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.

Effects of dietary yeast β-glucan on nutrient digestibility and serum profiles in pre-ruminant Holstein calves

This study aimed to investigate the effects of dietary supplementation of yeast 13-glucan on the nutrient digestibility and serum profiles in pre-ruminant Holstein calves. Forty-two neonatal Holstein calves （（39.6＋4.2） kg） were randomly allotted to six groups, and each was offered one of the following diets： a basal diet （control） or the basal diet supplemented with 25, 50, 75, 100 or 200 mg of yeast 13-glucan kg-~ feed （dry matter basis）. The basal diet consisted of a milk replacer and a starter feed. The trial lasted for 56 d. Two digestibility trials were conducted from d 14 to 20 and from d 42 to 48. Blood samples were collected on d 0, 14, 28 and 42 for serum profile analyses. On d 56, three calves from each group were slaughtered, and intestinal samples were collected to assess the villous height, crypt depth and mucosal thickness. Although feed intake was not affected by dietary treatment （P〉0.05）, the average daily gain （ADG） and gain-to-feed ratios were higher （P〈0.05） for the calves fed 75 mg of yeast β-glucan kg^-1 feed than those in the other groups. The supplementation of yeast β-glucan at 75 mg kg^-1 feed increased the apparent digestibility of dry matter （DM）, crude protein （CP）, ether extract （EE）, and phosphorus （P） （P〈0.05） and the ratio of intestinal villous height to crypt depth （V/C） （P〈0.05） when compared with the control group. No effects of yeast β-glucan on the serum concentrations of total protein （TP）, albumin （ALB）, serum urea nitrogen （SUN） and glucose （GLU） were observed （P〉0.05）. Compared with the control group, supplementation of yeast β-glucan decreased （P〈0.05） the serum concentrations of triglycerides （TG） and total cholesterol （TC）. The serum concentration of immunoglobulin G （IgG） and immunoglobulin M （IgM） increased quadratically （P〈0.05）, whereas the serum concentration of immunoglobulin A （IgA） was unaffected by dietary treatments （P〉0.05）. The supplementation of yeast β-glucan stimu- lated the enzymatic activity of alkaline phosphatase （ALP） （P〈0.05） compared with the control group. The lysozyme （LYZ） concentration increased quadratically （P〈0.05） with increasing yeast β-glucan levels. The results suggested that dietary supplementation of yeast 13-glucan at 75 mg kg^-1 feed improved nutrient digestibility, enhanced immunity by increasing the immunoglobulin concentration and stimulating ALP, and exerted no adverse effects on metabolism in pre-ruminant calves.

A Double-Blind, Randomized, Placebo-Controlled Nutritional Study Using an Insoluble Yeast Beta-Glucan to Improve the Immune Defense System

Purpose: In a placebo-controlled, double-blind, randomized clinical trial, the effect of an insoluble yeast beta-glucan preparation on the incidences of common colds and its effect on common cold symptoms were compared to placebo. Methods: 100 healthy participants with recurring infections were randomly assigned to receive either placebo or yeast beta-glucan (Yestimun?;n = 50 each group) over a period of 26 weeks. The subjects had to document each common cold episode in a diary, and rate 6 predefined infections symptoms on a 3-point rating scale during an infection period, resulting in an infection score. The common cold episodes were confirmed by the investigators. Results: A total of 171 common cold episodes were documented. Of these, 76 were experienced by 38 subjects in the beta-glucan group and 96 were experienced by 48 subjects in the placebo group (p = 0.406). The beta-glucan group had significantly more subjects without incidences of common cold than the placebo group (15.6% vs 2.0%;p = 0.019). During the most intense infection season (first 13 weeks of the study), the beta-glucan group had significantly less infections compared to placebo (p = 0.02). Beta-glucan significantly reduced the typical cold symptoms (“sore throat and/or difficulty swallowing”, “hoarseness and/or cough” and “runny nose”) as opposed to placebo. Conclusion: The present study demonstrates a prophylactic effect of yeast beta-glucan on the occurrence of common colds as opposed to placebo. In addition, when these episodes occurred, they were from the beginning less pronounced and subsided faster.

