions with members of spoilage microbiota, such as C. krusei, might play an important role for the survival and dissemination of E. coli O157:H7 and Salmonella enterica in food-processing environments. Based on the data obtained from the present study, much more attention should be given to prevent the contamination of these pathogens in acidic drinks.     

First observation on the mating behaviour of the endangered scalloped hammerhead shark <Emphasis Type="Italic">Sphyrna lewini</Emphasis> in the Tropical Eastern Pacific

Here we provide a detailed analysis of the first complete sequence of a mating event for the endangered scalloped hammerhead shark, Sphyrna lewini. This analysis is based on a mating event recorded at Isla del Coco National Park, Costa Rica, where large schools of hammerhead sharks are frequently encountered. S lewini mating sequence can be characterized by: (1) an open water encounter, (2) pre-copulatory biting, (3) grabbing of pectoral fin/copulation, (4) free fall, (5) separation and (6) following. Based on this single observation we found that only one male appears to be involved in a copulation cycle and that mating took place in a high current zone potentially to favor respiration when both individuals are unable to swim. This observation highlights the difficulty in observing mating behavior for this species since mating is likely to occur in open waters.     

Mutant tRNA<Superscript>His</Superscript> Ineffective in Repression and Lacking Two Pseudouridine Modifications

TRANSFER RNA has been implicated in the regulation of a number of amino-acid biosynthetic operons^1–4. Histidyl-tRNA^His has been shown to be involved in regulation of the histidine operon by analysis of six genes (hisO, hisR, hisS, hisT, hisU, hisW), mutation of which causes derepression of the enzymes of the histidine biosynthetic pathway in Salmonella typhimurium^5–7. A class of derepressed mutants (hisR) has only about 55% as much tRNA^His as the wild type⁴ and in the one example sequenced, contains tRNA^HIS with a structure identical to that of the wild type⁸. Studies of mutants of the gene for histidyl-tRNA synthetase (hisS) indicated that the derepressed phenotype was associated with defects in the charging of tRNA^HISin vitro². The amounts of charged and uncharged tRNA^His present in vivo during physiological derepression of the wild type and in the six classes of regulatory mutants, have been determined⁹. This work has shown that repression of the histidine operon is correlated directly with the concentration of charged histidyl-tRNA^Hisin vivo and not with the ratio of charged to uncharged or the absolute amount of uncharged tRNA^His. The derepression observed in mutants, of hisS (the gene for histidyl-tRNA synthetase), hisR (the presumed structural gene for the single species of tRNA^His) and hisU and hisW (genes presumably involved in tRNA modification) may be explained by the lower cellular concentration of charged tRNA^His which these mutants contain.     

<Emphasis Type="Italic">Limnobacter humi</Emphasis> sp. nov., a thiosulfate-oxidizing,heterotrophic bacterium isolated from humus soil,and emended description of the genus <Emphasis Type="Italic">Limnobacter</Emphasis> Spring <Emphasis Type="Italic">et al.</Emphasis> 2001

Three Gram-negative, strictly aerobic, chemolithoheterotrophic bacterial strains, designated UCM-30, UCM-33, and UCM-39^T, were isolated in South Korea. Based on their 16S rRNA gene sequences, the three isolated strains were found to be similar to Limnobacter thiooxidans CS-K2^T (97.41–97.68%), Limnobacter litoralis KP1-19^T (95.55–95.76%), and various genera belonging to the class Betaproteobacteria (90.34–93.34%). DNA-DNA hybridization showed 79.3–83.9% similarity between the genomic DNA of UCM-39^T, UCM-30, and UCM-33, while the sequence similarity between UCM-39^T and L. thiooxidans KACC 13837T or L. litoralis LMG 24869T was 23.7% and 18.6%, respectively. The DNA G+C content of UCM 39T was 59.7 mol%, the major ubiquinone was Q-8, and the optimal oxidation rate was observed at 10 mM thiosulfate. The major fatty acids (≥ 10%) were summed features 3 (C_16:1 ω7c and/or C_16:1 ω6c) and 8 (C_18:1 ω7c and/or C_18:1 ω6c), and C_16:0. The major polar lipids (diphosphatidylglycerol, phosphatidylethanolamine, and phosphatidylglycerol) were found in all members of genus Limnobacter. Based on phenotypic, physiological, and phylogenetic analyses, the UCM-39T strain was found to be significantly distinct to represent a novel species affiliated to the genus Limnobacter. We propose to name it Limnobacter humi sp. nov. with the type strain UCM-39^T (=KACC 18574^T =NBRC 111650^T).     

