Saccharomyces cerevisiae prevents postoperative recurrence of Crohn's disease modeled by ileocecal resection in HLA-B27 transgenic rats

BACKGROUND Postoperative recurrence(POR)after ileocecal resection(ICR)affects most Crohn's disease patients within 3-5 years after surgery.Adherent-invasive Escherichia coli(AIEC)typified by the LF82 strain are pathobionts that are frequently detected in POR of Crohn's disease and have a potential role in the early stages of the disease pathogenesis.Saccharomyces cerevisiae CNCM I-3856 is a probiotic yeast reported to inhibit AIEC adhesion to intestinal epithelial cells and to favor their elimination from the gut.AIM To evaluate the efficacy of CNCM I-3856 in preventing POR induced by LF82 in an HLA-B27 transgenic(TgB27)rat model.METHODS Sixty-four rats[strain F344,38 TgB27,26 control non-Tg(nTg)]underwent an ICR at the 12th wk(W12)of life and were sacrificed at the 18th wk(W18)of life.TgB27 rats were challenged daily with oral administration of LF82(109 colony forming units(CFUs)/day(d),n=8),PBS(n=5),CNCM I-3856(109 CFUs/d,n=7)or a combination of LF82 and CNCM I-3856(n=18).nTg rats receiving LF82(n=5),PBS(n=5),CNCM I-3856(n=7)or CNCM I-3856 and LF82(n=9)under the same conditions were used as controls.POR was analyzed using macroscopic(from 0 to 4)and histologic(from 0 to 6)scores.Luminal LF82 quantifications were performed weekly for each animal.Adherent LF82 and inflammatory/regulatory cytokines were quantified in biopsies at W12 and W18.Data are expressed as the median with the interquartile range.RESULTS nTg animals did not develop POR.A total of 7/8(87%)of the TgB27 rats receiving LF82 alone had POR(macroscopic score≥2),which was significantly prevented by CNCM I-3856 administration[6/18(33%)TgB27 rats,P=0.01].Macroscopic lesions were located 2 cm above the anastomosis in the TgB27 rats receiving LF82 alone and consisted of ulcerations with a score of 3.5(2-4).Seven out of 18 TgB27 rats(39%)receiving CNCM I-3856 and LF82 had no macroscopic lesions.Compared to untreated TgB27 animals receiving LF82 alone,coadministration of CNCM I-3856 and LF82 significantly reduced the macroscopic[3.5(2-4)vs 1(0-3),P=0.002]and histological lesions by more than 50%[4.5(3.3-5.8)vs 2(1.3-3),P=0.003].The levels of adherent LF82 were correlated with anastomotic macroscopic scores in TgB27 rats(r=0.49,P=0.006),with a higher risk of POR in animals having high levels of luminal LF82(71.4%vs 25%,P=0.02).Administration of CNCM I-3856 significantly reduced the levels of luminal and adherent LF82,increased the production of interleukin(IL)-10 and decreased the production of IL-23 and IL-17 in TgB27 rats.CONCLUSION In a reliable model of POR induced by LF82 in TgB27 rats,CNCM I-3856 prevents macroscopic POR by decreasing LF82 infection and gut inflammation.

Reducing Yield of Fusel Alcohols by Saccharomyces cerevisiae of Compound Mutagenesis Through UV-MPMS Method

Excessive fusel alcohol contents will cause the beer to produce off-flavors and cause dizziness and headaches.Reducing the contents of fusel alcohols in beer is very important to people's health.The excessive fusel alcohol contents in beer is a common problem in the industry.How to control the contents of fusel alcohols in a reasonable range is of great significance for improving beer quality.After one round of ultraviolet(UV)and one round of multifunctional plasma mutagenesis system(MPMS)mutagenesis,the yeast strains with lower fusel oil yield and more stablility could be screened.According to the relationship between the fusel alcohol Harris metabolic pathway of brewer's yeast and lactic acid metabolism,excellent strains were obtained by triple screening with lactic acid medium,calcium carbonate medium and 2,3,5-triphenyl tetrazolium chloride upper medium.The content of fusel alcohol in the finished beer fermentation test of screened strain Z43 was 52.1±0.142 mg•L^(-1),which was 43%lower than that of the starting strain,and other fermentation properties remained unchanged.After eight passages,it was verified that the strain was stable and heritable.These results showed that strain Z43 presented promising characteristics for use in the production of beer with a potentially low contents of fusel alcohols.

