Dataset and measurements from a current density sensor during experimental testing of dynamic load cycling for a parallel-serpentine design of a proton exchange membrane fuel cell.

A dataset from experimental tests of a proton exchange membrane fuel cell (PEMFC) with an active area of approximately 50 cm2, parallel-serpentine channels and cross-flow field distribution between anode and cathode is presented. Tests were performed for four different gas inlet and outlet configurations. In particular, tests were performed for the original configuration, hydrogen inlet and outlet reversed, air inlet and outlet reversed, and hoses reversed for both gases. The operating conditions for all gas configurations were: pressure of 0.5 bar, temperature of 65 °C, anode and cathode relative humidity of 60 %, and anode and cathode stoichiometry of 1.3 and 2.5 respectively. The tests performed were the polarization curve (PC) for each gas configuration and the dynamic load cycles (FC-DLC) also for each hose position. A current density mapping (CDM) sensor, capable of measuring both the current density distribution and the temperature distribution inside the cell, was inserted into the fuel cell system during all tests. The use of the sensor during the experiments makes it possible to know how these distributions behave and to observe whether or not there is homogeneity in its measurements, thus verifying that the design of the flow channels is adequate and fulfilling its function. The results can be used to investigate and compare other bipolar plates and channel designs, or to compare with results from other test benches and environmental conditions.

A genetically modulated Toll-like-receptor-tolerant phenotype in peripheral blood cells of children with multisystem inflammatory syndrome.

Dysregulated innate immune responses contribute to multisystem inflammatory syndrome in children (MIS-C), characterized by gastrointestinal, mucocutaneous, and/or cardiovascular injury occurring weeks after SARS-CoV-2 exposure. To investigate innate immune functions in MIS-C, we stimulated ex vivo peripheral blood cells from MIS-C patients with agonists of Toll-like receptors (TLR), key innate immune response initiators. We found severely dampened cytokine responses and elevated gene expression of negative regulators of TLR signaling. Increased plasma levels of zonulin, a gut leakage marker, were also detected. These effects were also observed in children enrolled months after MIS-C recovery. Moreover, cells from MIS-C children carrying rare genetic variants of lysosomal trafficking regulator (LYST) were less refractory to TLR stimulation and exhibited lysosomal and mitochondrial abnormalities with altered energy metabolism. Our results strongly suggest that MIS-C hyperinflammation and/or excessive or prolonged stimulation with gut-originated TLR ligands drive immune cells to a lasting refractory state. TLR hyporesponsiveness is likely beneficial, as suggested by excess lymphopenia among rare LYST variant carriers. Our findings point to cellular mechanisms underlying TLR hyporesponsiveness; identify genetic determinants that may explain the MIS-C clinical spectrum; suggest potential associations between innate refractory states and long COVID; and highlight the need to monitor long-term consequences of MIS-C.

Effect of bacterial volatiles on the mycelial growth of mushrooms.

