• Journal of the Korean Society of Food Science and Nutrition
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• v.14 no.2
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• pp.164-170
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• 1985

Yellowish modified wool, dithiocarbamate(DTC) wool, was synthesized by partial hydrolysis in 0.2 N-NaOH reacting with carbon disulfide to use as ${\alpha}-amylase$ immobilization matrix. ${\alpha}-amylase$ was immobilized reacting with sulfide group of DTC-wool by covalent binding within 1 hour. 0.5 gram of this preparation, $DTC-wool-{\alpha}-amylase$, contained 150 ug of enzyme protein and its specific activity was about 90% of the native one. General properties of $DTC-wool-{\alpha}-amylase$ were a little different from optimum temperature, optimum pH, heat stability, kinetic constants and activation energy. An apparent Michaelis constant and maximum velocity of $DTC-wool-{\alpha}-amylase$ were 5.56 mg/ml and 0.37 mg/ml. $min^{-1}$ respectively, while activation energy was 16.6 kcal/mole.

• The Korean Journal of Mycology
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• v.1 no.2
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• pp.15-23
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• 1973

Mold producing cellulase were isolated from rotten woods, and identified as the three species: Aspergillus niger van Tieghem, Aspergillus schiemanni Thom and Trichoderma viride Pers. In this paper, culture conditions in the media and characteristics of these strains were investigated. Using these strains, we have conducted a research concerning the utilization of farm product waste materia's. 1. Optimum conditions for the cellulase formation were as follows. KM 10-1; pH 5.2-5.5, $35^{\circ}C$, incubation time 6 days. OL 11-1; pH 5.5, $30-35^{\circ}C$, incubation time 6 days. SH 9-2; pH 5.5, $30^{\circ}C$, incubatoin time 6 days. 2. Their cellulase activities in their optimum condition were as follows: KM 10-1; CMC-LP 78.5% CMC-SP 4.0 glucose mg/gm of the cultures/min. OL 11-1; CMC-LP 89.9%, CMC-SP 4.9 glucose mg/gm of the cultures/min. SH 9-2; CMC-I.P 77.4%, CMC-SP 3.9 glucose mg/gm of the cultures/min. 3. Hydrolysis of animal feed containing a large quantity (23-30%) of cellulose by means of the crude enzyme in the selected strains resolved 30% of the cellulose contained in the animal feed.

• Journal of Life Science
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• v.28 no.11
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• pp.1339-1346
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• 2018

In Korea, edible mushrooms are produced largely on commercial artificial media, so the annual production of spent mushroom substrate (SMS), as a by-product of the mushroom industry, is estimated at over 200 million tons. This SMS is assumed to contain abundant fungal mycelia and pre-fruiting bodies, as well as various nutritive and bioactive compounds that are presently discarded. This study examined the physico-chemical, nutritional, and enzymatic characteristics of uninoculated sterilized medium (USM) and SMS of shiitake mushrooms with the aim of developing a high-value added product from SMS. The contents of crude protein, crude lipid, and ash were higher after the third SMS harvest ($SMS-A-3^{rd}$) than in USM or $SMS-A-1^{st}$. The contents of Ca, Mg, and P in $SMS-A-3^{rd}$ were 2.95, 2.35, and 2.1-fold higher compared than in USM. No As or Cd was detected in USM or SMS. The pH, Brix, and acidity were 4.6, 20.0, and 1.4, respectively in $SMS-A-3^{rd}$, but 5.6, 6.0, and 0.0, respectively, in USM. These results suggest a highly active production of soluble components and organic acids in $SMS-A-3^{rd}$. The distinct color differences noted for USM, $SMS-A-1^{st}$, and $SMS-A-3^{rd}$ could be used as a mycelial growth indicator. Enzyme activity assays using the APIZYM system showed that SMS is a potent source of hydrolysis-related enzymes, especially esterase (C4) and ${\beta}$-glucuronidase. Our results suggested that the SMS of shiitake has a high potential for use in environmental, agricultural, and stock-breeding industries, for example, as active ingredients for sewage treatment, waste-polymer degradation, and feed additives.