伴有辅酶再生过程的Saccharomyces cerevisiae B5不对称还原2’-氯-苯乙酮的催化反应动力学

对以5%(体积比)乙醇为辅助底物的伴有辅酶再生过程的SaccharomycescerevisiaeB5不对称还原2’-氯-苯乙酮制备手性药物中间体R-2’-氯-1-苯乙醇的生物催化反应建立了描述底物消耗和产物合成的动力学模型。考察了反应过程中辅酶的种类和含量,以及底物和产物随时间的变化量。研究表明,参加反应的还原剂是辅酶Ⅰ。当底物初始浓度≤8.09mmol?L?1,可不考虑底物对微生物的毒害作用,反应可看作两个均符合顺序反应机制的氧化还原反应的耦联。通过实验数据对动力学方程式的拟合,得到动力学参数:Vm1=8.0×10?4mol?L?1?h?1,KmB1=9.0×10-4mol?L?1,KiA1=2.0×10-6mol?L?1。动力学模型模拟计算结果与实验值能较好地吻合。

利用Saccharomyces cerevisiae KD控制苹果汁中棒曲霉素的污染

研究一株食品生产用酿酒酵母Saccharomyces cerevisiae KD在培养基及市售100%苹果汁中对棒曲霉素污染的控制作用。通过高效液相色谱法对棒曲霉素进行定量,分析起始棒曲霉素浓度、菌体接种量和培养基p H对S.cerevisiae KD去除棒曲霉素活力的影响;利用酶标仪监测S.cerevisiae KD的生长状况,且通过检测可溶性固形物、酸度、总酚、黄酮含量对菌体发酵后苹果汁的品质进行了评估。结果表明:有氧条件下S.cerevisiae KD能够在28 h内完全去除培养基中的棒曲霉素,其去除机理包括物理吸附和酶解;在较低的起始棒曲霉素浓度和较高的菌体接种量条件下,S.cerevisiae KD对棒曲霉素的去除率较高,但在培养后期,不同菌体接种量下棒曲霉素的去除率接近一致;实验还发现酸性条件有利于S.cerevisiae KD去除棒曲霉素。此外,S.cerevisiae KD对棒曲霉素的耐受性较强,甚至在棒曲霉素浓度高达100 mg/L的环境中依然能较好生长。在市售100%苹果汁中,S.cerevisiae KD也能高效控制棒曲霉素的污染,且与Lactococcus lactis MG1363联合发酵2 d后,果汁中已无棒曲霉素检出,总酚含量显著高于发酵前苹果汁(p<0.05),发酵果汁的品质较好。结论:S.cerevisiae KD可有效控制食品中棒曲霉素的污染,具有潜在的应用前景。

响应面法优化高选择性羰基还原酶产生菌Saccharomyces cerevisiae B5的培养基组成

借助于SAS软件,采用部分因子实验设计(FFD)和响应面分析法(RSM),对能够产生高选择性羰基还原酶的菌株Saccharomyces cerevisiae B5进行发酵培养基的优化.部分因子实验设计结果表明葡萄糖、硫酸铵、硫酸镁及磷酸氢二钾为影响Saccharomyces cerevisiae B5产生高选择性羰基还原酶的四个显著性因素.通过响应面分析法,得到最优发酵培养基组成为:葡萄糖29.7 g/L,酵母粉3 g/L,硫酸铵4.784 g/L,无水硫酸镁0.267 2 g/L,K2HPO4.3H2O 1.026 g/L,KH2PO41g/L.在优化的培养基条件下,羰基还原酶活力最高可达1 498.2 U/g.

