Tricholoma matsutake dominates diverse microbial communities in different forest soils

Fungal and actinobacterial communities were analyzed together with soil chemistry and enzyme activities in order to profile the microbial diversity associated with the economically important mushroom Tricholoma matsutake. Samples of mycelium-soil aggregation (shiro) were collected from three experimental sites where sporocarps naturally formed. PCR was used to confirm the presence and absence of matsutake in soil samples. PCR-denaturing gradient gel electrophoresis (DGGE) fingerprinting and direct sequencing were used to identify fungi and actinobacteria in the mineral and organic soil layers separately. Soil enzyme activities and hemicellulotic carbohydrates were analyzed in a productive experimental site. Soil chemistry was investigated in both organic and mineral soil layers at all three experimental sites. Matsutake dominated in the shiro but also coexisted with a high diversity of fungi and actinobacteria. Tomentollopsis sp. in the organic layer above the shiro and Piloderma sp. in the shiro correlated positively with the presence of T. matsutake in all experimental sites. A Thermomonosporaceae bacterium and Nocardia sp. correlated positively with the presence of T. matsutake, and Streptomyces sp. was a common cohabitant in the shiro, although these operational taxonomic units (OTUs) did not occur at all sites. Significantly higher enzyme activity levels were detected in shiro soil. These enzymes are involved in the mobilization of carbon from organic matter decomposition. Matsutake was not associated with a particular soil chemistry compared to that of nearby sites where the fungus does not occur. The presence of a significant hemicellulose pool and the enzymes to degrade it indicates the potential for obtaining carbon from the soil rather than tree roots.     

Eco-physiological responses of Polytrichum commune to soil contamination by polychlorinated biphenyls

 通过微体繁殖技术在多氯联苯(PCBs)污染土壤基质上进行大金发藓(Polytrichum commune)的室内培养, 研究了不同浓度(5、10和20 mg·kg^–1)低氯PCBs (Aroclor 1242)和高氯PCBs (Aroclor 1254)对大金发藓生理生态指标的影响。经6个月的培养, 大金发藓的密度和盖度分别达93%和50株·cm^–2以上, PCBs处理组与对照组相比无显著差异, 表明PCBs对大金发藓茎叶碎片再生成新植株体的能力没有产生不利影响。大金发藓鲜质量和株高随低氯PCBs (Aroclor 1242)浓度增加而增加、随高氯PCBs (Aroclor 1254)浓度增加而减小, 但均高于对照, 表明PCBs处理对大金发藓的生长具有一定的促进作用。PCBs处理组大金发藓叶绿素a、b以及叶绿素a + b含量较对照组有所增加, 叶绿素a/b值与对照组相比基本没有变化。PCBs处理组大金发藓膜脂过氧化产物丙二醛含量和超氧化物歧化酶活性与对照组相比无显著差异, 谷胱甘肽含量较对照组显著增加, 表明谷胱甘肽在大金发藓体内活性氧清除过程中起重要作用。总体来看, 大金发藓能在所设浓度的PCBs范围内正常生长, 对PCBs有较强的耐性。     

大金发藓对土壤多氯联苯污染的生理生态响应

通过微体繁殖技术在多氯联苯(PCBs)污染土壤基质上进行大金发藓(Polytrichum commune)的室内培养, 研究了不同浓度(5、10和20 mg·kg^-1)低氯PCBs (Aroclor 1242)和高氯PCBs Aroclor 1254)对大金发藓生理生态指标的影响。经6个月的培养, 大金发藓的密度和盖度分别达93%和50株·cm^-2以上, PCBs处理组与对照组相比无显著差异, 表明PCBs对大金发藓茎叶碎片再生成新植株体的能力没有产生不利影响。大金发藓鲜质量和株高随低氯PCBs (Aroclor 1242)浓度增加而增加、随高氯PCBs (Aroclor 1254)浓度增加而减小, 但均高于对照, 表明PCBs处理对大金发藓的生长具有一定的促进作用。PCBs处理组大金发藓叶绿素a、b以及叶绿素a + b含量较对照组有所增加, 叶绿素a/b值与对照组相比基本没有变化。PCBs处理组大金发藓膜脂过氧化产物丙二醛含量和超氧化物歧化酶活性与对照组相比无显著差异, 谷胱甘肽含量较对照组显著增加, 表明谷胱甘肽在大金发藓体内活性氧清除过程中起重要作用。总体来看, 大金发藓能在所设浓度的PCBs范围内正常生长, 对PCBs有较强的耐性。     

The capacities of earthworms to heal wounds and to destroy allografts are modified by polychlorinated biphenyls (PCB).

