Advances in selenium supplementation:From selenium-enriched yeast to potential selenium-enriched insects,and selenium nanoparticles

Selenium(Se)is an essential micronutrient that plays an important role in animal and human development and physiological homoeostasis.This review surveys the role of Se in the environment,plants and animal bodies,and discusses data on Se biofortification with different sources of supplementation,from inorganic to organic forms,with special focus on Se-enriched yeast(Se-yeast).Although Se-yeast remains one of the main sources of organic Se,other emerging and innovative sources are reviewed,such as Se-enriched insects and Se-nanoparticles and their potential use in animal nutrition.Se-enriched insects are discussed as an option for supplying Se in organic form to livestock diets.Se-nanoparticles are also discussed,as they represent a more biocompatible and less toxic source of inorganic Se for animal organisms,compared to selenite and selenate.We also provide up to date information on the legal framework in the EU,USA,and Canada of Se that is contained in feed additives.From the scientific evidence available in the literature,it can be concluded that among the inorganic forms,sodium selenite is still one of the main options,whereas Se-yeast remains the primary organic form.However,other potential sources such as Se-enriched insects and Se-nanoparticles are being investigated as they could potentially combine a high bioavailability and reduced Se emissions in the environment.

Selenium-enriched and ordinary green tea extracts prevent high blood pressure and alter gut microbiota composition of hypertensive rats caused by high-salt diet

High-salt diet is well recognized as a risk factor for hypertension,and dietary intervention plays a critical role in the prevention of hypertension.The current study investigated the effects of selenium-enriched green tea(Se-GT)and ordinary green tea(GT)on prevention of hypertension of rats induced by high-salt diet,as well as their potential regulatory and mechanism.Our results showed that GT and Se-GT supplementations significantly prevented the increase of blood pressure(BP),activated the phosphoinosmde-3-kinase/protein kinase B(PI3K/Akt)signaling pathway,and regulated the gene expression related to BP,as well as improved the tissue damage like heart,liver,and kidneys.Besides,the key parameters associated with oxidative stress,inflammation and endothelial dysfunction were also altered by GT and Se-GT treatments.Importantly,GT or Se-GT administration adjusted the diversity and composition of the intestinal flora.Moreover,GT and Se-GT supplementations increased the abundance of beneficial bacteria and reduced the abundance of harmful or conditional pathogenic bacteria.More specifically,GT intake specifically and significantly enriched the relative abundance of Paraprevotella and Bacteroides,whereas Se-GT was characterized by specific and significant enrichment for Allobaculum and Bifidobacterium.Our results proved that dietary supplement of GT and Se-GT remarkably improved the vascular functions and effectively prevented tissue damage by regulation of intestinal flora,and thus preventing hypertension induced by high-salt diet.

Research on Strategies for the Development of Selenium-enriched Tea in Ankang City of Shaanxi Province in the Context of Targeted Poverty Alleviation

As an important symbol of agricultural and sideline products in Ankang City,selenium-enriched tea affects the development of regional agricultural and sideline industries.In this paper,the development status and problems of the selenium-enriched tea products of Ankang were analyzed in terms of capital,technology,management and sales mode.This research is of positive significance to the development of selenium-enriched products and other agricultural and sideline products of health value,and plays a very important role in promoting the cultivation of village-level characteristic industries and the effective realization of targeted poverty alleviation.

Study on Extraction Method of Selenium-enriched Rice

[Objectives] The aims were to optimize the extraction process of selenoproteins from selenium-enriched rice in Guangxi and provide references for the intensive processing and comprehensive utilization of selenium protein resources. [Methods]Selenium-enriched rice was used as materials to extract selenoproteins by phosphate buffer extraction method and to optimize the extraction process of selenoproteins by using the orthogonal experiment. Proteins and selenium content was measured by Coomassie Brilliant Blue G-250 reagent and AFS（ atomic fluorescence spectrometry） respectively. [Results] The most significant factor affecting extraction of rice Selenoproteins was extraction NaO H concentration,followed by the ratio of solid-liquid,temperature and then extraction time. The optimum extraction conditions of selenoproteins from rice were extraction temperature of 50 ℃,NaO H concentration of 0. 14 mol/L,extraction time of 5 h,and solid-liquid ratio of 1∶ 30. [Conclusions]The alkali extraction process optimized by orthogonal test could effectively improve the extraction rate of selenoproteins,and the optimized process parameters could be popularized and applied in practical production.