水/有机相两相体系中Saccharomyces cerevisiae B5不对称还原制备手性药物中间体R-2′-氯-1-苯乙醇的研究

本文对水/有机相两相体系中Saccharomyces cerevisiae B5催化2-氯-苯乙酮不对称还原制备R-氯丙那林中间体R-2-氯-1-苯乙醇进行了详细研究。结果表明,水/十二烷两相体系还原2-氯-苯乙酮可获得较高产率,R-2'-氯-1-苯乙醇的对映体过剩值可达100%ee,最佳转化时间为72h,证实了在水/有机溶剂两相系统中还原反应的活力倍数与有机溶剂的Log_(Poct)

植物乳杆菌Saccharomy cescerevisiae P13对大黄鱼的促生长作用研究

[目的]研究植物乳杆菌Saccharomyces cerevisiae P13对大黄鱼生长和抗病能力的影响.[方法]用合0、104、106、108、1010cfu/kg植物乳杆菌Saccharomyces cerevisiae P13含量的饲料喂养大黄鱼4周后,测定大黄鱼的体重增长率、饲料转化率和感染病菌后的存活率.[结果]大黄鱼后肠中的Saccharomyces cerevisiae P13菌数量在喂食过程中显著增加,含106～1010 cfu/kg Saccharomyces cerevisiae P13的配方饲料明显促进了大黄鱼的体重增长率和摄食率.喂食含106～ 1010cfu/kg Saccharomyces cerevisiae P13的配方饲料后大黄鱼对Streptococcus sp.的抵抗力明显增强.[结论]植物乳杆菌Saccharomyces cerevisiae P13能促进大黄鱼生长,并增强大黄鱼的抗病力.

Effects of different forms of yeast Saccharomyces cerevisiae on growth performance,intestinal development,and systemic immunity in early-weaned piglets

The present study was conducted to determine effects of different forms of yeast （Saccharomyces cerevisiae, strain Y200007） on the growth performance, intestinal development, and systemic immunity in early-weaned piglets. A total of 96 piglets （14-d old, initial average body weight of 4.5 kg） were assigned to 4 dietary treatments： （1） basa diet without yeast （Control）; （2） basal diet supplemented with 3.00 g/kg live yeast （LY）; （3） basal diet supplemented with 2.66 g/kg heat-killed whole yeast （HKY）; and （4） basal diet supplemented with 3.00 g/kg superfine yeast powders （SFY）. Diets and water were provided ad libitum to the piglets during 3-week experiment. Growth performance of piglets was measured weekly. Samples of blood and small intestine were collected at days 7 and 21 of experiment. Dietary supplementation with LY and SFY improved G：F of piglets at days ]-21 of the experiment （P 〈 0.05） compared to Control group. Serum concentrations of growth hormone （GH）, triiodothyronine （T3）, tetraiodothyronine （T4）, and insulin growth factor 1 （iGF-1） in piglets at day 21 of the experiment were higher when fed diets supplemented with LY and SFY than those in Control group （P 〈 0.05）. Compared to Control group, contents of serum urea nitrogen of piglets were reduced by the 3 yeast-supplemented diets （P 〈 0.05）. Diets supplemented with LY increased villus height and villus-to-crypt ratio in duodenum and jejunum of piglets （P 〈 0.05） compared to other two groups at day 7 of the experiment. Feeding diets supplemented with LY and SFY increased （P 〈 0.05） serum concentrations of IgA, IL-2, and IL-6 levels in piglets compared to Control. The CD4＋/CD8＋ ratio and proliferation of T-lymphocytes in piglets fed diets supplemented with LY were increased compared to that of Control group at day 7 of the experiment （P 〈 0.05）. In conclusion, dietary supplementation with both LY and SFY enhanced feed conversion, small intestinal development, and systemic immunity in early-weaned piglets, with better improvement in feed conversion by dietary supplementation with LY, while dietary supplementation with SFY was more effective in increasing systemic immune functions in early-weaned piglets.