Earthworms (Lumbricus terrestris) were maintained at 15 degrees C and exposed on filter paper to 10 micrograms/cm2 of the polychlorinated biphenyl (PCB) Aroclor 1254 for 5 days prior to surgical treatments which consisted of wounds, autografts, and allografts. At 1 day after surgery, we observed a higher percentage of healing defects and a significantly greater number of early signs of allograft rejection in exposed worms. Observations for 25 days post-transplantation revealed no response to autografts, but an acceleration of the allograft rejection process in exposed earthworms. We postulate that Aroclor modified host coelomocytes and/or their interactions associated with antigen recognition and inflammation.     

Response of microbial communities to elevated thallium contamination in river sediments

Abstract

The study of microbial communities in river sediments contaminated by thallium (Tl) is necessary to achieve the information for in-situ microbially mediated bioremediation. However, little is known about the microbial community in Tl-contaminated river sediments. In the present study, we characterized the microbial community and their responses to Tl pollution in river sediments from the Tl-mineralized Lanmuchang area, Southwest Guizhou, China. Illumina sequencing of 16S rRNA amplicons revealed that over 40 phyla belong to the domain bacteria. In all samples, Proteobacteria, Cyanobacteria, and Actinobacteria were the most dominant phyla. Based on the UPGMA (Unweighted Pair Group Method with Arithmetic Mean) tree and PCoA (Principal Coordinates Analysis) analysis, microbial composition of each segment was distinct, indicating in-situ geochemical parameters (including Tl, sulfate, TOC, Eh, and pH) had influenced on the microbial communities. Moreover, canonical correspondence analysis (CCA) was employed to further elucidate the impact of geochemical parameters on the distribution of microbial communities in local river sediments. The results indicated that a number of microbial communities including Cyanobacteria, Spirochaete, Hydrogenophaga, and Acinetobacter were positively correlated with total Tl, suggesting potential roles of these microbes to Tl tolerance or to biogeochemical cycling of Tl. Our results suggested a reliable location for the microbial community’s diversity in the presence of high concentrations of Tl and might have a potential association for in-situ bioremediation strategies of Tl-contaminated river. Overall, in situ microbial community could provide a useful tool for monitoring and assessing geo-environmental stressors in Tl-polluted river sediments.     

Banana-associated microbial communities in Uganda are highly diverse but dominated by Enterobacteriaceae

Bananas are among the most widely consumed foods in the world. In Uganda, the country with the second largest banana production in the world, bananas are the most important staple food. The objective of this study was to analyze banana-associated microorganisms and to select efficient antagonists against fungal pathogens which are responsible for substantial yield losses. We studied the structure and function of microbial communities (endosphere, rhizosphere, and soil) obtained from three different traditional farms in Uganda by cultivation-independent (PCR-SSCP fingerprints of 16S rRNA/ITS genes, pyrosequencing of enterobacterial 16S rRNA gene fragments, quantitative PCR, fluorescence in situ hybridization coupled with confocal laser scanning microscopy, and PCR-based detection of broad-host-range plasmids and sulfonamide resistance genes) and cultivation-dependent methods. The results showed microhabitat-specific microbial communities that were significant across sites and treatments. Furthermore, all microhabitats contained a high number and broad spectrum of indigenous antagonists toward identified fungal pathogens. While bacterial antagonists were found to be enriched in banana plants, fungal antagonists were less abundant and mainly found in soil. The banana stem endosphere was the habitat with the highest bacterial counts (up to 10(9) gene copy numbers g(-1)). Here, enterics were found to be enhanced in abundance and diversity; they provided one-third of the bacteria and were identified by pyrosequencing with 14 genera, including not only potential human (Escherichia, Klebsiella, Salmonella, and Yersinia spp.) and plant (Pectobacterium spp.) pathogens but also disease-suppressive bacteria (Serratia spp.). The dominant role of enterics can be explained by the permanent nature and vegetative propagation of banana and the amendments of human, as well as animal, manure in these traditional cultivations.     

