High genetic diversity and different type VI secretion systems in Enterobacter species revealed by comparative genomics analysis.

The human-pathogenic Enterobacter species are widely distributed in diverse environmental conditions, however, the understanding of the virulence factors and genetic variations within the genus is very limited. In this study, we performed comparative genomics analysis of 49 strains originated from diverse niches and belonged to eight Enterobacter species, in order to further understand the mechanism of adaption to the environment in Enterobacter. The results showed that they had an open pan-genome and high genomic diversity which allowed adaptation to distinctive ecological niches. We found the number of secretion systems was the highest among various virulence factors in these Enterobacter strains. Three types of T6SS gene clusters including T6SS-A, T6SS-B and T6SS-C were detected in most Enterobacter strains. T6SS-A and T6SS-B shared 13 specific core genes, but they had different gene structures, suggesting they probably have different biological functions. Notably, T6SS-C was restricted to E. cancerogenus. We detected a T6SS gene cluster, highly similar to T6SS-C (91.2%), in the remote related Citrobacter rodenitum, suggesting that this unique gene cluster was probably acquired by horizontal gene transfer. The genomes of Enterobacter strains possess high genetic diversity, limited number of conserved core genes, and multiple copies of T6SS gene clusters with differentiated structures, suggesting that the origins of T6SS were not by duplication instead by independent acquisition. These findings provide valuable information for better understanding of the functional features of Enterobacter species and their evolutionary relationships.

From salty to thriving: plant growth promoting bacteria as nature's allies in overcoming salinity stress in plants.

Soil salinity is one of the main problems that affects global crop yield. Researchers have attempted to alleviate the effects of salt stress on plant growth using a variety of approaches, including genetic modification of salt-tolerant plants, screening the higher salt-tolerant genotypes, and the inoculation of beneficial plant microbiome, such as plant growth-promoting bacteria (PGPB). PGPB mainly exists in the rhizosphere soil, plant tissues and on the surfaces of leaves or stems, and can promote plant growth and increase plant tolerance to abiotic stress. Many halophytes recruit salt-resistant microorganisms, and therefore endophytic bacteria isolated from halophytes can help enhance plant stress responses. Beneficial plant-microbe interactions are widespread in nature, and microbial communities provide an opportunity to understand these beneficial interactions. In this study, we provide a brief overview of the current state of plant microbiomes and give particular emphasis on its influence factors and discuss various mechanisms used by PGPB in alleviating salt stress for plants. Then, we also describe the relationship between bacterial Type VI secretion system and plant growth promotion.

The characteristics of soil microbial co-occurrence networks across a high-latitude forested wetland ecotone in China.

To understand the effect of seasonal variations on soil microbial communities in a forested wetland ecotone, here, we investigated the dynamics of the diversities and functions of both soil bacterial and fungal communities inhabiting three wetland types (forested wetland, shrub wetland and herbaceous vegetation wetland) from forest-wetland ecotone of northern Xiaoxing'an Mountains spanning different seasons. ß-diversity of soil microbial communities varied significantly among different vegetation types (Betula platyphylla-Larix gmelinii, Alnus sibirica, Betula ovalifolia, and Carex schmidtii wetlands). We totally detected 34 fungal and 14 bacterial indicator taxa among distinctive groups by using Linear discriminant analysis effect size (LEfSe) analysis, and identified nine network hubs as the most important nodes detected in whole fungi, bacteria, and fungi-bacteria networks. At the vegetation type-level, bacterial and fungal microbiome living in C. schmidtii wetland soil possessed fewer positive interactions and lower modularity than those in other types of wetland soil. Furthermore, we also discovered that ectomycorrhizal fungi were dominant in the fungal microbiota existing in forested and shrub wetland soils, whereas arbuscular mycorrhizal fungi were predominated in those residing in herbaceous vegetation wetland soil. The distribution of the predicted bacterial functional enzymes also obviously varied among different vegetation-types. In addition, the correlation analysis further revealed that the key fungal network modules were significantly affected by the contents of total N and soil water-soluble K, whereas most of the bacterial network modules were remarkably positively driven by the contents of total N, soil water-soluble K, Mg and Na. Our study suggested that vegetation type are substantive factors controlling the diversity, composition and functional group of soil microbiomes from forest-wetland ecotone of northern Xiaoxing'an Mountains.

Complete Genome Sequence of Rhodococcus qingshengii Strain PM1, Isolated from a Selenium-Rich Mine in China.

