Core Species Research Articles

Structural Stability of Ant-plant Mutualistic Networks Mediated by Extrafloral Nectaries: Looking at the Effects of Forest Fragmentation in the Brazilian Amazon

Rainforest fragmentation drastically affects biodiversity and species composition, mainly due to habitat loss. Several studies have already shown the effects of forest fragmentation on plant and ant communities. To date, however, there is limited empirical knowledge of how forest fragmentation affects ant-plant interaction in networks. We investigated the effects of the configuration of rainforest fragments on the structure of ant-plant interaction networks mediated by extrafloral nectaries (EFNs). We carried out this study in ten forest fragments, ranging in size from approximately 5 to 3,000 ha, located in the Brazilian Amazon. In each fragment we established a plot of 6,250 m2, in which all ant-plant interactions were recorded, and calculated the following network descriptors: number of interactions, network size, network specialization, diversity of interactions, and nestedness. We used four explanatory variables to investigate the effects of forest fragmentation on these network descriptors: three metrics of the configuration of fragments (i.e., fragment area, edge irregularity, and connectivity) and the forest structure within each fragment, represented by canopy cover. We did not detect any effect of the explanatory variables on the network descriptors. The structural stability of the networks sampled in forest fragments with different configurations is possibly related to the observed constancy of ant species in the central core of highly interacting species. Our results corroborate other studies highlighting the structural stability of these facultative ant-plant networks mediated by EFNs in different spatial and temporal gradients. Nonetheless, the low constancy of plant species in the generalist core should be understood as a warning, mainly because the functionality of this protective mutualism (i.e., food secretions in exchange for protection against herbivory) remains unknown.

Electron acceptors determine the BTEX degradation capacity of anaerobic microbiota via regulating the microbial community

Anaerobic degradation is the major pathway for microbial degradation of benzene, toluene, ethylbenzene, and xylenes (BTEX) under electron acceptor lacking conditions. However, how exogenous electron acceptors modulate BTEX degradation through shaping the microbial community structure remains poorly understood. Here, we investigated the effect of various exogenous electron acceptors on BTEX degradation as well as methane production in anaerobic microbiota, which were enriched from the same contaminated soil. It was found that the BTEX degradation capacities of the anaerobic microbiota gradually increased along with the increasing redox potentials of the exogenous electron acceptors supplemented (WE: Without exogenous electron acceptors < SS: Sulfate supplement < FS: Ferric iron supplement < NS: Nitrate supplement), while the complexity of the co-occurring networks (e.g., avgK and links) of the microbiota gradually decreased, showing that microbiota supplemented with higher redox potential electron acceptors were less dependent on the formation of complex microbial interactions to perform BTEX degradation. Microbiota NS showed the highest degrading capacity and the broadest substrate-spectrum for BTEX, and it could metabolize BTEX through multiple modules which not only contained fewer species but also different key microbial taxa (eg. Petrimonas, Achromobacter and Comamonas). Microbiota WE and FS, with the highest methanogenic capacities, shared common core species such as Sedimentibacter, Acetobacterium, Methanobacterium and Smithella/Syntrophus, which cooperated with Geobacter (microbiota WE) or Desulfoprunum (microbiota FS) to perform BTEX degradation and methane production. This study demonstrates that electron acceptors may alter microbial function by reshaping microbial community structure and regulating microbial interactions and provides guidelines for electron acceptor selection for bioremediation of aromatic pollutant-contaminated anaerobic sites.

Comparative study on the copper plasma confined with upward and downward conical cavities in laser-induced breakdown spectroscopy

In this study, the confinement effects of upward and downward conical cavities on laser-induced copper plasma were investigated by optical emission spectroscopy and fast imaging technique. It follows from the time-integrated spectra, the time-resolved spectra, and the spatial distributions of spectral intensity that the superior enhancement effects on spectral intensity are obtained in the upward conical cavity. Compared to the plasmas without confinement, plasma temperature and electron number density are increased in the presence of upward conical cavity, while no enhancements are obtained in the downward conical cavity. Reflection model of shockwave in a conical cavity is established to interpret these phenomena. The enhancement of the plasma plume confined in the upward conical cavity results from the compression of the plume towards its central region by the shockwave, as well as the accelerated collisions between the particles therein. No enhancement effect of the plasma in the downward conical cavity is obtained because of the radial expansion of plasma plume and the population reduction of excited species in the plasma primary core due to the pressure of oblique downward shockwave. This shockwave reflection model is further verified by the fast imaging, where the direct observation of the plasma plume agrees well with the enhancement effects of the two cavities on the spectral intensity.

