• Journal of Microbiology and Biotechnology
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• v.3 no.4
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• pp.298-302
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• 1993

Pullulan was produced from starch hydrolysate with Aureobasidium pullulans SH8646. We could measure the correct amount of pullulan produced without the interference of starch from the culture supernatant by using a bacterial $\alpha$-amylase treatment and ethanol: acetone (1:1) precipitation. When 5% acid-hydrolyzed starch was used as a carbon source, the dry cell weights obtained were similar irrespective of DE values of starch hydrolysates. The dry cell weights of those on the starch hydrolysate media prepared with 0.1 N HC1 treatment, were slightly higher (9.5~10.5 g/l) than those on the starch hydrolysate media prepared with 1.0 N HCl (8.5~9.5 g/l). And among the starch hydrolysates showing DE values lower than 50, maximum pullulan production of 15 g/l was obtained at DE 30~40 starch hydrolysate but those showing DE values higher than 50, the pullulan production was increased with the increase of the DE value of starch hydrolysates. From the media containing 5%, 10%, and 15% starch hydrolysate (DE 25, 45, and 75), about 20~34% pullulan yield was obtained and the maximum pullulan yield of 34% (17g/l) was obtained from 5% DE 75 starch hydrolysate. The pullulan yields from starch hydrolysate media were much lower than those from glucose, maltose, maltotriose, and sucrose media.

• Microbiology and Biotechnology Letters
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• v.14 no.5
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• pp.399-405
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• 1986

Corn starch was saccharified without cooking in an agitated bead reaction system. Uncooked corn starch was effectively hydrolyzed even at the concentration as high as 39%(w/v). After 24 hours. the extent of saccharification reached at 92%, which corresponds glucose concentration of 425g/L. Fed-batch feeding of starch was more effective than batch feeding for saccharification of uncooked corn starch. The composition of hydrolysated of uncooked starch was analyzed. which was composed of 95% glucose, 0.7% of maltose, and 4.5% of high saccharide, similar with that of cooked starch. The hydrolysate can be successfully utilized for HFCS manufacture. The starch liquefying and saccharifying enzyme was relatively stable even be the physical impact of the attrition-milling media. The enzyme stabilizer, $Ca^{++}$, played an essential role in preventing the enzyme deactivation caused by the physical impact.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.1
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• pp.79-87
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• 1997

A study on the processing method of anchovy hydrolysate paste (AHP) was carried out to improve the sensory quality of salted and fermented fish. Homogenized whole anchovy was hydrolyzed using commercial pretenses, Complex enzyme-2000 (CE, Pacific Chem. Co.) and Alcalase (AL, Novo), in a cylindrical vessel with 4 baffle plates and 6-bladed turbine impeller. Optimal pH, temperature, and enzyme concentration for the hydrolysis with CE and AL were $7.0,\;52^{\circ}C,\;7\%$, and $8.0,\;60^{\circ}C,\;6\%$, respectively. The rational amount of water for homogenization, agitation speed, and hydrolyzing time were $100\%\;(w/w)$, 100 rpm, and 210 min, respectively. To make the hydrolysate to paste type, it was effective to mix the additives, such as starch, soybean protein, agar, and carrageenan gum to the hydrolysate 5 min before the end of boiling at $100^{\circ}C$ for 30 min. Minimal NaCl concentration for long-term preservation was $15\%$, and this could be reduced to $12\%$ by adding $5\%$ of KCl. yield of the AHP based on the total nitrogen content was $94.6\~97.0\%,\;and\;86.0\~89.2\%$, of the nitrogen was amino nitrogen. Salinity, pH and histamine content of the AHP prepared with $12\%$ NaCl and $5\%$ KCl were $9.3\~9.9\%,\;6.1\~6.2$, and below 13 mg/100 g, respectively. The AHP was stable at $26{\pm}3^{\circ}C$ for 60 days on bacterial growth, and addition of $0.05\%$ of rosemary (Herbalox) extract was effective to inhibit the lipid oxidation of the AHP during storage.

• Korean Journal of Food Science and Technology
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• v.32 no.3
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• pp.618-628
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• 2000

The indigestible dextrin I was prepared by hydrolyzing pyrodextrin with thermostable ${\alpha}-amylase$. The mean values of indigestible fraction and dieatry fiber of indigestible dextrin I prepared from yellow dextrin were 50.0% and 25.0%, respectively. Also the indigestible dextrin II was prepared by removing low molecular weight saccharides containing glucose with ethanol from enzyme hydrolysate of pyrodextrins. Over 80% of glucose and maltose in initial enzyme hydrolysate were removed, therefore the indigestible fraction and dietary fiber of the indigestible dextrins increased. The indigestible dextrin from ethanol precipitate of enzyme hydrolysate of yellow dextrin by ${\alpha}-amylase$ and amyloglucosidase showed a higher contents of indigestible fraction and dietary fiber than ethanol precipitates by any other enzyme combination, and its mean values were 83.6% and 62.8%, respectively. Consequently, it was found that the indigestible dextrins which are resistant to starch-hydrolysing enzyme can be easily prepared from pyrodextrin, and presumed that they can perform physiological functions as soluble dietary fiber.

