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.

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.

Dairy Farming Conditions and Utilization Levels of Liquid Brewers’ Yeast in Kenya

Dairy production plays an integral part in supporting smallholder farmers’ livelihoods. The desire to increase the number of dairy cattle is not feasible due to the reduced output of feed resources occasioned by climate change. Consequently, the need to increase productivity per cow is inevitable. Conventional protein supplements are costly;hence, the need to explore affordable nutrientdense alternative feed resources. Liquid brewers’ yeast (LBY), a by-product of the brewing industry, is a rich protein supplement in dairy production. This study aimed to assess the dairy farming conditions and utilization levels of LBY as a feed supplement in Githunguri Sub-county, Kiambu. Semi-structured questionnaires were administered to 457 dairy farmers in a cross-sectional survey. The findings revealed that most farmers (94.2%) fed their cattle on established forage/fodder and crop residues with supplementation. Even though 53.1% of the respondents were aware of the use of LBY, only 30.6% utilized it to supplement dairy cows, most of whom (96.0%) used it fresh without preservation. Membership in farmers’ organizations increased awareness of LBY (r = 0.732). Principal component analysis indicated that the benefits of using LBY outweigh the challenges involved with a loading matrix of 0.891 - 0.954 and 0.681 - 0.807, respectively. The low adoption and use levels of LBY as a source of protein supplements were due to low awareness. There is a need for concerted efforts by stakeholders in the industry to increase farmers’ knowledge base on the utilization and effectiveness of LBY in dairy production.

Recovery of Residual Brewer’s Yeast by Electroactivation

Yeasts resulting from the brewing process (RBY) are a valuable by-product, with an important content of minerals, vitamins and, especially, proteins. The purpose of the research was the electroactivation of RBY and the simultaneous obtaining of two products—protein concentrates and hydrolyzed protein from residual brewer’s yeast. Electroactivation is a non-residual process, without the use of chemical reagents and relatively inexpensive. The variation of the electroactivation conditions allowed the separation of 90% - 94% of the proteins in the form of protein concentrates. During the process, it is attested to increase the pH value and decrease the redox potential, which characterizes the multiple redox processes that take place in the cathode cell, including sedimentation at the isoelectric point. The presence of albumin in the protein fractions of RBY allows the formation of protein complexes with calcium, attributing a higher biological value to the obtained products.

The setereoselective preparation ofβ-keto esters using baker's yeast in the presence of rice wine koji

By the addition of rice wine koji, enhancement of the reactivity was observed for the baker＇s yeast reduction of β-keto esters into （S）-β-hydroxy esters with high enantiomeric purity （73-98%）.

Baker's Yeast Mediated Reduction of Optically Active Diketone

Baker's Yeast mediated reduction of optically active diketone has been described.

A rapid absorbance-based growth assay to screen the toxicity of oligomer Aβ42 and protect against cell death in yeast

Multiple lines of evidence show that soluble oligomer forms of amyloidβprotein(Aβ42)are the most neurotoxic species in the brain and correlates with the degree of neuronal loss and cognitive deficit in Alzheimer’s disease.Although many studies have used mammalian cells to investigate oligomer Aβ42 toxicity,the use of more simple eukaryotic cellular systems offers advantages for large-scale screening studies.We have previously established and validated budding yeast,Saccharomyces cerevisiae to be a simple and a robust model to study the toxicity of Aβ.Using colony counting based methods,oligomeric Aβ42 was shown to induce dose-dependent cell death in yeast.We have adapted this method for high throughput screening by developing an absorbance-based growth assay.We further validated the assay with treatments previously shown to protect oligomer Aβ42 induced cell death in mammalian and yeast cells.This assay offers a platform for studying underlying mechanisms of oligomer Aβ42 induced cell death using gene deletion/overexpression libraries and developing novel agents that alleviate Aβ42 induced cell death.

Helicobacter is preserved in yeast vacuoles! Does Koch's postulates confirm it?

The manuscript titled "Vacuoles of Candida yeast behave as a specialized niche for Helicobacter pylori(H.pylori)" not only has not been prepared in a scientific manner but the methodology used was not adequate, and therefore the conclusion reached was not correct. First of all, "yeast" is a broad terminology covering a great number of genera and species of unicellular micro-organisms. The authors should have defined the organism with its binary scientific name. This measure would allow experiment reproduction by the scientific community. Moreover, the criteria established by Robert Koch to identify a specific microorganism or pathogen was not adopted in the methodology used. Regarding the methodology applied, use of the chicken eggyolk(Ig Y) antibody and PCR of the apparently tainted yeast population to prove H. pylori existence in the yeast vacuoles might be main factors for their wrong conclusions. Bacterial tropism toward yeast extract is a known phenomenon, and yeast extract is one of the main ingredients in culture media. Their internalization through phagocytosis or similar pathways does not seem possible or practical because of the thick and cellulosic yeast wall. While the small size of yeast cells does not support their ability in harboring several H. pylori, other observations such as inefficiency of antifungal therapy as anti-Helicobacter therapy strongly reject the conclusion reached by the above-mentioned article.