• Food Engineering Progress
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• v.21 no.4
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• pp.318-325
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• 2017

Alcoholic steatosis is a fundamental metabolic disorder and may precede the onset of more severe forms of alcoholic liver disease. In this study, we isolated enzymatichydrolysate from Semisulcospira libertine by alcalase hydrolysis and investigated the protective effect of Semisulcospira libertine hydrolysate on liver injury induced by alcohol in the mouse model of chronic and binge ethanol feeding (NIAAA). In an in vitro study, the hydrolysate protects HepG2 cells from ethanol toxicity. Liver damage was assessed by histopathological examination, as well as by quantitating activities of serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP). After the administration of S. libertina hydrolysate, fat accumulation and infiltration of inflammatory cells in liver tissues were significantly decreased in the NIAAA mouse model. The elevated levels of serum AST, ALT, and ALP activities, along with the lipid contents of a damaged liver, were recovered in experimental mice administrated with S. libertina hydrolysate, suggesting its role in blood enzyme activation and lipid content restoration within damaged liver tissues. Moreover, treatment with S. libertine hydrolysate reduced the expression rate of cyclooxygenase (COX-2), interleukin $(IL)-1{\beta}$, and IL-6, which accelerate inflammation and induces tissue damage. All data showed that S. libertine hydrolysate has a preventive role against alcohol-induced liver damages by improving the activities of blood enzymes and modulating the expression of inflammation factor, suggesting S. libertine hydrolysate could be a commercially potential material for the restoration of hepatotoxicity.

• Research in Plant Disease
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• v.28 no.2
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• pp.69-81
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• 2022

This study was performed to screen the efficacy of antagonistic bacterial isolates from various sources against the bacterial fruit blotch (BFB) causing pathogen (Acidovorax citrulli) in cucurbit crops. In addition, plant growth promoting traits of these antagonistic bacterial isolates were characterized. Two thousand seven hundred ninety-four microorganisms were isolated from the collected samples. Molecular identification revealed two A. citrulli out of 2,794 isolates. In vitro antagonistic results showed that, among the 28 antagonistic bacterial isolates, 24 and 14 bacterial isolates exhibited antagonism against HPP-3-3B and HPP-9-4B, respectively. Antagonistic and growth promotion characterization of the antagonistic bacterial isolates were further studied. Results suggested that, 4 antagonistic bacteria commonly showed both antagonism and growth promotion phenotypes. Moreover, 3 isolates possessed growth promoting activities. Overall results from this study suggests that BFB causing bacterial pathogen (A. citrulli) was suppressed in in vitro antagonism assay by antagonistic bacterial isolates. Furthermore, these antagonistic bacterial isolates possessed growth promotion and antagonistic enzyme production ability. Therefore, data from this study can provide useful basic data for the in vivo experiments which ultimately helps to develop the eco-friendly agricultural materials to control fruit rot disease in cucurbit crops in near future.

• Applied Biological Chemistry
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• v.27
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• pp.29-46
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• 1984

To utilize several species of hard wood as raw materials of feed products, fermentation characteristics of cellulosic substrates to single cell protein was investigated, and results were summarized as follows. Among the microorganisms investigated, Tricoderma viride was selected as one of the most cellulolytic. Mixed culture of fungi did not show a synergistic effect on cellulose degradation. When the fungi were cultured at $28^{\circ}C$ for 7 days in a medium containing wheat bran 25 g, cellulose 0.25 g, proteose peptone 0.025 g and tween 800.025 g, cellulotic activities on carboxy methyl cellulose and filter paper reached maximum at 12 hr. The alkali treatment resulted in increased degradation of substrate from 13 to 18% when treated with enzymes for 12h, and reducing sugar formation increased with decreased size of substrates. Glucose was a very good feedback inhibitor of the enzyme from T.viride than that of xylose. When the substrate was rehydrolyzed, hydrolysis rate was 31% to reducing sugars within 12 hr. Quantative anlysis with HPLC showed the ratio of glucose to xylose in sugar syrups as 1.77 to 1. For the purpose of producing cellulosic-single cell protein from the sawdust of mulberry tree, 15 strains of xylose-assimilating yeast were isolated from 42 samples of rotten woods and compost soils and examined for their ability to utilize xylose. Then three strains were selected by their strong xylose-assimilating activities. The cultivative condition, the growth characteristics, and protein and nucleic acid productivities of three strains were investigated. The results obtained were, 1. Wood hydrolysate of mulberry tree was assimilated by 5 strains of CHS-2, CHS-3, ST-40, CHS-12 and CHS-13. 2. The optimum initial pH and temperature for the growth of strain CHS-13 were 4.4 and $30^{\circ}C$. 3. The specific growth rate of strain CHS-13 was $0.23h^{-1}$ and generation time was 3.01 hrs at the optimum condition. 4. CHS-13 strain assimilated 81 % of sugar in wood hydrolysate. 5. CHS-13 strain was identified as Candida guilliermondii var. guilliermondii 6. When the CHS-13 strain was cultured in the wood hydrolysate containing yeast extract, L-protein content was increased with yeast extract concentration. 7. The L-protein and nucleic acid yields from wood hydrolysate were 0.73 mg/ml and $4.92{\times}10^{-2}\;mg/ml$ respectively. 8. An optimal nucleic acid content of CHS-13 strain was observed in the medium containing 0.2% of yeast extract.

