Review: Are there indigenous Saccharomyces in the digestive tract of livestock animal species? Implications for health,nutrition and productivity traits

All livestock animal species harbour complex microbial communities throughout their digestive tract that support vital biochemical processes, thus sustaining health and productivity. In part as a consequence of the strong and ancient alliance between the host and its associated microbes, the gut microbiota is also closely related to productivity traits such as feed efficiency. This phenomenon can help researchers and producers develop new and more effective microbiome-based interventions using probiotics, also known as direct-fed microbials (DFMs), in Animal Science. Here, we focus on one type of such beneficial microorganisms, the yeast Saccharomyces. Saccharomyces is one of the most widely used microorganisms as a DFM in livestock operations. Numerous studies have investigated the effects of dietary supplementation with different species, strains and doses of Saccharomyces (mostly Saccharomyces cerevisiae) on gut microbial ecology, health, nutrition and productivity traits of several livestock species. However, the possible existence of Saccharomyces which are indigenous to the animals’ digestive tract has received little attention and has never been the subject of a review. We for the first time provide a comprehensive review, with the objective of shedding light into the possible existence of indigenous Saccharomyces of the digestive tract of livestock. Saccharomyces cerevisiae is a nomadic yeast able to survive in a broad range of environments including soil, grass and silages. Therefore, it is very likely that cattle and other animals have been in direct contact with this and other types of Saccharomyces throughout their entire existence. However, to date, the majority of animal scientists seem to agree that the presence of Saccharomyces in any section of the gut only reflects dietary contamination; in other words, these are foreign organisms that are only transiently present in the gut. Importantly, this belief (i.e. that Saccharomyces come solely from the diet) is often not well grounded and does not necessarily hold for all the many other groups of microbes in the gut. In addition to summarizing the current body of literature involving Saccharomyces in the digestive tract, we discuss whether the beneficial effects associated with the consumption of Saccharomyces may be related to its foreign origin, though this concept may not necessarily satisfy the theories that have been proposed to explain probiotic efficacy in vivo. This novel review may prove useful for biomedical scientists and others wishing to improve health and productivity using Saccharomyces and other beneficial microorganisms.     

羊朊毒体单抗结合表位分析

通过分段表达PrP核心片段和人工合成多肽,分析5株羊朊毒体单抗结合表位。分段表达PrP核心片段,通过PCR方法扩增目的片段,经酶切、连接后,将目的片段插入质粒pET32a,在大肠杆菌BL21中表达。将表达的系列融合蛋白与单抗进行免疫转印试验,根据反应情况确定单抗结合的大致部位,在此基础上设计合成多条针对性多肽,用ELISA方法进一步确定3株单抗的结合部位;通过与6段融合蛋白反应证明5株单抗的结合部位分别为:2H3在199aa～213aa之间,4C6、5F11和7F11在139aa～168aa之间,7F1在214aa～227aa之间,与3段人工合成多肽进行ELISA反应进一步得到4C6、5F11和7F11抗原结合表位在149aa～158aa之间;本研究确定了5株单抗在PrP分子上的结合部位,为羊痒病和牛海绵状脑病的检测、发病机制的研究奠定了基础。     

Identifying a dynamic transcriptomic landscape of the cynomolgus macaque placenta during pregnancy at single-cell resolution

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Inhibition of the elongation step of protein synthesis by vaccinia virus

Vaccinia cores inhibit translation in cell-free protein synthesis systems at two stages: initiation; and, as shown here, elongation. The former effect tends to obscure the latter. Elongation control could, however, be revealed as follows: when, in a reticulocyte of L-cell lysate, initiation was blocked by a drug (edein), the residual [35S]methionine incorporation was severely reduced by the subsequent addition of vaccinia cores. The elongation block could also be demonstrated by analysis of ribosome profiles: treatment with edein alone permitted ribosomal run-off; treatment with either the elongation inhibition anisomycin or with cores preserved the polyribosomes.     

Physiological significance of 3-h bright and dim light exposure prior to taking a bath for core and forehead skin temperatures and heart rate during 1-h bathing of 38.5°C

1. The study investigated the effect of exposure to 3-h bright light (2500 lx) or dim light (200 lx) just prior to taking a hot bath upon thermophysiological responses during the 1-h bath (at 38.5°C water temperature). 2. Core and forehead skin temperature increases during the bath were significantly lower after bright than after dim light exposure. 3. Heart rate during the bath was significantly lower after exposure to bright light than dim light. 4. These results are discussed in terms of a reduced set-point of core temperature due to a probable higher secretion of melatonin under the bright light condition.     