Rhodococcus qingshengii PM1 was isolated from selenium-rich carbonaceous mudstones in Enshi, Hubei, China. Here, we report the complete genome sequence of this strain, which was obtained by combining Illumina and Nanopore sequencing.

Aquatic exercises in the knee injury rehabilitation of athletes / Exercícios aquáticos na reabilitação das lesões nos joelhos de atletas / Ejercicios acuáticos en la rehabilitación de lesiones de rodilla en deportistas

ABSTRACT Introduction: Volleyball requires jumping and strenuous movements and certain sports injuries inevitably occur during the sport. The surface of the knee joint is considerably large and shallow, making the lever effect strong and negative, easily targeted for injury in the unstable movements caused by this sport. Objective: Investigate the main causes of knee joint injuries in volleyball players and evaluate the effect of treatment with intervention through aquatic therapy. Methods: Eight volleyball players from a university with different degrees of knee joint injury were randomly divided into an experimental group and a control group. The experimental group used intervention training with aquatic exercise therapy, while the control group did not include additional rehabilitation measures. The knee condition of the subjects before and after the experiment was analyzed and compared. Results: The knee joint injury in the subjects in the experimental group was significantly improved, and the recovery from the knee joint injury of the subjects in the experimental group was better than that of the subjects in the control group. Conclusion: Water sports therapy can significantly improve the knee joint injury of volleyball players, leading to the belief that water sports therapy can effectively improve the agility, strength, and endurance of muscles adjacent to knee joints in patients, reducing their pain, and increasing the range of motion of these joints. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

RESUMO Introdução: O voleibol exige saltos e movimentos extenuantes sendo inevitável que certas lesões esportivas ocorram no decurso do esporte. A superfície da articulação do joelho é consideravelmente grande e pouco profunda, tornando o efeito de alavanca forte e negativo, facilmente alvo de lesões nos movimentos instáveis ocasionados por esse esporte. Objetivo: Investigar as principais causas das lesões da articulação do joelho nos jogadores de voleibol e avaliar o efeito do tratamento com intervenção através de terapia aquática. Métodos: Oito jogadores de voleibol de uma universidade, com diferentes graus de lesão articular do joelho, foram divididos aleatoriamente em um grupo experimental e um grupo controle. O grupo experimental utilizou treino de intervenção com terapia de exercício aquático, enquanto o grupo de controle não contemplou medidas de reabilitação adicionais. A condição do joelho dos indivíduos antes e depois da experiência foi analisada e comparada. Resultados: A lesão articular do joelho nos sujeitos do grupo experimental foi significativamente melhorada, e a recuperação da lesão articular do joelho dos sujeitos do grupo experimental foi melhor do que a dos sujeitos do grupo de controle. Conclusão: A terapia com esportes aquáticos pode melhorar significativamente a lesão da articulação do joelho dos jogadores de voleibol, levando a acreditar que a terapia com esportes aquáticos pode efetivamente melhorar a agilidade, força e resistência dos músculos adjacentes às articulações do joelho nos pacientes, reduzindo a sua dor, e aumentando a amplitude de movimento dessas articulações. Nível de evidência II; Estudos terapêuticos - investigação dos resultados do tratamento.

RESUMEN Introducción: El voleibol requiere saltos y movimientos extenuantes y es inevitable que se produzcan ciertas lesiones deportivas en el transcurso del deporte. La superficie de la articulación de la rodilla es considerablemente grande y poco profunda, lo que hace que el efecto de palanca sea fuerte y negativo, siendo fácilmente objeto de lesiones en los movimientos inestables que provoca este deporte. Objetivo: Investigar las principales causas de las lesiones de la articulación de la rodilla en jugadores de voleibol y evaluar el efecto del tratamiento con intervención mediante terapia acuática. Métodos: Ocho jugadores de voleibol de una universidad, con diferentes grados de lesión en la articulación de la rodilla, fueron divididos aleatoriamente en un grupo experimental y un grupo de control. El grupo experimental utilizó un entrenamiento de intervención con terapia de ejercicios acuáticos, mientras que el grupo de control no contempló medidas adicionales de rehabilitación. Se analizó y comparó el estado de las rodillas de los sujetos antes y después del experimento. Resultados: La lesión de la articulación de la rodilla en los sujetos del grupo experimental mejoró significativamente, y la recuperación de la lesión de la articulación de la rodilla de los sujetos del grupo experimental fue mejor que la de los sujetos del grupo de control. Conclusión: La terapia de deportes acuáticos puede mejorar significativamente la lesión de la articulación de la rodilla de los jugadores de voleibol, lo que lleva a pensar que la terapia de deportes acuáticos puede mejorar eficazmente la agilidad, la fuerza y la resistencia de los músculos adyacentes a las articulaciones de la rodilla de los pacientes, reduciendo su dolor y aumentando la amplitud de movimiento de estas articulaciones. Nivel de evidencia II; Estudios terapéuticos - investigación de los resultados del tratamiento.