Quantitative study on core bacteria producing flavor substances in Huangjiu (Chinese yellow rice wine)

In the process of Huangjiu fermentation, microbial succession plays an important role in quality control of Huangjiu. In this study, Lactobacillus acetotolerans was screened as internal standards, and the bacterial communities in Huangjiu fermentation were quantified definitively by high-throughput amplandin-qPCR. Based on the absolute quantitative results, multivariate statistics combined with flavor substance content analysis showed that Lactobacillus was significantly correlated with 11 core flavor substances. Macrotranscriptomics was further used to examine the transcription levels of genes related to flavor substances. The results showed that Lactobacillus was involved in the biosynthesis of several core flavor substances such as ethyl acetate during fermentation, and the correlation was strongest at the post-fermentation stage (day 5–23). It was confirmed that Lactobacillus was the core species in the formation of flavor substance in Huangjiu. This study provided valuable reference for further revealing the mechanism of microbial interaction during Huangjiu fermentation and improving the quality of Huangjiu.

Poly(acrylic acid) block copolymers as stabilizers for dispersion polymerization

Dispersion polymerization stabilized with poly(acrylic acid) has been performed for decades to produce polymer particles whose surfaces are modified with pH-responsive poly(acrylic acid) moieties. To improve stabilizer efficiency, poly(acrylic acid) block copolymers, in which a poly(acrylic acid) chain is attached to the terminus of a polystyrene or PMMA chain, were used as stabilizers for the dispersion polymerization of styrene or MMA. Compared with the poly(acrylic acid) homopolymer, polystyrene-block-poly(acrylic acid) was found to improve the controllable ranges of particle size and the carboxylic-acid-group surface density of the resulting polystyrene particles. Furthermore, we also investigated the effect of heterogeneity between the polymer species of the particle core and the attached polystyrene or PMMA chains in the poly(acrylic acid) block copolymers. Finally, we also examined the applicability of polystyrene-block-poly(acrylic acid) as a stabilizer and surface modifier for the dispersion polymerization of various monomers.

Neighboring plants and core herbivores determine the importance of Swietenia macrophylla in the plant–herbivore network

Species contribute differently to the structure and stability of networks of interacting species. However, species contributions to the importance of other species is usually neglected, thus limiting our understanding of species dynamics beyond the general network structure. We combined knowledge on diversity effects on focal species and network ecology to analyze the influence of plants and herbivores on big-leaf mahogany's (Swietenia macrophylla) importance in the plant–herbivore network. To this end, we built interaction networks using information from a large-scale tree diversity experiment and performed computer simulations of species removal with redistribution of interactions. We compared the importance of big-leaf mahogany in the observed networks to simulated networks where we removed: (a) tree species with similar beetle assemblages to mahogany, (b) the most interconnected (core) tree species and (c) the core beetle species. Removal of the core and similar tree species increased the importance of mahogany, whereas eliminating core beetle species decreased it. Interestingly, the effect of core tree species on mahogany’s importance was mediated by core beetles (R2 = 0.46). Neither tree nor core beetle species’ effects were contingent on tree species richness or abundance. These results indicate that highly connected tree and herbivore species jointly determine the role of mahogany in the plant–herbivore network. Likewise, these results provide insight into the effect of tree species composition and highly interactive herbivores in shaping the role of species in the herbivore network.