Capsular perstraction as a novel methodology for the recovery and purification of geldanamycin

The molecular complex “Heat shock protein 90” has become a novel target for anticancer drugs in recent times on account of its ability to perform as a chaperone toward proteins involved in cancer progression. The geldanamycin binds to this complex with high affinity and prevents it from performing correctly, which results in tumor destruction. The aim of this study was to investigate the feasibility of applying liquid‐core microcapsules as a novel technique (termed “capsular perstraction”), for the recovery and purification of geldanamycin from culture media. Results demonstrated how this procedure was capable of rapidly extracting >70% of geldanamycin from culture media using a liquid‐core volume to medium ratio of only 1%. Optimum conditions for removal, including agitation speed, microcapsule size, and membrane thickness were examined, and it was shown how the stagnant aqueous film around the microcapsules was the main resistance to mass transfer. A volumetric mass transfer coefficient of 5.66 × 10^?6 m/s was obtained for the highest agitation speed (400 rpm), which was considerable greater compared to the value of 0.88 × 10^?6 m/s achieved for the lowest speed of 100 rpm. Removal of geldanamycin from microcapsules was also examined to fully investigate the potential of such particles for in situ product recovery, and it was demonstrated how the methodology can be used as a simple mechanism for purifying the compound (>99%) through solvent extraction and crystallization. The results of this work demonstrate the novel use of capsular perstraction as a methodology for the recovery and purification of geldanamycin from culture environments. © 2011 American Institute of Chemical Engineers Biotechnol. Prog., 2011     

Competing two enzymatic reactions realizing one‐step preparation of cell‐enclosing duplex microcapsules

The usefulness of cell‐enclosing microcapsules in biomedical and biopharmaceutical fields is widely recognized. In this study, we developed a method enabling the preparation of microcapsules with a liquid core in one step using two enzymatic reactions, both of which consume H₂O₂ competitively. The microcapsule membrane prepared in this study is composed of the hydrogel obtained from an alginate derivative possessing phenolic hydroxyl moieties (Alg‐Ph). The cell‐enclosing microcapsules with a hollow core were obtained by extruding an aqueous solution of Alg‐Ph containing horseradish peroxidase (HRP), catalase, and cells into a co‐flowing stream of liquid paraffin containing H₂O₂. Formation of the microcapsule membrane progressed from the surface of the droplets through HRP‐catalyzed cross‐linking of Ph moieties by consuming H₂O₂ supplied from the ambient liquid paraffin. A hollow core structure was induced by catalase‐catalyzed decomposition of H₂O₂ resulting in the center region being at an insufficient level of H₂O₂. The viability of HeLa cells was 93.1% immediately after encapsulation in the microcapsules with about 250 µm diameter obtained from an aqueous solution of 2.5% (w/v) Alg‐Ph, 100 units mL^?1 HRP, 9.1 × 10⁴ units mL^?1 catalase. The enclosed cells grew much faster than those in the microparticles with a solid core. In addition, the thickness of microcapsule membrane could be controlled by changing the concentrations of HRP and catalase in the range of 13–48 µm. The proposed method could be versatile for preparing the microcapsules from the other polymer derivatives of carboxymetylcellulose and gelatin. © 2013 American Institute of Chemical Engineers Biotechnol. Prog., 29:1528–1534, 2013     

Sampling volume in root studies: the pitfalls of under‐sampling exposed using accumulation curves

Root systems are important for global models of below‐ground carbon and nutrient cycling. Notoriously difficult sampling methods and the fractal distribution of root diameters in the soil make data being used in these models especially susceptible to error resulting from under‐sampling. We applied the concept of species accumulation curves to root data to quantify the extent of under‐sampling inherent to minirhizotron and soil coring sampling for both root uptake and carbon content studies. Based on differences in sample size alone, minirhizotron sampling missed approximately one third of the root diameters observed by soil core sampling. Sample volumes needed to encounter 90% of root diameters averaged 2481 cm³ for uptake studies and 5878 cm³ for root carbon content studies. These results show that small sample volumes encounter a non‐representative sample of the overall root pool, and provide future guidelines for determining optimal sample volumes in root studies.     

Quick start guide to soil methods for ecologists

Increasingly biologists and ecologists are becoming aware of the vital importance of soil to processes observed aboveground and are incorporating soil analyses into their research. Because of the dynamic and heterogeneous nature of soil, proper incorporation of soil analysis into ecological studies requires knowledge and planning. Unfortunately, many ecologists may not be current (or trained at all) in soil science. We provide this review, based on our cumulative >60 years of work in soil science, to help familiarize researchers with essential information to appropriately incorporate soil analyses into ecological studies. Specifically, we provide a brief introduction into soils and then discuss issues related to soil sterilization, choosing a soil for a greenhouse project, sampling soils, and soil analyses.