Liver lipid peroxidation in the ontogeny of rats during perinatal exposure to polychlorinated biphenyls

We studied the activity of NADPH-cytochrome P-450 reductase, NADPH- and ascorbate-dependent systems of lipid peroxidation in liver microsomes, the activity of superoxide dismutase in the supernatant and the level of malonic acid dialdehyde in liver tissue of rats of various age. The activity of lipid peroxidation system and the malonic dialdehyde content in the early postnatal period increased to the adult level. The NADPH-cytochrome P-450 reductase activity increased during the first four months of animals life while that of superoxide dismutase increased until the animals were seven months old. A single administration of polychlorinated diphenyls at a dose of 500 mg/kg (1/10 LD50) to pregnant rats drastically stimulated and changed the pattern of the studied activities in their offspring. The role of lipid peroxidation in modification of microsomal membranes after the monooxygenase system induction by polychlorinated diphenyls in early ontogenesis is discussed.     

Effects of nutritional input and diesel contamination on soil enzyme activities and microbial communities in antarctic soils

Pollution of Antarctic soils may be attributable to increased nutritional input and diesel contamination via anthropogenic activities. To investigate the effect of these environmental changes on the Antarctic terrestrial ecosystem, soil enzyme activities and microbial communities in 3 types of Antarctic soils were evaluated. The activities of alkaline phosphomonoesterase and dehydrogenase were dramatically increased, whereas the activities of β-glucosidase, urease, arylsulfatase, and fluorescein diacetate hydrolysis were negligible. Alkaline phosphomonoesterase and dehydrogenase activities in the 3 types of soils increased 3- to 10-fold in response to nutritional input, but did not increase in the presence of diesel contamination. Consistent with the enzymatic activity data, increased copy numbers of the phoA gene, encoding an alkaline phosphomonoesterase, and the 16S rRNA gene were verified using quantitative real-time polymerase chain reaction. Interestingly, dehydrogenase activity and 16S rRNA gene copy number increased slightly after 30 days, even under diesel contamination, probably because of adaptation of the bacterial population. Intact Antarctic soils showed a predominance of Actinobacteria phylum (mostly Pseudonorcarida species) and other phyla such as Proteobacteria, Chloroflexi, Planctomycetes, Firmicutes, and Verrucomicrobia were present in successively lower proportions. Nutrient addition might act as a selective pressure on the bacterial community, resulting in the prevalence of Actinobacteria phylum (mostly Arthrobacter species). Soils contaminated by diesel showed a predominance of Proteobacteria phylum (mostly Phyllobacterium species), and other phyla such as Actinobacteria, Bacteroidetes, Planctomycetes, and Gemmatimonadetes were present in successively lower proportions. Our data reveal that nutritional input has a dramatic impact on bacterial communities in Antarctic soils and that diesel contamination is likely toxic to enzymes in this population.     

Distinct microbial communities associated with buried soils in the Siberian tundra

Cryoturbation, the burial of topsoil material into deeper soil horizons by repeated freeze–thaw events, is an important storage mechanism for soil organic matter (SOM) in permafrost-affected soils. Besides abiotic conditions, microbial community structure and the accessibility of SOM to the decomposer community are hypothesized to control SOM decomposition and thus have a crucial role in SOM accumulation in buried soils. We surveyed the microbial community structure in cryoturbated soils from nine soil profiles in the northeastern Siberian tundra using high-throughput sequencing and quantification of bacterial, archaeal and fungal marker genes. We found that bacterial abundances in buried topsoils were as high as in unburied topsoils. In contrast, fungal abundances decreased with depth and were significantly lower in buried than in unburied topsoils resulting in remarkably low fungal to bacterial ratios in buried topsoils. Fungal community profiling revealed an associated decrease in presumably ectomycorrhizal (ECM) fungi. The abiotic conditions (low to subzero temperatures, anoxia) and the reduced abundance of fungi likely provide a niche for bacterial, facultative anaerobic decomposers of SOM such as members of the Actinobacteria, which were found in significantly higher relative abundances in buried than in unburied topsoils. Our study expands the knowledge on the microbial community structure in soils of Northern latitude permafrost regions, and attributes the delayed decomposition of SOM in buried soils to specific microbial taxa, and particularly to a decrease in abundance and activity of ECM fungi, and to the extent to which bacterial decomposers are able to act as their functional substitutes.     

