A unique midgut-associated bacterial community hosted by the cave beetle \u3cem\u3eCansiliella servadeii\u3c/em\u3e (Coleoptera: Leptodirini) reveals parallel phylogenetic divergences from universal gut-specific ancestors

Background Cansiliella servadeii (Coleoptera) is an endemic troglobite living in deep carbonate caves in North-Eastern Italy. The beetle constantly moves and browses in its preferred habitat (consisting in flowing water and moonmilk, a soft speleothem colonized by microorganisms) self-preens to convey material from elytra, legs, and antennae towards the mouth. We investigated its inner and outer microbiota using microscopy and DNA-based approaches. Results Abundant microbial cell masses were observed on the external appendages. Cansiliella’s midgut is fully colonized by live microbes and culture-independent analyses yielded nearly 30 different 16S phylotypes that have no overlap with the community composition of the moonmilk. Many of the lineages, dominated by Gram positive groups, share very low similarity to database sequences. However for most cases, notwithstanding their very limited relatedness with existing records, phylotypes could be assigned to bacterial clades that had been retrieved from insect or other animals’ digestive traits. Conclusions Results suggest a history of remote separation from a common ancestor that harboured a set of gut-specific bacteria whose functions are supposedly critical for host physiology. The phylogenetic and coevolutionary implications of the parallel occurrences of these prokaryotic guilds appear to apply throughout a broad spectrum of animal diversity. Their persistence and conservation underlies a possibly critical role of precise bacterial assemblages in animal-bacteria interactions

Modeling the Impact of Residual Fat-Soluble Vitamin (FSV) Contents on the Oxidative Stability of Commercially Refined Vegetable Oils

Fat-soluble vitamins (FSVs) may prevent or delay bulk lipid oxidation by exerting antioxidant action. However, literature data obtained from storage tests on commercial edible oils do not necessarily confirm a direct correlation between FSV contents of bulk oils and their measured oxidative stability. This, of course, may be predominantly due to their refining history, which can strip them of much of their FSV contents and/or standardize these values. The main goal of this study was to quantify the magnitude of the role of FSVs in hindering commercial edible lipid oxidation. Fatty acid composition and FSV content data were collected on a large mixed set of commercial vegetable oils devoid of added antioxidant stabilizers (n = 123) in order to establish baseline values for these constituents. Next, a random subset of these oils (n = 50) was then subjected to the oil stability index test (OSI at 120 °C), as well as accelerated storage testing over time (60 °C) whilst monitoring a host of classical methodologies used to monitor oxidation progress. A new aggregate parameter (i.e., a sum area under the lipid oxidation curves, or \u27All Area\u27) was introduced to better capture the total quantity of primary and secondary oxidation products accumulated in the samples tested over the storage period. Multivariate regression modeling was used to correlate the fatty acid composition of the samples with their oxidative stability data both including and excluding FSV contents in order to determine a magnitude for this relationship. As noted herein, the addition of FSV data improved the fitting of the model from R 2 Adj. 0.877 to 0.925 using OSI data alone and from R 2 Adj. 0.938 to 0.960 using the \u27All Area\u27 parameter. Correlations between specific FSVs and fatty acid compositional parameters exhibited a strong relationship with lipid category. Furthermore, principal component analysis of FSV contents revealed clustering of lipids based both on lipid category and refining history

Oxidative Stability of Commodity Fats and Oils: Modeling Based on Fatty Acid Composition

Although fatty acid (FA) composition is known to be of fundamental importance to oxidative stability in lipids, consistent quantifications of the magnitude of this association have proved elusive. The objective of this study was to quantify the relationship between FA composition and stability on a large scale within comparable lipid systems, with the numerical effects of individual outcome factors (e.g. output of a singular assay, oxidative products after a brief period of time, etc.) attenuated by incorporation into a comprehensive summation of stability. The stability of 50 plant-based oils and fats was modeled according to FA composition, utilizing a quantification of stability that encompassed the complete oxidation curves of four distinct classical assays (two 1° and two 2° oxidation assessments) throughout 2 months of accelerated storage (60 °C). In our models, the concentrations of monounsaturated FA (MUFA), diunsaturated FA (DiUFA), and triunsaturated FA (TriUFA) together demonstrated a very strong correlation with our consolidated measure of stability (r 2 = 0.915; greater than observed with our assessments by individual assays). The resultant model also indicated the relative effect upon magnitude of oxidation of MUFA:DiUFA:TriUFA to be approximately 1:3:12 - substantially greater than the 1:2:3 ratio of their relative unsaturation

A New foodweb based on microbes in calcitic caves: The Cansiliella (Beetles) case in Northern Italy

The troglobitic beetle, Cansiliella servadeii (Leptodirini), has specialized mouthparts modified for browsing and feeding under percolating water on moonmilk, a speleothem formation in Grotta della Foos, Italy. Results from analyses of stable isotopes of carbon and nitrogen suggest thatacquires and assimilates dissolved allochthonous organic carbon, inorganic nitrogen, and possibly phosphorus and other nutrients from the microbial fauna associated with moonmilk

A new foodweb based on microbes in calcitic caves. The Cansiliella (Beetles) case in Northern Italy

The troglobitic beetle, Cansiliella servadeii (Leptodirini), has specialized mouthparts modified for browsing and feeding under percolating water on moonmilk, a speleothem formation in Grotta della Foos, Italy. Results from analyses of stable isotopes of carbon and nitrogen suggest that acquires and assimilates dissolved allochthonous organic carbon, inorganic nitrogen, and possibly phosphorus and other nutrients from the microbial fauna associated with moonmilk

A New foodweb based on microbes in calcitic caves: The Cansiliella (Beetles) case in Northern Italy