• Korean Chemical Engineering Research
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• v.53 no.1
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• pp.1-5
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• 2015

Lactic acid, the most widely occurring hydroxy-carboxylic acid, has traditionally been used as food, cosmetic, pharmaceutical, and chemical industries. Even though it has tremendous potential for large scale production and use in a wide variety of applications, high cost lactic acid materials are primarily problems. Lactic acid can be obtained on either by fermentation or chemical synthesis. In recent years, the fermentation approach has become more successful because of the increasing market demand for naturally produced lactic acid. Generally, lactic acid was produced from pure starch or from glucose. As an alternative, biomass which is the most abundant renewable resources on earth have been considered for conversion to readily utilizable hydrolysate. In this study, we conducted the fermentation method to produce L(+)-lactic acid production from pretreated hydrolysate was investigated by Lactobacillus rhamnosus ATCC 10863. The hydrolysate was obtained from pretreatment process of biomass using Ammonia percolation process (AP) followed by enzymatic hydrolysis. In order to effectively enhance lactic acid conversion and product yield, controlled medium, temperature, glucose concentration was conducted under pure glucose conditions. The optimum conditions of lactic acid production was investigated and compared with those of hydrolysate.

• The Korean Journal of Food And Nutrition
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• v.11 no.5
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• pp.565-569
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• 1998

The strain BY-445 which produces new inhihitors of ${\alpha}$-amylase was isolated from a soil sample and identified. The aerial hyphae of this strain develope in the from of open spirals. The spore chain of BY-445 strain appears in spiral shape with spiny surface. Melanoid and soulble pigments were not observed. Gelatin was liquefied, and skin milk and starch was also hydrolyzed. The isolate contained LL-diaminopimelic acid in its cell wall hydrolysate. The content of fatty acid 16:iso, 15:0 anteiso and 16:0 was 25:30, 16.19 and 13.16%, respectively. BY-445 strain was closely related to Streptomyces violaceusinger but it was different from this strain in some cultural and physiological characteristics. This strain was, therefore, designated as Streptomyces sp. BY 445.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1978.10a
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• pp.207.5-208
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• 1978

Effects of the plant growth regulator (P. G. R.)on the reaction of proteinase, $\gamma-amylase$ and acid phosphatase were investigated, and also were the conditions of production of P. G. R. by Stroptomyces sp. 445. The P. G. R. had no effect on the act ivities of such enzymes in mung bean seedling. But in germinating seed previously treated with P. G. R. it effected the activity of protease in cotyledon. In the conditions of production of P. G. R., the maxim, activity was appeared in shaking cutlure at $30^{\circ}C$ for 5 days, and by the addition of peptone or casein hydrolysate as nitrogen source, soluble starch as carbon source, and sulfur as metal ion.

• Microbiology and Biotechnology Letters
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• v.22 no.5
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• pp.561-563
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• 1994

For the more effective isolation of soil actinomycetes, we have developed HHV (Hair hydrolysate-vitamin) agar medium, containing hair as the sole source of carbon and nitrogen. The HHV agar medium was superior to other media such as colloidal chintin agar, glycerol-arginine agar and starch-casein-nitrate agar, and HV (humic acid-vitamin) agar. The maximum effect of this medium has been shown in hair dry weight 0.4 g/l medium. Of each soil sample, the greatestest number of actinomycetes was isolated from the potato annual planted soil among the tested samp- les. The genus of actinomycetes isolated from the potato annual planted soil sample was identified such 5 group as Stretomyces, Micromonospora, Microbispora, Nocardia and Saccharopolyspora.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.6
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• pp.823-828
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• 1998

The objective of this study is to investigate cryoprotective effects of corn starch enzyme hydrolysates of nonsweet and low-calories on denaturation of frozen fish protein. The cryoprotective effects of were examined in Alaska pollack actomyosin solution by changes in SDS-PAGE pattern, solubility, and $Ca^{2+}$-ATPase activity. When samples stored for 0 and 30 days were compared on SDS-PAGE patterns, severe changes in all bands were shown on the control sample regardless of storage temperature, especially in myosin heavy chain (MHC). Not much difference no appeared the electrophoretic pattern in case of the samples containing sucrose at any storage temperature during 30 days of storage. The cryoprotective effect of the hydrolysates were markedly dependant on storage temperature and no MHC band was found in the samples stored at $-5^{\circ}C$. The SDS-PAGE patterns of sample stored at $-20^{\circ}C$, however, completely maintained after 30 days or storage. When the samples were stored at $-5^{\circ}C$, the solubility of the sample containing sucrose was retained at $90\%$ after 30 days of storage, whereas dramatically decreased in other samples. The samples including sucrose, D.E. 10, 15, and 20 revealed $90\%$ in solubility when stored at $-20^{\circ}C$. The tendency of remaining $Ca^{2+}$-ATPase activity was almost shown the same as that of solubility.

• Food Science and Preservation
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• v.31 no.1
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• pp.149-160
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• 2024

Dextran is a glucose homo-polysaccharide with a predominantly α-1,6 glycosidic linkage of microbial source and is known to be produced primarily by lactic acid bacteria. However, it can also be obtained through the dextran dextrinase of acetic acid bacteria (Gluconobacter oxydans). The dextrin-based dextran was obtained from rice starch using G. oxydans fermentation of rice hydrolysate, and its properties were studied. Both dextrin- and rice hydrolysate-added media maintained the OD value of 6 after 20 h of incubation with acetic acid bacteria, and the gel permeation chromatography (GPC) analysis of the supernatant after 72 h of incubation confirmed that a polymeric material with DP of 480 and 405, which was different from the composition of the substrate in the medium, was produced. The glucose linkage pattern of the polysaccharide was confirmed using the proton nuclear magnetic resonance (¹H-NMR) and the increased α-1,4:α-1,6 bond ratio from 0.23 and 0.13 to 1:2.37 and 1:4.4, respectively, indicating that the main bonds were converted to α-1,6 bonds. The treatment of dextrin with a rat-derived alpha-glucosidase digestive enzyme resulted in a slow release of glucose, suggesting that rice hydrolysate can be converted to dextran using acetic acid bacteria with glycosyltransferase activity to produce high-value bio-materials with slowly digestible properties.