Response of water column microbial communities to sudden exposure to deltamethrin in aquatic mesocosms

Sudden exposure of an aquatic system to an insecticide can have significant effects on populations other than susceptible organisms. Although this is intuitively obvious, little is actually known about how such exposure might affect bacterial communities and their relative metabolic activity in ecosystems. Here, we assessed small sub-unit (ssu)-RNA levels in open and shaded 9 m(3) aquatic mesocosms (16 units - 2 x 2 factorial design in quadruplicate) to examine the effects of sudden addition of deltamethrin to the units. When deltamethrin was added, a cascade of bacterial then phytoplankton "blooms" occurred over time. The bacterial bloom, which most likely included organisms from the plastid/cyanobacterial phylogenetic guild, was almost immediate (within hours), whereas the phytoplankton (algal) bloom lagged by about 4 days. This sequential response can be explained by an apparent sudden release of nutrients consequent to arthropod death that triggered a series of responses in the microbial loop. Interestingly, bacterial blooms were noted in both open and shaded mesocosms, whereas the algal bloom was only seen in open units, suggesting that both deltamethrin addition (and presumptive nutrient release) and an adequate light supply was required for the phytoplankton response. Overall, this work shows that microbial activities as reflected by ssu-rRNA levels can respond dramatically via apparently indirect effects following insecticide application.     

The influence of microbial communities for triadimefon enantiomerization in soils with different pH values

Enantiomers of chiral molecules can undergo interconversion leading to markedly different toxicities, which can introduce significant uncertainty when evaluating biological and environmental fates. However, enantiomerization (the reversible conversion of one enantiomer into the other) related to soil microorganism is rarely understood. For better understanding, S‐triadimefon and R‐triadimefon enantiopure were incubated in different soils with different pH value. Both high‐performance liquid chromatography and high‐throughput sequencing technology were used to explore target analytes quantitatively and microbial taxa related to the conversion process. Results revealed a significant enantiomerization among the soils. The alkaline soil from Beijing had a faster conversion than neutral soil from Changchun, while acidic soil from Wuhan had no conversion. At the same results, analysis of bacteria community showed higher abundance of Arthrobacter and Halomonas genus in alkaline soil than neutral soil after treatments, but the acidic soil was lower. Moreover, Arthrobacter and Halomonas were responsible for converting S‐triadimefon to R‐triadimefon and R‐triadimefon to S‐triadimefon in alkaline and neutral soil, respectively. Thus, these genera may be one of the reasons to explain the enantiomerization in different soils observed in this study. Thus, research at microbial level is necessary for efficient ecological risk assessment of chiral fungicide.     

Time dependent and cell-specific action of polychlorinated biphenyls (PCB 153 and PCB 126) on steroid secretion by porcine theca and granulosa cells in mono- and co-culture.

To characterize PCB action on follicular cell steroidogenesis two PCB congeners were selected as model substances. PCB 126 because of its dioxin-like configuration and high toxicity and PCB 153 because it is one of the most commonly detected PCB congeners in breast milk. The direct effect of PCBs was investigated using a culture system of porcine theca and granulosa cells collected from porcine preovulatory follicles. Granulosa and theca cells were cultured in M199 medium supplemented with 1, 10 or 100 pg/ml of PCB 126 or 1, 10 and 100 ng/ml of PCB 153. The media were changed after 48, 96 and 144 h and frozen until further estradiol (E2) analysis. Additionally, progesterone (P4) was measured in the granulosa cells culture medium and testosterone (T) in theca cells culture medium. Decrease of testosterone concentration in the theca cells culture medium was found after 96 and 144 hours in culture by both investigated PCB congeners. A decrease in E2 concentration was found after exposure to PCB 153. These findings suggest different actions of two congeners on the steroid synthesis in theca cells. The lack of an increase in E2 secretion after the exposure to PCB 126 could be due to depletion of androgen precursor. In granulosa cell culture PCB153 decreased E2 secretion and increased P4 secretion suggesting luteinization and disruption of aromatization process. PCB 126 in a doses from 1 to 10 pg had no effect on granulosa cells steroidogenesis. However, the highest dose (100 pg) increased concentration of both E2 and P4. This observation suggest that PCB 126 in a pharmacological doses may affect cell membrane permeability, thereby increasing steroid outflow into the medium. These results suggest time dependent and cell-specific differences in PCB 153 and 126 action on follicular cells steroidogenesis. Further studies are required to elucidate the mechanism of PCBs action on ovarian steroidogenesis.     