Development of a Markerless Deletion Mutagenesis System in Nitrate-Reducing Bacterium Rhodanobacter denitrificans.

Rhodanobacter has been found as the dominant genus in aquifers contaminated with high concentrations of nitrate and uranium in Oak Ridge, TN, USA. The in situ stimulation of denitrification has been proposed as a potential method to remediate nitrate and uranium contamination. Among the Rhodanobacter species, Rhodanobacter denitrificans strains have been reported to be capable of denitrification and contain abundant metal resistance genes. However, due to the lack of a mutagenesis system in these strains, our understanding of the mechanisms underlying low-pH resistance and the ability to dominate in the contaminated environment remains limited. Here, we developed an in-frame markerless deletion system in two R. denitrificans strains. First, we optimized the growth conditions, tested antibiotic resistance, and determined appropriate transformation parameters in 10 Rhodanobacter strains. We then deleted the upp gene, which encodes uracil phosphoribosyltransferase, in R. denitrificans strains FW104-R3 and FW104-R5. The resulting strains were designated R3_Δupp and R5_Δupp and used as host strains for mutagenesis with 5-fluorouracil (5-FU) resistance as the counterselection marker to generate markerless deletion mutants. To test the developed protocol, the narG gene encoding nitrate reductase was knocked out in the R3_Δupp and R5_Δupp host strains. As expected, the narG mutants could not grow in anoxic medium with nitrate as the electron acceptor. Overall, these results show that the in-frame markerless deletion system is effective in two R. denitrificans strains, which will allow for future functional genomic studies in these strains furthering our understanding of the metabolic and resistance mechanisms present in Rhodanobacter species. IMPORTANCE Rhodanobacter denitrificans is capable of denitrification and is also resistant to toxic heavy metals and low pH. Accordingly, the presence of Rhodanobacter species at a particular environmental site is considered an indicator of nitrate and uranium contamination. These characteristics suggest its future potential application in bioremediation of nitrate or concurrent nitrate and uranium contamination in groundwater ecosystems. Due to the lack of genetic tools in this organism, the mechanisms of low-pH and heavy metal resistance in R. denitrificans strains remain elusive, which impedes its use in bioremediation strategies. Here, we developed a genome editing method in two R. denitrificans strains. This work marks a crucial step in developing Rhodanobacter as a model for studying the diverse mechanisms of low-pH and heavy metal resistance associated with denitrification.

Gene sdaB Is Involved in the Nematocidal Activity of Enterobacter ludwigii AA4 Against the Pine Wood Nematode Bursaphelenchus xylophilus.

Bursaphelenchus xylophilus, a plant parasitic nematode, is the causal agent of pine wilt, a devastating forest tree disease. Essentially, no efficient methods for controlling B. xylophilus and pine wilt disease have yet been developed. Enterobacter ludwigii AA4, isolated from the root of maize, has powerful nematocidal activity against B. xylophilus in a new in vitro dye exclusion test. The corrected mortality of the B. xylophilus treated by E. ludwigii AA4 or its cell extract reached 98.3 and 98.6%, respectively. Morphological changes in B. xylophilus treated with a cell extract from strain AA4 suggested that the death of B. xylophilus might be caused by an increased number of vacuoles in non-apoptotic cell death and the damage to tissues of the nematodes. In a greenhouse test, the disease index of the seedlings of Scots pine (Pinus sylvestris) treated with the cells of strain AA4 plus B. xylophilus or those treated by AA4 cell extract plus B. xylophilus was 38.2 and 30.3, respectively, was significantly lower than 92.5 in the control plants treated with distilled water and B. xylophilus. We created a sdaB gene knockout in strain AA4 by deleting the gene that was putatively encoding the beta-subunit of L-serine dehydratase through Red homologous recombination. The nematocidal and disease-suppressing activities of the knockout strain were remarkably impaired. Finally, we revealed a robust colonization of P. sylvestris seedling needles by E. ludwigii AA4, which is supposed to contribute to the disease-controlling efficacy of strain AA4. Therefore, E. ludwigii AA4 has significant potential to serve as an agent for the biological control of pine wilt disease caused by B. xylophilus.