<Emphasis Type="Italic">Roseovarius tibetensis</Emphasis> sp. nov., a halophilic bacterium isolated from Lake LongmuCo on Tibetan Plateau

Two Gram-stain negative halophilic strains, designated as LM2^T and LM4, were isolated from Lake LongmuCo on Tibetan Plateau. These two strains were aerobic, catalaseand oxidase-positive, nonmotile and rod-shaped organisms. Phylogenetic analysis based on 16S rRNA gene sequences indicated that LM2^T and LM4 belong to the genus Roseovarius, with Roseovarius tolerans EL-172^T (97.3% and 97.4% 16S rRNA gene sequence similarity, respectively) and Roseovarius azorensis SSW084^T (95.5% and 95.6% 16S rRNA gene sequence similarity, respectively) as their closest neighbors. Q-10 was the sole respiratory quinone of these two strains. The major fatty acids were C_18:1ω7c/C_18:1ω6c, C_16:0, C_19:0 cyclo ω8c, and 11-methyl C_18:1ω7c. The polar lipids included phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, phospholipid of unknown structure containing glucosamine, and unidentified aminolipid. The DNA G + C content was between 64.2 and 64.5 mol%. DNA-DNA hybridization showed 96.7% relatedness between LM2^T and LM4, 24.9% relatedness between LM2^T and R. tolerans EL-172^T, and 36.3% relatedness between LM4 and R. tolerans EL-172^T. Based on phylogenetic analysis, DNA-DNA hybridization, a range of physiological and biochemical characteristics, LM2^T and LM4 belong to the same species and were clearly distinguished from the type strains of the genus Roseovarius. It was evident that LM2^T and LM4 could be classified as a novel species of the genus Roseovarius, for which the name Roseovarius tibetensis sp. nov. is proposed. The type strain is LM2^T (= CGMCC 1.16230^T = KCTC 62028^T).     

<Emphasis Type="Italic">Paenibacillus seodonensis</Emphasis> sp. nov., isolated from a plant of the genus <Emphasis Type="Italic">Campanula</Emphasis>

Strain DCT-19^T, representing a Gram-stain-positive, rodshaped, aerobic bacterium, was isolated from a native plant belonging to the genus Campanula on Dokdo, the Republic of Korea. Comparative analysis of the 16S rRNA gene sequence showed that this strain was closely related to Paenibacillus amylolyticus NRRL NRS-290^T (98.6%, 16S rRNA gene sequence similarity), Paenibacillus tundrae A10b^T (98.1%), and Paenibacillus xylanexedens NRRL B-51090^T (97.6%). DNADNA hybridization indicated that this strain had relatively low levels of DNA-DNA relatedness with P. amylolyticus NRRL NRS-290^T (30.0%), P. xylanexedens NRRL B-51090^T (29.0%), and P. tundrae A10b^T (24.5%). Additionally, the genomic DNA G + C content of DCT-19^T was 44.8%. The isolated strain grew at pH 6.0–8.0 (optimum, pH 7.0), 0–4% (w/v) NaCl (optimum, 0%), and a temperature of 15–45°C (optimum 25–30°C). The sole respiratory quinone in the strain was menaquinone-7, and the predominant fatty acids were C_15:0 anteiso, C_16:0 iso, and C_16:0. In addition, the major polar lipids were diphosphatidylglycerol and phosphatidylethanolamine. Based on its phenotypic properties, genotypic distinctiveness, and chemotaxonomic features, strain DCT-19^T is proposed as a novel species in the genus Paenibacillus, for which the name Paenibacillus seodonensis sp. nov. is proposed (=KCTC 43009^T =LMG 30888^T). The type strain of Paenibacillus seodonensis is DCT-19^T.     

