Impact of Dietary Sodium Butyrate and Salinomycin on Performance and Intestinal Microbiota in a Broiler Gut Leakage Model

Unfavorable alterations of the commensal gut microbiota and dysbacteriosis is a major health problem in the poultry industry. Understanding how dietary intervention alters the microbial ecology of broiler chickens is important for prevention strategies. A trial was conducted with 672 Ross 308 day-old male broilers fed a basic diet (no additives, control) or the basic diet supplemented with 500 mg/kg encapsulated butyrate or 68 mg/kg salinomycin. Enteric challenge was induced by inclusion of 50 g/kg rye in a grower diet and oral gavage of a 10 times overdose of a vaccine against coccidiosis. Compared to control and butyrate-supplemented birds, salinomycin supplementation alleviated growth depression. Compared to butyrate and non-supplemented control, salinomycin increased potentially beneficial Ruminococcaceae and reduced potentially pathogenic Enterobacteriaceae and counts of Lactobacillus salivarius and Clostridium perfringens. Further, salinomycin supplementation was accompanied by a pH decrease and succinic acid increase in ceca, while coated butyrate (0.5 g/kg) showed no or limited effects. Salinomycin alleviated growth depression and maintained intestinal homeostasis in the challenged broilers, while butyrate in the tested concentration showed limited effects. Thus, further investigations are required to identify optimal dietary inclusion rates for butyrate used as alternative to ionophore coccidiostats in broiler production.

Enrichment of Homoacetogens Converting H2/CO2 into Acids and Ethanol and Simultaneous Methane Production

An anaerobic granular sludge was enriched to utilize H2/CO2 in a continuous gas-fed up-flow anaerobic sludge reactor by applying operating conditions expected to produce acetic acid, butyric acid and ethanol. Three stages of fermentation were found: Stage I with acetic acid accumulation with the highest concentration of 35 mM along with a pH decrease from initial 6 to 4.5. In Stage II, H2/CO2 was replaced by 100% H2 to induce solventogenesis, whereas butyric acid was produced with the highest concentration of 2.5 mM. At Stage III with 10 μM tungsten (W) addition, iso-valeric acid, valeric acid and caproic acid were produced at pH 4.5 -5.0. In the batch tests inoculated with the enriched sludge taken from the bioreactor (day 70), however, methane production occurred at pH 6. Exogenous 15 mM acetate addition enhanced both the H2 and CO2 consumption rate compared to exogenous 10, 30 and 45 mM acetate by the enriched sludge. Exogenous acetate failed to be converted to ethanol using H2 as electron donor by the enriched acetogens.

Groundwater Interacting at Depth With Hot Plastic Magma Triggers Phreatic Eruptions at Yugama Crater Lake of Kusatsu-Shirane Volcano (Japan)

Interpreting the triggering mechanisms for phreatic eruptions is a key to improving the hazard assessment of crater lakes. Yugama Crater Lake at Kusatsu-Shirane volcano, Japan, is the site of frequent phreatic eruptions with the recent eruptions in 1982–83, 1989, and 1996, as well as volcanic unrest, including earthquake swarms in 2014 and 2018. To understand the magma–hydrothermal interaction beneath Yugama Crater Lake, we analyzed lake waters from November 2005 to May 2021. From 2005 to 2012, Cl and SO4 concentrations decreased slowly, suggesting the development of a self-sealing zone surrounding the crystallizing magma. We focused on Ca, Al, and Si concentrations as representatives of the breach and dissolution of minerals comprising the self-sealing zone and the Mg/Cl ratio as an indicator for enhanced interaction between groundwater and hot plastic rock within the self-sealing zone. In 2006–2007, the Ca, Al, Si concentrations and the Mg/Cl ratio increased. No Cl and SO4 increase during this period suggests the self-sealing zone was leached by deep circulating groundwater rather than by magmatic fluids injection. After the 2014 earthquakes, Ca, Al, and Si increased again but were associated with a significant Cl increase and a pH decrease. We believe that the HCl-rich magmatic fluids breached the self-sealing zone, leading to fluids injection from the crystallizing magma to the Yugama crater. During this period, the Mg/Cl ratio did not increase, meaning that magmatic fluids ascending from the breached area of the self-sealing zone inhibited deep intrusion of groundwater into the hot plastic rock region. In 2018, magmatic fluids ascended through the self-sealing zone again with less intensity than in 2014. All eruptions since 1982 have been accompanied by a Mg/Cl ratio increase and a Cl decrease, whereas, when a significant HCl input occurs, as in 2014, no eruptions and no Mg/Cl ratio increase occurred. This demonstrates that the groundwater–hot plastic rock interaction, rather than the magmatic fluids input, played an essential role in triggering phreatic eruptions; i.e., phreatic eruptions can potentially occur without clear signs of fresh magma intrusions.

