Distribution Of Genus Research Articles

Ordovician paleobiogeography of the Suborder Cheirurina (Trilobita)

The Suborder Cheirurina is a diverse trilobite clade, ranging from the latest Cambrian to the Devonian. The Ordovician paleobiogeography of the group is explored based on the distribution of genera. Major tectonostratigraphic units and Ordovician ages (Tremadocian, Floian, Dapingian, Darriwilian, Sandbian and Katian) were recorded for each genus. Cluster analysis (agglomerative hierarchical clustering) and non-metric multidimensional scaling (NMDS) were performed independently for each Ordovician age. The results characterize the Ordovician distribution of Cheirurina as two main general patterns. First, there was a marked decrease in endemicity through the Ordovician. Second, latitude seems to play a significant role in the distribution of Cheirurina, at both genus and family levels. Pliomerids and encrinurids occur overwhelmingly at low latitudes. The two main exceptions are Placoparia (Pliomeridae) and Dindymene (Encrinuridae), which are distributed in high latitude terranes. Within Cheiruridae, members of Eccoptochilinae are typical of high latitude Gondwana. Conversely, acanthoparyphines, cheirurines, deiphonines, heliomerines and sphaerexochines are mainly distributed in low or intermediate latitudes.

Human Colonic Microbiota and Short-Term Postoperative Outcomes in Colorectal Cancer Patients: A Pilot Study.

Despite the advances in surgical techniques and perioperative care, the complication rates after colorectal cancer surgery have remained stable. Recently, it has been suggested that colon microbiota may be implicated in several pathways that can lead to impaired colonic homeostasis and, thereby, to the development of complications after colorectal surgery. The aim of this study was to evaluate the potential impact of colonic dysbiosis on postoperative course. This prospective human clinical study recruited patients operated on for left colon, sigmoid colon or rectal cancer. Colon mucosa and fecal samples were collected to study mucosa associated microbiota (MAM) and luminal microbiota (LM), accordingly. Preliminary analysis for the first 25 consecutive patients with V3–V4 16S rRNA metagenomic analysis was performed. Bacterial composition and abundance in patients who developed postoperative complications over a 90-day follow-up period were compared to those without postoperative complications. Abundance and distribution of genera in MAM differed significantly when compared to LM with a significant impact on neoadjuvant therapy on bacterial composition. Preliminary analysis revealed no statistically significant differences in LM nor in MAM composition when individuals with and without postoperative surgical complications were compared. In cases of postoperative complications, LM and MAM showed significantly decreased diversity. Composition of the colonic microbiota is altered by neoadjuvant therapy. Results on the impact of colonic dysbiosis on postoperative complications are pending the end of the present study, with 50 patients enrolled.

Gut microbial communities associated with phenotypically divergent populations of the striped stem borer Chilo suppressalis (Walker, 1863)

Chilo suppressalis (Walker, 1863) is a serious stem borer of rice and water-oat plants, and has phenotypically diverged into rice and water-oat populations. Insect gut microbiota plays an important role in the host life and understanding the dynamics of this complicated ecosystem may improve its biological control. The effect of diet and gut compartments on the gut microflora of divergent populations of C. suppressalis is not fully clear. Herein, we characterized the gut microbiota of C. suppressalis populations fed on two hosts (i.e., water-oats fruit pulps and rice seedlings), by sequencing the V3–V4 hypervariable region of the 16S rRNA gene using the Illumina MiSeq platform. Gut bacterial communities showed variation in relative abundance among C. suppressalis populations fed on water-oats fruit pulps or rice seedlings. Proteobacteria and Firmicutes became the predominant phyla, and Enterobacteriaceae, Enterococcaceae and Halomonadaceae were the predominant family in all C. suppressalis populations. The highest bacteria diversity was found in the midgut of the rice population fed on water-oat fruit pulps. Bacterial communities in the midgut were more diverse than those in the hindgut. The bacterial genera distribution showed great differences due to diet types and gut compartments among populations. Our results demonstrated that the host plants tested had a considerable impact on gut bacterial composition of C. suppressalis populations. Additionly, the unique gut morphology and physiological conditions (viz., oxygen content, enzymes) also contributed to variation in microbiomes. In conclusion, our study provided an important insight into investigation of insect-bacteria symbioses, and biocontrol of this species and other related lepidopterans.