Bacteria play an important role in the life cycle of fungi by influencing positively or negatively morphological features, mycelial growth and/or fruiting body induction. However, little is known about the underlying mechanisms and their species-dependence, especially among fungi of the phylum Basidiomycota. Hence, we analyzed the effects of seven bacterial isolates, that were previously obtained from Pleurotus ostreatus HK35, on the mycelial growth of P. ostreatus HK35, Pleurotus eryngii DSMZ 8264, Pleurotus sapidus DSMZ 8266, Pleurotus citrinopileatus DSMZ 5341, Cyclocybe aegerita AAE-3, Lentinula edodes CBS 389.89 and Kuehneromyces mutabilis DSMZ 1013 during eight days. Notably, the bacterial isolates only showed significant mycelial growth-promoting effects when co-cultivated on Petri dishes with Pleurotus species, except for P. citrinopileatus. In particular, Paenibacillus peoriae strain M48F induced remarkably the mycelial growth in P. ostreatus (∼47 %), P. eryngii (∼32 %) and P. sapidus (∼27 %) during the early cultivation stages, but with ongoing cultivation this strain inhibited the growth of all fungi. To investigate the impact of bacterial volatile organic compounds (VOCs) on the mycelial growth, P. ostreatus and P. eryngii were co-cultivated with the bacteria on bi-plates. No growth inhibition on bi-plates was observed while bacterial isolates and mycelia were separated by a physical barrier, assuring that late mycelial growth inhibition was not caused by bacterial volatile compounds. VOCs from strain M48F induced the strongest growth of P. ostreatus (∼50 %) and P. eryngii (∼20 %) mycelia compared to controls. Furthermore, we analyzed the VOCs of strain M48F alone and in combination with P. ostreatus, P. eryngii, P. sapidus and L. edodes using bi-plates and SPME-GC-MS. Strain M48F triggered the formation of ß-bisabolene when co-cultivated with P. ostreatus or P. eryngii, which may indicate a fungal defense reaction. Additionally, 2,5-diisopropylpyrazine dominated the volatilome of strain M48F on all eight sampling days. In samples of strain M48F, alone and co-cultivated with L. edodes, the amount of 2,5-diisopropylpyrazine remained quite constant. In contrast, the quantity of this substance declined substantially in co-cultures with P. ostreatus. Interestingly, 2,5-diisopropylpyrazine enhanced P. ostreatus mycelial growth significantly although the growth-promoting effect was not as pronounced as during co-cultivation with strain M48F. Our results show that the mycelial growth-promoting effects of bacteria are remarkably species-dependent, and that bacterial VOCs such as 2,5-diisopropylpyrazine can enhance mycelial growth.

Dataset and mesh of the CFD numerical model for the modelling and simulation of a PEM fuel cell.

A CFD mesh corresponding to a Proton Exchange Membrane Fuel Cell (PEMFC) with an active area of 50 cm2, serpentine channels and cross-flow field distribution is presented. The mesh was developed using ANSYS ICEM CFD hexa (v12.0) and it is divided into 3D regions corresponding to the different components of the fuel cell: bipolar plates (anode and cathode), gas diffusion layers (GDLs), catalytic layers (CLs) and membrane. The mesh was generated following Best Practice Guidelines, and mesh quality parameters are reported including minimum cell angle or maximum aspect ratio amongst others. Mesh independence results were checked in the corresponding CFD model and simulation of an experimental fuel cell ANSYS FLUENT with the PEM Fuel Cell module. Simulation results were also validated with the experimental data available from a fuel cell test bench for a set of different operating conditions. The experimental validation provides credibility to the CFD model and supports the use of the proposed mesh for fuel cell research, ensuring accurate results and enabling further validation works and comparison of different designs and operating conditions using numerical simulations.

Factores asociados al autocuidado de la salud en los pacientes diabéticos / Factors associated with self-care in diabetic patients