Analysis of Influencing Factors in Production of Selenium-enriched Eggs

Selenium is an essential trace element for human health.Eating selenium-enriched eggs is conducive to easily and effectively solving the problem of selenium deficiency.In the production process of selenium-enriched eggs,different selenium sources,additive doses,feeding time,and the addition of other vitamins,trace elements,and methionine in the diet will influence the deposition of selenium in eggs.Through this review,it is intended to provide a reference for the practical,safe and economical production of selenium-enriched eggs.

Recommendations for Sustainable Development of Selenium-enriched Functional Agriculture in Guangxi under the New Normal

Taking Scientific Outlook on Development as the guiding principle,this paper introduced the principles of innovation,coordination,green,openness and sharing. Based on gifted advantages of selenium-enriched soil and selenium-enriched industry development in Guangxi,it discussed current practice,stressed green,ecological,characteristic demonstration,transformation and upgrading,and targeted poverty alleviation. Finally,it came up with perspective,practical,and operational strategies and recommendations for development of selenium-enriched industry,to provide reference for sustainable development of selenium-enriched functional industry in Guangxi.

Effect of Soil Selenium on Nutritional Quality of Vegetables in the Selenium-enriched Areas of Qinghai Plateau

In order to improve the added value of the main vegetable products in Qinghai Province,we researched the effect of soil selenium content on vegetable quality in selenium-enriched area of Qinghai. Through the analysis of Qinghai selenium-enriched soil selenium content and5 kinds of main vegetables corresponds to the total selenium,part of the mineral elements and soluble sugar and VC content,the effects of soil selenium levels on selenium absorption and nourishment quality of vegetables were researched. The results showed that he Qinghai selenium-enriched soil selenium content in the range of 100. 00-563. 00 μg/kg,among them,the soil samples with sufficient selenium and rich selenium accounted for 76. 53% and 18. 88%,respectively. Soil selenium content of garlic sampling area was relatively high,and soil selenium content of sugar beet sampling area was relatively low. Vegetable selenium content was in the range of 11. 00-340. 94 μg/kg,the average content of total selenium content of garlic was up to 170. 40 μg/kg,and the average content of the total selenium content of radish is 73. 00 μg/kg.90. 63% of the vegetables in the region reached the level of sufficient selenium,and 70. 31% reached the level of selenium enrichment. The average content of Ca and Mg was higher than the national average. There was no significant correlation between selenium content of soil and vegetable and nutritional quality.

Improving Semi-Dried Brown Rice Noodle Quality via Mixed Fermentation of Lactobacillus and Yeast

To address the coarse texture and poor cooking quality of brown rice flour,we employed fermentation using lactobacillus and yeast in varying proportions.The fermented flour from early indica rice Pear 13 was then processed into semi-dried brown rice noodles.

Effect of β-Glucan (Angel Yeast) Compared to a Placebo on Cold and Flu Incidence and Symptoms in an Adult Population—A Double Blind, Randomised Controlled Trial

Background: 1-3, 1-6 β-glucan derived from Baker’s yeast (Saccharomyces cerevisiae) has been widely studied for its immune stimulatory capabilities and safety. Previous studies found β-glucan to have efficacy at reducing incidence of URTIs as well as being a low risk for negative side effects. The current study aimed to examine the effects of yeast β-glucan (Angel Yeast) on cold and flu incidences and symptoms in healthy adults. Methods: Two hundred and thirty-one males and females aged 18 to 65 years old supplemented with either β-glucan or a placebo for 3-months. Participants completed a general health questionnaire every 4 weeks and in addition, if participants experienced any cold or flu symptoms, these were recorded daily (along with severity) until resolved or up to 2 weeks. Results: Supplementation with β-glucan reduced the self-reported severity of sore throats and improved sleep quality compared to the placebo group. Conclusions: Yeast β-glucan supplementation appears to be able to help reduce certain symptoms experienced during a cold or flu episode and is safe and well tolerated.

