• Title/Summary/Keyword: Acid and Alkali

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Biochemicl Caracterization of Entomocidal Parasporal Crystals of Bacillus thuringiensis Strains (Bacillus thuringiensis 결정성독소의 생화학적 특성)

  • Lee, Yeong-Geun;Gang, Seok-Gwon;Kim, Sang-Hyeon
    • Journal of Sericultural and Entomological Science
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    • v.31 no.1
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    • pp.37-44
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    • 1989
  • The parasporal crystals of Bacillus thuringinsis subspecies kurstaki, dendrolimus, finitimus, aizawai and israelensis were compared by polyacrylamide electrophoresis, amino acid composition and immunological analysis. In the subspecies of kurstaki, dendrolimus, finitimus and aizawai, the molecular weights of main subusnits of crystal solubilized by alkaline solution were 1.3${\times}$105 and 6.5${\times}$104 while those of subsp. israelensis were 4${\times}$104 and 1,4${\times}$104. The degradation of lepidopteran toxic subspecies crystals by silkworm midgut protease showed 6.0-6.4${\times}$104 molecular weight and the pattern of degradation of subsp. israelensis crystals was similar to that of alkaline solution treatment. In the amino acid composition, aspartic acid in subsp. israelensis and glutiamic acid in the other four subspecies were the most abundant. The immunological characteristics of the crystals revealed that the antibody produced against the alkali-solubilized crystal protein of subsp. israelensis reacted with only its antigen, but the crystal antigens from the other four lepidopteran toxic subspecies did cross-react with each other as well as with their own homologous antisera.

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Chemical Characteristics of Commercial Korean Soy Sauce Produced by Alkali Treatment Following Acidic Hydrolysis

  • Cho, Woo-Jin;Kim, Hun;Jeong, Eun-Jeong;Lee, Young-Mi;Kim, Hyoun-Jin;Lee, Jung-Suck;Cha, Woung-Jun
    • Preventive Nutrition and Food Science
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    • v.7 no.4
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    • pp.427-431
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    • 2002
  • Alkali treatment following acidic hydrolysis (ATAH) is a commonly used practice for reducing the levels of monochloropropanediol in commercial Korean soy sauce. This study investigated the chemical compounds produced in commercial Korean soy sauce made by ATAB. The levels of amino-N, total acidity, pH, salinity and Brix of the soy sauce were 6.66%, 2.52%, 19.81%, 4.57 and 35.01, respectively. The major fatty acids were C18:2n-6, C16:0, Cl8:ln-9 and C18:3n-6. The concentration of polyunsaturated fatty acids were especially high, with of C18:2n-6 (49.8%) being the highest followed by C18:3n-6 (3.8%) and C18:3n-3 (2.4%) in that order. Among the non-volatile organic acids, the concentration of levulinic acid (1,206.28 mg/100 g) was the highest, while the taste value of citric acid was the highest. Among the ATP related compounds, IMP concentration (31.19 mg/100 g) was highest followed by AMP, hypoxanthine and GMP in that order. The concentrations of free and total amino acids in soy sauce were 6,136.94 mg/100 g and 8,702.76 mg/100 g, respectively. On the other hand, the taste value of glutamic acid, a major amino acid flavor determinant in soy sauce, was highest of all the amino acids, which is desirable since most free amino acids such as methionine, histidine and phenylalanine have a bitter taste that detracts from the flavor of soy sauce.

Effects of Solvent Treatment of Bamboo Fiber on Physical Properties of Polypropylene/Glass Fiber/Bamboo Fiber Composite (엔진커버용 폴리프로필렌/유리섬유/대나무섬유 복합체의 물리적 특성에 대한 대나무섬유의 용제 처리의 영향)

  • Lee, Su Kyoung;Lim, Sung Wook;Shin, Hyung Shik;Woo, Seung-Keon;Park, Eun Young
    • Textile Coloration and Finishing
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    • v.31 no.1
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    • pp.42-47
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    • 2019
  • In this study, the effects of surface treatment of bamboo fiber on the physical properties of polypropylene(PP)/glass fiber(GF)/Bamboo fiber(BF) composite for engine cover were investigated. PP, GF and BF were fixed at 40%, 40% and 20% and the surface of bamboo fibers were treated to 0.5, 1.0 and 2.0% as an acid and alkali solution. PP/GF/BR composites using surface treated bamboo fibers were prepared and their tensile strength, bursting strength and impact strength were measured by universal testing machine(UTM). The composites with alkali treated bamboo fiber showed better mechanical properties than the acid treated composites. It was checked that the optimum alkali content was at 1.0% from the results of mechanical properties. The effect of surface treatment on the mechanical properties was confirmed by SEM images of fractured surface.

