Combined Elevation of Temperature and CO2 Levels Impacts the Production and Sugar Composition of Aphid Honeydew

Honeydew is the keystone of many interactions between aphids and their predators, parasitoids, or mutualistic partners. Despite the crucial importance of honeydew in the aphid-ant mutualism, very few studies have investigated the potential impact of climate change on its production and composition. Here, we quantified changes in the sugar compounds and in the amount of honeydew droplets released by Aphis fabae reared on Vicia faba plants, under elevated levels of temperature and/or CO2. A combined elevation of these two abiotic factors increased honeydew production as well as the total amount in sugars, in particular the concentration of fructose and melezitose. Increased amount of sugars in phloem sap under elevated CO2 conditions, along with a raise of aphid metabolism and sap ingestion to compensate for water loss under elevated temperatures might explain these observed changes increase in honeydew production and sugar content. A higher amount of excreted honeydew coupled with a higher concentration in melezitose and fructose are expected to enhance both the feeding behavior and the laying of a recruitment trail by ant foragers, thereby reinforcing the ant-homopteran mutualism under a scenario of elevated temperature and CO2 levels. We discuss about the enhancing and counteracting effects of climate change on other biological agents (gut microorganisms, predators, parasitoids) that interact with aphids in a complex multitrophic system.

​Development and Nutritional Evaluation of Foxtail Millet (Setaria italica) based Laddu

Backround: Foxtail millet (Setaria italica) is known for its health benefits as it is nutritionally superior to conventional food grains. Laddu are ball-shaped sweets which are popular in India and are often served at festive or religious occasions. Hence, an attempt was made to develop foxtail millet based value added laddu. Methods: Besan laddu was taken as control. Optimized foxtail millet laddu were nutritionally evaluated for proximate composition, sugars and minerals. Paired ‘t’ test was used to compare the physical parameters and nutrient composition of besan and foxtail millet laddu. Result: The developed foxtail millet laddu had the 11.61, 17.52, 2.64, 1.11 and 66.85% per 100g of protein, fat, crude fibre, ash and carbohydrate respectively. There was no significant difference in sugar composition between the control and the optimised laddu. However, it was observed that the calcium, iron, zinc, copper and manganese of foxtail millet laddu were high as compared to control laddu.

Dietary calcium phosphate strongly impacts gut microbiome changes elicited by inulin and galacto-oligosaccharides consumption

Background Fructo-oligosaccharides (FOS), inulin, and galacto-oligosaccharides (GOS) are widely recognized prebiotics that profoundly affect the intestinal microbiota, including stimulation of bifidobacteria and lactobacilli, and are reported to elicit several health benefits. The combination of dietary FOS and inulin with calcium phosphate was reported to stimulate commensal Lactobacillus populations and protect the host against pathogenic Enterobacteriaceae, but little is known about the effects of GOS in diets with a different level of calcium phosphate. Methods We investigated the microbiome changes elicited by dietary supplementation with GOS or inulin using diets with high (100 mmol/kg) and low (30 mmol/kg) calcium phosphate levels in adult Wistar rats. Rats were acclimatized to the respective experimental diets for 14 days, after which fecal material was collected, DNA was extracted from fecal material, and the V3‑V4 region of the bacterial 16S rRNA gene was amplified with PCR, followed by microbial composition analysis. In tandem, the organic acid profiles of the fecal material were analyzed. Results Feeding rats non-supplemented (no prebiotic-added) diets revealed that diets rich in calcium phosphate favored members of the Firmicutes and increased fecal lactic, succinic, acetic, propionic, and butyric acid levels. In contrast, relatively low dietary calcium phosphate levels promoted the abundance of mucin degrading genera like Akkermansia and Bacteroides, and resulted in increased fecal propionic acid levels and modest increases in lactic and butyric acid levels. Irrespective of the calcium phosphate levels, supplementation with GOS or inulin strongly stimulated Bifidobacterium, while only high calcium phosphate diets increased the endogenous Faecalibaculum populations. Conclusions Despite the prebiotic’s substantial difference in chemical structure, sugar composition, oligomer size, and the microbial degradation pathway involved in their utilization, inulin and GOS modulated the gut microbiota very similarly, in a manner that strongly depended on the dietary calcium phosphate level. Therefore, our study implies that the collection of detailed diet information including micronutrient balance is necessary to correctly assess diet-driven microbiota analysis.

Fine Carbohydrate Structure of Dietary Resistant Glucans Governs the Structure and Function of Human Gut Microbiota

Increased dietary fiber consumption has been shown to increase human gut microbial diversity, but the mechanisms driving this effect remain unclear. One possible explanation is that microbes are able to divide metabolic labor in consumption of complex carbohydrates, which are composed of diverse glycosidic linkages that require specific cognate enzymes for degradation. However, as naturally derived fibers vary in both sugar composition and linkage structure, it is challenging to separate out the impact of each of these variables. We hypothesized that fine differences in carbohydrate linkage structure would govern microbial community structure and function independently of variation in glycosyl residue composition. To test this hypothesis, we fermented commercially available soluble resistant glucans, which are uniformly composed of glucose linked in different structural arrangements, in vitro with fecal inocula from each of three individuals. We measured metabolic outputs (pH, gas, and short-chain fatty acid production) and community structure via 16S rRNA amplicon sequencing. We determined that community metabolic outputs from identical glucans were highly individual, emerging from divergent initial microbiome structures. However, specific operational taxonomic units (OTUs) responded similarly in growth responses across individuals’ microbiota, though in context-dependent ways; these data suggested that certain taxa were more efficient in competing for some structures than others. Together, these data support the hypothesis that variation in linkage structure, independent of sugar composition, governs compositional and functional responses of microbiota.