Screening of hepatocyte proteins binding to complete S protein of hepatitis B virus by yeast-two hybrid system

AIM: To investigate the biological function of complete S protein and to look for proteins interacting with complete S protein in hepatocytes.METHODS: We constructed bait plasmid expressing complete S protein of HBV by cloning the gene of complete S protein into pGBKT7, then the recombinant plasmid DNA was transformed into yeast AH109 (a type). The transformed yeast AH109 was mated with yeast Y187 (α type) containing liver cDNA library plasmid in 2xYPDA medium. Diploid yeast was plated on synthetic dropout nutrient medium (SD/Trp-Leu-His-Ade) containing X-α-gal for selection and screening. After extracting and sequencing of plasmids from positive (blue) colonies, we underwent sequence analysis by bioinformatics.RESULTS: Nineteen colonies were selected and sequenced.Among them, five colonies were Homo sapiens solute carrier family 25, member 23 (SLC25A23), one was Homo sapiens calreticulin, one was human serum albumin (ALB)gene, one was Homo sapiens metallothionein 2A, two were Homo sapiens betaine-homocysteine methyltransferase,three were Homo sapiensNa+ and H+ coupled amino acid transport system N, one was Homo sapiens CD81 antigen (target of anti-proliferative antibody 1) (CD81), three were Homo sapiens diazepam binding inhibitor, two colonies were new genes with unknown function.CONCLUSION: The yeast-two hybrid system is an effective method for identifying hepatocyte proteins interacting with complete S protein of HBV. The complete S protein may bind to different proteins i.e., its multiple functions in vivo.

Yeast One-hybrid System Used to Identify the Binding Proteins for Rat Glutathione S-transferase P Enhancer I

Objective To detect the trans-factors specifically binding to the strong enhancerelement (GPEI) in the upstream of rat glutathione S-transferase P (GST-P) gene. MethodsYeast one-hybrid system was used to screen rat lung MATCHMAKER cDNA library toidentify potential trans-factors that can interact with core sequence of GPEI(cGPEI).Electrophoresis mobility shift assay (EMSA) was used to analyze the binding of trans-factors to cGPEI. Results cDNA fragments coding for the C-terminal part of thetranscription factor c-Jun and rat adenine nucleotide translocator (ANT) were isolated. Thebinding of c-Jun and ANT to GPEI core sequence were confirmed. Conclusions Rat c-juntranscriptional factor and ANT may interact with cGPEI. They could play an important rolein the induced expression of GST-P gene.

Transcriptional activation function of hepatitis B virus Pre S1 protein in yeast

OBJECTIVE: To explore the feasibility of cloning of the hepatocyte receptor interacting with the Pre Slprotein of HBV by two-hybrid system.METHODS: Yeast expression plasmids encoding fusion proteins of full length or portions of Pre Sl ofHBV and DNA binding domain of yeast protein GAL4 were constructed and used to transform yeastreporter strain SFY526. Reporter gene product β-galactosidase activity was assayed as a measure oftranscriptional activation in yeast, Mammalian expression plasmid encoding fusion proteins of full lengthPre Sl and DNA binding domain of GAL4 was constructed and used to cotransfect hepatoma cell lineHuh-7 together with CAT reporter plasmid. Cell extracts were assayed for CAT activity by thin-layerchromatography.RESULTS: The fusion proteins of full length Pre Sl protein and GAL4 DNA binding domain presentedtranscriptional activation function in yeast. The transcription activating sequence was localized to the 21 to47 amino acids of Pre Sl protein. Fusion proteins of full length Pre Sl and GAL4 DNA binding domaindid not show transcriptional activation function in mammalian cells.CONCLUSIONS: The transcription activating sequence of HBV Pre Sl protein in yeast overlaps thehepatocyte receptor binding site. The transcriptional activation function of HBV Pre Sl protein in yeastmay prevent researchers from using yeast two-hybrid system to clone HBV receptor interacting with Pre Slprotein. However, the Pre Sl protein does not show transcriptional activation function in mammaliancells. Mammalian two-hybrid system may be a practical method to clone the HBV hepatocyte receptorinteracting with Pre Sl protein.