Insights into the structure-activity relationships of highly efficient CuCe oxides for the low temperature CO oxidation and CO-SCR

A series of Cu-doped Ce-based mixed metal oxide catalysts were prepared by the simplest impregnation method for CO oxidation and CO selective reduction of NOx (CO-SCR), respectively. Among them, 10Cu/CeO2 catalyst showed excellent catalytic activity and stability in both reactions. The catalysts were characterized by XRD, BET, SEM, TEM, XPS, H2-TPR, Raman, O2-TPD and in-situ DRIFTS. The results show that the preferential exposure of the (111) crystal plane of CeO2 is beneficial to the dispersion of Cu species. The introduced Cu enters the surface or lattice of CeO2, exposeing more catalyst active sites, which improves the catalyst reducibility and activity. In addition, the introduction of Cu into Ce-based catalyst also increases the types of active oxygen on the catalyst surface, improves the mobility of oxygen, and thus enhances the activity of the catalyst. The in-situ DRIFTS analysis shows that CO oxidation follows the M − K mechanism with Cu+ as the core species, while CO-SCR follows the E-R mechanism at low temperature (50–150 °C) and the L-H mechanism at high temperature (200–400 °C). These results show that CuCeO2 bifunctional catalyst can simultaneously meet the requirements of CO oxidation and CO-SCR reaction, which is of great significance for environmental governance.

Association of key species of vaginal bacteria of recurrent bacterial vaginosis patients before and after oral metronidazole therapy with short- and long-term clinical outcomes.

Bacterial vaginosis (BV) is associated with a state of vaginal dysbiosis typically involving depletion of otherwise dominant populations of Lactobacillus. The causes of this microbial succession are not known; there may be multiple causes. Standard treatment includes oral metronidazole, which typically restores Lactobacillus species to dominance. However, recurrence rates are high; recurrent BV patients recur 3–4 times annually and are often refractory to treatment. Our previous qPCR-based study of recurrent BV patients pointed to putatively more virulent species of Gardnerella that were associated with refractory responses to oral metronidazole, and less robust recovery of Lactobacillus species associated with recurrence after an initial period of remission. However, these associations did not account for outcomes in all patients, suggesting that other bacterial species were involved. In this follow-up study, we sequenced the V4 domain of 16S rRNA sequences of 41of these same patients pre- and posttreatment. Overall compositions among pretreatment clinical outcome groups were not different, although alpha diversity significantly decreased: refractory > recurrent > remission. Combinations of key species were associated with and prognostic for outcome. Higher pretreatment abundance of Megasphaera lornae together with lower abundance of Gardnerella Gsp07 and Finegoldia magna predicted long term remission after oral metronidazole. Furthermore, a subset of refractory patients that did not have high levels of Gardnerella Gsp07, instead had elevated levels of alternative species including Atopobium vaginae, Mageeibacillus indolicus (BVAB3), and Prevotella timonensis. Patients who recurred after transient remission had elevated abundance of species including Atopobium vaginae, Gardnerella, and Aerococcus christensenii, compared to long-term remission patients. Core bacterial species among refractory patients did not change in abundance after metronidazole, suggesting resistance or tolerance, in contrast to the loss in abundance of the same species among recurrent or remission patients. These findings have potential prognostic and therapeutic implications.

Changes in the core species of the ant-plant network of oak forest converted to grassland: replacement of its ant functional groups.

Land-use change in terrestrial environments is one of the main threats to biodiversity. The study of ant-plant networks has increased our knowledge of the diversity of interactions and structure of these communities; however, little is known about how land-use change affects ant-plant networks. Here we determine whether the change in land use, from native oak forest to induced grassland, affected the network properties of ant-plant networks in a temperate forest in Mexico. We hypothesize that the disturbed vegetation will be more nested and generalized due to the addition of generalist species to the network. The oak forest network comprises 47 plant species and 11 ant species, while the induced grassland network has 35 and 13, respectively. Floral nectar was the resource used most intensely by the ants in both vegetation types. The ant-plant network of the induced grassland was significantly more nested and generalist than that of the oak forest; however, none of the networks were nested when considering the frequency of interaction. In both vegetation types, the ants were more specialized than the plants, and niche overlap was low. This could be related to the dominant species present in each type of vegetation: Prenolepis imparis in the oak forest and Camponotus rubrithorax in the grassland. The central core of cold climate ant species in the oak forest was replaced by a central core of subordinate Camponotini and tropical specialists in the induced grassland. These results suggest that the increase in nestedness and generalization in the grassland may be related to the loss of the cold climate specialists from the core of the oak forest network. Our findings provide evidence that land-use change increases the level of generalization in the ant-plant interaction networks of temperate forests.