Long-Term Impact of Suppressive Antibiotic Therapy on Intestinal Microbiota.

The aim was to describe the safety of indefinite administration of antibiotics, the so-called suppressive antibiotic therapy (SAT) and to provide insight into their impact on gut microbiota. 17 patients with SAT were recruited, providing a fecal sample. Bacterial composition was determined by 16S rDNA massive sequencing, and their viability was explored by PCR-DGGE with and without propidium monoazide. Presence of antibiotic multirresistant bacteria was explored through the culture of feces in selective media. High intra-individual variability in the genera distribution regardless of the antibiotic or antibiotic administration ingestion period, with few statistically significant differences detected by Bray-Curtis distance-based principle component analysis, permutational multivariate analysis of variance and linear discriminant analysis effect size analysis. However, the microbiota composition of patients treated with both beta-lactams and sulfonamides clustered by a heat map. Curiously, the detection of antibiotic resistant bacteria was almost anecdotic and CTX-M-15-producing E. coli were detected in two subjects. Our work demonstrates the overall clinical safety of SAT and the low rate of the selection of multidrug-resistant bacteria triggered by this therapy. We also describe the composition of intestinal microbiota under the indefinite use of antibiotics for the first time.

Geomicrobial dynamics of Trans-Himalayan sulfur–borax spring system reveals mesophilic bacteria’s resilience to high heat

Geomicrobiology of sulfur–boron-dominated, neutral-pH hydrothermal systems was revealed in a Trans-Himalayan spring named Lotus Pond, located at 4436 m, in Puga Valley, Ladakh (India), where water boils at 85°C. Water sampled along Lotus Pond’s outflow (vent to an adjacent river called Rulang), representing an 85–14°C gradient, had high microbial diversity and boron/chloride/sodium/sulfate/thiosulfate concentration; potassium/silicon/sulfide/sulfite was moderately abundant, whereas cesium/lithium small but definite. Majority of the bacterial genera identified in the 85–72°C samples have no laboratory-growth reported at >45°C, and some of those mesophiles were culturable. Sulfur-species concentration and isotope-ratio along the hydrothermal gradient, together with the distribution of genera having sulfur-oxidizing members, indicated chemolithotrophic activities in the 85–72°C sites. While biodiversity increased in the vent-to-river trajectory all-day, maximum rise was invariably between the vent (85–81°C) and the 78–72°C site; below 72°C, diversity increased gradually. Biodiversity of the vent-water exhibited diurnal fluxes relatable to the sub-surface-processes-driven temporal fluxes in physicochemical properties of the discharge. Snow-melts infiltrating (via tectonic faults) the ~160°C geothermal reservoir located within the breccia, at ~450 m depth, apparently transport mesophilic microbes into the thermal waters. As these micro-organisms emanate with the vent-water, some remain alive, illustrating that natural bacterial populations are more heat-resilient than their laboratory counterparts.

River damming affects seedling communities of a floodplain forest in the Central Amazon

ABSTRACT The flood pulse of black water rivers in the Amazon basin determines the composition of species along the flood gradient in igapo forests. The Balbina dam, built on the Uatuma River, has altered the flood pulse and caused changes in the floristic composition of adult trees throughout the downstream area. There is a lack of studies on how communities of seedlings in igapo forests respond to changes in the flood pulse. This study investigates the response of seedling communities in the igapo forest downstream the Balbina dam and compares it with two pristine areas. The areas were sampled with transects of 1x25 m within 36 plots (25x25 m) along the flood gradient. Richness and dominance were calculated by simple regression and ordination analyses. The pristine areas had the same pattern of richness, dominance and genera distribution along the flood gradient. However, the affected Uatuma area formed different groups of genera by NMDS analysis, which divided them along the flood gradient with significantly increased dominance of three genera. The insertion of the Balbina dam resulted a loss of lateral and longitudinal connectivity for the Uatuma River, and the alteration to seedling communities may alter the future landscape of downstream igapo forests.