Concentration and distribution of metals, total fluorine, per- and poly-fluoroalkyl substances (PFAS) in vertical soil profiles in industrialized areas.

The widespread usage of per- and poly-fluoroalkyl substances (PFAS) has caused great concern due to their potential toxicology to human and environmental health. However, there have been limited investigations on the vertical distribution of PFAS in fluorine (F) contaminated soils. In this study, the spatial and vertical distribution of metals, total F, and PFAS in the soil profiles were investigated at different areas in an industrial city. The higher F concentrations in the farmland soils with intensive agricultural activities suggested the impacts of soil tillage. The ΣPFAS concentrations ranged from 0.187 to 1.852 ng g-1 in all soil samples, with PFOA as the dominant pollutant, which accounted for 17.2%-51.6% of the ΣPFAS in all samples. Highest level of PFAS was found in the shallow layer of the soil profiles. The long-chain PFAS such as PFUdA and PFTeDA tended to remain in the topsoil, while the short-chains (PFBA, PFPeA, and PFHxA) have migrated to depth of 100 cm in the vertical soil profile. The application of F-enriched phosphorus fertilizers and atmospheric deposition may be important sources of F and PFAS in soils in this area. Correlation analysis indicated that most of PFAS have similar common sources, and the significantly positive correlation between Zn and PFAS suggested they may share similar sources. This study highlights the need for further work to monitor the PFAS level in soil environments in industrialized areas, in addition to focusing on soil metal and F pollution.

Differences between the effects of plant species and compartments on microbiome composition in two halophyte Suaeda species.

Root-related or endophytic microbes in halophytes play an important role in adaptation to extreme saline environments. However, there have been few comparisons of microbial distribution patterns in different tissues associated with halophytes. Here, we analyzed the bacterial communities and distribution patterns of the rhizospheres and tissue endosphere in two Suaeda species (S. salsa and S. corniculata Bunge) using the 16S rRNA gene sequencing. The results showed that the bacterial abundance and diversity in the rhizosphere were significantly higher than that of endophytic, but lower than that of bulk soil. Microbial-diversity analysis showed that the dominant phyla of all samples were Proteobacteria, Actinobacteria, Bacteroidetes, Acidobacteria and Firmicutes, among which Proteobacteria were extremely abundant in all the tissue endosphere. Heatmap and Linear discriminant analysis Effect Size (LEfSe) results showed that there were notable differences in microbial community composition related to plant compartments. Different networks based on plant compartments exhibited distinct topological features. Additionally, the bulk soil and rhizosphere networks were more complex and showed higher centrality and connectedness than the three endosphere networks. These results strongly suggested that plant compartments, and not species, affect microbiome composition.

Genomic Features and Pervasive Negative Selection in Rhodanobacter Strains Isolated from Nitrate and Heavy Metal Contaminated Aquifer.

Rhodanobacter species dominate in the Oak Ridge Reservation (ORR) subsurface environments contaminated with acids, nitrate, metal radionuclides, and other heavy metals. To uncover the genomic features underlying adaptations to these mixed-waste environments and to guide genetic tool development, we sequenced the whole genomes of eight Rhodanobacter strains isolated from the ORR site. The genome sizes ranged from 3.9 to 4.2 Mb harboring 3,695 to 4,035 protein-coding genes and GC contents approximately 67%. Seven strains were classified as R. denitrificans and one strain, FW510-R12, as R. thiooxydans based on full length 16S rRNA sequences. According to gene annotation, the top two Cluster of Orthologous Groups (COGs) with high pan-genome expansion rates (Pan/Core gene ratio) were "replication, recombination and repair" and "defense mechanisms." The denitrifying genes had high DNA homologies except the predicted protein structure variances in NosZ. In contrast, heavy metal resistance genes were diverse with between 7 to 34% of them were located in genomic islands, and these results suggested origins from horizontal gene transfer. Analysis of the methylation patterns in four strains revealed the unique 5mC methylation motifs. Most orthologs (78%) had ratios of nonsynonymous to synonymous substitutions (dN/dS) less than one when compared to the type strain 2APBS1, suggesting the prevalence of negative selection. Overall, the results provide evidence for the important roles of horizontal gene transfer and negative selection in genomic adaptation at the contaminated field site. The complex restriction-modification system genes and the unique methylation motifs in Rhodanobacter strains suggest the potential recalcitrance to genetic manipulation. IMPORTANCE Despite the dominance of Rhodanobacter species in the subsurface of the contaminated Oak Ridge Reservation (ORR) site, very little is known about the mechanisms underlying their adaptions to the various stressors present at ORR. Recently, multiple Rhodanobacter strains have been isolated from the ORR groundwater samples from several wells with varying geochemical properties. Using Illumina, PacBio, and Oxford Nanopore sequencing platforms, we obtained the whole genome sequences of eight Rhodanobacter strains. Comparison of the whole genomes demonstrated the genetic diversity, and analysis of the long nanopore reads revealed the heterogeneity of methylation patterns in strains isolated from the same well. Although all strains contained a complete set of denitrifying genes, the predicted tertiary structures of NosZ differed. The sequence comparison results demonstrate the important roles of horizontal gene transfer and negative selection in adaptation. In addition, these strains may be recalcitrant to genetic manipulation due to the complex restriction-modification systems and methylations.