Engineering the Biosynthesis of Caffeic Acid in Saccharomyces cerevisiae with Heterologous Enzyme Combinations

Engineering the biosynthesis of plant-derived natural products in microbes presents several challenges, especially when the expression and activation of the plant cytochrome P450 enzyme is required. By recruiting two enzymes—HpaB and HpaC—from several bacteria, we constructed functional 4- hydroxyphenylacetate 3-hydroxylase (4HPA3H) in Saccharomyces cerevisiae to take on a role similar to that of the plant-derived cytochrome P450 enzyme and produce caffeic acid. Along with a common tyrosine ammonia lyase (TAL), the different combinations of HpaB and HpaC presented varied capabilities in producing the target product, caffeic acid, from the substrate, L-tyrosine. The highest production of caffeic acid was obtained with the enzyme combination of HpaB from Pseudomonas aeruginosa and HpaC from Salmonella enterica, which yielded up to (289.4 ± 4.6) mg-L1 in shake-flask cultivation. The compatibility of heterologous enzymes within a yeast chassis was effectively improved, as the caffeic acid production was increased by 40 times from the initial yield. Six key amino acid residues around the flavin adenine dinucleotide (FAD) binding domain in HpaB from Pseudomonas aeruginosa were differentiate from those other HpaBs, and might play critical roles in affecting enzyme activity. We have thus established an effective approach to construct a highly efficient yeast system to synthesize non-native hydroxylated phenylpropanoids.

Feeding a Saccharomyces cerevisiae fermentation product improves udder health and immune response to a Streptococcus uberis mastitis challenge in mid-lactation dairy cows

Background:We aimed to characterize the protective effects and the molecular mechanisms of action of a Saccharomyces cerevisiae fermentation product(NTK)in response to a mastitis challenge.Eighteen mid-lactation multiparous Holstein cows(n=9/group)were fed the control diet(CON)or CON supplemented with 19 g/d NTK for 45 d(phase 1,P1)and then infected in the right rear quarter with 2500 CFU of Streptococcus uberis(phase 2,P2).After 36-h,mammary gland and liver biopsies were collected and antibiotic treatment started until the end of P2(9 d post challenge).Cows were then followed until day 75(phase 3,P3).Milk yield(MY)and dry matter intake(DMI)were recorded daily.Milk samples for somatic cell score were collected,and rectal and udder temperature,heart and respiration rate were recorded during the challenge period(P2)together with blood samples for metabolite and immune function analyses.Data were analyzed by phase using the PROC MIXED procedure in SAS.Biopsies were used for transcriptomic analysis via RNA-sequencing,followed by pathway analysis.Results:DMI and MY were not affected by diet in P1,but an interaction with time was recorded in P2 indicating a better recovery from the challenge in NTK compared with CON.NTK reduced rectal temperature,somatic cell score,and temperature of the infected quarter during the challenge.Transcriptome data supported these findings,as NTK supplementation upregulated mammary genes related to immune cell antibacterial function(e.g.,CATHL4,NOS2),epithelial tissue protection(e.g.IL17C),and anti-inflammatory activity(e.g.,ATF3,BAG3,IER3,G-CSF,GRO1,ZFAND2A).Pathway analysis indicated upregulation of tumor necrosis factorα,heat shock protein response,and p21 related pathways in the response to mastitis in NTK cows.Other pathways for detoxification and cytoprotection functions along with the tight junction pathway were also upregulated in NTK-fed cows.Conclusions:Overall,results highlighted molecular networks involved in the protective effect of NTK prophylactic supplementation on udder health during a subclinical mastitic event.