Top-Down Enrichment Strategy to Co-cultivate Lactic Acid and Lignocellulolytic Bacteria From the Megathyrsus maximus Phyllosphere

Traditionally, starting inoculants have been applied to improve ensiling of forage used for livestock feed. Here, we aimed to build up a bioinoculant composed of lactic acid-producing and lignocellulolytic bacteria (LB) derived from the Megathyrsus maximus (guinea grass) phyllosphere. For this, the dilution-to-stimulation approach was used, including a sequential modification of the starting culture medium [Man, Rogosa, and Sharpe (MRS) broth] by addition of plant biomass (PB) and elimination of labile carbon sources. Along 10 growth-dilution steps (T1–T10), slight differences were observed in terms of bacterial diversity and composition. After the sixth subculture, the consortium started to degrade PB, decreasing its growth rate. The co-existence of Enterobacteriales (fast growers and highly abundance), Actinomycetales, Bacillales, and Lactobacillales species was observed at the end of the selection process. However, a significant structural change was noticed when the mixed consortium was cultivated in higher volume (500ml) for 8days, mainly increasing the proportion of Paenibacillaceae populations. Interestingly, Actinomycetales, Bacillales, and Lactobacillales respond positively to a pH decrease (4–5), suggesting a relevant role within a further silage process. Moreover, gene-centric metagenomic analysis showed an increase of (hemi)cellulose-degrading enzymes (HDEs) during the enrichment strategy. Reconstruction of metagenome-assembled genomes (MAGs) revealed that Paenibacillus, Cellulosimicrobium, and Sphingomonas appear as key (hemi)cellulolytic members (harboring endo-glucanases/xylanases, arabinofuranosidases, and esterases), whereas Enterococcus and Cellulosimicrobium have the potential to degrade oligosaccharides, metabolize xylose and might produce lactic acid through the phosphoketolase (PK) pathway. Based on this evidence, we conclude that our innovative top-down strategy enriched a unique bacterial consortium that could be useful in biotechnological applications, including the development/design of a synthetic bioinoculant to improve silage processes.

Size and Structure of Empty and Filled Nanocontainer Based on Peptide Dendrimer with Histidine Spacers at Different pH

Novel peptide dendrimer with Lys-2His repeating units was recently synthesized, studied by NMR (Molecules, 2019, 24, 2481) and tested as a nanocontainer for siRNA delivery (Int. J. Mol. Sci., 2020, 21, 3138). Histidine amino acid residues were inserted in the spacers of this dendrimer. Increase of their charge with a pH decrease turns a surface-charged dendrimer into a volume-charged one and should change all properties. In this paper, the molecular dynamics simulation method was applied to compare the properties of the dendrimer in water with explicit counterions at two different pHs (at normal pH with neutral histidines and at low pH with fully protonated histidines) in a wide interval of temperatures. We obtained that the dendrimer at low pH has essentially larger size and size fluctuations. The electrostatic properties of the dendrimers are different but they are in good agreement with the theoretical soft sphere model and practically do not depend on temperature. We have shown that the effect of pairing of side imidazole groups is much stronger in the dendrimer with neutral histidines than in the dendrimer with protonated histidines. We also demonstrated that the capacity of a nanocontainer based on this dendrimer with protonated histidines is significantly larger than that of a nanocontainer with neutral histidines.

Development of a new Brazilian semi-hard (Coalho) Buffalo cheese made with the inclusion of cow milk and functional potential / Desenvolvimento de um novo queijo semiduro brasileiro (Coalho) de búfalo feito com a inclusão de leite de vaca e potencial funcional

This study aimed to produce a new Brazilian Coalho buffalo cheese with 45% cow milk and potential functional through inulin and Lactobacillus plantarum addition. The Four treatments were made: the control (CTL) without functional ingredients, prebiotic (PRE) with Inulin, probiotic (PRO) with L. plantarum, and symbiotic (SYM) with both Inulin and L. plantarum. The starter culture (Lactococcus spp.) and L. plantarum viability and pH were analyzed during cheese ripening (0, 4, 8, and 10 days). While moisture, fat, and fat in the dry matter parameters were evaluated after ten days of storage ripening. During the ripening, the Lactococcus spp. growth was significant in the first eight days. The starter culture stabilized in counts above 7.1 log UFC.g-1. In the same period, L. plantarum was no growth ( 10) neither in PRO nor SYM treatments. The higher Lactococcus spp. counts (up to 10.6 Log UFC.g-1) in PRE and PRO cheeses leads to the most intense pH decrease (5.4) during the ripening. All treatments pointed to a moisture content between 38.09% to 40.49% and classified as Brazilian Coalho cheeses. The PRE had a higher FDM content (42.66%), while the lowest values were from SYM (35.53%). Thus, inulin addition does not negatively affect parameters tested, indicating a good fiber source for prebiotic semi-cooked and semi-hard cheeses. The L. plantarum viability was compromised during the process. Future studies about temperature adaptation, previous activation of strains or even encapsulation techniques associated with starter function should be evaluated to draw the best inoculation strategies for this probiotic for Coalho buffalo cheese.