Macroinvertebrate communities in Wheeler Reservoir (Alabama) tributaries after prolonged exposure to DDT contamination

Quarterly measurements were conducted of the structure, abundance, and diversity of macroinvertebrates comprising two distinct, but overlapping zoobenthic communities in backwaters to Wheeler Reservoir Alabama. The study area included portions of Huntsville Spring Branch (HSB) and Indian Creek (IC) which contain massive quantities of DDT residues (DDTR = DDT, DDD, DDE). Additionally, sewage effluents entering HSB just upstream from the study area have resulted in nutrient enrichment, especially at the two uppermost stations. Herpobenthos (burrowed in bottom sediments) and haptobenthos (attached to substrates) were collected at seven stations along an east-west gradient including a control site above the DDT contamination, and sites with mean sediment residues ranging from 2,730 ppm DDTR in HSB down to 12 ppm DDTR at the mouth of IC.Fifty taxa were collected from dredge samples of the herpobenthos; Tubificid oligochaetes and chironomid larvae comprised 97% of the herpobenthos. At the two uppermost stations in HSB, the control site and the site with the highest sediment DDTR, oligochaete density averaged twice that of chironomids. Downstream, densities of both groups were similar. Mean density at the upper two stations was 9431 and 10 644 organisms m^–2, respectively, significantly (P < 0.05) higher than downstream stations. Herpobenthos was dominated by detrital-algal feeders in HSB while in IC, predaceous chironomids were more numerous. Taxa diversity was also lowest (P < 0.05) at the two upper sites.Forty-five taxa were collected from artificial substrate (Hester-Dendy multiplate samplers) samples of the haptobenthos. Naidid oligochaetes and chironomids dominated the haptobenthos, although nematodes were occasionaly abundant. Chironomids were more abundant than oligochaetes at all sites except the control station, which received the greatest nutrient enrichment from sewage effluents. Mean haptobenthic density in the middle portion of the study area ranged from 31 163 to 37 310 organisms m^–2 and was diferent (P < 0.05) from upper and lower stations. Taxa diversity was lowest at the upper-most station, but no trends were evident among stations.Nutrient enrichment from sewage effluents apparently had greater impact on zoobenthic communities in the HSB-IC System than did DDT contamination. However, the presence of DDTR undoubtedly contributed, in part, to the few Ephemeroptera, Plecoptera, and Trichoptera collected at contaminated stations. Based on the density of oligochaetes and chironomid larvae at station 2 (highest DDTR), macroinvertebrates in this system are resistant to DDTR.     

Structural and functional response of methane-consuming microbial communities to different flooding regimes in riparian soils

Climate change will lead to more extreme precipitation and associated increase of flooding events of soils. This can turn these soils from a sink into a source of atmospheric methane. The latter will depend on the balance of microbial methane production and oxidation. In the present study, the structural and functional response of methane oxidizing microbial communities was investigated in a riparian flooding gradient. Four sites differing in flooding frequency were sampled and soil-physico-chemistry as well as methane oxidizing activities, numbers and community composition were assessed. Next to this, the active community members were determined by stable isotope probing of lipids. Methane consumption as well as population size distinctly increased with flooding frequency. All methane consumption parameters (activity, numbers, lipids) correlated with soil moisture, organic matter content, and conductivity. Methane oxidizing bacteria were present and activated quickly even in seldom flooded soils. However, the active species comprised only a few representatives belonging to the genera Methylobacter, Methylosarcina, and Methylocystis, the latter being active only in permanently or regularly flooded soils.This study demonstrates that soils exposed to irregular flooding harbor a very responsive methane oxidizing community that has the potential to mitigate methane produced in these soils. The number of active species is limited and dominated by one methane oxidizing lineage. Knowledge on the characteristics of these microbes is necessary to assess the effects of flooding of soils and subsequent methane cycling therein.     

Induction of glutathione-S-transferase in the Northern quahog Mercenaria mercenaria after exposure to the polychlorinated biphenyl (PCB) mixture Aroclor 1248

The glutathione-S-transferases (GSTs) from the Northern quahog (Mercenaria mercenaria) were examined after an injection of a polychlorinated biphenyl (PCB) mixture, Aroclor 1248, to a concentration of ~50 ppm. Enzymatic analysis indicated a fourfold increase in the GST activity of quahogs injected with PCBs compared with that of the control. An electrophoretic analysis of the GST from the PCB-exposed quahogs showed a 1.5-fold increase in the concentration over that of the control. Purification of the GST on a glutathione affinity column yielded a glutathione binding protein, in addition to the GSTs. However, the amount of the glutathione binding protein in the PCB-injected quahogs was found to decrease by ~50% in comparison to the glutathione binding protein in the control quahogs.     

