Review： Utilization of yeast of Saccharomyces cerevisiae origin in artificially raised calves

Yeast of Saccharomyces cerevisiae（SCY） origin has over long time been incorporated into domestic animal diets. In calves, several products have offered improved performance and health. Although several types of research have been completed, the mode of action of SCY is not clear in calves. Under this review, we have highlighted the works available in the literature on the use of SCY in calves performance, health, immunity, and the gut environment. Both active live yeast and yeast culture have positive effects on growth, rumen, small intestines, immunity and general health of the calf. Specifically, SCY can improve DMI, growth, feed efficiency and reduce diarrhea in calves. Furthermore, subtle improvements are seen in rumen fermentation（increased butyrate production） and rumen papillae growth. These positive results are, however, more pronounced in calves that are under stress or exposed to significant levels of disease-causing agents. There is a need for further research in areas such as gut morphology, gut microbiology and immunity using latest molecular methods to fully understand how SCY helps the growth and development of calves.

Effect of Active Dried Yeast on Intestine Development,Intestinal Flora and Serum Cholesterol Mass Concentration of Quails

[ Objective] The experiments aimed to investigate the effect of dietary active dried yeast on intestine development, intestinal flora and serum cholesterol mass concentration of quails. [ Method] One-day-old 180 quails were randomly divided into 4 groups, 3 repetitions, each with 15 quails. Control group was fed with basic dietary, while experimental groups were added with 0.6, 1,2 g/kg active dried yeast respectively in basic dietary, [ Result] Addition of active dried yeast had little effect on quails＇ intestine development（ P 〉0.05）. With the increasing adding amount active dried yeast, the number of colibacillus decreased significantly （P 〈0.05） while lactobacillus content increasing sharply （P 〈 0.05）. Dietary with 1 and 2 g/kg active dried yeast can significantly decrease the mass concentration of cholesterol in serum （ P 〈 0.05）. [ Conclusion ] Adding active dried yeast in feed can decrease the number of colibacillus while increasing lactobacillus content in intestinal tract of quails, also can low serum cholesterol mass concentration.

Application of Active Dry Yeast in Pigs

Active dry yeast is dried by a certain way or retains most of its fermentation capacity, and it does not contain any grains or animal microbial preparations of other fillers. Its main components are active yeast thallus with content ≥90% and a small amount of emulsifier. In pig production, active dry yeast can enhance animal appetite, feed intake, animal growth, hindgut fermentation, breeding environment and anti- stress capability of animals, or reduce feed coefficient, animal constipation, incidence of swine and the number of pathogens in feces to prevent piglets from diarrhea. Studies have been proved that high active dry yeast has a very good application effect on sows, piglets and growing -finishing pigs. Active dry yeast in use should be noted that it should be used up within 3 -6 months after being mixed with feed, while its dosage for pigs at different stages is as follows： nursery pigs of 500 -1 000 g/t complete feed; sows of 500 -800 g/t complete feed; fattening pigs of 250 -500 g/t complete feed. Active dry yeast is very sensitive to the hot and humid, and is also not used in granulated feed and extruded feed.

Effects of Emulsifier on Fermentation Performance of Active Dry Wine Yeast

[Objectives]To explore the influence of emulsifier on the fermentation performance of wine active dry yeast.[Methods]Angel active dry yeast RV002 was selected as the test strain,and the simulated grape juice was used as the fermentation medium to investigate the fermentation rate,the yeast cell number and morphology,and the physicochemical indexes of the produced wine.[Results]It was found that the viable cell rate of the active dry yeast without the emulsifier was significantly reduced,and the fermentation rate was significantly slowed down.However,the emulsifier had no significant effect on the morphology of yeast cells,the fermentation cycle,the final number of viable cells,and the quality of the produced wine.[Conclusions]The active dry wine yeast without emulsifier can reduce the formation of grape juice foam and reduce the risk of grape juice spillover.

Active dry yeast supplementation benefits ruminal fermentation,bacterial community,blood immunoglobulins,and growth performance in young dairy goats,but not for intermittent supplementation