Mathematical Modeling of Cell Polarity Establishment of Budding Yeast

The budding yeast Saccharomyces cerevisiae is a powerful model system for studying the cell polarity establishment.The cell polarization process is regulated by signaling molecules,which are initially distributed in the cytoplasm and then recruited to a proper location on the cell membrane in response to spatial cues or spontaneously.Polarization of these signaling molecules involves complex regulation,so the mathematical models become a useful tool to investigate the mechanism behind the process.In this review,we discuss how mathematical modeling has shed light on different regulations in the cell polarization.We also propose future applications for the mathematical modeling of cell polarization and morphogenesis.

Influence of nitrogen status on fermentation performances of non-Saccharomyces yeasts:a review

Nitrogen,one of the most crucial nutrients present in grapes and musts,plays a key role in yeast activities during alcoholic fermentation.Such influences are imposed on yeast growth and fermentation performances including the formation of secondary metabolites.Saccharomyces cerevisiae,the main yeast responsible for fermentation,has been studied extensively regarding nitrogen impacts.On the other hand,a similar study for non-Saccharomyces yeasts,whose contributions to winemaking have gradually been acknowledged,remains to be fully explored,with a few studies being reported.This review starts by discussing nitrogen impacts on non-Saccharomyces yeast growth and fermentation kinetics in different case scenarios,then proceeds to summarize the nitrogen preferences of individual yeast strains with regulation mechanisms elucidated by recent studies.Detailed discussions on the influences on the production of volatile compounds and proposed pathways therein are made,followed by future work suggested as the final section.In summarizing the nitrogen impacts on non-Saccharomyces yeasts throughout alcoholic fermentation,this review will be helpful in obtaining a more comprehensive view on these non-conventional wine yeasts in terms of nutrient requirements and corresponding volatile production.Research gaps will therefore be elucidated for future research.

Impact of Storage Temperature on Microbial Diversity and Probiotic Effect of Liquid Brewers’ Yeast

Using probiotics as animal feed additives instead of antibiotics is gaining momentum to avert adverse negative effects on human health. Liquid brewers yeast (LBY) is an industrial by-product containing probiotic microorganisms and is also used as a protein supplement for dairy animals. Nevertheless, value chain actors lack of appropriate handling practices compromises the by-products quality and safety. This study aimed to determine the effect of variation in temperature on microbial diversity and probiotic effects during the storage time of LBY sampled from distributors and farmers from Githunguri sub-county of Kenya. The samples were stored at 20C, 25C and 30C, then tested on 0, 5, 10, 15 and 20 days. The studys parameters involved determining the pH levels, lactic acid bacteria (LAB), total coliform count (TCC), mould, and yeast in LBY. The rate (k) of the reaction kinetics model was used to extrapolate the expected probiotic shelf life. The LAB and yeast populations were reduced in a first-order reaction at all storage temperatures. The rate of reduction in the numbers of LAB reduced with an increase in temperature (k = 0.019 and 0.023) at 20C and 30C, respectively. Yeasts highest rate of growth reduction was 25C (k = 0.009) and least at 30C (k = 0.043). The minimum effective concentration for probiotics of 106 CFU/mL needed to observe the beneficial physiological impact on farm animals was achieved between 34.9 and 35.5 days at the tested storage temperatures. The study provides insight into the unexploited low-cost probiotic potential of LBY in dairy production. Conversely, handling practices and environmental microbial contamination along the value chain can compromise product quality and safety. There is a need to advocate its use in dairy for improved productivity and sensitize farmers to appropriate hygienic measures along the LBY value chain.