Determination of polychlorinated biphenyls in small-size serum samples by solid-phase extraction followed by gas chromatography with micro-electron-capture detection

An new method for the determination of polychlorinated biphenyls (PCBs) in serum samples of up to 1 ml has been developed. The procedure consisted in the solid-phase extraction (SPE) of the analytes on an Oasis cartridge and the subsequent on-line elimination of the fat by directly dropping of the eluate from the SPE cartridge on a multilayer column placed below the cartridge. This configuration allowed minimising of the sample manipulation as well as the time, solvent and sorbent consumption (i.e. complete sample preparation can be accomplished in about 1 h with only 3 ml of toluene and 300 mg of silica). The SPE plus clean-up method developed showed a satisfactory performance for the analysis of PCBs in rat serum samples providing similar recoveries (i.e. range 73-128% for most of the congeners selected) at the different spiking levels investigated (1.25, 0.50 and 0.25 ng/ml). Detection limits using a microelectron capture detector were in the range 0.01-0.30 ng/ml of serum and the relative standard deviations of the complete method better than 18% irrespective of the PCB concentration. The validated method has been applied to the evaluation for the first time of the PCB levels in serum samples of up to 1 ml from individuals of an Egyptian Vulture colony in Spain.     

Composition of microbial communities in hexachlorocyclohexane (HCH) contaminated soils from Spain revealed with a habitat-specific microarray

Microarray technology was used to characterize and compare hexachlorocyclohexane (HCH) contaminated soils from Spain. A library of 2,290 hypervariable 16S rRNA gene sequences was prepared with serial analysis of ribosomal sequence tags (SARST) from a composite of contaminated and uncontaminated soils. By designing hybridization probes specific to the 100 most abundant ribosomal sequence tags (RSTs) in the composite library, the RST array was designed to be habitat-specific and predicted to monitor the most abundant polymerase chain reaction (PCR)-amplified phylotypes in the individual samples. The sensitivity and specificity of the RST array was tested with a series of pure culture-specific probes and hybridized with labelled soil PCR products to generate hybridization patterns for each soil. Sequencing of prominent bands in denaturing gradient gel electrophoresis (DGGE) fingerprints derived from these soils provided a means by which we successfully confirmed the habitat-specific array design and validated the bulk of the probe signals. Non-metric multidimensional scaling revealed correlations between probe signals and soil physicochemical parameters. Among the strongest correlations to total HCH contamination were probe signals corresponding to unknown Gamma Proteobacteria, potential pollutant-degrading phylotypes, and several organisms with acid-tolerant phenotypes. The strongest correlations to alpha-HCH were probe signals corresponding to the genus Sphingomonas, which contains known HCH degraders. This suggests that the population detected was enriched in situ by HCH contamination and may play a role in HCH degradation. Other environmental parameters were also likely instrumental in shaping community composition in these soils. The results highlight the power of habitat-specific microarrays for comparing complex microbial communities.     

Eukaryotic microbial communities in hypersaline soils and sediments from the alkaline hypersaline Huama Lake as revealed by 454 pyrosequencing

In hypersaline ecosystems, microbial assemblages are structurally distinctive and play important roles in many microbiological and ecological processes. Here, eukaryotic microorganisms in hypersaline samples were investigated by 454 pyrosequencing of internal transcribed spacer (ITS) gene libraries. In total, 4,645, 1,677, and 5,912 reads were obtained from ITS libraries of waterlogged samples, salt crusts, and saline loess from the alkaline Huama Lake in Shaanxi, China. Analyses of pyrosequencing data revealed that the dominant genera were Dunaliella, Alternaria and Chlamydomonas, which dominated the microbial assemblages in the waterlogged sediments, the salt crusts and the saline loess from the lake banks, respectively. The various infrequent species were not commonly shared by the three types of samples, demonstrating that the eukaryotic microbial compositions of the different environments were distinct. However, the micro-eukaryotic assemblages associated with similar environmental conditions shared some components and were phylogenetically related. The eukaryotic microbial community composition was correlated with the pH value of the site (p = 0.001; r² = 0.99), but not with the concentration of total nitrogen or the inorganic ions investigated in this study. The results of this study demonstrated that the hypersaline ecosystems hosted surprisingly diverse eukaryotic microbial community.     

Response of microbial communities to pesticide residues in soil restored with Azolla imbricata

Applied Microbiology and Biotechnology - Under conditions of Azolla imbricata restoration, the high-throughput sequencing technology was employed to determine change trends of microbial community...