Study of the helminth fauna in eagle owl (Bubo bubo) in the south of Spain.

In this study we show the results of the eagle owls’ (Bubo bubo) helminthfauna found in Andalusia. A total number of 50 specimens have been analysed in a period of 10 years (from 2011 to 2020). Prevalence (), mean intensity (IM) and mean abundance (AM) of parasitation have been obtained. The percentage of parasitation in the total sample was 80% (40 out of 50 eagle owls): 78% nematodes, 8% trematodes, 6% cestodes and 4% acantocephalans. 7 species of helminths were identified: 6 nematodes, and 1 trematode. In the case of cestodes and acantocephalans it was not possible to determine species and only the genus was identified.The intestinal nematode Capillaria tenuissima ( = 58% (44–71.2); IM = 11,52 (5.83–28.9)) was the core species whereas Synhimantus laticeps (P% = 16 (7.5–28.8); IM = 4 (1.75–7.25)) and Hartertia hispanica (P% = 16 (7.5–28.8); IM = 1,5 (1–2)) were the secondary species. The remainder species were considered satellite species, with low prevalence and average abundance. Likewise, descriptive parameters of the helminth community were determined: species richness, 1.56 (1.29–1.94), total abundance, 12 (7.24–26.40), Brillouin's diversity index, 0.18 (0.10–0.29) and Berger-Parker dominance index, 0.88 (0.81–0.93).The data from this study show a non-diverse helminthic community, without species dominance with C. tenuissima as the central species, followed by S. laticeps and H. hispanica as secondary species. Worth mentioning is the presence of H. hispanica, which is considered an endemic species in Spain and specifically in Andalusia.To the authors’ knowledge, this is the largest population sample taken in parasitological studies about helminths of this raptor in Europe and the first one carried out in the south of Spain (Andalusia).

Using hierarchical stable isotope to reveal microbial food web structure and trophic transfer efficiency differences during lake melt season

The microbial food web (MFW) is a material and energy source in lake water ecosystems. Although it is crucial to determine its structure and function for water ecological health, MFW changes during lake melt period have not been well studied. In this study, the MFW was divided into three categories by analyzing its structure and trophic transfer efficiency using hierarchical C/N stable isotopes and eDNA sequencing techniques, including the detrital food web (DFC, 15 %), classical grazing food web (CFC, 60 %), and mixed trophic food web (MFC, 25 %). The trophic structure and type of MFW in ice-melting lakes are always in the process of succession and adaptation, which is in a relatively low trophic transfer efficiency stage under stable conditions (i.e. CFC), whereas the input of exogenous debris and organic pollutants may lead to an increase in MFW trophic transfer efficiency (i.e. MFC, DFC). The trophic transfer efficiency from the previous trophic level to protozoa and micrometazoa was 16.32 % and 20.77 % in DFC and 10.20 % and 29.43 % in MFC, respectively. Both are obviously higher than those of the CFC (11.69 % and 9.45 %, respectively). In terms of trophic structure, the community interaction and trophic cascade effect of DFC and MFC were enhanced but easily changed with environmental factors. In contrast, the core species and cascading effects of the CFC were clearer, and the MFW structure was relatively stable. Overall, this study reveals that the explosive increase in MFW trophic transfer efficiency induced by exogenous input during the lake melt period may subsequently lead to the destabilization of the microbial community structure and cause potential ecological risks. These are manifested in the absence of ecological trophic processes, the decrease in trophic structure complexity and stability, and the weakening of microecology self-adaptive regulation ability.

Intestinal Microbes in Patients With Schizophrenia Undergoing Short-Term Treatment: Core Species Identification Based on Co-Occurrence Networks and Regression Analysis.