Scale precipitation on HDPE pipe by degassing of CO2 dissolved in water

In Algeria, high-density polyethylene (HDPE) is widely used in drinking water pipes. This study is focused on the precipitation of calcium carbonate, a major constituent of scale, from calcocarbonically pure (CCP) water in HDPE pipe. Studying scaling in natural conditions is very difficult because it occurs over many years. For this, accelerated scaling is caused by the degassing CO2 dissolved in water. The kinetic study has shown that the germination time and the critical pH decrease with the hardness (30, 40 and 50 °f) and temperature (30, 40 and 50 °C) of water. On the other hand, scaling process efficiency (η) and the supersaturation coefficient (Ωcal) of CaCO3 increase with these parameters. The CaCO3 precipitation occurs both in solution and on walls of HDPE. By the weighing method, it is shown that the deposit mass increases with hardness and temperature. Calcium carbonate precipitates much more in homogeneous phase than in heterogeneous one. The study also showed that heterogeneous nucleation on HDPE is much less important than on PA, PVC, chrome and Inox. These measurements are supported by the characterization of X-ray diffraction deposits and by scanning electron microscopy, which recognizes that the precipitate obtained consists mainly of calcite.

Weak impact of microorganisms on Ca, Mg-bearing silicate weathering

Assessment of the microbial impact on mineral dissolution is crucial for a predictive understanding of basic (Ca, Mg bearing) silicate weathering and the associated CO2 consumption, bioerosion, and CO2 storage in basaltic rocks. However, there are controversies about the mechanism of microbial effect, which ranges from inhibiting via nil to accelerating. Here we studied diopside interaction with the heterotrophic bacterium Pseudomonas reactants and the soil fungus Chaetomium brasiliense using a combination of mixed-flow and batch reactors and in situ (AFM) and ex situ (SEM) microscopy. The results provide new nano-level insights into the degree to which microorganisms modify silicate dissolution. Taking into account negligible effects of organic ligands on diopside dissolution as reported earlier, we conclude that the microbial effect on Ca-Mg silicates is weak and the acceleration of dissolution of “basic” silicate rocks in the presence of soil biota is solely due to pH decrease in porewaters.

Could Artificial Downwelling/Upwelling Mitigate Oceanic Deoxygenation in Western Subarctic North Pacific?

Subpolar gyre regions such as the Western Subarctic North Pacific (WSNP) contain sluggish, low-oxygen water, and are threatened by loss of oxygen (deoxygenation). Our simulations under RCP 8.5 emission scenario suggest that installing pipes to induce artificial downwelling and upwelling (AD and AU) provides short-term solutions to combat deoxygenation in the WSNP. With no engineering, the WSNP's subsurface oxygen decreases by 30–100 mmol/m3 by the year 2100. Continuous implementation of AD and AU instead counters this declining trend, and AD is more effective than AU. The oxygenation effect is primarily a consequence of how the two engineering schemes vertically redistribute oxygen via physical processes. AD directly improves oxygen at depth via advecting surface water toward the ocean interior and subsequent enhanced pycnocline mixing, and AU does so via generating compensatory downwelling outside of the pipes. Both schemes take near 40 years to complete the oxygenation. After that, oxygen reaches a new equilibrium state in the WSNP with no further improvement by the engineering. AD and AU both strongly increase primary production surrounding the deployment sites, but lead only to weak enhancement of aerobic respiration in subsurface water and thus a minor impact on the oxygenation. Other unwanted environmental side effects are negligible compared to those caused by rapid climate change within this century, including outgassing of carbon dioxide, pH decrease, and precipitation reduction.

Release Profiles of Dyes and Proteins from Calcium Phosphate Microspheres with Different Crystalline Phases

Calcium phosphate is attracting attention as a bone repair material and a controlled-release carrier of various drugs such as bone disease therapeutic agents and anticancer agents. Compared with some bioabsorbable polymers, calcium phosphates have the advantage of preventing a pH decrease in the surrounding body fluid. However, there are few studies comparing the effect of supporting substances with different physicochemical properties on the production of calcium phosphate microspheres with different crystalline phases. In this study, we investigated conditions for obtaining low crystallinity apatite and octacalcium phosphate (OCP) microspheres from calcium carbonate microspheres with different crystalline structures using a simple phosphoric acid treatment. Furthermore, we investigated the adsorption and release behavior of different dyes and proteins from the apatite and OCP microspheres. Overall, the factors governing the adsorption and release behavior are different depending on the molecular size and surface charge of the dye and protein adsorbates.