腾格里沙漠东南缘藻结皮与藓结皮放线菌多样性及其潜在代谢功能

PDF HTML阅读 XML下载 导出引用 引用提醒 腾格里沙漠东南缘藻结皮与藓结皮放线菌多样性及其潜在代谢功能 DOI: 10.5846/stxb201901070055 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（41661053）；北方民族大学校级一般科研项目（2018XYZSK01） Potential functions of actinobacteria diversity in cyanobacteria and moss crusts in the southeastern Tengger Desert Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:放线菌作为干旱、半干旱环境中生物土壤结皮（Biological Soil Crusts，BSCs）组成的重要生命存在形式之一，不仅是潜在临床有用天然产物化学多样性的重要来源，也是该生态系统物质循环与能量流动的重要参与者。以腾格里沙漠东南缘广泛分布的藻结皮和藓结皮为研究对象，通过宏基因组测序比较分析两种BSCs放线菌种群的分布特征、组成及其潜在代谢功能。结果表明，腾格里沙漠东南缘藻结皮与藓结皮土壤微生物组主要形成以地嗜皮菌属、红色杆菌属、类诺卡氏菌属、游动放线菌属、芽生球菌属、链霉菌属、贫养杆菌属、糖丝菌属、土壤红杆菌属、假诺卡氏菌属、小单孢子菌属、康奈斯氏杆菌属、大理石雕菌属、小月菌属以及弗兰克氏菌属等为主要类群的放线菌群落结构，在两种BSCs类型之间各属分布存在差异。藓结皮中放线菌参与的氨基糖与核苷酸糖代谢、原核生物中的碳固定途径、丁酸代谢、丙酸代谢、丙氨酸/天门冬氨酸和谷氨酸代谢、甲烷代谢、2-羰基羧酸代谢、肽聚糖生物合成、淀粉与蔗糖代谢以及缬氨酸/亮氨酸与异亮氨酸降解显著高于藻结皮。藓结皮中地嗜皮菌属和红色杆菌属对相对丰度前10的代谢功能分类的贡献度显著低于藻结皮，而类诺卡氏菌属、芽生球菌属、贫养杆菌属、游动放线菌属、链霉菌属、假诺卡氏菌属和糖丝菌属等对这些功能的相对贡献在藓结皮中具有重要作用。这些结果可为全面、深入理解腾格里沙漠东南缘藻结皮与藓结皮放线菌资源多样性及其潜在功能多样性提供科学数据，也为理解放线菌在不同类型BSCs中的生态功能提供参考。 Abstract:As one of the significant life forms found in biological soil crusts in arid and semiarid environment, actinomycetes are not only important sources of chemical diversity in natural products that are of potential clinical value but also vital participators in the material cycle and energy flows in the ecological systems. Taking cyanobacteria crusts and moss crusts that are widely distributed in the southeastern Tengger Desert as research objects, metagenome sequencing was performed to compare and analyze the distribution characteristics, components and potential metabolic functions of the actinomycete population in two biological soil crusts. The results showed that the actinomycete community structure of the soil microbiome was mainly composed of the genera Geodermatophilus, Rubrobacter, Nocardioides, Actinoplanes, Blastococcus, Streptomyces, Modestobacter, Saccharothrix, Solirubrobacter, Pseudonocardia, Micromonospora, Conexibacter, Marmoricola, Microlunatus and Frankia. There were differences in the distribution of genera between the two biological soil crust types. The participation of actinomycetes in amino sugar and nucleotide sugar metabolism, glycolysis/gluconeogenesis, carbon fixation pathways of prokaryotes, butanoate metabolism, propanoate metabolism, alanine metabolism, aspartate/glutamate metabolism, methane metabolism, 2-oxocarboxylic acid metabolism, peptidoglycan biosynthesis, starch/sucrose metabolism, and valine/leucine/isoleucine degradation was significantly higher in moss crusts than that in cyanobacteria crusts. However, the contributions of Geodermatophilus and Rubrobacter to the top ten most abundant metabolic functions were obviously lower in moss crusts than that in cyanobacteria crusts. In contrast, the relative contributions of Nocardioides, Blastococcus, Modestobacter, Actinoplanes, Streptomyces, Pseudonocardia, and Saccharothrix to these functions was of great significance in moss crusts. The results provide the scientific data for a comprehensive and in-depth understanding of the diversity of actinomycete resources and potential functions in algae and moss crusts in the southeastern Tengger Desert and for understanding the ecological functions of actinomycetes in different types of biological soil crusts. 参考文献 相似文献 引证文献

Potential influence of Mesozoic and Tertiary tectonics on the evolution of European Hepialidae (Lepidoptera)