The troglobitic beetle, Cansiliella servadeii percolating water on moonmilk, a speleothem formation in Grotta della Foos, Italy. Results from analyses of stable isotopes of carbon and nitrogen suggest that acquires and assimilates dissolved allochthonous organic carbon, inorganic nitrogen, and possibly phosphorus and other nutrients from the microbial fauna associated with moonmilk

Comparative microbial community composition from secondary carbonate (moonmilk) deposits: implications for the Cansiliella servadeii cave hygropetric food web

The microbial diversity of moonmilk, a hydrated calcium carbonate speleothem, was evaluated from two Italian caves to provide context for the food web of highly-specialized troglobitic beetles, Cansiliella spp. (Leptodirinae), with distinctive carbon and nitrogen isotope values indicative of a novel food source. The moonmilk and associated percolating waters had low to no extractable chlorophyll, with an average organic C:N ratio of 9, indicating limited allochthonous input and a significant contribution from microbial biomass. The biomass from moonmilk was estimated to be ~104 micro- and meiofaunal individuals per m2 and ~108 microbial cells/ml. Betaproteobacteria dominated the 16S rRNA gene sequences retrieved from the moonmilk from both caves. The distribution of other proteobacterial classes and phyla in the moonmilk were statistically similar to each other, even though the two caves are geographically separated from each other. Comparing the moonmilk gene sequences to sequences from previously described environmental clones or cultured strains revealed the uniqueness of the moonmilk habitat, as ~ 15% of all of the moonmilk sequences were more closely related to each other than to sequences retrieved from any other habitat. However, comparative analyses confirmed that as much as ~34% of the clones sequences were also closely related to environmental clones and cultured strains derived from soil and freshwater habitats, which is likely due to the fact that the putative inoculation source for the moonmilk bacterial communities is from overlying soil and percolating fluids from the surface. Prior to our studies of Cansiliella spp., moonmilk has not been considered a food source for cave animals. Our findings provide unique insight into moonmilk microbial diversity that could reveal the underpinnings of the moonmilk carbon and nitrogen cycle that influences the isotopic composition and the morphological adaptations of the troglobitic beetles associated with the moonmilk

Comparative microbial community composition from secondary carbonate (moonmilk) deposits: implications for the Cansiliella servadeii cave hygropetric food web

The microbial diversity of moonmilk, a hydrated calcium carbonate speleothem, was evaluated from two Italian caves to provide context for the food web of highly-specialized troglobitic beetles, Cansiliella spp. (Leptodirinae), with distinctive carbon and nitrogen isotope values indicative of a novel food source. The moonmilk and associated percolating waters had low to no extractable chlorophyll, with an average organic C:N ratio of 9, indicating limited allochthonous input and a significant contribution from microbial biomass. The biomass from moonmilk was estimated to be ~104 micro- and meiofaunal individuals per m2 and ~107 microbial cells/ml. Proteobacteria dominated the 16S rRNA gene sequences retrieved from the moonmilk from both caves. The distribution of other proteobacterial classes and phyla in the moonmilk were statistically similar to each other, even though the two caves are geographically separated from each other. Comparing the moonmilk gene sequences to sequences from previously described environmental clones or cultured strains revealed the uniqueness of the moonmilk habitat, as ~15% of all of the moonmilk sequences were more closely related to each other than to sequences retrieved from any other habitat. However, comparative analyses confirmed that as much as ~34% of the clones sequences were also closely related to environmental clones and cultured strains derived from soil and freshwater habitats, which is likely due to the fact that the putative inoculation source for the moonmilk bacterial communities is from overlying soil and percolating fluids from the surface. Prior to our studies of Cansiliella spp., moonmilk has not been considered a food source for cave animals. Our findings provide unique insight into moonmilk microbial diversity that could reveal the underpinnings of the moonmilk carbon and nitrogen cycle that influences the isotopic composition and the morphological adaptations of the troglobitic beetles associated with the moonmilk

Comparative microbial community composition from secondary carbonate (moonmilk) deposits: implications for the \u3ci\u3eCansiliella servadeii\u3c/i\u3e cave hygropetric food web

The microbial diversity of moonmilk, a hydrated calcium carbonate speleothem, was evaluated from two Italian caves to provide context for the food web of highly-specialized troglobitic beetles, Cansiliella spp. (Leptodirinae), with distinctive carbon and nitrogen isotope values indicative of a novel food source. The moonmilk and associated percolating waters had low to no extractable chlorophyll, with an average organic C:N ratio of 9, indicating limited allochthonous input and a significant contribution from microbial biomass. The biomass from moonmilk was estimated to be ~104 micro- and meiofaunal individuals per m2 and ~107 microbial cells/ml. Betaproteobacteria dominated the 16S rRNA gene sequences retrieved from the moonmilk from both caves. The distribution of other proteobacterial classes and phyla in the moonmilk were statistically similar to each other, even though the two caves are geographically separated from each other. Comparing the moonmilk gene sequences to sequences from previously described environmental clones or cultured strains revealed the uniqueness of the moonmilk habitat, as ~15% of all of the moonmilk sequences were more closely related to each other than to sequences retrieved from any other habitat. However, comparative analyses confirmed that as much as ~34% of the clones sequences were also closely related to environmental clones and cultured strains derived from soil and freshwater habitats, which is likely due to the fact that the putative inoculation source for the moonmilk bacterial communities is from overlying soil and percolating fluids from the surface. Prior to our studies of Cansiliella spp., moonmilk has not been considered a food source for cave animals. Our findings provide unique insight into moonmilk microbial diversity that could reveal the underpinnings of the moonmilk carbon and nitrogen cycle that influences the isotopic composition and the morphological adaptations of the troglobitic beetles associated with the moonmilk