Increasing isobutanol yield by double-gene deletion of PDC6 and LPD1 in Saccharomyces cerevisiae

As a new biofuel, isobutanol has received more attentions in recent years. Because of its high tolerance to higher alcohols, Saccharomyces cerevisiae has potential advantages as a platform microbe to produce isobutanol. In this study, we investigated integration effects of enhancing valine biosynthesis by overexpression of ILV2 and BAT2 with eliminating ethanol formation by deletion of PDC6 and decreasing acetyl-Co A biosynthesis by deletion of LPD1 on isobutanol titers. Our results showed that deletion of LPD1 in strains overexpressing BAT2 and ILV2 increased isobutanol titer by 5.3-fold compared with control strain. Additional deletion of PDC6 in lpd1Δ strains carrying overexpressed BAT2 and ILV2 further increased isobutanol titer by 1.5 fold. Overexpression of BAT2 and ILV2 in lpd1Δ strains and pdc6Δ strains decreased ethanol titers. Glycerol titers of the engineered strains did not have greater changes than that of control strain, while their acetic acid titers were higher, perhaps due to the imbalance of cofactors in isobutanol synthesis. Our researches suggest that double-gene deletion of PDC6 and LPD1 in strains overexpressing BAT2 and ILV2 could increase isobutanol production dramatically than single-gene deletion of PDC6 or LPD1. This study reveals the integration effects of overexpression of ILV2/BAT2 and double-gene deletion of LPD1 and PDC6 on isobutanol production, and helps understanding future developments of engineered strains for producing isobutanol.

Integrated Expression of the Oenococcus oeni mleA Gene in Saccharomyces cerevisiae

Malolactic enzyme is the function enzyme which catalyses the reaction for L-malate converting to L-lactic during malolactic fermentation （MLF）. In this paper, researches concerning the malolactic enzyme gene mleA cloned from a patent strain Oenococcus oeni SD-2a screened in Chinese wine and integrated expressing in Saccharomyces cerevisiae were performed in order to carry out both alcoholic fermentation （AF） and malolactic fermentation （MLF） during winemaking, with a view to achieving a better control of MLF in enology. To construct the expression plasmid named pYILmleA, cloned mleA gene, PGK1 promoter, and ADH1 terminator were ligated and inserted into integrating vector YIp5. Yeast transformants were screened on SD/-Ura and identified by auxotrophic test, mating type test, and colony PCR. Target protein was detected by SDS-PAGE and the targeted gene integrated to the chromosome was detected by dot bloting hybridization. After the transformant was cultured in SD/-Ura adding glucose （10%） and L-malate （5 648 mg L-1） for 4 d, the culture supernatant was collected and L-malate and L-lactic acid contents were detected by HPLC. 1 278-1 312 mg L-1 L-lactic acids were detected, while the comparative drop rates of L-malate were 20.18-20.85%. L-malate and L-lactic contents of the transformants showed extra significant difference and significant difference with the control ones by t-test respectively. The result indicated that the functional expression was achieved in recombinants S. cerevisiae.

Effect of yeast Saccharomyces cerevisiae supplementation on serum antioxidant capacity, mucosal sIgA secretions and gut microbial populations in weaned piglets

