• Asian-Australasian Journal of Animal Sciences
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• v.23 no.7
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• pp.931-936
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• 2010

This experiment was conducted to evaluate the bioavailability of different organic selenium (Se) products in finishing pigs. A total of 48 growing pigs, average body weight $47.6kg{\pm}0.05$, were allotted to four different treatments in a randomized complete block (RCB) design in three replicates with four pigs per pen. Three different organic Se products, Se-enriched yeast (treatments A and B) and Se-proteinate (treatment C), were used in conjunction with a basal diet with no added Se as a control treatment. In growing period, pigs were fed the same diet but finishing pigs were fed each treatment diet containing organic Se products for 6 weeks. During the experimental period, feed intake and body weight were measured and blood samples were collected to determine the Se concentration. At the end of this experiment, 3 pigs per treatment were killed and various tissues (loin, liver, kidney, pancreas and spleen) were collected to analyze the Se concentration. The body weight, and average daily feed intake (ADFI) were similar among treatments, but the average daily gain (ADG) was increased on Se-proteinate treatment (p<0.01) and gain-to-feed ratio (G/F ratio) was improved on Se yeast B or Se-proteinate treatment (p<0.01). The tissue Se content was also increased when pigs were fed organic Se sources, and Se was retained efficiently in loin (p<0.01) and kidney (p<0.05) when Se yeast B was provided. The serum Se concentration was increased when organic Se was provided and was higher when pigs were fed Se-proteinate (p<0.01); subsequently liver Se was also higher on Se-proteinate treatment than other treatments. The Se yeast A treatment did not show any increment of Se concentration both in serum and tissues. This result demonstrated that Se retention and bioavailability in finishing pigs were varied by Se products although organic sources were provided. Consequently, each organic Se product should be evaluated before it is used as a supplement in animal feed.

• Environmental Mutagens and Carcinogens
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• v.21 no.2
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• pp.156-163
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• 2001

Vanadium has been known as environmental polluants resulted from the burning of fossil fuels in nature. It led to toxic responses by prooxidant activity, inducing free radicals and the accumulation in the tissues. Recently, there has been growing interest in an essential nutritional requirement of vandium and especially the treatment of diabetes. But because of its strong toxicity, thease chemicals have narrow safety margin. In order to reduce metal toxicity, and increase absorption and biological activities, metal ions such as selenium and chromium were uptaken in yeast cells. In this study, Vanadium yeast was prepared by uptaking vanadate in yeast cells. Vanadate induced hematological and biochemical changes in the experimental rat blood were inhibited by the treatments of vanadium yeast. Lipid peroxidation and catalase activity were significantly increased in kidney and liver after a single intraperitoneal injection of vanadate to rats. However, these observations were apparently reduced in the vanadium yeast treated group. Vanadium amount in blood, kidney and liver after a single intraperitoneal injection of vanadium yeast was significantly reduced than that of vanadate treated group. In conclusion, vanadium yeast uptaken vanadate in yeast cells could reduce toxic effects of vanadate.

• Microbiology and Biotechnology Letters
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• v.22 no.6
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• pp.584-592
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• 1994

Several mutation procedures have been compared to obtain an ethanol-tolerant Saccha- romyces diastaticus strain secreting glucoamylase. These procedures include spontaneous mutation, EMS treatment, UV irradiation, and combination of EMS treatment and UV irradiation. All these methods were followed by adaptation of the yeast cells to gradually higher ethanol concentration. Among these procedures, the combined method of EMS treatment and UV irradiation gave the promising result, i.e. the ethanol tolerance of the yeast increased from 11.5%(v/v) to 14.0%(v/v). Respiratory deficient petite mutants of industrial and ethanol-tolerant yeast strains have been isola- ted and hybridized with haploid S. diastaticus strains. The resulting hybrids showed increased ethanol tolerance and starch-fermentability.

• Korean Journal of Microbiology
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• v.7 no.3
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• pp.125-134
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• 1969

The effect of heat treatment on membrane permeabilities of yeast's cells was studied, the amounts of efflux out of yeast cells were put to analysis, and fraction survival was also counted by viable plate counting method. Effects of nutritional substances on thermally injured yeast cells were also investigated under the highlight of reabsorption mechanism, then the relationship between permeability and surviving action in injured yeast cells are discussed.