Yeast-Derived β-1,3-Glucan Substrate Significantly Increased the Diversity of Methanogens During In vitro Fermentation of Porcine Colonic Digesta

The β-1,3-glucan from yeast has been extensively examined for its immuno-enhancing effects in animals.However,investigation on the relationship among β-glucan,gut microbiota and immune-modulating effects remains limited particularly in pigs.Considering the critical roles of gut methanogens in the microbial fermentation,energy metabolism and disease resistance,we investigated the phylogenetic diversity of methanogens from fermented cultures of porcine colonic digesta with（G） or without（N） yeast β-glucan based on sequences of the archaeal 16S rRNA gene.A total of 145 sequences in the G library were assigned into 8 operational taxonomic units（OTUs） with the majority of sequences（114/145） related to strains Methanobrevibacter millerae or Methanobrevibacter gottschalkii with high identities ranging from 97.9 to 98.6%,followed by 23 sequences to Methanobrevibacter ruminantium,2 sequences to Methanobrevibacter smithii and one sequence to Methanobrevibacter wolinii.The 142 sequences in the N library were assigned to 2 OTUs with most sequences（127/142） related to strains M.millerae or M.gottschalkii with sequence identities ranging from 97.9 to 98.5%,and 15 sequences related to M.gottschalkii with 97.9% identity.Shannon diversity index showed that the G library exhibited significantly higher archaeal diversity（P0.05） and Libshuff analysis indicated the differences in the community structure between the two libraries were significant（P0.0001）.In conclusion,the current study provides evidence that addition of yeast β-glucan significantly increased the diversity of methanogens in in vitro fermented porcine colonic digesta.

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.

β-Glucan Fiber from Spent Brewer’s Yeast Reduces Early Atherosclerosis Greater Than Psyllium in Hypercholesterolemic Syrian Golden Hamsters

β-Glucans, mostly from oats, have been shown to reduce blood concentrations of total and LDL-cholesterol in animals and humans. After processing, spent brewer’s yeast, a by-product of the fermentation process, contains 85% - 90% β-glucans. The purpose of this study was to evaluate the effect of yeast-derived β-glucan fiber on plasma lipids and early atherosclerosis development in hamsters consuming a semi-purified hypercholesterolemic diet (HCD). Animals were fed either the HCD or the HCD containing psyllium or β-glucan fiber from yeast for 12 weeks. Both the psyllium and β-glucan fiber from yeast showed significant decreases in plasma total cholesterol, non-HDL-C, triacylglycerol, and aortic fatty streak area when compared to the HCD. Also, the β-glucan fiber from yeast had significantly less aortic fatty streak area compared to the psyllium diet. Findings from this study show that while both β-glucan fiber from yeast and psyllium produced similar reductions in plasma lipid and lipoprotein concentrations, the β-glucan fiber from yeast prevented the development early atherosclerosis better than psyllium in the hamsters.

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.

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.

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.

Protective Effect of Dietary Yeast Cultures on Lipopolysaccharide-induced Oxidative Stress,Immune and Inflammatory Responses in Pseudobagrus ussuriensis

This study aimed to evaluate the effects of dietary yeast culture(YC)on lipopolysaccharide(LPS)-induced oxidative stress,immune and inflammatory response in P.ussuriensis.The fish were randomly assigned into three groups as the control group,LPS group and YC+LPS group.The fish in the control were fed diet with no YC supplementation and no LPS challenge,and the fish in the LPS group or YC+LPS group were fed diet supplemented with no YC or 20 g·kg^(-1)YC,and with LPS challenge,respectively.The results showed that compared with the control group,intestinal total antioxidant capacity(T-AOC)level and superoxide dismutase(SOD)activity were significantly decreased,while intestinal malondialdehyde(MDA),plasma aspartate transaminase(AST)and alanine transaminase(ALT)levels were significantly increased in the LPS group(P<0.05).Besides,lower plasma alkaline phosphatase(ALP),alternative complement pathway(ACH50)activity and the albumin(ALB)level,as well as higher lysozyme(LZM)activity,were also found in the LPS group.However,dietary 20 g·kg^(-1)YC supplementation could relieve the above LPS-induced changes in Pseudobagrus ussuriensis.Furtherly,LPS challenge could significantly up-regulate gene expression of interleukin-8(IL-8),heat shock protein(HSP70)and NF-κBp65 except for toll-like receptors 2(TLR2),while dietary 20 g·kg^(-1)YC supplementation suppressed the increased expression of NF-κBp65 and IL-8 induced by LPS in P.ussuriensis.In summary,LPS challenge could induce immune impairment,oxidative stress and hepatic damage,and the protective effect of dietary 20 g·kg^(-1)YC supplementation on LPS-induced immune impairment and oxidative stress was observed in the present study,which was associated with the enhanced levels of antioxidant enzymes and immune parameters.Also,dietary 20 g·kg^(-1)YC supplementation could suppress LPS-induced inflammatory response by down-regulating NF-κBp65,HSP70 and IL-8 gene expression.