<Emphasis Type="Italic">Spirosoma lituiforme</Emphasis> sp. nov., isolated from soil

A Gram-staining-negative, non-motile, curved rod-shaped, aerobic bacterium, designated S1-2-4^T, was isolated from soil in Jeollabuk-do province, Republic of Korea, and was characterized taxonomically using a polyphasic approach. Comparative 16S rRNA gene sequence analysis showed that strain S1-2-4^T was a member of the family Cytophagaceae and most closely related to ‘Spirosoma radiotolerans’ DG5A (97.2%), Spirosoma fluviale MSd3^T (96.4%), and Spirosoma linguale DSM 74^T (96.3%). The genomic DNA G + C content of strain S1-2-4^T was 49.7 mol%. The major fatty acids were summed feature 3 (C_16:1ω7c/C_16:1ω6c), C_16:1ω5c, and C_16:0, and the major polar lipid was phosphatidylethanolamine. MK-7 was the predominant respiratory quinone. Phenotypic and chemotaxonomic data supported the affiliation of strain S1-2-4^T with the genus Spirosoma. DNA-DNA hybridization between strain S1-2-4^T and ‘Spirosoma radiotolerans’ showed relatively low DNA-DNA relatedness (31%). Strain S1-2-4^T could be distinguished from its closest phylogenetic neighbors based on its phenotypic, genotypic, and chemotaxonomic features. Therefore, strain S1-2-4^T represents a novel member of the genus Spirosoma, for which the name Spirosoma lituiforme sp. nov. is proposed. The type strain is S1-2-4^T (= KCTC 52724^T = JCM 32128^T).     

<Emphasis Type="Italic">Hymenobacter agri</Emphasis> sp. nov., a novel bacterium isolated from soil

A bacterial isolate was recovered from a soil sample collected in Jeollabuk-do Province, South Korea, and subjected to polyphasic taxonomic assessment. Cells of the isolate, designated strain S1-2-1-2-1^T, were observed to be rod-shaped, pink in color, and Gram-stain negative. The strain was able to grow at temperature range from 10 to 30 °C, with an optimum of 25 °C, and growth occurred at pH 6–8. Comparative 16S rRNA gene sequence analysis showed that strain S1-2-1-2-1^T belongs to the genus Hymenobacter, with closely related type strains being Hymenobacter daeguensis 16F3Y-2^T (95.8% similarity), Hymenobacter rubidus DG7B^T (95.8%), Hymenobacter soli PB^T (95.7%), Hymenobacter terrenus MIMtkLc17^T (95.6%), Hymenobacter terrae DG7A^T (95.3%), and Hymenobacter saemangeumensis GSR0100^T (95.2%). The genomic DNA G+C content of strain S1-2-1-2-1^T was 63.0 mol%. The main polar lipid of this strain was phosphatidylethanolamine, the predominant respiratory quinone was menaquinone-7, and the major fatty acids were C_15:0 iso (27.3%), summed feature 3 (C_16:1 ω7c/C_16:1 ω6c) (16.5%), C_15:0 anteiso (15.3%), and C_16:0 (14.7%), supporting the affiliation of this strain with the genus Hymenobacter. The results of this polyphasic analysis allowed for the genotypic and phenotypic differentiation of strain S1-2-1-2-1^T from recognized Hymenobacter species. On the basis of its phenotypic properties, genotypic distinctiveness, and chemotaxonomic features, strain S1-2-1-2-1^T is considered to represent a novel species of the genus Hymenobacter, for which the name Hymenobacter agri sp. nov. is proposed. The type strain is S1-2-1-2-1^T (=KCTC 52739^T?=?JCM 32194^T).