Author(s): Grehan, John; Knyazev, Svyatoslav | Abstract: The distributions of genera and species of Hepialidae in Europe are documented and mapped, along with species distributions extending to eastern Asia. Patterns of species allopatry in Korscheltellus, Pharmacis, and Triodia are consistent with vicariance resulting from late Cretaceous and early Cenozoic tectonics along the Alpine-Mediterranean Mobile Belt. Widespread northern and sympatric distributions are interpreted as the result of range expansion at the end of the Pleistocene. We suggest that the origin of high elevation endemic species of Hepialidae, particularly in the European Alps, is the result of passive tectonic uplift. Pleistocene cooling and glaciation is seen as responsible for extinction of populations in northern Europe, but without discernible impact on divergence. Absence of the northern Eurasian Hepialidae further south is attributed to an original Laurasian ancestral distribution in the Mesozoic. Fossil-calibrated divergence estimates generate minimum clade ages only, and current estimates for some European Hepialidae probably considerably underestimate their phylogenetic age.

Bacterial community succession in dairy manure composting with a static composting technique.

This study applied high-throughput sequencing technology and PICRUSt (phylogenetic investigation of communities by reconstruction of unobserved state) to examine the microbial population dynamics during the composting of dairy manure and rice straw in a static (without turning) composting system. The results showed that the composition of the bacterial community varied significantly during the composting process. The dominant phyla included Firmicutes, Proteobacteria, Bacteroidetes, Actinobacteria, and Chloroflexi. Biodiversity indices showed that bacterial community diversity had the peak value during the mesophilic phase. Redundancy analysis indicated that nitrogen was the most important factor in the distribution of genera during the composting process. Finally, the Pearson correlation results suggested that Thermomonospora and Thermopolyspora could be the biomarkers of the composting maturation phase. The metabolic characteristics of the bacterial communities were predicted by PICRUSt. The result showed that metabolism of amino acids, lipids, and most of the carbohydrates increased during the whole composting treatment. However, methane metabolism, carbon fixation pathways in prokaryotes, and nucleotide metabolism decreased after the thermophilic phase. The present study provides a better understanding for bacterial community composition and function succession in dairy manure composting.

Sapwood biomass carbon in northern boreal and temperate forests

AbstractAimInformation on the amount of carbon stored in the living tissue of tree stems (sapwood) is crucial for carbon and water cycle applications. Here, we aim to investigate sapwood‐to‐stem proportions and differences therein between tree genera and derive a sapwood biomass map.LocationNorthern Hemisphere boreal and temperate forests.Time period2010.Major taxa studiedTwenty‐five common tree genera.MethodsFirst, we develop a theoretical framework to estimate sapwood biomass for a given stem biomass by applying relationships between sapwood cross‐sectional area (CSA) and stem CSA and between stem CSA and stem biomass. These measurements are extracted from a biomass and allometry database (BAAD), an extensive literature review and our own studies. The established allometric relationships are applied to a remote sensing‐based stem biomass product in order to derive a spatially continuous sapwood biomass map. The application of new products on the distribution of stand density and tree genera facilitates the synergy of satellite and forest inventory data.ResultsSapwood‐to‐stem CSA relationships can be modelled with moderate to very high modelling efficiency for different genera. The total estimated sapwood biomass equals 12.87 ± 6.56 petagrams of carbon (PgC) in boreal (mean carbon density: 1.13 ± 0.58 kgC m−2) and 15.80 ± 9.10 PgC in temperate (2.03 ± 1.17 kgC m−2) forests. Spatial patterns of sapwood‐to‐stem biomass proportions are crucially driven by the distribution of genera (spanning from 20–30% in Larix to > 70% in Pinus and Betula forests).Main conclusionsThe presented sapwood biomass map will be the basis for large‐scale estimates of plant respiration and transpiration. The enormous spatial differences in sapwood biomass proportions reveal the need to consider the functionally more important sapwood instead of the entire stem biomass in global carbon and water cycle studies. Alterations in tree species distribution, induced by forest management or climate change, can strongly affect the available sapwood biomass even if stem biomass remains unchanged.

Genetic Bioaugmentation of Activated Sludge with Dioxin-Catabolic Plasmids Harbored by Rhodococcus sp. Strain p52.