Effects of β-Glucan Supplementation on Repairing of Phenol-Induced Vaginal Mucosal Epithelium Damage in Rats

Objective: To investigate the effects of different concentrations of β-glucan on the repair of damaged vaginal mucosa, the expression of vascular endothelial growth factor (VEGF), and the inflammatory factor-6 (IL-6) in vaginal tissues. Methods: Thirty-six adult female specific pathogen free (SPF)-grade Wistar rats were randomly divided into 3 phase groups with 12 rats each. Vaginal inflammation rat models were established by injecting phenol gel into the vagina of each rat at a dose of 0.1 ml/100g body weight. After modeling, rats were divided into 4 groups based on different concentrations of the test agent. The control group was injected with 0.5 ml of saline, experimental group A was injected with 0.375 ml saline 0.125 ml β-glucan, experimental group B was injected with 0.25 ml saline 0.25 ml β-glucan, and experimental group C was injected with 0.50 ml β-glucan. The injection sites were selected at the 3 o’clock and 9 o’clock positions of the vagina. Rats were sacrificed at 7-, 14-, and 28-days post-injection, and tissue samples were collected from the injection sites and prepared for histological analysis. New blood vessels and fibroblast numbers in the tissues were observed after Hematoxylin-eosin (HE) staining. The expression levels of VEGF and IL-6 in the tissues were measured using quantificational reverse transcription polymerase chain reaction (qRT-PCR). Results: Histological examination of vaginal tissue specimens at 7-, 14-, and 28-days post-injection showed that on day 7, there were no significant changes in the experimental groups compared to the control group. However, on days 14 and 28, the experimental groups showed more new blood vessels, macrophages, and fibroblasts with increased activity compared to the control group. The expression levels of VEGF in vaginal tissues were elevated on days 14 and 28 in the experimental groups. The comparison of IL-6 levels in vaginal tissues on day 28 showed that serum IL-6 levels returned to normal, and there was no statistically significant difference between the experimental and control groups. Conclusion: In the 3 experimental phases, the increase in VEGF levels in vaginal tissues on day 14 post-injection was more pronounced with higher concentrations of β-glucan, and IL-6 levels returned to normal on day 28. β-Glucan can enhance VEGF levels in damaged vaginal tissues, promote the repair of damaged vaginal tissues, and higher concentrations of β-glucan have a better effect.

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.

Construction of a Yeast Hybrid Library and Identification of Proteins Regulating CaABI3/VP1-1 Expression in Capsicum annuum var.conoides

Hot pepper(Capsicum annuum var.conoides)is a significant vegetable that is widely cultivated around the world.Currently,global climate change has caused frequent severe weather events,and waterlogging stress harms the pepper industry by affecting the planting period,growth conditions,and disease susceptibility.The gene CaABI3/VP1-1 could improve pepper waterlogging tolerance.In order to explore the upstream regulatory mechanism of CaABI3/VP1-1,a high-quality standardized yeast hybrid library was successfully constructed for yeast one-,two-,and threehybrid screening using pepper‘ZHC2’as the experimental material,with a library recombinant efficiency of up to 100%.The length of inserted fragments varied from 650 to 5000 bp,the library titer was 5.18×10^(6)colony-forming units(CFU)·mL-1,and the library capacity was 1.04×10^(7)CFU of cDNA inserts.The recombinant bait plasmid was used to successfully identify 78 different proteins through the yeast one-hybrid system,including one transcription factor within the ethylene-responsive factor family and the other within the growth-regulating factor family.The interaction happened between LOC124895848 and CaABI3/VP1-1 promoter by point-to-point yeast one-hybrid experiment.The expression level of the 12 selected protein-coding genes was then evaluated by quantitative real-time polymerase chain reaction.Results indicated the protein coding genes showed different responses to waterlogging stress and that the activity of the CaABI3/VP1-1 promoter could be inhibited or activated by up-regulating or down-regulating gene expression,respectively.The identification of these proteins interacting with the promoter provides a new perspective for understanding the gene regulatory network of hot pepper operating under waterlogging stress and provides theoretical support for further analysis of the complex regulatory relationship between transcription factors and promoters.

