• Textile Coloration and Finishing
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• v.31 no.4
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• pp.249-257
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• 2019

Baker's yeast(Saccharomyces cerevisiae) was used as a biocatalyst for eco-friendly indigo dyeing and the reducing power of yeast according to the alkaline solution type was compared. NaOH solution, lye, and buffer solution were used as alkaline solutions. The reducing power(K/S value, oxidation/reduction potential(ORP), pH) was monitored according to the elapsed time including the initiation of reduction, peak reduction, and the end of reduction. In all alkaline solutions, it was confirmed that yeast can be used reducing agent in indigo reduction dyeing. The pH stability and reducing power of buffer solution was better than that of NaOH alone. Although, pH and ORP stability of the reduction bath in lye were better than that of buffer solution, K/S value in buffer solution was higher compared to lye. The reducing power was different depending on the starting pH of the dye bath, and it was better when starting at pH 10.70 than at pH 11.30. Fastnesses to washing, rubbing, and light were relatively good with above rating 4. There was no significant difference in colorfastness depending on the type of alkaline solutions.

• Journal of Aquaculture
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• v.9 no.4
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• pp.345-351
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• 1996

Mass production of resting egg of the rotifer, Brachionus plicatilis was carried out in 1 $m^3$ tank for L-type rotifer and in 1 $m^3$ and 4 $m^3$ tank for S-type rotifer. L-type rotifer was fed on concentrated Chlorella + baker's yeast and only baker's yeast for 15 days. S-type rotifer was fed on concentrated Chlorella in 1 $m^3$ tank for 7 days and frozen Chlorella + baker's yeast in 4 $m^3$ for $6\~8$ days. Total number of resting egg and number of resting egg from $10^8$ rotifers and 1 g dry weight diet for L-type rotifer fed on Chlorella + baker's yeast were $54.5{\times}10^6$ eggs, $30.5{\times}10^6$ eggs and $100{\times}10^3$ eggs, respectively. These were higher than those of rotifer fed on baker's yeast only. Total number of resting egg and number of resting egg from $10^8$ rotifers and 1 g dry weight diet for S-type rotifer fed on concentrated Chlorella in 1 $m^3$ tank were $50\~104{\times}10^6$ eggs, $47\~82{\times}10^6$ eggs and $136\~260{\times}10^3$ eggs, respectively. In 4 $m^3$ tank with frozen Chlorella + baker's yeast, these were $149\~567{\times}10^6$ eggs, $36\~123{\times}10^6$ eggs and $131\~338{\times}10^3$ eggs, respectively. This result suggests that S-type rotifer are better than L-type rotifer for the mass production of resting egg of the Korean rotifer.

• Bulletin of the Korean Chemical Society
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• v.12 no.5
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• pp.464-465
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• 1991

• Journal of the Korean Chemical Society
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• v.20 no.2
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• pp.146-152
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• 1976

It was found that petroleum ether extract of White Ginseng had a very slightly stimulating effect on the RNA biosynthesis of Baker's yeast, while both ethanol extract of White Ginseng(WGpet-alc) and Red Ginseng Extract(RGE) showed a significant stimulating effect on the RNA biosynthesis and its activity to change mononucleotide composition of the yeast RNA was noticeable; RGE induced a remarkable decrease of AMP, CMP and especially of UMP, however a marked increase of GMP, and it was observed that the molar ratio of GMP was 78.5 % of all mononucleotides of the yeast RNA. It is of interest that these results are closely related with the stimulating effect of protein biosynthesis of Baker's yeast cells.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.3
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• pp.225-229
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• 2000

This study was performed to investigate production and hatching rate of the resting egg of freshwater rotifer, Brachionus calyciflorus fed the 5 different diets (ESP, freshwater Chlorella, baker's yeast, the mixture off$70{\%}\;ESP\;and\;30{\%}$freshwater Chlorelia, and the mixture of $30{\%}$ baker's yeast and $70{\%}$ freshwater Chlorella). The highest productions of resting eggs were 123.3 egg/ml and 126.7 egg/ml in the mixture of $70{\%}$ ESP and $30{\%}$ freshwater Chlorella, and the mixture of $30{\%}$ baker's yeast and $30{\%}$ and $70{\%}$ freshwater Chlorella, respectively, which were significantly better than ESP, freshwater Chlorella or baker's yeast alone (P<0.05). Hatching rate of the resting eggs from rotifer fed the mixture of $70{\%} ESP\;and\;30{\%}$ freshwater Chlorella was the highest, $71.9{\%}$ although this value was not significantly different compared with the mixture of $30{\%}$ baker's yeast and $70{\%}$ freshwater Chlorella, and freshwater Chlorella (P^lt;9.05). The results showed that the mixture of baker's yeast or ESP with the freshwater Chlorella seemed to be the best feeding regime for the production and hatching rate of resting egg of freshwater rotifer.