• Journal of Dairy Science and Biotechnology
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• v.34 no.2
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• pp.99-116
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• 2016

We herein performed animal safety assessment in accordance with Good Laboratory Practice (GLP) regulations with the aim of developing sialic acid from glycomacropeptide (hereafter referred to as "GMP") as an index ingredient and functional component in functional foods. GMP is a type of whey protein derived from milk and a safe food, with multiple functions, such as antiviral activity. A test substance was produced containing 7% (w/w) sialic acid and mostly-hydrolyzed whey protein (hereafter referred to as "7%-GNANA") by enzymatic treatment of substrate GMP. The maximum intake test dose level was selected based on 5,000 mg/kg/day dose set for male NOEL (no-observed-effect-level) and female NOAEL (no-observed-adverse-effect-level) determined by a dose-range finding (DRF) test (GLP Center of Catholic University of Daegu, Report No. 15-NREO-001) that was previously conducted with the same test substance. To evaluate the toxicity of a repeated oral dose of the test substance in connection with the previous DRF study, 1,250, 2,500, and 5,000 mg/kg of the substance were administered by a probe into the stomachs of 6-week-old SPF Sprague-Dawley male and female rats for 90 d. Each test group consisted of 10 male and 10 female rats. To determine the toxicity index, all parameters, such as observation of common signs; measurements of body weight and food consumption; ophthalmic examination; urinalysis, electrolyte, hematological, and serum biochemical examination; measurement of organ weights during autopsy; and visual and histopathological examinations were conducted according to GLP standards. After evaluating the results based on the test toxicity assessment criteria, it was determined that NOAEL of the test substance, 7%-GNANA, was 5,000 mg/kg/day, for both male and female rats. No animal death was noted in any of the test groups, including the control group, during the study period, and there was no significant difference associated with test substance, as compared with the control group, with respect to general symptoms, body weight changes, food consumption, ophthalmic examination, urinalysis, hematological and serum biochemical examination, and electrolyte and blood coagulation tests during the administration period (P<0.05). As assessed by the effects of the test substance on organ weights, food consumption, autopsy, and histopathological safety, change in kidney weight as an indicator of male NOAEL revealed up to 20% kidney weight increase in the high-dose group (5,000 mg/kg/day) compared with the change in the control group. However, it was concluded that this effect of the test substance was minor. In the case of female rats, reduction of food consumption, increase of kidney weight, and decrease of thymus weight were observed in the high-dose group. The kidney weight increased by 10.2% (left) and 8.9% (right) in the high-dose group, with a slight dose-dependency compared with that of the control group. It was observed that the thymus weight decreased by 25.3% in the high-dose group, but it was a minor test substance-associated effect. During the autopsy, botryoid tumor was detected on the ribs of one subject in the high-dose group, but we concluded that the tumor has been caused by a naturally occurring (non-test) substance. Histopathological examination revealed lesions on the kidney, liver, spleen, and other organs in the low-dose test group. Since these lesions were considered a separate phenomenon, or naturally occurring and associated with aging, it was checked whether any target organ showed clear symptoms caused by the test substance. In conclusion, different concentrations of the test substance were fed to rats and, consequently, it was verified that only a minor effect was associated with the test substance in the high-dose (5,000 mg/kg/day) group of both male and female rats, without any other significant effects associated with the test substance. Therefore, it was concluded that NOAEL of 7%-GNANA (product name: Helicobactrol) with male and female rats as test animals was 5,000 mg/kg/day, and it thus was determined that the substance is safe for the ultimate use as an ingredient of health functional foods.