La diabetes es una enfermedad que afecta a la población mundial, y los adultos mayores son los más propenso a padecerla, como consecuencia a los niveles de estrés y malos hábitos alimenticios que llevaron a lo largo de su vida productiva. Es por ello, que el: Objetivo de esta investigación es, describir los factores asociados al autocuidado de la salud en los pacientes diabéticos. Materiales y métodos: Investigación documental. Se incluyeron estudios de cohortes que analizaron diagnóstico y tratamiento oportuno en el autocuidado de pacientes diabéticos en bases de datos electrónicas, como lo son Porta Scielo, PubMed, Medline PLUS, Embase, Scopus y Web of Science, del 2015 al 2020. Las medidas de autocuidado son habilidades que los individuos practican para el mantenimiento de su salud, sobre todo cuando hay una patología de base que ponga en riesgo el estado de salud y el bienestar en general. Resultado: La diabetes es una enfermedad complicada, requiere vigilancia constante, conocimiento de la enfermedad y del apoyo de varios especialistas en salud, la mayor parte del cuidado y control debe prevenir del paciente mismo. Es importante que los pacientes no solo perciban los daños o la severidad de la ausencia de autocuidado, lo que puede influir en el adecuado control de la diabetes mellitus, sino que se le proporcione mediante la educación para la salud, estrategias que faciliten en ellos el aprendizaje de habilidades que le permitan percibir los beneficios de la adopción de estilos de vida saludables. Conclusiones: el equipo básico de salud desempeña un rol importante en la realización de acciones que faciliten el autocuidado en los pacientes diabéticos, lo que puede constituir una vía para que las personas tomen decisiones serias respecto al mantenimiento de un adecuado estado de su salud. Por ende, es necesario que se realicen programas que desarrollen el ajuste adecuado de expectativas, objetivos definidos, el manejo adecuado del refuerzo, el incremento del sentimiento de autoeficacia, el autocontrol, y que brinden alternativas que favorezcan un autocuidado óptimo(AU)

Diabetes is a disease that affects the world population, and older adults are the most prone to suffer from it, as a consequence of the levels of stress and poor eating habits that they led throughout their productive lives. That is why the: Objective of this research is to describe the factors associated with self-care of health in diabetic patients. Materials and methods: Documentary research. Cohort studies that analyzed diagnosis and timely treatment in the self-care of diabetic patients were included in electronic databases, such as Porta Scielo, PubMed, Medline PLUS, Embase, Scopus and Web of Science, from 2015 to 2020. The measures of Self-care are skills that individuals practice to maintain their health, especially when there is an underlying pathology that puts the state of health and well-being in general at risk. Result: Diabetes is a complicated disease, it requires constant vigilance, knowledge of the disease and the support of various health specialists, most of the care and control must be prevented by the patient himself. It is important that patients not only perceive the damage or the severity of the absence of self-care, which can influence the adequate control of diabetes mellitus, but that it is provided through health education, strategies that facilitate in them the learning skills that allow you to perceive the benefits of adopting healthy lifestyles. Conclusions: the basic health team plays an important role in carrying out actions that facilitate self-care in diabetic patients, which can constitute a way for people to make serious decisions regarding the maintenance of an adequate state of their health. Therefore, it is necessary to carry out programs that develop the adequate adjustment of expectations, defined objectives, the adequate management of reinforcement, the increase of the feeling of self-efficacy, self-control, and that provide alternatives that favor a more optimal self-care(AU)

Spirosoma endbachense sp. nov., isolated from a natural salt meadow.

A Gram-stain-negative bacterium, designated I-24T, was isolated from soil of a natural salt meadow. Strain I-24T was aerobic, non-motile, rod-shaped, catalase-positive, oxidase-positive and grew optimally at pH 7 and 25 °C. Comparative 16S rRNA gene analysis indicated that strain I-24T has closest similarities to Spirosoma agri KCTC 52727T (95.9 %) and Spirosoma terrae KCTC 52035T (95.5 %). Strain I-24T contained summed feature 3 (C16 : 1 ω7c/C16 : 1 ω6c) and C16 : 1 ω5c as the major fatty acids, the predominant respiratory quinone was menaquinone MK-7, and the major polar lipids were phosphatidylethanolamine as well as an unidentified phosphoaminolipid. The draft genome of strain I-24T consists of 10 326 072 base pairs with 9153 predicted coding sequences and a G+C content of 47.7 mol%. Clear distinctions between strain I-24T and S. agri KCTC 52727T or S. terrae KCTC 52035T were shown in the pairwise average nucleotide identity results with values of 76.71 and 74.01 %, respectively. Moreover, the digital DNA-DNA relatedness values to these strains were 20.8 and 19.0 %. Based on its phenotypic, genotypic and chemotaxonomic characteristics, strain I-24T represents a novel species of the genus Spirosoma, for which the name Spirosoma endbachense sp. nov. is proposed. The type strain is I-24T (DSM 111055T=KCTC 72613T).