This study was conducted to determine the effect of different forms of yeasts Saccharomyces cerevisiae supplementation on serum antioxidant capacity, mucosal secretory immunoglobulin A（s Ig A） secretions and gut microbial populations in weaned piglets. A total of 96 piglets weaned at 14 d of age were randomly allotted to 4 dietary treatments：（1） basal diet without yeast（Control）;（2） basal diet supplemented with 3.00 g kg–1 live yeast（LY）;（3） basal diet supplemented with 2.66 g kg–1 heat-killed whole yeast（HKY）; and（4） basal diet supplemented with 3.00 g kg–1 superfine yeast powders（SFY）. Each treatment had 4 replicates（pens）, with 6 piglets per replicate. The experiment lasted for 3 wk. At d 7 and 21 of the experiment, the samples of serum, mucosa and mesenteric lymph node（MLN） from jejunum, and digesta from the ileum and cecum were collected for determinations. Compared with the Control, dietary SFY supplementation increased serum superoxide dismutase（SOD） activity and lysozyme levels at d 7, and jejunum mucosal s Ig A secretions at d 21 of the experiment（P〈0.05）. Dietary LY supplementation increased serum SOD activity and jejunum mucosal s Ig A secretions, but decreased serum malondialdehyde（MDA） concentration at d 7 and 21（P〈0.05）. Piglets fed diets supplemented with LY and SFY had lower p H values and decreased numbers of Escherichia coli in the ileum and cecum contents at d 21 compared with the Control（P〈0.05）. Moreover, the ratio of Lactobacilli to E. coli in the ileum and cecum contents was increased by dietary LY and SFY supplementations（P〈0.05）. Collectively, different forms of yeasts, especially LY and SFY, may modulate body antioxidant capacity and enhance the intestinal immunity by regulation of secretions of mucosal s Ig A and reduction of pathogenic bacteria colonization, thus improving intestinal health of weaned piglets.

Effects of Saccharomyces cerevisiae fermentation products on performance and rumen fermentation and microbiota in dairy cows fed a diet containing low quality forage

Background： A possible option to meet the increased demand of forage for dairy industry is to use the agricultural byproducts, such as corn stover. However, nutritional value of crop residues is low and we have been seeking technologies to improve the value. A feeding trial was performed to evaluate the effects of four levels of Saccharomyces cerevisiae fermentation product（SCFP; Original XP; Diamond V） on lactation performance and rumen fermentation in mid-lactation Holstein dairy cows fed a diet containing low-quality forage. Eighty dairy cows were randomly assigned into one of four treatments： basal diet supplemented with 0, 60, 120, or 180 g/d of SCFP per head mixed with 180, 120, 60, or 0 g of corn meal, respectively. The experiment lasted for 10 wks, with the first 2 weeks for adaptation.Results： Dry matter intake was found to be similar（P 〉 0.05） among the treatments. There was an increasing trend in milk production（linear, P ≤ 0.10） with the increasing level of SCFP supplementation, with no effects on contents of milk components（P 〉 0.05）. Supplementation of SCFP linearly increased（P 〈 0.05） the N conversion, without affecting rumen pH and ammonia-N（P 〉 0.05）. Increasing level of SCFP linearly increased（P 〈 0.05） concentrations of ruminal total volatile fatty acids, acetate, propionate, and butyrate, with no difference in molar proportion of individual acids（P 〉 0.05）. The population of fungi and certain cel ulolytic bacteria（Ruminococcus albus, R. flavefaciens and Fibrobacter succinogenes）increased linearly（P 〈 0.05） but those of lactate-utilizing（Selenomonas ruminantium and Megasphaera elsdeni） and lactate-producing bacteria（Streptococcus bovis） decreased linearly（P ≤ 0.01） with increasing level of SCFP. The urinary purine derivatives increased linearly（P 〈 0.05） in response to SCFP supplementation, indicating that SCFP supplementation may benefit for microbial protein synthesis in the rumen.Conclusions： The SCFP supplementation was effective in maintaining milk persistency of mid-lactation cows receiving diets containing low-quality forage. The beneficial effect of SCFP could be attributed to improved rumen function; 1）microbial population shift toward greater rumen fermentation efficiency indicated by higher rumen fungi and cel ulolytic bacteria and lower lactate producing bacteria, and 2） rumen microbial fermentation toward greater supply of energy and protein indicated by greater ruminal VFA concentration and increased N conversion. Effects of SCFP were dose-depended and greater effects being observed with higher levels of supplementation and the effect was more noticeable during the high THI environment.