Agricultural activities impact on soil and sediment fluorine and perfluorinated compounds in an endemic fluorosis area.

Perfluorinated compounds (PFCs) are organo-fluorine compounds which have been identified at significant levels in soils due to their widespread usage in industrial and commercial applications. However, few studies are available regarding the occurrence of PFCs in the environment of endemic fluorosis areas. To address the issue, soils collected from an endemic fluorosis area of southwestern China were analyzed for the distribution of fluorine and 21 kinds of PFCs. The average water-soluble fluorine concentration in cultivated soil (4.87 mg kg-1) was significantly higher than that in uncultivated soil (3.15 mg kg-1), which mainly ascribed to the utilization of fluorine-enriched fertilizers during agricultural practices. Concentrations of ΣPFCs in all soils ranged from 0.508 to 6.83 ng g-1, with an average of 2.81 ng g-1, dominated by perfluorononanoic acid (PFNA) and perfluorooctanoic acid (PFOA). Highest ΣPFCs was found in the soil samples collected from cropland with intensive agricultural activities. Long-chain PFCs, including four perfluoroalkylcarboxylic acids (PFCAs, C ≥ 8) and one perfluoroalkylsulfonic acids (PFSAs) (perfluorooctane sulfonate (PFOS), C8), exhibited high levels in soils, probably due to their higher hydrophobicity and lower water-solubility than short-chain PFCs. While in sediments, short-chain PFCAs were the dominant compounds. Based on correlation analysis, the relationship between total fluorine and PFCs was insignificant, and soil organic matter was a relevant factor affecting PFCs distribution in soils. This study is expected to present a more comprehensive information about fluorine contamination under the influence of agricultural activities in an endemic fluorosis area.

Variations in Soil Functional Fungal Community Structure Associated With Pure and Mixed Plantations in Typical Temperate Forests of China.

Forest plants are in constant contact with the soil fungal community, which plays an important role in the circulation of nutrients through forest ecosystems. The objective of this study was to evaluate the fungal diversity in soil and elucidate the ecological role of functional fungal communities in forest ecosystems using soil samples from seven different plantations in northeastern China. Our results showed that the fungal communities were dominated by the phyla Ascomycota, Basidiomycota, and Mortierellomycota, and the mixed plantation of Fraxinus mandshurica and Pinus koraiensis had a soil fungal population clearly divergent from those in the other plantations. Additionally, the mixed plantation of F. mandshurica and P. koraiensis, which was low in soil nutrients, contained a highly diverse and abundant population of ectomycorrhizal fungi, whereas saprophytic fungi were more abundant in plantations with high soil nutrients. Redundancy analysis demonstrated a strong correlation between saprophytic fungi and the level of soil nutrients, whereas ectomycorrhizal fungi were mainly distributed in soils with low nutrient. Our findings provide insights into the importance of functional fungi and the mediation of soil nutrients in mixed plantations and reveal the effect of biodiversity on temperate forests.

Correction: De novo assembly and analysis of the transcriptome of Rumex patientia L. during cold stress.

[This corrects the article DOI: 10.1371/journal.pone.0186470.].

De novo assembly and analysis of the transcriptome of Rumex patientia L. during cold stress.