Schizophrenia, a common mental disorder, has a tremendous impact on the health and economy of people worldwide. Evidence suggests that the microbial-gut-brain axis is an important pathway for the interaction between the gut microbiome and the development of schizophrenia. What is not clear is how changes in the gut microbiota composition and structure during antipsychotic treatment improve the symptoms of schizophrenia. In this study, 25 patients with schizophrenia were recruited. Their fecal samples were collected before and after hospital treatment for 14–19 days. The composition and structure of the intestinal microbiota were evaluated by 16S rRNA sequencing analysis, and the results showed significant differences in fecal microbiota before and after treatment. Firmicutes (relative abundances of 82.60 and 86.64%) and Gemminger (relative abundances of 14.17 and 13.57%) were the first dominant species at the phylum and genus levels, respectively. The random forest algorithm and co-occurrence network analysis demonstrated that intestinal flora (especially the core species ASV57) could be used as biomarkers to distinguish different clinical states and match treatment regimens accordingly. In addition, after fecal microbiota transplantation, antibiotic-treated recipient mice showed multiple behavioral improvements. These included decreased psychomotor hyperactivity, increased social interaction, and memory. In conclusion, this study suggests that differences in the composition and structure of gut microbiota after treatment are associated with the development and severity of schizophrenia. Results may provide a potential target for the treatment of this disorder.

Evaluation of different primers of the 18S rRNA gene to profile amoeba communities in environmental samples

Amoeboid protists, an assemblage of organisms belonging to different phylogenetic lineages, have drawn increasing attention due to their crucial ecological roles in various environments and their potential health risks. Currently, 18S rRNA gene sequencing is widely applied for the detection of amoebae. However, it is not clear which is the best primer pair for 18S rRNA gene amplification in amoebae. This study compared the four most commonly used primer pairs for revealing the diversity, composition, core species, and community assembly processes of amoebae in water and sediments. We found that the choice of primers artificially influences the detection of community composition of amoebae. We also found that short-read fragments may lead to mismatches in taxonomy and were not suitable for phylogenetic analyses. In contrast, full-length primers could detect the highest number of amoeba lineages and annotate 80% of reads belonging to amoebae to known species. However, full-length primers did not detect as many amoeba species as V4 primers. Moreover, we showed that beta diversity and community assembly determination were largely unaffected by primer choice, but different primers could influence our interpretations of the ecological process underlying stochasticity and determinism. This study indicates that full-length read sequencing and V4 region Illumina sequencing are suitable for profiling amoeba diversity in the environment.

How Microbiome Composition Correlates with Biochemical Changes during Sauerkraut Fermentation: a Focus on Neglected Bacterial Players and Functionalities.

ABSTRACTThis study provided a new perspective on the bacterial community succession during sauerkraut fermentation, and on resulting metabolic functions. While culture-dependent methods confirmed the key role of the well-known core microbiome species, metagenomic approach (shotgun) revealed Secundilactobacillus malefermentans as a species of the core microbiome, especially during the last weeks of fermentation. Although the potentiality of S. malefermentans has not yet fully explored, it held core functional genes usually attributed to others lactic acid bacteria driving sauerkraut fermentation. Based on our results it is arguable that S. malefermentans might have a key a role during sauerkraut fermentation carried out at low temperature. Under our experimental conditions, the profile of phenolic compounds changed throughout sauerkraut fermentation. The amount of free phenolics, including free phenolic acids, increased at the beginning of the fermentation, whereas the conversion of phenolic acids into microbial derivatives was consistent during the last part of the sauerkraut fermentation. We pioneered correlating changes in the phenolics profile to changes in the microbiome, although the framework presented is still fragmentary. Annotated genes linked to the phenolic compounds metabolism (VprA and padA) were found in many core species during the whole process. A high metabolic potential for phenolics bioconversion emerged for lactobacilli and Pediococcus spp. through correlation analysis between microbiome composition and phenolics profile.IMPORTANCE Our study was not limited to describe the succession pattern of the microbial community during sauerkraut fermentation, but also revealed how some neglected bacterial players belong to the core species during sauerkrauts processing, especially at low temperature. Such species might have a role as potential starters to optimize the fermentation processes and to obtain sauerkrauts with improved and standardized nutritional and sensory features. Furthermore, our correlations between microbiome composition and phenolics profile might also represent new references for sauerkraut biotechnology, aiming to identify new metabolic drivers of potential sauerkraut functionalities. Finally, sauerkraut ecosystem is a tractable model, although with high level of complexity, and resultant ecological information might be extended to other plant ecosystems.