Mec1-Dependent Phosphorylation of the Scc3 Subunit of Cohesin during Mitosis in Budding Yeast

Cohesin is an evolutionary conserved complex that controls chromosome segregation during mitosis. Here we show that, in response to DNA damage, Saccharomyces cerevisiae Scc3, one of the major regulatory subunits of the Smc1-Smc3-Scc1 cohesin ring, is phosphorylated on S/T-Q residues. This event depended on the Mec1 checkpoint kinase as well as on cell cycle arrest triggered by the DNA damage checkpoint network. This phosphorylation event also took place during mitosis of an unperturbed cell cycle. The present finding that S. cerevisiae Scc3 is phosphorylated during mitosis represents a potentially important new regulatory step in cohesin’s mitotic functions.

Isolation and Partial Evaluation of a Potential Indigenous Yeast Strain <i>Pichia kudriavzevii</i>from a Traditional Rice Beer—“Gora” Prepared by the Koloi Tribes of Tripura

As per tradition from hundreds of years the Koloi tribes of Tripura are preparing “Gora”-therice based fermented beer which is very good in taste and aroma applying their traditional indigenous brewing techniques. In this study, an attempt has been made to identify the indigenous yeast which is the main causative agent for fermentation and to investigate its fermentation ability with an industrial Saccharomyces cerevisiaes train. After investigation based on culture dependent phenotypic characteristics like-staining and biochemical characterization, primarily the responsible yeast species was determined as Pichia kudriavzevii and further confirmed followed by 18S rRNA ribotyping and the sequences was deposited at Gene bank and NCBI bearing specific accession number. In the comparative analysis, it has been found a significant similarities in all aspects of nutritional and alcohol percentages with the industrial strain in laboratory condition. The alcohol percentage in the rice beer “Gora” measured 6.40 ± 0.008% v/v. The study may be the first scientific investigation of its kind about this indigenous yeast strain isolated from “Gora” of this Indo-Burma biodiversity region and may provide sufficient background and potentiality for promoting these kinds of indigenous alcoholic beverages for small scale commercialization to strengthen the rural livelihood as well as to maintain immaterial cultural heritage.

Efficacy of Xiaojin Capsules Combined with Selenium Yeast Capsules on 120 Cases of Hashimoto's Thyroiditis with Abnormal Thyroid Function

[Objectives]To explore the efficacy of Xiaojin Capsules combined with Selenium Yeast Capsules in the treatment of Hashimoto's thyroiditis(HT)with abnormal thyroid function.[Methods]A total of 180 HT patients who were treated in the First Affiliated Hospital of Henan University and Henan Provincial People's Hospital from December 2020 to December 2021 were selected as the research subjects and randomly divided into the observation group(n=120)and the control group(n=60)in at a tratio of 2∶1 ratio according to their visiting time.The observation group was treated with Xiaojin Capsules(oral,5 capsules each time,twice a day for 12 weeks)and Selenium Yeast Capsules(oral,1 capsule each time,twice a day for 12 weeks).The control group was treated with only Selenium Yeast Capsules(oral,1 capsule each time,twice a day for 12 weeks).[Results]The difference in the levels of thyroid peroxidase antibody(TPO-Ab),thyroglobulin antibody(TGAb),serum free triiodothyronine(FT_(3)),serum free thyroxine(FT_(4)),and thyroid stimulating hormone(TSH)between the observation group and control group was statistically significant(P<0.05).The diameters of thyroid between the observation group and the control group before,during and after treatment were significantly different(P<0.05).The total effective rate of the observation group was 82.5%(99/120),which was significantly higher than 56.67%(34/60)in the control group,and the difference was statistically significant(P<0.05).The cure rate(22.50%)in the observation group was significantly higher than the control group(3.33%),and the difference was statistically significant(P<0.01).The ineffective rate of the observation group was 17.50%,which was significantly lower than that of the control group(40.00%),and the difference was statistically significant(P<0.01).The markedly effective rate of the observation group was 40.83%,which was significantly higher than that of the control group(31.67%),and the difference was statistically significant(P<0.05).The effective rate in the observation group was 191%,and the effective rate in the control group was 21.67%,and the difference was not statistically significant(P>0.05).[Conclusions]Xiaojin Capsules combined with Selenium Yeast Capsules in the treatment of HT can eliminate or alleviate the clinical symptoms and signs,significantly reduce the levels of TPO-Ab and TGAb in serum,restore thyroid function,improve thyroid shape and structure in the treatment of HT,and the clinical effect is satisfactory.