Draft Genome Sequences of Spirosoma agri KCTC 52727 and Spirosoma terrae KCTC 52035.

Spirosoma agri S7-3-3 (KCTC 52727) and Spirosoma terrae 15J9-4 (KCTC 52035) are type strains isolated from an apple orchard and beach soil in South Korea, respectively; their draft genome sequences were assembled and annotated. The draft genome sequences of S7-3-3T (7,239,915 bp; G+C content, 50.6%) and 15J9-4T (7,551,610 bp; G+C content, 47.3%) are reported.

Complete Genome Sequence of the Plant Growth-Promoting Bacterium Hartmannibacter diazotrophicus Strain E19T.

Strain E19T described as Hartmannibacter diazotrophicus gen. nov. sp. nov. was isolated from the rhizosphere of Plantago winteri from a natural salt meadow in a nature protection area. Strain E19T is a plant growth-promoting rhizobacterium able to colonize the rhizosphere of barley and to promote its growth only under salt stress conditions. To gain insights into the genetic bases of plant growth promotion and its lifestyle at the rhizosphere under salty conditions, we determined the complete genome sequence using two complementary sequencing platforms (Ilumina MiSeq and PacBio RSII). The E19T genome comprises one circular chromosome and one plasmid containing several genes involved in salt adaptation and genes related to plant growth-promoting traits under salt stress. Based on previous experiments, ACC deaminase activity was identified as a main mechanism of E19T to promote plant growth under salt stress. Interestingly, no genes classically reported to encode for ACC deaminase activity are present. In general, the E19T genome provides information to confirm, discover, and better understand many of its previously evaluated traits involved in plant growth promotion under salt stress. Furthermore, the complete E19T genome sequence helps to define its previously reported unclear 16S rRNA gene-based phylogenetic affiliation. Hartmannibacter forms a distinct subcluster with genera Methylobrevis, Pleomorphomonas, Oharaeibacter, and Mongoliimonas subclustered with genera belonging to Rhizobiales.

Effect of Different Soil Phosphate Sources on the Active Bacterial Microbiota Is Greater in the Rhizosphere than in the Endorhiza of Barley (Hordeum vulgare L.).

Phosphate is a macronutrient and often the limiting growing factor of many ecosystems. The aim of this work was to assess the effect of various phosphate sources on the active bacterial microbiota of barley rhizosphere and endorhiza. Barley was grown on poor soil supplemented with either Ca(H2PO4)2 (CaP), Gafsa rock phosphate (Gafsa), sodium hexaphytate (NaHex), or not amended (P0). RNA was extracted and cDNA synthesized via reverse transcription from both rhizosphere and endorhiza of barley roots; the obtained 16S rRNA cDNA was sequenced by Ion Torrent and analyzed with QIIME and co-occurrence network analysis. Phosphatase activity was measured in the rhizosphere. The phosphate source significantly affected alpha- and beta-diversities of the active microbiota, especially in the rhizosphere. CaP enriched the relative abundance of a broad range of taxa, while NaHex and Gafsa specifically enriched one dominant Massilia-related OTU. Co-occurrence network analysis showed that the most abundant OTUs were affected by phosphate source and, at the same time, were low connected to other OTUs (thus they were relatively "independent" from other bacteria); this indicates a successful adaptation to the specific abiotic conditions. In the rhizosphere, the phosphatase activities were correlated to several OTUs. Moreover, the phosphodiesterase/alk. phosphomonoesterase ratio was highly correlated to the dominance index of the microbiota and to the relative abundance of the dominant Massilia OTU. This study shows the differential response of the rhizosphere- and endorhiza bacterial microbiota of barley to various phosphate sources in soil, thus providing insights onto this largely unknown aspect of the soil microbiome ecology and plant-microbe interactions.