Oxygen-Induced Elemental Mercury Oxidation in Chemical Looping Combustion of Coal.

Mercury emission is an important issue during chemical looping combustion (CLC) of coal. The aim of this work is to explore the effects of different flue gas components (e.g., HCl, NO, SO2, and CO2) on mercury transformation in the flue gas cooling process. A two-stage simulation method is used to reveal the reaction mechanism of these gases affecting elemental mercury (Hg0) oxidation. Furthermore, using this method, Hg0 oxidation by eight oxygen carriers (Co3O4, CaSO4, CeO2, Fe2O3, Al2O3, Mn2O3, SiO2, and CuO) commonly used in CLC are investigated and their Hg0 oxidation efficiencies were compared with the existing experimental results. The results show that HCl, NO, and CO2 promote Hg0 oxidation during flue gas cooling, while SO2 inhibits Hg0 oxidation. The stronger the oxygen release capacity of oxygen carriers, the higher the oxidation efficiency of Hg0 becomes. The order of Hg0 removal efficiency from high to low is Co3O4, CuO, Mn2O3, CaSO4, Fe2O3, CeO2, Al2O3, and SiO2, and this sequence is in good agreement with the existing experimental results. Different flue gas components directly or indirectly affect the O2 content, thus affecting the content of gaseous oxidized mercury (Hg2+). Different oxygen carriers have different oxygen release capacities and different Hg0 oxidation efficiencies. Therefore, O2 is the core species affecting the mercury transformation in CLC.

Mix-cultured aerobic denitrifying bacteria augmented carbon and nitrogen removal for micro-polluted water: Metabolic activity, coexistence and interactions, and immobilized bacteria for reservoir raw water treatment

Less attention has been paid on the oligotrophic water body nitrogen treatment with mix-cultured aerobic denitrifying bacteria (Mix-CADB). In this study, three Mix-CADB communities were screened from the sediments of reservoirs. The nitrate and dissolved organic carbon (DOC) removal efficiencies of Mix-CADB communities were higher than 92 % and 91 %, respectively. Biolog results suggested that Mix-CADB communities displayed excellent carbon source metabolic activity. The nirS gene sequencing indicated that Pseudomonas sp. and Pseudomonas stutzeri accounted for more proportions in the core species of three Mix-CADB communities. The network model revealed that Pseudomonas sp. and Pseudomonas stutzeri mainly drove the total nitrogen and DOC removal of Mix-CADB communities. More importantly, the immobilized Mix-CADB communities could reduce >91 % nitrate in the adjusted reservoir raw water. Overall, this study showed that the three Mix-CADB communities could be regarded as potential candidates for the nitrogen treatment in oligotrophic water body ecosystems.

Patterns and drivers of Nothobranchius killifish diversity in lowland Tanzania.