• Korean Journal of Microbiology
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• v.6 no.4
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• pp.122-130
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• 1968

Action of various wavelengths of visible light on ultraviolet-radiation damage to haploid yeast cells, Saccharomyces cerevisiae 23971, was studied. The results were obtained on the basis of the survival and respiration rates by pre- and post-illuminations of various wavelengths before and after U.V.-irradiations on the yeast cells. Among the wavelengths tested, 635 $m{\mu}$, 429 $m{\mu}$ and white light which caused increase of respiration in pre-treatment alone, induced less resistance to the U. V.-damage than in the control, in both pre- and U.V.-treatment. On the contrary, such wavelengths as 574 $m{\mu}$and 530 $m{\mu}$, showing a weak effect on respiration in pre-treatment increased the susceptability to U.V.-radiation. Photoinactivation was generally obtained by both pre- and post- illuminations along with U.V.-treatment. At 635 $m{\mu}$ the PI rate was the lowest and also a low PI rate was shown at 429 $m{\mu}$. But 429 $m{\mu}$, in the post-treatment of the yeast cells pre-treated by the white light and the darkness respectively, showed the highest PI rate. In both pre- and post- treatment of 574, 530 and 473 $m{\mu}$,the PI rates were high to the same degree. Post-treatments of the wavelengths on U.V.-treated yeasts incubated rather under the white light than the darkness induced lower PI rate. It is assumed that there are great differences in action even of the same wavelength, depending upon the various combination of pre- and post-treatments, and that, moreover, the action of various wavelengths of visible light on U.V.-damage on the cells are concerned with the doses and dose rates of U.V. and visible lights. These observations led to an interpretation that each wavelength of visible light might exert distinctively different effects oil U. V.-damage, mainly causing the inhibition or stimulation of enzymes in the yeast cells.

• Preventive Nutrition and Food Science
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• v.14 no.2
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• pp.123-128
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• 2009

This study was conducted to evaluate the weight reduction effect of yeast hydrolysate-SR101. Thirty female college students participated in a 6 week weight control program. All subjects were randomly assigned to either the placebo group, YH-SR101 (yeast hydrolysate-SR101) group, or eX diet (product of yeast hydrolysate-SR101) group. The mean energy intake of the placebo group was 1445.2${\pm}$364.0 kcal (carbohydrate: 60.1%, protein: 25.6%, fat: 14.3%), while those of the YH-SR101 and the eX diet group were 1505.6${\pm}$296.2 kcal (carbohydrate: 60.5%, protein: 22.2%, fat: 14.8%) and 1353.8${\pm}$326.3 kcal (carbohydrate: 63.2%, protein: 20.9%, fat: 15.9%), respectively. The placebo group lost 0.19${\pm}$1.14 kg of body weight, while the treatment groups (YH-SR101 and eX diet) lost 1.13${\pm}$0.83 and 1.54${\pm}$0.74 kg of body weight, respectively. There were significant differences in the decrease in body weight between the placebo and the treatment group (p<0.05). There were also significant differences in the decrease in fat mass between the placebo and treatment group (p<0.05). Furthermore, the BMI of the YH-SR101 and the eX diet groups also differed significantly before and after the diet program (p<0.05). Additionally, the BMI and waist size reduction of the treatment groups (YH-SR101 and eX diet group) differed significantly when compared to the placebo (p<0.05). The reduction of the resting metabolic rate (RMR) blood glucose, total-cholesterol, HDL-cholesterol, LDL-cholesterol and triglyceride did not differ significantly among groups. Taken together, these findings indicate that consumption of yeast hydrolysate-SR101 and eX Diet may lead to decreased body weight and fat.

• Journal of Microbiology and Biotechnology
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• v.9 no.1
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• pp.70-77
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• 1999

An extremely cadmium-tolerant budding yeast, Hansenula anomala B-7 underwent a morphological switch in response to either heat shock treatment or cadmium stress, respectively. It exhibited a morphological transition from a unicellular yeast form to a pseudohyphae-like coagulation when subjected to prolonged heat shock treatment. In contrast, the yeast cells showed an irregularity in surface morphology when given thermal stress for a short time. Patterns of proteins expressed in the pseudohyphae-like cells demonstrated that several proteins were overexpressed while others were underexpressed in comparison with those prepared from the cells in the yeast form. It was a striking feature, however, that nearly 40％ of the proteins extracted from the cells in the pseudohyphae form appeared to be composed of a single polypeptide. This polypeptide was apparently overexpressed during the pseudohyphae phase and its molecular weight was estimated to be 58 kDa according to SDS-PAGE analysis. However, a significant level of the protein was not observed in the cells before transition to pseudohyphae. The architecture of the cell shape was also damaged when incubated in a medium containing more than 1,000 ppm (8.9mM) of cadmium ions, although able to proliferate at a slow rate. However, the irregularity in the cell morphology exerted either by the brief heat shock treatment or by the cadmium stress with the high concentrations of the metal ions was not repaired, even though the damaged cells were allowed to grow for sufficient time in fresh, cadmium-free medium.