Isolation of bacteria at different points of Pleurotus ostreatus cultivation and their influence in mycelial growth.

Pleurotus ostreatus is one of the most cultivated edible mushrooms worldwide and few approaches have been done to analyze bacterial influence during its cultivation. Therefore, bacteria from commercial spawn, mycelial-colonized straw and fruiting bodies from healthy productive samples were counted, isolated and tested for their mycelial growth promoting ability. Bacterial cell numbers at different steps of the process showed low bacterial cell numbers in spawn and in fruiting bodies inner tissue compared to the high concentration in mycelial-colonized straw. The majority of the 38 isolates belonged to phyla Firmicutes and Actinobacteria were identified as Bacillus, Paenibacillus and Micromonospora species. Similarly, 16S rRNA gene bacterial clones obtained from mycelial biomass DNA samples showed bacterial presence of various genera including Bacillus and Paenibacillus. In the mycelial growth promoting ability tests, 30 isolates negatively affected mycelial growth, two isolates showed no effect on mycelial growth, and six isolates promoted mycelial growth. Moreover, mycelial thickness was influenced in different ways by the bacterial growth. In general, nearly all isolates growth-preventing were isolated from healthy spawn and mycelial-colonized straw, whereas fruiting bodies were the best source for isolation of mycelial growth-promoting bacteria. Characterization of bacterial isolates revealed that growth-preventing isolates exhibited various enzymatic activities in comparison with positive influencing bacteria that exhibited none or weak enzymatic activities. In addition, the influence of volatile compounds being present in the headspace of bi-plate co-cultures on P. ostreatus mycelial growth was demonstrated. The effect of isolates, that promoted mycelial growth in co-cultivation, to reduce P. ostreatus spawn running time, was evaluated on sterilized rye seeds. Results showed that not all mycelial promoted isolates were able to significantly promote P. ostreatus colonization. However, isolate M46F identified as Micromonospora lupini significantly reduce spawn running time. This is one of few studies to estimate cultivable bacteria from healthy samples of P. ostreatus cultivation, to evaluate a bacterial effect on mycelial growth, to show that fruiting bodies are a good source for mycelia growth-promoting isolates, and the first to report a shorter P. ostreatus spawn running time due to bacterial inoculation.

Spirosoma pollinicola sp. nov., isolated from pollen of common hazel (Corylus avellana L.).

A Gram-negative bacterium, strain HA7T, was isolated from the microhabitat of common hazel (Corylus avellana L.) pollen. HA7T was found to be an aerobic, rod-shaped, catalase-positive, oxidase-negative bacterium with an optimum growth temperature of 25 °C and pH of 7. The nearly complete 16S rRNA gene sequence of HA7T strain showed the closest similarities to Spirosoma linguale DSM 74T (97.4 %) and Spirosoma fluviale DSM 29961T (97.43 %). The major fatty acids (>5 %) were C16 : 1ω5c, summed feature 3 (C16 : 1ω7c and/or iso-C15 : 0 2-OH), iso-C15 : 0 and iso-C17 : 0 3-OH. The major polar lipids were an unidentified aminophospholipid and phosphatidylethanolamine. The major respiratory quinone detected was menaquinone MK-7 (95 %). The draft genome sequence included 8 794 837 bases, which contained 3665 predicted coding sequences and had a G+C content of 47.9 mol%. The genome-based comparison between HA7T and S. linguale DSM 74T and S. fluviale DSM 29961T with pairwise average nucleotide identity indicated a clear distinction, between 76.2-76.3 %. Moreover, the digital DNA-DNA relatedness of HA7T to these strains was 26.5 and 25.1 %. Based on the differential genotypic, phenotypic and chemotaxonomic properties to closely related type strains, strain HA7T ought to be assigned with the status of a new species, for which the name Spirosomapollinicola sp. nov. is proposed. The type strain is HA7T (DSM 105799T=LMG 30282T).

