• Journal of Microbiology and Biotechnology
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• v.3 no.3
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• pp.194-198
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• 1993

${\beta}-1$, 4-Mannobiose was prepared by the enzymatic hydrolysis of brown copra meal and the subsequent elimination of mono-saccharides from the resultant hydrolysate with a yeast. The enzyme system hydrolyzed brown copra meal and produced monosaccharides and $\beta$-1, 4-mannobiose without other oligomers at the final stage of the reaction. Brown copra meal (30 g) was hydrolyzed at $50^{\circ}^C$ and pH 5 for 48 hr with the crude enzyme solution (300 ml) from Penicillium purpurogenum. By the elimination of monosaccharides from the hydrolysis products with a yeast (Candida parapsilosis var. komabaensis k-75), 5.2 g of crystalline mannobiose was obtained without the use of chromatographic techniques. After 50 hours of yeast cultivation, the total sugar content fell from 3.5% to 2.4%, and the average degree of polymerization rose from 1.8 to 2.2.

• Proceedings of the Korean Nutrition Society Conference
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• 2003.05a
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• pp.198.2-198.2
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• 2003

• The Korean Journal of Mycology
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• v.39 no.3
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• pp.243-248
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• 2011

We studied the repeated-batch process for the bioethanol production from the hydrolysate of Ulva pertusa Kjellman using yeast Pichia stipitis, which is able to assimilate C6- and C5-monosaccharides. During 180-hour operations, the repeated-batch process was carried out stably, and the average bioethanol concentration reached 11.9 g/L from about 30 g/L of reducing sugar in the hydrolysate. Meanwhile, the bioethanol yields, based on the reducing sugar and the quantitative TLC analysis, were 0.40 and 0.37, respectively, which corresponded to 78.4% and 72.5% of theoretical value, respectively. Throughout the quantitative process analysis, it was also demonstrated that 39.67 g-bioethanol could be produced from 1 kg of dried Ulva pertusa Kjellman. In this study, we verified that the bioethanol production from the hydrolysate of Ulva pertusa Kjellman was feasible using a yeast Pichia stipitis, particularly during the repeated-batch operation.

• KSBB Journal
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• v.25 no.3
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• pp.283-288
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• 2010

We investigated the feasibility of bioethanol production from hydrolysate of brown seaweed Sargassum sagamianum. Prior to bioethanol production using yeasts, six yeast strains were compared and the best ones in terms of the ethanol production levels were selected. Pichia stipitis ATCC 7126, Pichia stipitis ATCC 58784, and Pichia stipitis ATCC 58376 were superior to others in terms of ethanol production. These yeast strains were used for producing bioethanol by the shaking bottle culture and the fermentor culture. Out of approximately 30 g/L reducing sugar, about 3~6 g/L and 4~7 g/L bioethanol were produced in the bottle culture and the fermentor one, respectively. Furthermore, it was observed that around 12~28 g-bioethanol was produced from 1 kilogram of Sargassum sagamianum. Compared with those previously published, these data were almost three to eight times higher in value.

• Journal of Microbiology and Biotechnology
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• v.24 no.9
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• pp.1245-1253
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• 2014

One-step sulfuric acid saccharification of the red alga Pterocladiella capillacea was optimized, and various detoxification methods (neutralization, overliming, and electrodialysis) of the acid hydrolysate were evaluated for fermentation with the thermotolerant yeast Kluyveromyces marxianus. A proximate composition analysis indicated that P. capillacea was rich in carbohydrates. A significant galactose recovery of $81.1{\pm}5%$ was also achieved under the conditions of a 12% (w/v) biomass load, 5% (v/v) sulfuric acid, $121^{\circ}C$, and hydrolysis for 30 min. Among the various detoxification methods, electrodialysis was identified as the most suitable for fermentable sugar recovery and organic acid removal (100% reduction of formic and levulinic acids), even though it failed to reduce the amount of the inhibitor 5-HMF. As a result, K. marxianus fermentation with the electrodialyzed acid hydrolysate of P. capillacea resulted in the best ethanol levels and fermentation efficiency.

• Korean journal of applied entomology
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• v.38 no.1
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• pp.35-39
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• 1999

An aphid predator, Chrysopa pallens Ramber, was reared on the artificial diets containing chicken egg yolk, yeast hydrolysate, brewer's yeast or Vanderzant's vitamin mixture, sucrose andlor bee honey, casein hydrolysate, and cholesterol. On these diets, 20.0 to 70.0% of the 1st instar larvae developed to apparently normal adults depending on diets used. The adults fed on one of these diets which was the most effective laid 230 fertile eggs for her 36 days of adult life span. The nonlipid part of the aphid, Myzus persicae Sulzer was thought to be nutritionally more important than the lipid part for the development of the green lacewing.