BACKGROUND: Rumex patientia L. is consumed as a green vegetable in several parts of the world, and can withstand extremely low temperatures (-35°C). However, little or no available genomic data for this species has been reported to date. Here, we used Illumina Hiseq technology for transcriptome assembly in R. patientia under normal and cold conditions to evaluate how it responds to cold stress. RESULTS: After an in-depth RNA-Seq analysis, 115,589 unigenes were produced from the assembled transcripts. Based on similarity search analysis with seven databases, we obtained and annotated 60,157 assembled unigenes to at least one database. In total, 1,179 unigenes that were identified as differentially expressed genes (DEGs), including up-regulated (925) and down-regulated ones (254), were successfully assigned GO annotations and classified into three major metabolic pathways. Ribosome, carbon metabolism, oxidative phosphorylation and biosynthesis of amino acids were the most highly enriched pathways according to KEGG analysis. Overall, 66 up-regulated genes were identified as putatively involved in the response to cold stress, including members of MYB, AP2/ERF, CBF, Znf, bZIP, NAC and COR families. CONCLUSION: To our knowledge, this investigation was the first to provide a cold-responsive (COR) transcriptome assembly in R. patientia. A large number of potential COR genes were identified, suggesting that this species is suitable for cultivation in northern China. In summary, these data provide valuable information for future research and genomic studies in R. patientia.

Comparative mitochondrial proteomic, physiological, biochemical and ultrastructural profiling reveal factors underpinning salt tolerance in tetraploid black locust (Robinia pseudoacacia L.).

BACKGROUND: Polyploidy is an important phenomenon in plants because of its roles in agricultural and forestry production as well as in plant tolerance to environmental stresses. Tetraploid black locust (Robinia pseudoacacia L.) is a polyploid plant and a pioneer tree species due to its wide ranging adaptability to adverse environments. To evaluate the ploidy-dependent differences in leaf mitochondria between diploid and tetraploid black locust under salinity stress, we conducted comparative proteomic, physiological, biochemical and ultrastructural profiling of mitochondria from leaves. RESULTS: Mitochondrial proteomic analysis was performed with 2-DE and MALDI-TOF-MS, and the ultrastructure of leaf mitochondria was observed by transmission electron microscopy. According to 2-DE analysis, 66 proteins that responded to salinity stress significantly were identified from diploid and/or tetraploid plants and classified into 9 functional categories. Assays of physiological characters indicated that tetraploids were more tolerant to salinity stress than diploids. The mitochondrial ultrastructure of diploids was damaged more severely under salinity stress than that of tetraploids. CONCLUSIONS: Tetraploid black locust possessed more tolerance of, and ability to acclimate to, salinity stress than diploids, which may be attributable to the ability to maintain mitochondrial structure and to trigger different expression patterns of mitochondrial proteins during salinity stress.

The Effect of Land Use on Bacterial Communities in Saline-Alkali Soil.

Saline-alkali soil can inhibit the growth of crops as a consequence of cellular damage through oxidation of lipids and proteins and degradation of nucleic acids, ultimately leading to cell death. The bacterial community composition and diversity in saline-alkali soil across different land uses, such as agricultural land, forest land, and grassland, were evaluated using high-throughput sequencing of the bacterial 16S rRNA gene. Significant differences in the soil physicochemical characteristics and bacterial community among different land uses were observed in this study. The soil pH value and electrical conductivity were much higher in grassland soil than in agricultural and forest soils. There were high proportions of Actinobacteria and Proteobacteria (phyla) in agricultural and forest soils, while Actinobacteria, Bacteroidetes, Gemmatimonadetes were more predominant in grassland soil. The relative abundance of dominant taxa exhibited a highly significant correlation with soil pH, water content, EC, and organic matter. The percentage of species that are shared among the different soil samples ranged from 5.3 to 30.5%. The haloalkaliphilic Actinobacterial genus Nitriliruptor was detected in grassland but not in areas with other types of land use. Results of both heatmap and principal component analysis (PCA) indicated that the soil properties and bacterial communities in the areas studied have been greatly influenced by long-term land use by different management.

Bacterial Community Diversity of Oil-Contaminated Soils Assessed by High Throughput Sequencing of 16S rRNA Genes.