Consistent associations with beneficial bacteria in the seed endosphere of barley (Hordeum vulgare L.).

The importance of the plant microbiome for host fitness has led to the concept of the "plant holobiont". Seeds are reservoirs and vectors for beneficial microbes, which are very intimate partners of higher plants with the potential to connect plant generations. In this study, the endophytic seed microbiota of numerous barley samples, representing different cultivars, geographical sites and harvest years, was investigated. Cultivation-dependent and -independent analyses, microscopy, functional plate assays, greenhouse assays and functional prediction were used, with the aim of assessing the composition, stability and function of the barley seed endophytic bacterial microbiota. Associations were consistently detected in the seed endosphere with Paenibacillus, Pantoea and Pseudomonas spp., which were able to colonize the root with a notable rhizocompetence after seed germination. In greenhouse assays, enrichment with these bacteria promoted barley growth, improved mineral nutrition and induced resistance against the fungal pathogen Blumeria graminis. We demonstrated here that barley, an important crop plant, was consistently associated with beneficial bacteria inside the seeds. The results have relevant implications for plant microbiome ecology and for the holobiont concept, as well as opening up new possibilities for research and application of seed endophytes as bioinoculants in sustainable agriculture.

Ancylobacter pratisalsi sp. nov. with plant growth promotion abilities from the rhizosphere of Plantago winteri Wirtg.

A Gram-negative bacterium, designated E130T, was isolated from rhizospheric soil of Plantago winteri Wirtg. from a natural salt meadow as part of an investigation on rhizospheric bacteria from salt-resistant plant species and evaluation of their plant growth-promoting abilities. Cells were rods, non-motile, aerobic, and oxidase and catalase positive, grew in a temperature range of between 4 and 37 °C, and in the presence of 0.5-5 % NaCl (w/v). Based on 16S rRNA gene sequence analysis, strain E130T is affiliated within the genus Ancylobacter, sharing the highest similarity with Ancylobacter rudongensis DSM 17131T (97.6 %), Ancylobacter defluvii CCUG 63806T (97.5 %) and Ancylobacter dichloromethanicus DSM 21507T (97.4 %). The DNA G+C content of strain E130T was 65.1 mol%. Its respiratory quinones were Q-9 and Q-10 and its major polar lipids comprised phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine and unidentified phospholipid. Major fatty acids of the strains E130T were C12 : 0, C16 : 0, C18 : 1ω7c and C19 : 0cycloω8c. The DNA-DNA relatedness of E130T to A. rudongensis DSM 17131T, A. defluvii CCUG 63806T and A. dichloromethanicus DSM 21507T was 29.2, 21.2 and 32.2 % respectively. On the basis of our polyphasic taxonomic study the new isolate represents a novel species, for which the name Ancylobacter pratisalsi sp. nov. is proposed. The type strain is E130T (LMG 29367T=DSM 102029T).

Paradox of plant growth promotion potential of rhizobacteria and their actual promotion effect on growth of barley (Hordeum vulgare L.) under salt stress.

From the rhizosphere of two salt tolerant plant species, Hordeum secalinum and Plantago winteri growing in a naturally salt meadow, 100 strains were isolation on enrichment media for various plant growth-promoting (PGP) functions (ACC deaminase activity, auxin synthesis, calcium phosphate mobilization and nitrogen fixation). Based on the taxonomic affiliation of the isolated bacteria and their enrichment medium 22 isolates were selected to test their growth promotion effect on the crop barley (Hordeum vulgare) under salt stress in pot experiment. In parallel the isolates were characterized in pure culture for their plant growth-promoting activities. Surprisingly the best promotors did not display a promising set of PGP activities. Isolates with multiple PGP-activities in pure culture like Microbacterium natoriense strain E38 and Pseudomonas brassicacearum strain E8 did not promote plant growth. The most effective isolate was strain E108 identified as Curtobacterium flaccumfaciens, which increased barley growth up to 300%. In pure culture strain E108 showed only two out of six plant growth promoting activities and would have been neglected. Our results highlight that screening based on pure culture assays may not be suitable for recognition of best plant growth promotion candidates and could preclude the detection of both new PGPR and new plant promotion mechanisms.