Microbiological Quality of “Rabilé”, a Yeast Used for Fermentation of Dolo, a Local Beer in Dédougou, Burkina Faso

Sorghum beer or dolo is part of the eating habits of part of the population of Dédougou because of its low price compared with industrial beers. Its production is an ancestral tradition that uses traditional equipment and gives dolo organoleptic properties that are not found in industrial beers. The production process involves several stages, including fermentation, which itself comprises natural lactic fermentation followed by alcoholic fermentation using traditional yeasts, which are not controlled in any way. The general aim of this study is to assess the microbiological quality of these fermentative yeasts in the town of Dédougou, in order to contribute to the health safety of the population and the promotion of these local beers. Twenty samples of fermenting yeast were analyzed according to ISO standards, to isolate enterobacteria, total and faecal coliforms according to standard procedures for isolating these micro-organisms. The isolated strains were identified using the API20E gallery. Microbiological analyses revealed the presence of 51.17% enterobacteria, 45.38% total coliforms and 3.45% thermotolerant coliforms. We counted 40% Escherichia coli, 20% Enterobacter cloacae, 20% Klebsiella pneumoniae and 20% Klebsiella spp. All the strains detected are capable of surviving in hostile conditions and could harm the quality of the dolo, consumer health and cause real collective food poisoning in the town of Dédougou. This enabled us to assess the microbial quality of these yeasts and to propose more suitable measures for producing and preserving dolo under hygienic conditions to protect consumer health.

Immobilization techniques for beverage production using yeast cell systems: challenges, types, and future perspectives - a mini review

Yeast immobilization is a process of physical entrapment of yeast cells using different techniques while maintaining their biological activity.Continuous fermentation systems have significant advantages over conventional methods.Research highlights that immobilized yeast cell systems have several benefits as compared to free yeast cells.The immobilized yeast cell systems improve fermentation rates,especially when paired with continuous fermentation and appropriate immobilization techniques.Understanding various immobilization techniques,continuous fermentation processes,yeast metabolic activity related to beverage flavor production,and bioreactor designs is vital for optimizing the use of immobilized yeast cells systems on industrial scale.This review provides an overview of recent basic research on immobilized yeast cell systems,with a focus on continuous beverage fermentation.In this study,different reactor configurations and immobilization techniques are explored.The study focus on the impacts of immobilization on the yeast cells,and discuss the recent advancements in these techniques.The review concludes with a discussion on the practical applications of immobilized yeast cells and continuous fermentation in beverage production.

De novo biosynthesis of phytohormone jasmonates in engineered yeast

The plant defense hormone jasmonates not only play important roles in plant growth,development,and resistance,but also hold promise for bringing new strategies in plant protection and cancer therapy.Recently,de novo biosynthesis of natural and unnatural jasmonates in refactored yeast with integration of 15 heterologous genes and 3 native genes deleted was reported.Here,we highlight the feasible and sustainable platform to efficiently produce jasmonates,which would benefit both agriculture and human health.

产油酵母的研究现状与展望

生物能源是从生物来源的材料制成的可再生能源,主要分为生物质能、生物燃料、生物气体三大类,具有绿色、低碳、清洁、可再生等优点.微生物油作为第三代生物柴油,有可能成为传统化石燃料的绿色替代品,是缓解能源挑战和环境问题的研究热点.本文综述产油酵母油脂合成与调控机制以及代谢工程等研究进展.产油酵母作为微生物油生产的主体,其异柠檬酸脱氢酶的活性依赖一磷酸腺苷(AMP),使得它们在限氮条件下大量积累油脂;酵母积累油脂受到各种条件的影响(比如碳氮源、温度、溶氧、pH值等),相关碳氮源利用与胁迫调控转录因子GAT1、MIG1、ASG1、MYB、GRAS、CBF11、TORC1 bHLH8和PHD等也调控其脂代谢.但产油酵母相对于酿酒酵母来说,其油脂合成机制与遗传背景依旧不清晰,限制了其工业化应用.因此,未来还需要加强微生物油生产技术的研究,从提高菌株鲁棒性、增加经济性代谢副产物产量、提高廉价底物利用能力等方面降低微生物油的生产成本,使其成为传统化石燃料的有效替代品.