This study evaluated the effects of active dry yeast(ADY)supplementation and supplementation stra-tegies on ruminal fermentation,bacterial community,blood metabolites,and growth performance in young dairy goats.Sixty young female Guanzhong dairy goats of similar age(4.00±0.50 months)and BW(19.65±0.41 kg)were randomly divided into 3 groups(n=20):(1)basal diet group(CON);(2)basal diet continuously supplemented with 3.0 g/goat per day commercial ADY(a proprietary strain of Saccharomyces cerevisiae with 5.0×10^(9)cfu/g)group(CSY);(3)basal diet with intermittently supple-mented ADY group(ISY;5 d supplementation with ADY at 4.5 g/goat per day following 5 d of no sup-plementation).The experiment lasted 67 d with the first 7 d as an adaptive period.Rumen fluid and blood samples were collected bi-weekly.Data were analyzed using the MIXED procedure combined with the SLICE option in SAS.Specific orthogonal contrasts of ADY vs.CON and CSY vs.ISY were also analyzed.During the experimental period,ADY supplementation resulted in greater DMI(P=0.03),ruminal ac-etate proportion(P<0.01)and acetylesterase activity(P=0.01),and blood contents of glucose(P=0.01)and IgM(P=0.02)and tended to have greater ADG(P=0.05)and paunch girth(P=0.06)than the CON,despite the propionate proportion(P=0.03)and contents of total protein(P=0.04)and IgA(P=0.03)being lower.The lower ruminal NH_(3)-N(P<0.01)and blood urea nitrogen(P=0.07)contents indicated greater nitrogen utilization with ADY supplementation.ADY supplementation showed persistent effects after it was stopped because the BW at 12 months of age(P=0.03)and birth weight of lambs(P=0.02)were greater than the CON.However,the ISY did not show those benefits and had significantly lower relative abundances of fiber-degrading related bacteria than the CSY.In conclusion,ADY supplementa-tion,especially continuously supplemented,may enhance ADG and ADG:DMI ratio by improving DMI,ruminal cellulolytic bacteria abundance and enzyme activity,nitrogen utilization,and immune status.These findings provide a theoretical basis for the rational application of ADY and have important practical implications for the design of nutritional strategies in growing dairy goats.

Expression and Activities Experiment of DNA Transduction Motif Based on GAL4 in Pichia Pastoris

The genes encoding DNA-binding domain（BD） designed based on the yeast transcriptional activator GAL4 and protein transduction domain of HIV-1 Tat protein were fused via soft linker peptide sequence, and cloned into yeast expression vector pPIC9k. The resulted plasmid pTG was linearized and transfected into Pichia pastoris strains GS 115 by electroporation. High copies of transformants were obtained with Muts and HIS＋ phenotype identi- fication, PCR amplification and screening of G418. After flask culture and expression induced by methanol, the target protein named TG was well expressed and analyzed by SDS-PAGE and Western blot. Under optimized conditions, the yield of soluble recombinant protein was approximately 39.7 mg/L. DNA binding activity and cell transduction property of TG were analyzed by gel eleetrophoresis and fluorescent microscopy. The results show that the recombinant protein could bind strongly to the plasmid containing upstream activating sequence（UAS）. The cell experiments revealed that TG could deliver the binding plasmid into HEK-293 cells effectively. In summary, the work presented here suggests that TG is specific toward UAS containing plasmid and has the potential for use as nonviral DNA delivery agent.

Active dry yeast supplementation improves the growth performance,rumen fermentation, and immune response of weaned beef calves

The objective of this experiment was to investigate the potential benefits of active dry yeast(ADY)on the growth performance,rumen fermentation,nutrient digestibility,and serum parameters of weaned beef calves.Thirty Simmental crossbred male calves(body weight=86.47±4.41 kg and 70±4 d of age)were randomly divided into 2 groups:control(CON)(fed basal ration)and ADY(fed basal ration and 5 g/d ADY per calf).The dietary concentrate-to-roughage ratio was 35:65.All the calves were regularly provided rations 3 times a day at 07:00,13:00,and 19:00 and had free access to wate r.The experiment lasted for 60 d.The average daily gain of ADY group was higher(P=0.007)than that of the CON group,and the ratio of feed intake to average daily gain in the ADY group was reduced(P=0.022)as compared to the CON group.The concentration of ruminal ammonia-N was higher(P=0.023)in the CON group than that in the ADY group,but an opposite trend of microbial protein was found between the 2 groups.Also,the ruminal concentrations of propionate and butyrate were higher(P<0.05)in the ADY group than those in the CON group.Calves fed ADY exhibited higher(P<0.05)crude protein and neutral detergent fiber digestibility.Supplementation of ADY increased(P<0.05)the contents of glucose,glutathione peroxidase,superoxide dismutase,immunoglobulin A,immunoglobulin M,and interleukin 10 in the serum of calves,but an opposite trend was observed in malondialdehyde,interleukin 1 beta,and tumor necrosis factor alpha contents between the 2 groups.In conclusion,dietary supplementation with ADY could improve the growth performance,rumen fermentation,nutrient digestibility,antioxidant ability,and immune response of weaned beef calves.