Soil bacteria play a major role in ecological and biodegradable function processes in oil-contaminated soils. Here, we assessed the bacterial diversity and changes therein in oil-contaminated soils exposed to different periods of oil pollution using 454 pyrosequencing of 16S rRNA genes. No less than 24,953 valid reads and 6246 operational taxonomic units (OTUs) were obtained from all five studied samples. OTU richness was relatively higher in contaminated soils than clean samples. Acidobacteria, Actinobacteria, Bacteroidetes, Chloroflexi, Planctomycetes and Proteobacteria were the dominant phyla among all the soil samples. The heatmap plot depicted the relative percentage of each bacterial family within each sample and clustered five samples into two groups. For the samples, bacteria in the soils varied at different periods of oil exposure. The oil pollution exerted strong selective pressure to propagate many potentially petroleum degrading bacteria. Redundancy analysis (RDA) indicated that organic matter was the highest determinant factor for explaining the variations in community compositions. This suggests that compared to clean soils, oil-polluted soils support more diverse bacterial communities and soil bacterial community shifts were mainly controlled by organic matter and exposure time. These results provide some useful information for bioremediation of petroleum contaminated soil in the future.

Crystal structure of (E)-4-{4-[eth-yl(2-hydroxy-eth-yl)amino]-styr-yl}-1-methyl-pyridinium nitrate hemihydrate.

The asymmetric unit of the title compound, C18H23N2O(+)·NO3 (-)·0.5H2O, contains two independent 4-{4-[eth-yl(2-hy-droxy-eth-yl)amino]-styr-yl}-1-methyl-pyridin-1-ium cations, two nitrate anions and one lattice water mol-ecule. In the cations, the pyridine ring is twisted with respect by 7.98 (12) and 18.42 (10)° to the benzene ring. In the crystal, the cations, the anions and the lattice water mol-ecules are linked by O-H⋯O hydrogen bonds and weak C-H⋯O hydrogen bonds, forming a three-dimensional supra-molecular architecture. π-π stacking occurs between pyridine and benzene rings of adjacent cations, the centroid-centroid distances being 3.8169 (15) and 3.8663 (14) Å. In the crystal, one of the independent cations is disordered, the central vinyl unit and the terminal hy-droxy-lethyl group being disordered over two sets of sites with site occupancy factors of 0.600 (6) and 0.400 (6).

Correlation between anterior chamber angle diameter and ciliary sulcus distance measured by Suowei panoramic 50-MHz digital ultrasound blomicroscopy / 中华实验眼科杂志

Background Measurement of ciliary sulcus distance is important for phakic intraocular lens implantation.Suowei panoramic 50-MHz digital ultrasound biomicroscopy makes it possible for the direct measurement of ciliary sulcus distance.Objective The aim of this study was to investigate the correlation between anterior chamber(AC)angle diameter and ciliary sulcus distance in different AC depth population and offer a clinical guide.Methods The anterior chamber angle diameter and ciliary sulcus distance were measured in 30 right eyes with shallow anterior chamber caused by suspect glaucoma and 30 right eyes with deep anterior chamber dut to the high myopia with Suowei panoramic 50-MHz digital ultrasound biomicroscopy.Three horizontal B-scans with the focal plane approximately at a depth corresponding to the iris plane were acquired for each eye.The differences of the anterior chamber angle diameter and ciliary sulcus distance were calculated and compared between the two groups.The correlation of the anterior chamber angle diameter and ciliary sulcus distance were evaluated in respective group.Results In shallow AC group,the mean angle diameter was(11.49+0.75)mm,the mean ciliary sulcus distance was (10.97±0.86)mm with the mean standard deviation of the difference of(-5.14± 0.55)mm,showing a statistically significant difference(t =-5.092,P =0.000).In shallow AC group,linear regression analysis showed a statistically significant correlation between ciliary sulcus distance and angle diameter(R2=0.593,P=0.000)and the Pearson's correlation coefficient was 0.767.In deep AC group,the angle diameter was(12.69±0.67)mm;while ciliary sulcus distance was(12.31 ± 0.61)mm with the mean slandard deviation(-0.38 ± 0.17)mm,which was statistically significantly different(t=-5.531,P=0.000).The ciliary sulcus distance was found to be linear correlation with the angle diameter(R2 =0.699,P=0.000)and Pearson' s correlation coefficient of 0.836.Conclusions Panoramic ultrasound biomicroscopy is an useful tool to the measurement of ciliary sulcus distance.This study exhibited that the ciliary sulcus distance is significant associated with the anterior chamber angle diameter,which may offer a guide for phakic intraocular lens implantation.