• The Korean Journal of Food And Nutrition
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• v.1 no.2
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• pp.102-107
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• 1988

Production of calcium lactate very useful for medical supplies of Ca-therapy was obtained by lactic acid fermentation of lactobacillus sporogenes, a spore forming lactic acid bacterium. Corn steep liquor 1%, soybean enzyme hydrolysate 3%, yeast extract powder 2% can substitute for yeast extract and peptone as nutrient sort traces in fermentation medium using 10% glucose concentration. In the calcium lactate production medium containing yeast extract powder 2%, glucose 18%, CaCO3 12%, the lactic acid fermentation was carried out at 45$^{\circ}C$ for 4days with continuous agitation of 100 rpm. As results, fermentation yield was 97.5%. The five steps such as protein coagulation, decolorizing evaporating, crystallizing, and drying were carried out to harvest calcium lactate from 10l of supernatant of fermented medium to be removed cell and CaCO3. As results, 2065.0g of white crystal calcium lactate dihyrate was recovered and a yield of 84.9% was obtained.

• Preventive Nutrition and Food Science
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• v.16 no.2
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• pp.110-116
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• 2011

This study examined the growth effects of yeast hydrolysate (YH) and a traditional Korean herbal mixture (HM, a mixture of safflower seed and gasiogapi extract). Three-week old male SD rats were divided into the following five groups: negative control (saline), positive control (foremilk 0.5 g/kg/day), YH (YH 0.5 g/kg/day), HM (HM 0.2 g/kg/day), and YH+HM (YH 0.5 g/kg/day and HM 0.2 g/kg/day). Tibia bone length was 9.22 mm in the normal control rats, while both the YH and YH+HM groups had significantly longer tibia bones than the control rats (9.75 mm and 10.46 mm, respectively). The proximal epiphyses of YH, HM, and YH+HM measured 0.75, 0.70, and 0.75 mm, respectively, while the length in the control group was 0.50 mm. Plasma insulin growth factor-1 (IGF-1) level was slightly higher in the YH group (1.36 mg/mL) than in the control rats (1.29 mg/mL), but the difference was not significant. Plasma IGF-1 level was significantly increased in the HM (1.49 mg/mL) and YH+HM (1.53 mg/mL) groups compared to the control group (1.29 mg/mL). Growth hormone (GH) levels in YH (17.45 ng/mL), HM (15.49 ng/mL), and YH+HM (16.07 ng/mL) were significantly different compared to the control group (3.63 ng/mL).

• Journal of Microbiology and Biotechnology
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• v.24 no.12
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• pp.1622-1628
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• 2014

DagA, a ${\beta}$-agarase, was produced by cultivating a recombinant Streptomyces lividans in a glucose medium or a mixed-sugar medium simulating microalgae hydrolysate. The optimum composition of the glucose medium was identified as 25 g/l glucose, 10 g/l yeast extract, and $5g/l\;MgCl_2{\cdot}6H_2O$. With this, a DagA activity of 7.26 U/ml could be obtained. When a mixed-sugar medium containing 25 g/l of sugars was used, a DagA activity of 4.81 U/ml was obtained with very low substrate utilization efficiency owing to the catabolic repression of glucose against the other sugars. When glucose and galactose were removed from the medium, an unexpectedly high DagA activity of about 8.7 U/ml was obtained, even though a smaller amount of sugars was used. It is recommended for better substrate utilization and process economics that glucose and galactose be eliminated from the medium, by being consumed by some other useful applications, before the production of DagA.

• Food Science of Animal Resources
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• v.44 no.3
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• pp.723-737
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• 2024

Yeast protein can be a nutritionally suitable auxiliary protein source in livestock food. The breakdown of proteins and thereby generating high-quality peptide, typically provides nutritional benefits. Enzyme hydrolysis has been effectively uesed to generate peptides; however, studies on the potential applications of different types of enzymes to produce yeast protein hydrolysates remain limited. This study investigated the effects of endo- (alcalase and neutrase) and exotype (flavourzyme and prozyme 2000P) enzyme treatments on yeast protein. Endotype enzymes facilitate a higher hydrolysis efficiency in yeast proteins than exotype enzymes. The highest degree of hydrolysis was observed for the protein treated with neutrase, which was followed by alcalase, prozyme 2000P, and flavourzyme. Furthermore, endotype enzyme treated proteins exhibited higher solubility than their exotype counterparts. Notably, the more uniform particle size distribution was observed in endotype treated yeast protein. Moreover, compared with the original yeast protein, the enzymatic protein hydrolysates possessed a higher content of β-sheets structures, indicating their higher structural stability. Regardless of enzyme type, enzyme treated protein possessed a higher total free amino acid content including essential amino acids. Therefore, this study provides significant insights into the production of protein hydrolysates as an alternative protein material.