Horizontal transfer of catabolic plasmids is used in genetic bioaugmentation for environmental pollutant remediation. In this study, we examined the effectiveness of genetic bioaugmentation with dioxin-catabolic plasmids harbored by Rhodococcus sp. strain p52 in laboratory-scale sequencing batch reactors (SBRs). During 100 days of operation, bioaugmentation decreased the dibenzofuran content (120 mg L-1) in the synthetic wastewater by 32.6%-100% of that in the nonbioaugmented SBR. Additionally, dibenzofuran was removed to undetectable levels in the bioaugmented SBR, in contrast, 46.8 ± 4.1% of that in the influent remained in the nonbioaugmented SBR after 96 days. Moreover, transconjugants harboring pDF01 and pDF02 were isolated from the bioaugmented SBR after 2 days, and their abilities to degrade dibenzofuran were confirmed. After 80 days, the copy numbers of strain p52 decreased by 3 orders of magnitude and accounted for 0.05 ± 0.01% of the total bacteria, while transconjugants were present at around 106 copies mL-1 sludge and accounted for 8.2 ± 0.3% of the total bacteria. Evaluation of the bacterial community profile of sludge by high-throughput 16S rRNA gene sequencing revealed that genetic bioaugmentation led to a bacterial community with an even distribution of genera in the SBR. This study demonstrates the promise of genetic bioaugmentation with catabolic plasmids for dioxins remediation.

Galling Insects of the Brazilian Páramos: Species Richness and Composition Along High-Altitude Grasslands

In this work, we investigated the factors that determine the distribution of galling insects in high-altitude grasslands, locally called 'campos de altitude' of Mantiqueira Range and tested whether 1) richness of galling insects decreases with altitude, 2) galling insect richness increases with plant richness, 3) variation in galling insect diversity is predominantly a consequence of its β component, and 4) turnover is the main mechanism driving the beta diversity of both galling insects and plants. Galling insect richness did not exhibit a negative relationship with altitude, but it did increase with plant richness. The additive partition of regional richness (γ) into its local and beta components showed that local diversity (α) of galling insects and plants was relatively low in relation to regional diversity; the β component incorporated most of the regional diversity. This pattern was also found in the multiscale analysis of the additive partition for galling insects and plants. The beta diversity of galling insects and plants was driven predominantly by the process of turnover and minimally by nesting. The results reported here point out that the spatial distribution of galling insects is best explained by historical factors, such as the distribution of genera and species of key host plants, as well as their relation to habitat, than ecological effects such as hygrothermal stress - here represented by altitude.

Cutaneous Microflora from Geographically Isolated Groups of Bradysia agrestis, an Insect Vector of Diverse Plant Pathogens

Larvae of Bradysia agrestis, an insect vector that transports plant pathogens, were sampled from geographically isolated regions in Korea to identify their cutaneous fungal and bacterial flora. Sampled areas were chosen within the distribution range of B. agrestis; each site was more than 91 km apart to ensure geographical segregation. We isolated 76 microbial (fungi and bacteria) strains (site 1, 29; site 2, 29; site 3, 18 strains) that were identified on the basis of morphological differences. Species identification was molecularly confirmed by determination of universal fungal internal transcribed spacer and bacterial 16S rRNA gene sequences in comparison to sequences in the EzTaxon database and the NCBI GenBank database, and their phylogenetic relationships were determined. The fungal isolates belonged to 2 phyla, 5 classes, and 7 genera; bacterial species belonged to 23 genera and 32 species. Microbial diversity differed significantly among the geographical groups with respect to Margalef’s richness (3.9, 3.6, and 4.5), Menhinick’s index (2.65, 2.46, and 3.30), Simpson’s index (0.06, 0.12, and 0.01), and Shannon’s index (2.50, 2.17, and 2.58). Although the microbial genera distribution or diversity values clearly varied among geographical groups, common genera were identified in all groups, including the fungal genus Cladosporium, and the bacterial genera Bacillus and Rhodococcus. According to classic principles of co-evolutionary relationship, these genera might have a closer association with their host insect vector B. agrestis than other genera identified. Some cutaneous bacterial genera (e.g., Pseudomonas) displaying weak interdependency with insect vectors may be hazardous to agricultural environments via mechanical transmission via B. agrestis. This study provides comprehensive information regarding the cutaneous microflora of B. agrestis, which can help in the control of such pests for crop management.