Polysaccharide Structures and Their Hypocholesterolemic PoTential

Several classes of polysaccharides have been described to have hypocholesterolemic potential, namely cholesterol bioaccessibility and bioavailability. This review will highlight the main mechanisms by which polysaccharides are known to affect cholesterol homeostasis at the intestine, namely the effect (i) of polysaccharide viscosity and its influence on cholesterol bioaccessibility; (ii) on bile salt sequestration and its dependence on the structural diversity of polysaccharides; (iii) of bio-transformations of polysaccharides and bile salts by the gut microbiota. Different quantitative structure–hypocholesterolemic activity relationships have been explored depending on the mechanism involved, and these were based on polysaccharide physicochemical properties, such as sugar composition and ramification degree, linkage type, size/molecular weight, and charge. The information gathered will support the rationalization of polysaccharides’ effect on cholesterol homeostasis and highlight predictive rules towards the development of customized hypocholesterolemic functional food.

Perspective for a New Bioinspired Permanent Adhesive for dry Conditions - Insights in the Glue Producing Japanese art of Defence System of the Oita Salamander Hynobius dunni

Novel medical bioadhesives are proposed to fulfil numerous ideals as being biocompatible, non-toxic, include tissue healing and regeneration characteristics, have high mechanical properties onto different surfaces and other important key features. Mussel-inspired adhesives have provided the basis for many new applications under wet conditions. In contrast, the defence secretion system in amphibians may provide potential for novel fast-curing secretion able to adhere to surfaces under dry conditions. With the microanatomical and histochemical characterization of the endemic Japanese Oita salamander Hynobius dunni details on its anatomical organization, the nature of the chemical composition of both glue-producing glands and its divergence to the other well-characterized species Plethodon shermani are discussed. The study shows that the cutaneous glands of both glue-producing salamanders (H. dunni and P. shermani) exhibit certain morphological and histochemical similarities. Nevertheless, clear differences exist between the two species, especially with regard to the sugar composition of the mucous glands and the pH level of the granular glands. Moreover, the adhesive secretions of H. dunni show a clear reactivity to Arnow staining (indicating the presence of L-DOPA), which is lacking in P. shermani. This is the first indication of the presence of L-DOPA in the adhesive secretions of a terrestrial vertebrate, which has thus far only been found for marine invertebrates, such as mussels and polychaetes.

Characterizing the Volatile and Sensory Profiles, and Sugar Content of Beeswax, Beebread, Bee Pollen, and Honey

Bee products are a well-known remedy against numerous diseases. However, from the consumers’ perspective, it is essential to define factors that can affect their sensory acceptance. This investigation aimed to evaluate the volatile and sensory profiles, and sugar composition of beeswax, beebread, pollen, and honey. According to the HS-SPME/GC-MS results, 20 volatiles were identified in beeswax and honey, then 32 in beebread, and 33 in pollen. Alkanes were found to dominate in beeswax, beebread, and pollen, while aldehydes and monoterpenes in honey. In the case of sugars, a higher content of fructose was determined in beebread, bee pollen, and honey, whereas the highest content of glucose was assayed in beeswax. In the QDA, the highest aroma intensity characterized as honey-like and sweet was found in honey, while the acid aroma was typical of beebread. Other odor descriptors, including waxy, pungent, and plant-based aromas were noted only in beeswax, honey, and pollen, respectively.

Optimal Sugar Compostitions And Conditions For Enhanced Biobutanol Bioproduction From Agriculture Residues

Production of alternative non-fossil biofuels based on renewable resources has been the focus of research in the past few decades due to its environmental and economical advantages. The current study focuses on testing two Clostridia strains towards production of butanol. The work was performed in three parts: the first part includes introducing C acetobutylicum ATCC 4259 for butanol production and identifying the proper working conditions for this strain. The following part includes extending investigation of production to examine C. beijerinckiiBA101 and compare with results obtained from C. acetobutylicum. In the last part, an optimization study was conducted on a presently derived mathematical model in order to predict the best sugar composition in the feedstock for maximum production of butanol. Results showed that the agriculture residues are potential biomass resource for biofuel industry sin both Clostridia strains were successfully able to utilize all types of agricultural sugars including hexose and pentose. However, using C. beijerinkckii resulted in 53% higher butanol concentration than using introduced C. acetobutylicum. The yield was fairly comparable, while high acid accumulation found when using C. acetobutylicum made this strain inapplicable to anaerobic batch fermentation without effective system of pH control.