• Applied Biological Chemistry
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• v.7
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• pp.105-117
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• 1966

This experiment was conducted to investigate the effet of phthalimido-methyl-O,O-dimethyl-phosphorodithioate (Imidan) known as an acaricide and its possible metabolic products on the growth of plant, when sprayed on the leaves of rice plant. The results are summarized as follows. 1) Possible metabolic products of Imidan, the following compounds were synthesized or recrystallized for the present experiment a) N-Hydroxymethyl phthalimidem b) Phthalimide c) Phthalamidic acid d) Phthalic acid e) Anthranilic acid f) p-Amino benzoic acid g) p-Hydroxy benzoic acid h) Benzoic acid 2) Among the above materials, a), c), d), e), and Imidan were dissolved in a buffer solution respectively to be 10 and 20 p.p.m. and tested with the wheat coleoptile straight growth method. According to the results, Imidan inhibited the growth of coleoptile in both 10 and 20 p.p.m., whereas the others showed much better growth than the control, especially phthalamidic acid in 10 p.p.m. It appears that Imidan itself inhibits the coleoptile growth, whereas the metabolites derived from Imidan through various metabolisms, including hydrolysis in plant tissues show growth-regulating activity. (refer: Table 1, Fig. 1) 3) 20, 100 and 200 p.p.m. solutions of Imidall emulsion in xylene f·ere prepared. The lengths of shoot and root of rice seeds germinated on the re-respective media were measured after 12 days. The data showed that root was much more elongated in Imidan 20 p.p.m., whereas shoot in Imidan 100 p.p.m., respectively, than in the xylene control. An interesting finding was that xylene used as solvent had a tendency to inhibit seriously the root growth of rice seed. (refer: Table 2,5). 4) The emulsions of concentrations in 10, 25, 50 and 100 p.p.m's of control, Imidan, N-hydroxy methyl phthalimide, anthranilic acid, and phthalmide, respectively, were sprayed twice on the rice plant on pot. After a certain period of time lengths of rice culms were measured, showing that plots treated with Imidan and N-hydroxy methyl phthalimide exhibited much more growth than those of control and the others. 5) Loaves and stems of rice plant were sampled and extracted with dried acetone at the intervals of 3-, 5-, 7-, and 14 days after treated with Imidan 250 p.p.m. emulsion. This sample extracted with acetone was purified by means of prechromatographic purification method with acetonitrile and paperchromatographed to detect the following metabolic products. Imidan (Rf: 0.97-0,98), N-hydroxy-methyl phthalimide (Rf: 0.87) phthalimide (Rf: 0.86-0.87), phthalamidic acid (Rf: 0.13-0.14), phthalic acid (Rf: 0.02-0.03), benzoic acid (Rf: 0.42-0.43), p-amino benzoic acid or p-hydroxy benzoic acid (Rf: 0.08-0.09), and unidentified compounds (Rf: 0.73, 0.59, 0.33, 0.23. 0.07). In addition, in the early stages, such as 3- and 5 days nonhydrolyzed Imidan and its first hydrolytic product, N-hydroxymethyl phthalimide were detected in relatively large amounts, whereas in the last stages of 7- and 14 days due to further decomposition, the afore-mentioned two materials were reduced in the amount and p-hthalic, phthalamidic, benzoic, and p-Hydroxy benzoic, or p-Amino benzoic acids were detected in a considerably large amount. It is, therefore, believed that most of Imidan applied to the leaves of rice plant may be decomposed within almost 14 days. In the light of above observations it is considered that Imidan itself is not involved in plant growth regulating activity, whereas various phthaloyl derivatives produced in the course of metabolism (namelr, enzymic action) in plant tissues may have such effect.