Sea-level changes in the Paleocene (Danian–Thanetian) succession at the Dakhla Oasis, Western Desert, Egypt: implications from benthic foraminifera

The Danian–Thanetian benthic foraminiferal assemblages at the Gharb El-Mawohb section in the Dakhla Oasis of Western Desert (Egypt) are inferred in combination with characteristic species, genera distribution, Benthic Foraminifera Numbers (BFN), species diversity, and abundance of high flux-species to infer prevailing paleoenvironment, paleoproductivity and paleobathymetry vis-à-vis sequence stratigraphy, regional tectonics, climate and changes in sea-level. The response of benthic foraminiferal assemblages to sea-level changes during boundary successions, namely the Danian/Selandian (D/S) and the Selandian/Thanetian (S/Th) is also analyzed. Data suggests a remarkably highly equitable environment throughout the studied interval. Eighty eight percent of the data plot in the restricted littoral environment (mostly in brackish and some in normal lagoons) suggesting that the fauna are not stressed despite a largely shallow depositional setting (middle to outer neritic, at places upper bathyal). The dominance of calcareous taxa indicates a largely open marine condition, in a largely oxic and oligotrophic environment, except in the late Paleocene where high-organic-flux species suggest increased paleoproductivity possibly due to local upwelling. The end of Zone P2 marks the deepest part of the studied section (outer neritic to upper bathyal) followed by gradual shallowing across the section (inner to middle neritic), with intermittent deepening in the middle of Zone P3a and P3b (middle neritic). There is shallowing at the transitions of Zones P3a, P3b and P4 (inner neritic). The changes in the vertical facies and benthic foraminiferal assemblage at the D/S and S/Th boundaries are analyzed.

Shallow water agglutinated foraminiferal response to Late Cretaceous–Early Paleocene sea-level changes in the Dakhla Oasis, Western Desert, Egypt

The Late Cretaceous (Maastrichtian) to early Paleocene (Thanetian) shallow water (<100 m) agglutinated foraminifera from a section at Dakhla Oasis (Western Desert, Egypt) were analyzed for their assemblage, species and genera distribution, diversity, depositional environment, community structure and palaeobathymetry with respect to regional tectonics, climate and global eustasy. Data suggest an equitable benthic environment with low species dominance deposited in a brackish littoral and/or marsh setting. Sea level curves using characteristic benthic foraminiferal species, genera and assemblages corroborate quantitatively generated estimate and statistical analysis. Data suggests that in the absence of or of an impoverished benthic foraminiferal fauna, a high resolution agglutinated foraminiferal dataset can be as good a predictor of the benthic community structure and environment, as its calcareous counterpart, at least for shallow settings (<100 m). Present data also provides a good window in better understanding the distribution and interrelationship between the three dominant genera, Haplophragmoides, Trochammina and Ammobaculites. Faunal changes at boundaries (Cretaceous/Paleogene, Danian/Selandian and Selandian/Thanetian) are also evaluated.

Diversity of two families Libellulidae and Coenagrionidae (Odonata) in Regional Institute of Education Campus, Bhubaneswar, Odisha, India

Libellulidae and Coenagrionidae are the most dominant families among dragonflies and damselflies. The present study deals with the diversity, occurrence and present status of libellulids and coenagrionids within the Regional Institute of Education Campus in Bhubaneswar, Odisha, India (RIEC). The major objectives of this study are to prepare a preliminary checklist of libellulids and coenagrionids species in the RIEC and to find out the status and distribution of genera and species in their respective families. This study is also aimed at systematic planning for developing different strategies for conservation of odonates in the campus. During this study a total of 24 species have been recorded out of which 20 species belong to the family Libellulidae representing 15 genera and four species belong to the family Coenagrionidae representing four genera. The findings of this study are based on the survey which was carried out for a period of four months in 2015.