The Economic Potential of Brewer’s Spent Grain (BSG) as a Biomass Feedstock

This paper analyzes a pro-forma economic market and supply chain system for the reuse of a lignocellulose (brewer’s spent grain) in an industrial biotechnology environment. An extant literature review was conducted, followed by a technical analysis of BSG, and the development of a supply chain system and economic market analysis based upon a participant brewing company and industry experts. In this paper, it was found that, even with the potential for future improvements in the conversion of brewer’s spent grain (BSG) from an efficiency standpoint, this industrial residual is supply chain prohibitive as a biofeedstock in comparison to other lignocellulose materials, therefore, centralized market relationships would not be advantageous for sellers and buyers. Future research should consider the viability of centralized supply chain structures for alternatives that may exist as future bio-feedstocks.

富铬酵母中14种元素的ICP-AES测定

本文用ＩＣＰ－ＡＥＳ法同时测定富铬酵母中Ｋ、Ｆｅ、Ｐ、Ｚｎ、Ｃｒ、Ｃｕ、Ｍｎ、Ｃｏ、Ｂａ、Ｓｒ、Ｖ、Ｎａ、Ｍｇ、Ｃａ１４种元素的含量。结果表明，富铬酵母中的铬对其他元素的浓度有一定影响，并且，Ｋ、Ｍｎ、Ｐ、Ｖ、Ｍｇ、Ｃａ的浓度明显低于普通酵母。

pH对S-腺苷-L-蛋氨酸发酵的影响

研究了不同pH控制方式对S-腺苷-L-蛋氨酸(SAM)发酵过程及产量的影响。通过对发酵过程中不控制pH、控制恒定pH、两阶段控制pH和三阶段控制pH实验,研究了不同条件下对菌体干重、葡萄糖代谢和SAM产量的影响。控制合适的pH有利于菌体生长与SAM的生物合成,菌体生长最适pH为6.0,SAM转化最适pH为6.5,采用三阶段控制pH,使SAM产量比不控制pH提高了133%,比控制pH6.5提高了18.6%,比两阶段控制pH提高了10%。

固定化酵母不对称水解布洛芬乙酯制备S（＋）－布洛芬

用多种固定化载体对含有不对称水解布洛芬酯的脂肪酶的丝孢酵母进行固定化。海藻酸钙、卡拉胶、聚丙烯酰胺凝胶和ＰＶＡ固定化酵母后，酶活力回收分别为６％、１６％、１８％和７％；用自制的高脱乙酰度、高分子量的壳聚糖，通过成囊装置包埋酵母细胞，并用戊二醛交联，制得直径１．０ｍｍ左右的固定化酵母细胞壳聚糖多孔微球，酶活力回收达８０％以上，操作半衰期７５天以上，而且每次反应所产生的布洛芬的比旋光度均为［α］２０Ｄ＝＋５５°左右。固定化酶的最适温度从未固定化时的３５℃提高到４５℃。每克干重的壳聚糖可固定化１～５倍干重的酵母，固定化壳聚糖微球有较高机械强度。

发酵生产S-腺苷-L-蛋氨酸培养条件的优化研究

考察了摇瓶发酵生产S-腺苷-L-蛋氨酸过程中碳源、氮源、无机盐和生长因子以及培养过程中补加L-蛋氨酸时间对S-腺苷-L-蛋氨酸的产量、含量及生物量的影响。并通过均匀实验设计对培养基配方进行优化,在30℃、180 r/m in的培养条件下,得到最后的培养基配方为:葡萄糖30g,酵母粉11g,(NH4)2SO412g,K2HPO4.3H2O 5g,KH2PO410g,MnSO4.H2O 0.09g,ZnSO4.7H2O 0.14g,MgC l20.5g,CaC l20.3g,CuSO40.005g,自来水定容至1L。摇瓶中优化后的S-腺苷-L-蛋氨酸产量可以达到0.9g/L,比优化前产量提高了30%。采用优化后的培养基和培养条件在5L发酵罐中间歇培养,24h后一次性补加24g/L葡萄糖和1.0g/L L-蛋氨酸,继续培养24h后产量可达2.66g/L,生物量23.4g/L。

酵母静息细胞催化丙酮酸乙酯不对称还原制(S)-乳酸乙酯

从污水处理池及其附近土壤中分离到36株可将丙酮酸乙酯不对称还原成(S)-乳酸乙酯的菌株,经多次复筛,最终得到一株具有较高催化活性的酵母菌BTY18-6.以BTY18-6的静息细胞为催化剂,在水相中进行丙酮酸乙酯不对称还原成(S)-乳酸乙酯的反应,并对反应条件进行了优化.结果表明,以2.5%葡萄糖为辅助底物,反应体系初始pH=6.8,发酵培养48h的菌体湿度0.175g/ml,丙酮酸乙酯初始浓度65mmol/L,于32oC反应48h的条件下,丙酮酸乙酯转化率达95.5%,产物对映体过量值(ee值)为92.1%.