Synthesis of novel palladium(0) nanocatalysts by microorganisms from heavy-metal-influenced high-alpine sites for dehalogenation of polychlorinated dioxins.

In a search for new aqueous-phase systems for catalyzing reactions of environmental and industrial importance, we prepared novel biogenerated palladium (Pd) nanocatalysts using a "green" approach based on microorganisms isolated from high-alpine sites naturally impacted by heavy metals. Bacteria and fungi were enriched and isolated from serpentinite-influenced ponds (Totalp region, Parsenn, near Davos, Graubünden, Switzerland). Effects on growth dynamics were monitored using an automated assay in 96-well microtiter plates, which allowed for simultaneous cultivation and on-line analysis of Pd(II)- and Ni(II)-mediated growth inhibition. Microorganisms from Totalp ponds tolerated up to 3mM Pd(II) and bacterial isolates were selected for cultivation and reductive synthesis of Pd(0) nanocatalysts at microbial interfaces. During reduction of Pd(II) with formate as the electron donor, Pd(0) nanoparticles were formed and deposited in the cell envelope. The Pd(0) catalysts produced in the presence of Pd(II)-tolerant Alpine Pseudomonas species were catalytically active in the reductive dehalogenation of model polychlorinated dioxin congeners. This is the first report which shows that Pd(0) synthesized in the presence of microorganisms catalyzes the reductive dechlorination of polychlorinated dibenzo-p-dioxins (PCDDs). Because the "bioPd(0)" catalyzed the dechlorination reactions preferably via non-lateral chlorinated intermediates, such a pathway could potentially detoxify PCDDs via a "safe route". It remains to be determined whether the microbial formation of catalytically active metal catalysts (e.g., Zn, Ni, Fe) occurs in situ and whether processes involving such catalysts can alter the fate and transport of persistent organic pollutants (POPs) in Alpine habitats.

Hartmannibacter diazotrophicus gen. nov., sp. nov., a phosphate-solubilizing and nitrogen-fixing alphaproteobacterium isolated from the rhizosphere of a natural salt-meadow plant.

A phosphate-mobilizing, Gram-negative bacterium was isolated from rhizospheric soil of Plantago winteri from a natural salt meadow as part of an investigation of rhizospheric bacteria from salt-resistant plant species and evaluation of their plant-growth-promoting abilities. Cells were rods, motile, strictly aerobic, oxidase-positive and catalase-negative. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain E19(T) was distinct from other taxa within the class Alphaproteobacteria. Strain E19(T) showed less than 93.5 % 16S rRNA gene sequence similarity with members of the genera Rhizobium (≤93.5 %), Labrenzia (≤93.1 %), Stappia (≤93.1 %), Aureimonas (≤93.1 %) and Mesorhizobium (≤93.0 %) and was most closely related to Rhizobium rhizoryzae (93.5 % 16S rRNA gene sequence similarity to the type strain). The sole respiratory quinone was Q-10, and the polar lipids comprised phosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, an aminolipid and an unidentified phospholipid. Major fatty acids were C18 : 1ω7c (71.4 %), summed feature 2 (C14 : 0 3-OH and/or iso-C16 : 1; 8.3 %), C20 : 0 (7.9 %) and C16 : 0 (6.1 %). The DNA G+C content of strain E19(T) was 59.9±0.7 mol%. The capacity for nitrogen fixation was confirmed by the presence of the nifH gene and the acetylene reduction assay. On the basis of the results of our polyphasic taxonomic study, the new isolate represents a novel genus and species, for which the name Hartmannibacter diazotrophicus gen. nov., sp. nov. is proposed. The type strain of Hartmannibacter diazotrophicus is E19(T) ( = LMG 27460(T) = KACC 17263(T)).