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.

酵母水解物对哺乳犊牛生长性能、血清抗氧化指标和瘤胃菌群的影响

本试验旨在探讨补饲酵母水解物对哺乳犊牛生长性能、血清抗氧化指标及瘤胃菌群的影响。试验选取30头1日龄、健康、体重[(39±2)kg]相近的荷斯坦母犊牛,随机分为对照组(不补饲酵母水解物)和试验组(每头犊牛每天补饲5 g酵母水解物),每组15个重复,每个重复1头牛。试验期为63 d。记录犊牛体重和采食量,采集血清和瘤胃液样品,测定血清抗氧化指标和瘤胃菌群多样性。结果显示:1)补饲酵母水解物显著增加了犊牛14和28日龄的胸围以及28和42日龄的体斜长(P<0.05),但对生长性能和其他体尺指标未产生显著影响(P>0.05)。2)63日龄时,试验组血清中丙二醛(MDA)含量显著低于对照组(P<0.05),总抗氧化能力(T-AOC)显著高于对照组(P<0.05);7日龄时,试验组血清谷胱甘肽过氧化物酶(GSH-Px)活性显著高于对照组(P<0.05)。3)补饲酵母水解物使犊牛瘤胃菌群的Alpha多样性指数(Chao1和Observed-species指数)显著降低(P<0.05);同时,Beta多样性也发生了显著变化(P<0.05)。30日龄时,试验组瘤胃菌群中互养菌门(Synergistota)的相对丰度显著低于对照组(P<0.05),而放线菌门(Actinobacteriota)的相对丰度显著高于对照组(P<0.05);试验组瘤胃菌群中理研菌科RC9肠道群(Rikenellaceae_RC9_gut_group)的相对丰度在60日龄时显著低于对照组(P<0.05),而解琥珀酸菌属(Succiniclasticum)和普雷沃氏菌属7(Prevotella_7)的相对丰度在30日龄时显著高于对照组(P<0.05)。综上可知,在本试验条件下,每天每头补饲5 g酵母水解物对哺乳犊牛整体生长性能无显著影响,但显著提高了犊牛的抗氧化能力,并调节了瘤胃菌群结构,有助于改善犊牛健康状况。

蜂蜜中嗜渗酵母菌TaqMan实时荧光定量PCR方法的建立

【目的】建立蜂蜜中嗜渗酵母菌的快速检测方法,为保障蜂蜜品质提供理论基础。【方法】根据GenBank中嗜渗酵母菌26S rDNA D_(1)~D_(2)基因序列设计特异性引物,PCR扩增获得嗜渗酵母D_(1)~D_(2)基因片段,构建重组质粒pMD-18T-JM为阳性标准品,对荧光定量PCR反应条件进行优化,建立嗜渗酵母菌TaqMan探针实时荧光定量PCR方法,并对160份蜂蜜样品进行验证。【结果】建立的蜂蜜中嗜渗酵母菌TaqMan探针实时荧光定量PCR检测方法特异性好,灵敏度达0.004 pg/μL。TaqMan实时荧光定量PCR检测阳性率达98.5%,比普通PCR检测(阳性率84.1%)高14.4百分点,检测敏感性达100%。【结论】嗜渗酵母菌TaqMan探针实时荧光定量PCR方法特异、灵敏、快速、重复性好,适合于蜂蜜中嗜渗酵母菌的快速检测。

生物胁迫下黄瓜酵母双杂交cDNA文库构建与鉴定

以黄瓜抗病高代自交系D9320为试验材料,采用Gateway技术构建了黄瓜霜霉病和棒孢叶斑病菌胁迫下黄瓜酵母双杂交cDNA文库。结果表明:酵母文库克隆数为350个,文库滴度为3.5×10^(7)CFU/mL,重组率达到100%,插入片段长度在750~2000bp,平均片段长度超过1000bp。文库容量和重组率及插入片段大小均说明霜霉病菌和棒孢叶斑病菌胁迫下黄瓜酵母双杂交cDNA文库构建成功,可用于黄瓜双抗机制互作蛋白的筛选。

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。