The effect of Saccharomyces cerevisiae on digestion and mortality in the volcano rabbit(Romerolagus diazi)

An experiment was conducted to evaluate whether supplementation with a probiotic could enhance digestion and reduce mortality in the volcano rabbit in captivity. Two enclosures at Chapultepec Zoo, Mexico（114 individuals） were used in a crossover design（two periods of 60 days） with the following treatments： control group and supplementation with Saccharomyces cerevisiae（2×108 CFU/exhibit/day）. Supplementation with the probiotic negatively affected（P〈0.01） the digestibility of dry matter, organic matter, neutral detergent fiber（NDF） and energy. Mortality increased（P〈0.04） following supplementation with the probiotic（4.26% vs. 8.89%）, primarily in the juvenile rabbits. The results indicate that yeast supplementation in the volcano rabbit negatively affects digestion and mortality in captivity.

Saccharomyces cerevisiae CNCM I-3856 in irritable bowel syndrome: An individual subject meta-analysis

AIM To confirm previous conclusions on Saccharomyces cerevisiae(S. cerevisiae) CNCM I-3856 for irritable bowel syndrome(IBS) management.METHODS An individual patient data meta-analysis was performed on two randomized clinical trials studying the effect of S. cerevisiae CNCM I-3856 supplementation on gastrointestinal(GI) symptoms in IBS subjects. A total of 579 IBS subjects were included. Outcomes were the daily Likert scale scores of abdominal pain/discomfort and bloating [area under the curve(AUC) and weekly means], responder status, and bowel movements(stool frequency and consistency). Statistical analyses were conducted in Intent to Treat(ITT) population, IBS-C subjects and IBS-C subjects with an abdominal pain/discomfort score higher than or equal to 2 at baseline("IBS-C ≥ 2 subpopulation").RESULTS S. cerevisiae CNCM I-3856 significantly improved abdominal pain/discomfort and bloating during the second month of supplementation [AUC(W5-W8)]with improvement up to the minimal clinically relevant threshold of 10%: a 12.3% reduction of abdominal pain/discomfort in the ITT population compared to the Placebo group(P = 0.0134) has been observed. In the IBS-C ≥ 2 subpopulation, there were a 13.1% reduction of abdominal pain/discomfort and a 14.9% reduction of bloating compared to the Placebo group(P = 0.0194 and P = 0.0145, respectively). GI symptoms significantly decreased during supplementation but no statistical differences were reported between groups at the end of the supplementation period. Responder status was defined as a subject who experienced a decrease of 1 arbitrary unit(a.u.) or 50% of the abdominal discomfort score from baseline for at least 2 wk out of the last 4 wk of the study. A significant difference between groups was reported in the ITT population, when considering the first definition: subjects in the Active group had 1.510 higher odds to be a responder(reduction of 1 a.u. of abdominal pain/discomfort) compared with subjects in the Placebo group(P = 0.0240). At the end of supplementation period, stool consistency in the Active group of the ITT population was significantly improved and classified as "normal" compared to Placebo(respectively 3.13 ± 1.197 a.u. vs 2.58 ± 1.020 a.u., P = 0.0003). Similar results were seen in the IBS-C ≥ 2 subpopulation(Active group: 3.14 ± 1.219 a.u. vs Placebo group: 2.59 ± 1.017 a.u., P = 0.0009).CONCLUSION This meta-analysis supports previous data linking S. cerevisiae I-3856 and improvement of GI symptoms, in IBS overall population and in the IBS-C and IBS-C ≥ 2 subpopulations.