Rheinheimera hassiensis sp. nov. and Rheinheimera muenzenbergensis sp. nov., two species from the rhizosphere of Hordeum secalinum.

Two motile, Gram-staining-negative, aerobic, rod-shaped bacteria designated strains E48(T) and E49(T) were isolated from the rhizosphere of Hordeum secalinum from a natural salt meadow near Münzenberg, Germany. 16S rRNA gene sequence similarity analysis revealed that strains E48(T) and E49(T) shared similarities of 97.6 % with Rheinheimera pacifica KMM 1406(T) and 98.5 % with Rheinheimera nanhaiensis E407-8(T), respectively. Major fatty acids of strain E48(T) were C16 : 0, summed feature 3 (C16 : 1ω7c and/or iso-C15 : 0 2-OH) and C17 : 1ω8c, and of strain E49(T) were C16 : 0, summed feature 3 (C16 : 1ω7c and/or iso-C15 : 0 2-OH) and C18 : 1ω7c. The DNA G+C contents were 50.5 mol% (E48(T)) and 50.0 mol% (E49(T)). Strains E48(T) and E49(T) grew at 4-37 °C (optimum 28 °C) and with 0-6 % NaCl (optimum 0-3 %) and 0-5 % NaCl (optimum 0-3 %), respectively. The potential for nitrogen fixation by strains E48(T) and E49(T) was evaluated by molecular techniques and the acetylene reduction assay. The DNA-DNA hybridization, physiological and molecular data demonstrated that strains E48(T) and E49(T) represent two novel species of the genus Rheinheimera, and therefore the names Rheinheimera hassiensis sp. nov. (type strain E48(T) = LMG 27268(T) = KACC 17070(T)) and Rheinheimera muenzenbergensis sp. nov. (type strain E49(T) = LMG 27269(T) = KACC 17071(T)) are proposed.

Cellvibrio diazotrophicus sp. nov., a nitrogen-fixing bacteria isolated from the rhizosphere of salt meadow plants and emended description of the genus Cellvibrio.

Two Gram-reaction-negative, aerobic, nitrogen-fixing, rod-shaped bacteria, designated strains E20 and E50(T), were isolated from the rhizosphere of salt meadow plants Plantago winteri and Hordeum secalinum, respectively, near Münzenberg, Germany. Based on the 16S rRNA gene sequence analysis both strains E20 and E50(T) are affiliated with the genus Cellvibrio, sharing the highest similarity with Cellvibrio gandavensis LMG 18551(T) (96.4%) and (97.1%), respectively. Strains E20 and E50(T) were oxidase and catalase-positive, grew at a temperature range between 16 and 37 °C and in the presence of 0-5% NaCl (w/v). The DNA G+C contents were 52.1 mol% (E20) and 51.6 mol% (E50(T)). Major fatty acids of strains E20 and E50(T) were summed feature 3 (C16 : 1ω7c and/or iso-C(15 : 0) 2-OH), C(16 : 0), C(18 : 1)ω7c, C(12 : 0), C(18 : 0) and C(12 : 0) 3-OH. The DNA-DNA relatedness of the strains to Cellvibrio gandavensis LMG 18551(T) was 39% for strain E20 and 58% for strain E50(T). The nitrogen fixation capability of strains E20 and E50(T) was confirmed by the acetylene reduction assay. On the basis of our polyphasic taxonomic study, strains E20 and E50(T) represent a novel species of the genus Cellvibrio, for which the name Cellvibrio diazotrophicus is proposed. The type strain of Cellvibrio diazotrophicus is E50(T) ( = LMG 27267(T) = KACC 17069(T)). An emended description of the genus Cellvibrio is proposed based on the capability of fixing nitrogen and growth in presence of up to 5% NaCl (w/v).