Temporary pools are seasonal wetland habitats with specifically adapted biota, including annual Nothobranchius killifishes that survive habitat desiccation as diapausing eggs encased in dry sediment. To understand the patterns in the structure of Nothobranchius assemblages and their potential in wetland conservation, we compared biodiversity components (alpha, beta, and gamma) between regions and estimated the role and sources of nestedness and turnover on their diversity. We sampled Nothobranchius assemblages from 127 pools across seven local regions in lowland Eastern Tanzania over 2 years, using dip net and seine nets. We estimated species composition and richness for each pool, and beta and gamma diversity for each region. We decomposed beta diversity into nestedness and turnover components. We tested nestedness in three main regions (Ruvu, Rufiji, and Mbezi) using the number of decreasing fills metric and compared the roles of pool area, isolation, and altitude on nestedness. A total of 15 species formed assemblages containing 1–6 species. Most Nothobranchius species were endemic to one or two adjacent regions. Regional diversity was highest in the Ruvu, Rufiji, and Mbezi regions. Nestedness was significant in Ruvu and Rufiji, with shared core (N. melanospilus, N. eggersi, and N. janpapi) and common (N. ocellatus and N. annectens) species, and distinctive rare species. Nestedness apparently resulted from selective colonization rather than selective extinction, and local species richness was negatively associated with altitude. The Nothobranchius assemblages in the Mbezi region were not nested, and had many endemic species and the highest beta diversity driven by species turnover. Overall, we found unexpected local variation in the sources of beta diversity (nestedness and turnover) within the study area. The Mbezi region contained the highest diversity and many endemic species, apparently due to repeated colonizations of the region rather than local diversification. We suggest that annual killifish can serve as a flagship taxon for small wetland conservation.

Core fungal species strengthen microbial cooperation in a food-waste composting process

In ecosystem engineering research, the contribution of microbial cooperation to ecosystem function has been emphasized. Fungi are one of the predominant decomposers in composting, but thus far, less attention has been given to fungal than to bacterial cooperation. Therefore, network and cohesion analyses were combined to reveal the correlation between fungal cooperation and organic matter (OM) degradation in ten composting piles. Positive cohesion, reflecting the cooperation degree, was positively linked to the degradation rate of OM. From the community perspective, core species (i.e., Candida tropicalis, Issatchenkia orientails, Kazachstania exigua, and Dipodascus australiensis) with high occurrence frequency and abundance were the key in regulating positive cohesion. These species were highly relevant to functional genera associated with OM degradation in both fungal and bacterial domains. Therefore, focusing on these core fungal species might be an appropriate strategy for targeted regulation of functional microbes and promotion of degradation rates.

A Simplified Palaeoceanography Archiving System (PARIS) and GUI for Storage and Visualisation of Marine Sediment Core Proxy Data vs Age and Depth

Scientific discovery can be aided when data are shared following the principles of findability, accessibility, interoperability, reusability (FAIR) data (Wilkinson et al., 2016). Recent discussions in the palaeoclimate literature have focussed on defining the ideal database format for storing data and associated metadata. Here, we highlight an often overlooked primary process in widespread adoption of FAIR data, namely the systematic creation of machine readable data at source (i.e. at the field and laboratory level). We detail a file naming and structuring method that was used at LSCE to store data in text file format in a way that is machine-readable, and also human-friendly to persons of all levels of computer proficiency, thus encouraging the adoption of a machine-readable ethos at the very start of a project. Thanks to the relative simplicity of downcore palaeoclimate data, we demonstrate the power of this simple but powerful file format to function as a basic database in itself: we provide a Matlab-based GUI tool that allows users to search and visualise isotope data by sediment core location and species type, against either depth or age. We share the database format here so that other laboratories might consider developing a similar approach depending on their own needs and requirements.

The effect of vine variety and vintage on wine yeast community structure of grapes and ferments.

The yeast community structure associated with grapes is an essential part of the wine-growing chain with a significant effect on wine quality. The aim of the present study was to evaluate the effect of the varietal factor on the yeast community assembly on grapes and during must fermentation. We analysed the wine yeast populations associated with four different grape varieties from the Greek national collection vineyard of Lykovryssi. The vintage effect was also considered by sampling the grapes for two consecutive years. Fourteen yeast species were recovered and genotyped to distinct subpopulations. A relatively stable yeast community structure was detected across vintages, with Hanseniaspora guilliermondii being the core species of the vineyard under study. The detected species subpopulations shared a relatively high genetic similarity with several genotypes persisting across vintages. It was shown that different grape cultivars were associated with distinct yeast communities, pointing to their possible implication on wine chemical diversity. Present findings show that the varietal factor is an important sharpener of the vineyard-associated wine yeast community, which may interfere with the organoleptic profile of the resulting wines.