• Fisheries and Aquatic Sciences
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• v.9 no.4
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• pp.160-166
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• 2006

We explored the possibilities of using the freshwater rotifer Brachionus angularis as a live food for small fishes cultured in fresh- or brackish waters. Brachionus angularis were collected from a reservoir for isolation and laboratory culture. Length and width of the lorica were $102.3{\mu}m$ and $76.6{\mu}m$, respectively, and those of amictic eggs were $64.4{\mu}m\;and\;47.9{\mu}m$, respectively. When their growth rates were examined at six different temperatures, i.e., 15, 20, 25, 30, 35, and $40^{\circ}C$, the highest daily growth rate of 0.801 was observed at $35^{\circ}C$, and growth was lower with decreasing temperature. Adaptation to salinity change was evaluated with two different modes of salinity increase: step-wise elevation lasting for short durations of 5 to 30 min or a long duration of 24 h. With the short duration modes, no individuals survived salinity higher than 10 psu, and the number of live individuals did not increase throughout the experiment. However, in the 24-h elevation, the number of individuals increased when salinity was elevated by 1 to 2 psu per day for the first 2 or 3 days, while no increase in number occurred at salinity increments higher than 3 psu per day. In addition, to assess the effect of different diets, four single-component diets (Chlorella vulgaris, Nannochloris sp., baker's yeast, or dry yeast) and three combination diets (C. vulgaris + Nannochloris sp. + baker's yeast + dry yeast; C. vulgaris 70% + baker's yeast 30%; C. vulgaris 30% + baker's yeast 70%) were used. The specific growth rates of B. angularis fed combination diets were higher than those of rotifers fed any single-component diet, with the highest rate of 0.648 in B. angularis fed a mixture of C. vulgaris, Nannochloris sp., baker's yeast, and dry yeast, and the lowest rate of 0.200 in those fed dry yeast only. Our results indicate that the freshwater rotifer B. angularis can be used for seedling production of both freshwater and brackish-water fishes that require small (less than about $120{\mu}m$) live food during their early stages.

• KSBB Journal
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• v.26 no.1
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• pp.87-91
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• 2011

Automatic counting of yeast cells in baker's yeast culture was tried using a conventional light microscope equipped with a pc camera. Relatively good binary image was obtained by using white LED as microscope light source, but uneven brightness distribution in original image hindered counting accuracy. A block binarization method using local thresholds proportional to local brightnesses was used to get improved binary images. The brightnesses of the blocks were expressed as the value component in HSV color model. Good quality binary images were obtained by binarization on $8{\times}6$ blocks of original images and connected-component labelling of the binarized images produced reliable counting results in the concentration range $1.4{\times}10^5/mL{\sim}1.4{\times}10^7\;cells/mL$.

• Microbiology and Biotechnology Letters
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• v.19 no.4
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• pp.390-397
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• 1991

Ethanol production by calcium alginate-immobilized baker's yeast (Saccharor/tyces cereviszae) was studied in the batch fermentation using glucose medium as a feed. Immobilied cells were stable between $30^{\circ}C$ and $40^{\circ}C$ whereas free cells were stable between $30^{\circ}C$ and $37^{\circ}C$ The beads were showed constant ethanol productivity during 720 hours (30 days) over. Fermentation characteristics of immobilized baker's yeast were examined changing the initial glucose concentration of broth in fermentation. Initial glucose concentrations employed were 50, 100, 150 and 200 g/l, respectively. In 15% gucose medium, maximum specific growth rate, maximum ethanol yield and ethanol concentration were observed as 0.092 $h^{-1}$, 0.45, 67.5 g/l, respectively.

• Journal of Aquaculture
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• v.13 no.2
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• pp.147-152
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• 2000

To reduce the production cost of the rotifer, different combinations of Chlorella and Baker's yeast were used to mass culture of Brachionus calyciflorus. Rotifer density tended to decrease abruptly at 100% Chlorella-feeding, when unionized ammonia level ranged from 14.1 to 29.6 ppm and DO level from 0.2 to 0.3 ppm. Hence DO level > 0.3 ppm and unionized ammonia level < 14 ppm should be maintained. Production cost of the rotifer was the highest, when a combination of 100 % Chlorella was chosen as food source, but it was about 1.8 times less, when a combination of 70 % Chlorella and 30% yeast was used as food source. However, the highest rotifer density remained almost at the same level, when either of the combination was chosen as food source. A combination of 70 % Chlorella and 30 % yeast is recommended for maximum production of the rotifer at the lowest feed cost.

• Applied Biological Chemistry
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• v.37 no.5
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• pp.397-401
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• 1994

Bioreduction with active dried baker's yeast proceeded smoothly in n-hexane, pentane or petroleum ether as an organic solvent system. Ethyl(1) and octyl 3-oxohexanoate(2) were reduced to $({\underline{R}})-ethyl(3)$ and $({\underline{S}})-octyl$ 3-hyroxy-hexanoate(4) with high enantiomeric excess, respectively.