Benthic foraminiferal response to relative sea-level changes in the Maastrichtian–Danian succession at the Dakhla Oasis, Western Desert, Egypt

AbstractThe Maastrichtian–Danian benthic foraminiferal diversity and assemblages through sequence stratigraphy were studied at Dakhla Oasis, Egypt. Benthic foraminifera numbers (BFN), high-flux species and characteristic benthic foraminiferal species and genera distribution are also incorporated to assess palaeobathymetry, palaeoenvironment and palaeoproductivity. All these proxies are then taken together to construct a sea-level curve and interpreted in terms of regional tectonics, climate and eustasy. Data suggest a remarkably highly equitable benthic environment deposited in a brackish littoral and/or marsh setting with moderate (?) to low oxygen conditions and reduced salinity (oligotrophic), possibly due to increased precipitation and terrestrial runoff. The interrupted dominance of calcareous forms and high-organic-flux species suggests occasional marine incursions and high palaeoproductivity, due to local upwelling. The inferred sea-level curve replicates the global eustatic curve and suggests that the curve is more influenced by the prevailing climate and global eustasy rather than by regional tectonics. The post-Cretaceous–Palaeogene boundary displays improvement in the environment in terms of diversity and number of species and specimens, with a marked reduction in the abundance of high-organic-flux species during early Paleocene (Danian) time, indicating a shift from a more mesotrophic open marine environment to much reduced oligotrophic conditions.

A synopsis of gall midges associated with conifers, with description of a new species of the genus Kaltenbachiola Hedicke (Diptera, Cecidomyiidae: Lasiopterinae) from Yakutia, damaging cones of the Siberian spruce (Picea obovata)

The world fauna comprises 134 species from 52 genera of gall midges associated with plants of the order Pinales (3 families, 16 genera and 74 species); 14 genera are specific to Pinales. The distribution of genera and species of gall midges over host plant taxa is described. The Holarctic genus Kaltenbachiola comprises four species all developing in the spruce (Picea spp.) cones. Earlier, K. strobi (Winnertz), widely distributed in Europe, was the only species known in the Palaearctic. A new species Kaltenbachiola anastasiae sp. n. is described, which damages cones of Picea obovata in Central Yakutia. The phylogenetic relationships of Kaltenbachiola with close genera specific to Pinales are characterized, and an updated diagnosis of the genus with additional morphometric parameters and keys to the pine-specific genera of the tribe Dasineurini and to species of the genus Kaltenbachiola are given. The host associations and specific traits of biology and distribution of Kaltenbachiola species are considered.

Metagenomic Reconstruction of Key Anaerobic Digestion Pathways in Municipal Sludge and Industrial Wastewater Biogas-Producing Systems.

Anaerobic digestion (AD) is a microbial process widely used to treat organic wastes. While the microbes involved in digestion of municipal sludge are increasingly well characterized, the taxonomic and functional compositions of AD digesters treating industrial wastewater have been understudied. This study examined metagenomes from a biogas-producing digester treating municipal sludge in Shek Wu Hui (SWH), Hong Kong and an industrial wastewater digester in Guangzhou (GZ), China, and compared their taxonomic composition and reconstructed biochemical pathways. Genes encoding carbohydrate metabolism and protein metabolism functions were overrepresented in GZ, while genes encoding functions related to fatty acids, lipids and isoprenoids were overrepresented in SWH, reflecting the plants’ feedstocks. Mapping of genera to functions in each community indicated that both digesters had a high level of functional redundancy, and a more even distribution of genera in GZ suggested that it was more functionally stable. While fermentation in both samples was dominated by Clostridia, SWH had an overrepresentation of Proteobacteria, including syntrophic acetogens, reflecting its more complex substrate. Considering the growing importance of biogas as an alternative fuel source, a detailed mechanistic understanding of AD is important and this report will be a basis for further study of industrial wastewater AD.

Bacterial Richness of Soil Samples from Southern New Hampshire

As DNA sequencing has become more popular, knowledge about the soil microbiome has expanded considerably. This technological advancement has led to a greatly increased understanding about the role of bacteria in soil. Previous studies have shown that, while geographic proximity plays a minor role in determining species richness (1), there exists a direct correlation between microbial diversity and both soil pH (1) and plant variety (2). In this paper, we examine the microbial content of soil samples taken from three locations in southern New Hampshire with varying pH and plant composition. We found that a minority of genera were shared between all three sites, and most genera were present in only one site, confirming the theory that soil microbes are site-dependent. The three shared, genera as well as the genera unique to specific samples, were paraphyletic. Our data suggests that pH is not the only factor affecting microbial composition, thereby confirming previous research and contributing to the understanding of the interaction between microbial communities and soil. While pH may affect microbial species richness (1), our results demonstrate that other factors, such as soil management techniques, play a larger role in the distribution of genera between different soil sites.