以分子生物学鉴定结果为“金标准”评估Rapid ID Yeast Plus及API20C AUX对酵母样真菌的鉴定效能

目的以分子生物学方法为"金标准"对两种商品化酵母样真菌鉴定产品Rapid ID Yeast Plus(简称RapID YST)及API20C AUX(简称API20C)的鉴定效能进行评估。方法从2010年中国医院侵袭性真菌感染监测网菌株库中筛选酵母样真菌25种,共计194株。其中,包含临床最常见的5种酵母样真菌(白念珠菌、热带念珠菌、光滑念珠菌、近平滑念珠菌、新生隐球菌)共130株,占研究总菌株数的67.0%。所有菌株已经过分子生物学方法准确鉴定至种水平。菌株复苏分纯后,严格按照产品操作指南,平行进行RapID YST和API20C鉴定。结果所研究菌株中,有181株(18种)在RapID YST鉴定菌种数据库中,所有在库菌株种及复合体鉴定正确率为87.8%(159/181)。相比,API鉴定菌种库包含菌株174株(18种),在库菌株种及复合体鉴定正确率为92.0%(160/174)。RapID YST与API20C对于5种临床常见的酵母样真菌的种鉴定正确率分别为93.1%和97.1%。对于库外菌株,RapID YST的鉴定错误率分别为23.1%(3/13),相比API20C的鉴定错误率为60.0%(12/20)。综合此次评估结果,二者对酵母样真菌的鉴定效能无显著差异(McNemar检验,P>0.05)。结论两种商品化产品对酵母样真菌的鉴定效能基本一致;相较而言,RapID YST在操作便捷性、检测时间方面具有较大优势。

Yeast基因下游二级结构与多聚腺苷作用信号

形成真核生物mRNA 3′末端的多聚腺苷 (poly (A) )作用涉及前体mRNA下游的三个元件 :效率元件(EE)、定位元件 (PE)以及实际的剪切和 poly (A)作用位点 ,实验研究提出了一些EE和PE的碱基序列组成 .对 180个Yeast基因下游 (终止密码子后 2 0 0个碱基 )二级结构进行的详细分析显示 ,约 86 %的EE、 89%的PE与二级结构中碱基非配对的环 (发夹环、膨胀环、内环或多分支环 )区或连接单链区有关 .这个结果提示 ,反式因子对EE和PE的识别和作用在一定程度上有赖于EE和PE的二级结构特征 .

Yeast基因组编码区特征参数的研究

以碱基成分偏移量D值[1]为基本参数定义参数d ,以d为Yeast编码区的特征参数 ,对Yeast的第1、2、3类ORF(openreadingframe)进行了统计 ,得到d的特征参数区间。并且 ,以此区间为标准对Yeast的6类ORF ,以及5′帽、3′尾、内含子、组分随机序列等非编码序列进行了检验。结果表明 ,用d作编码区的特征参数是可行的 ,它可以很好地区分编码序列和非编码序列。另外 ,又讨论了参数d与基因表达水平 (用CAI值来衡量 )的关系。发现 ,参数d与基因表达水平成很好的正相关关系 ;发现密码子的第1位点和第2位点的某些碱基分布与基因表达水平有关。

Detection for Transcriptional Activity of Alternaria Tenuissim Protein Elicitor in Yeast Two-hybrid System

The peaT1 gene fragment was amplified from pGEM-6p-l-peaT1 by PCR, and recovered target gene was cloned into pLexA vector. After digestion and sequencing, the bait vector pLexA-peaT1 was transformed into yeast strain EGY48 [p8op-lacZ] by PEG/LiAC, and the transcriptional activity of bait vector was detected. The results showed that recombinant bait plasmid pLexA-PEMG1 was constructed, for the two bands of recombinant bait plasmid in agarose gel eleetrophoresis were expected after digesting by restriction endonuclease EcoR I and Xho I. Therefore, the recombinant bait plasmid could be used in yeast two-hybrid system to screen a cDNA library.