Construction of Saccharomyces cerevisiae Strain Stably Expressing a Fusion Protein Containing Ten Tandem Recombinant Human Glucagon-like Peptide-1 Analogues

The recombinant Saccharomyces cerevisiae strain stably expressing recombinant human glucagon-like peptide-l（rhGLP-1） analogue, as a potential oral drug delivery system for diabetes type II treatment, was successfully constructed by the homologous recombination between chromosomal DNA and yeast and integrating vector pNK-GLP containing yeast ribosomal DNA fragments. The amount of rhGLP-I analogue fusion protein in transformant SG2 reached ca. 0.84 mg per gram of packed cells when SG2 was grown for 24 h in the YPD medium with a inoculum and medium ratio of 1：1. Oral administration of 5 g lyophilized SG2/kg to hyperglycemic rats decreased serum glucose from （24.8±1.40） to （21.2±1.36） mmol/L.

Parameter Optimization for Enhancement of Ethanol Yield by Atmospheric Pressure DBD-Treated Saccharomyces cerevisiae

In this study, Saccharomyces cerevisiae （S. cerevisiae） was exposed to dielectric barrier discharge plasma （DBD） to improve its ethanol production capacity during fermenta- tion. Response surface methodology （RSM） was used to optimize the discharge-associated pa- rameters of DBD for the purpose of maximizing the ethanol yield achieved by DBD-treated S. cerevisiae. According to single factor experiments, a mathematical model was established using Box-Behnken central composite experiment design, with plasma exposure time, power supply volt- age, and exposed-sample volume as impact factors and ethanol yield as the response. This was followed by response surface analysis. Optimal experimental parameters for plasma discharge- induced enhancement in ethanol yield were plasma exposure time of 1 rain, power voltage of 26 V, and an exposed sample volume of 9 mL. Under these conditions, the resulting yield of ethanol was 0.48 g/g, representing an increase of 33% over control.

Identification of a Long-Chain Fatty Acid Elongase from Nannochloropsis sp. Involved in the Biosynthesis of Fatty Acids by Heterologous Expression in Saccharomyces cerevisiae

The marine microalga Nannochloropsis sp.contains various elongases and desaturases that are critical for biosynthesis of polyunsaturated fatty acids.A full-length cDNA encoding a long-chain fatty acid elongase,named Ns FAE,was cloned from Nannochloropsis sp..The open reading frame of Ns FAE(GenBank accession no.MF680548)consisted of 1068 bp and encoded a predicted protein of 355 amino acids with molecular mass 38.8 k Da.The deduced polypeptide showed 43%–44%identity to fatty acyl elongases from other algae.RT-PCR experiments indicated that the Ns FAE gene exhibited the highest expression in Nannochloropsis sp.at 72 h(i.e.,during the third growth stage)and the expression was significantly lower in the other four growth stages.Plasmid p Ns FAE-CRISPR and a recombinant DNA fragment(ADH1p-Ns FAE-CYCt)were transformed into Saccharomyces cerevisiae strain BY4742 using the CRISPR-Cas system.Yeast transformants containing Ns FAE produced three fatty acids not normally present in wild-type BY4742-linoleic acid,linolenic acid and eicosadienoic acid-indicating that Ns FAE encodes a functional elongase enzyme.

Enhancement of Simultaneous Xylose and Glucose Utilization by Regulating ZWF1 and PGI1 in Saccharomyces Cerevisiae

Xylose utilization is one of the key issues in lignocellulose bioconversion.Because of glucose repression,in most engineered yeast with heterogeneous xylose metabolic pathway,xylose is not consumed until glucose is completely utilized.Although simultaneous glucose and xylose utilization have been achieved in yeast by RPE1 deletion,we regulated ZWF1 and PGI1 transcription to improve simultaneous xylose and glucose utilization by controlling the metabolic flux from glucose into the PP pathway.Xylose and glucose consumption increased by approximately 80 and 72%,respectively,whereas ZWF1 was overexpressed by multi-copy plasmids with a strong transcriptional promoter.PGI1 expression was knocked down by promoter replacement; the glucose and xylose metabolism increased when PGI1p was replaced by weak promoters,SSA1p and PDA1p.ZWF1 overexpression decreased while PGI1 down-regulation increased the ethanol yield to some extent in the recombinant strains.