• Korean Journal of Microbiology
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• v.19 no.2
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• pp.63-77
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• 1981

The growth rate of yeast population (Saccharomyces uvarum) cultivated in the Knopp's modified medium (plus various carbon sources) appeared the highest value when the Knopp's minimal medium was treated to 1.5% with disaccharide such as maltose and sucrose. Also the treatment of lactose and raffinose resulted in polulation growth as to the population size in case of maltose and sucrose. However, the gorwth of yeast was not occurred at all when a polysaccharide, such as inulin, was added as carbon source. The growth from of yeast population in Knopp's modified medium are characterized by the fact that log phase continued 100hrs after inoculation and that stationary state phase appeared in general 250hrs after inoculation. Applying the various carbon sources to respiration substrate for yeast cell, the respiration rate of yeast showed the highest value in treatment of maltose and followed in order of raffinose, lactose, glucose, and sucrose. Determined the amount of poly-phosphate and turn over pathway of poly-phosphate according to culture phase of yeast, it is revealed that the yeast synthesized 3 types of poly phosphate (poly-P A,B, and C) and postulated that turn over pathway of poly-phosphate as follows ; Inorganic phosphate is converted into each kind of polyphosphates, and then one part of poly-P-C is converted into poly-P-B, the rest poly-p-C and poly-P-B are converted into poly-P-A. The synthesized poly-phosphate is considered to have a role as energy pool utilizing to synthesis of cellular organic materials. Of the 13 carbon sources used in this experiment, the useful carbon sources for biosynthesis of poly-phosphate and cellular organic materials are confirmed as disaccharide (maltose and sucrose) as well as glucose. Protein synthesis in yeast cell showed the two peaks on 6th and 8th day after inoculation ; nucleic acid on 2nd day (48hrs), carbohydrates on 2nd day (48hrs), and phospholipid on 2nd and 8th day after inoculation, respectively.

• Journal of Animal Science and Technology
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• v.45 no.1
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• pp.41-48
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• 2003

Two experiments were conducted to investigate the effect of dietary supplementation of yeast culture on the performance of broiler chicks and noxious gas emission in broiler houses. Two hundred forty and three hundred and twenty, one day old Cobb male broiler chicks in Expt 1 and Expt 2, respectively were alloted to four treatment levels of yeast culture (0, 0.1, 0.2, 0.4%). To each treatment, 60 birds were assigned in Expt 1 and 5 replicates of 16 birds each were assigned in Expt 2. Basal diets contained 21.5% and 19.0% CP, and 3,100kcal/kg ME for the starting and finishing periods, respectively. Ammonia and $CO_2$ gas emission were detected twice a day for seven days during the five week period of Expt 1. Weight gain, feed intake and feed efficiency were measured for five weeks in Expt 2. Intestinal microbes, blood cholesterol and ND antibody titer were examined at the end of Expt 2. In Expt 1, the concentration of $NH_3$ in the house of birds fed yeast culture tended to be lower than the control. It was significantly lower in the 0.4% yeast culture treatment than the control (P<0.05). $CO_2$ concentration was significantly lower in all yeast culture treatments regardless of its dietary supplemental level than the control (P<0.05). different from others. Feed efficiency (feed/gain), however, was significantly improved in all yeast culture treatments relative to that of the control for starting period (P<0.05) and that of 0.2% yeast culture treatment was significantly lower than those of the control and 0.4% for the overall period. Total number of E. coli in the ileum of birds fed yeast culture at 0.1 and 0.2% was significantly lower than those of the control and 0.4% in the ileum. The CFU of Lactobacillus spp. of birds fed yeast culture at 0.1% was higher in the cecum compared to other treatments (P<0.05). Total cholesterol level of chicks fed 0.1% yeast culture seemed to be lower compared to that of other treatments, whereas LDL-cholesterol level was significantly lower than those of the control and 0.4% treatment. ND antibody titer tended to be higher in the yeast culture treatments than the control, but was not significantly different. The results of these experiments indicated that 0.2% yeast culture may have a potential to reduce the noxious gas emission in broiler houses and maximize the performance of broiler chicks.

• Korean Journal of Poultry Science
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• v.48 no.4
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• pp.169-176
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• 2021

An experiment was conducted to investigate the effects of varying levels of hydrolyzed yeast on egg production and egg quality in aged laying randomly allotted to three dietary treatments such that egg production was similar in each treatment (6 replicates of 10 birds each). The layers were fed diets containing 0, 0.1, or 0.2% hydrolyzed yeast for eight weeks. No significant difference was observed in egg production during the first half of the experiment. Egg production and daily egg mass in groups fed diets containing hydrolyzed yeast were significantly higher (P<0.05) than those of the control groups during the second half of the experiment. Egg weight was not affected by the dietary treatment. Eggshell strength and thickness in groups fed diets containing hydrolyzed yeast were significantly higher than those of the control groups during the overall experimental period (P<0.05). Although no significant differences were observed in the Haugh units, yolk color in the group fed diets containing 0.1% hydrolyzed yeast was significantly higher than that in the control group (P<0.05). The mammillary layer thickness increased in a linear manner and significantly following treatment with dietary hydrolyzed yeast (P<0.05). Antibody titer against avian influenza virus in the group fed diets containing 0.2% hydrolyzed yeast was significantly higher (P<0.05) than that in the control group. In conclusion, dietary hydrolyzed yeast improved egg production and eggshell quality of laying hens in the late stages of production.