Hydrolysis of Silk Fibroin on Alkali Conditions (견 피브로인의 알칼리 가수분해)

  • 김남정;배도규
    • Journal of Sericultural and Entomological Science
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    • v.39 no.2
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    • pp.197-202
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    • 1997
  • To hydrolyze silk fibroin was treated with NaOH solution on various concentrations and times. And it was examined that the addition effects of NaHSO3 solution on the solubility and colouring of silk fibroin. As obtained results are as follows; The more increasement of concentration and time of NaOH treatment, the more increasement of solubility but solubility was slight above 3% concentration of NaOH. Fibroin yield was decreased above 3% concentration. This was due to formation of peptide or amino acids below molecular weight 3,000. Most of molecular weight distribution came out to be under 3,000 in 2% concentration and 4hrs of NaOH treatment. The more increasement of adding concentration and 4hrs of NaOH treatment. The more increasement of adding concentration of NaHSO3, the more reduction of solubility but white index of powder increased. In the results of FT-IR spectras of silk fibroin powder obtained by various concentrations of NaHSO3 treatment, the absorbent peak at 3,400 cm-1 which was considered as -CH=N- (azomethine) was disappeared by the more addition of NaHSO3. It showed that absorbent peak of $\beta$-fibroin moved into low temperature region and transferred to $\alpha$- and random coil structure through the DSC experiment. In the results of amino acid analysis, alkali hydrolysis reduced the oxy amino contents acid like serine and tyrosine, but increased the glycine content by the more addition of NaHSO3.

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Isolation and Characterization of Biopolymer Producing Alkali-Tolerant Bacterial Strain (생물고분자 생산 알칼리 내성 균주의 분리 및 특성)

  • Lee, Shin-Young;Lee, Beom-Su;Shin, Weon-Chul;Kwon, Ik-Boo;Yu, Ju-Hyun
    • Korean Journal of Food Science and Technology
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    • v.23 no.2
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    • pp.161-166
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    • 1991
  • For the production of useful products from microorganism, a bacterial strain producing the biopolymer was isolated from soil. The bacteriological characteristics of the strain were examined and some chemical properties of the biopolymer produced were investigated. The bacterial strain was identified as an alkali-tolerant Bacillus sp. The results of chemical composition, various color reactions and I.R. spectrum revealed that the biopolymer contained high protein content, low amino sugar and no uronic acid. However, the biopolymer was precipitated by treating with cetylpiridinium chloride and was found to be acidic.

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Estimation of Alkali Overdosing in a Lime Neutralization Process for Acid Mine Drainage

  • Cheong, Young-Wook;Cho, Dong-Wan;Lee, Jin-Soo;Hur, Won
    • Applied Chemistry for Engineering
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    • v.33 no.1
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    • pp.109-112
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    • 2022
  • Lime has been used for the neutralization of acidic waste because it is cheap and available in large quantities. The resulting sludge often contains a considerable amount of unreacted lime due to alkali overdosing, even during automatic neutralization processes, which mainly arises from the poor solubility of lime. The sludge cake from lime neutralization of Ilkwang Mine also contained high percentages of calcium and magnesium. The elemental content of the sludge cake was compared with those obtained from a simulation of the lime neutralization facility installed at Ilkwang Mine. A Goldsim® model estimated the degree of lime overdosing to be 19.1% based on the fractions of ferrous oxide. The analysis suggests that resolubilization of aluminum hydroxide could occur in the settling basin, in which pH exceeded 10 due to the continued dissolution of the overdosed lime. The present study demonstrated that chemical analysis of sludge combined with process simulation could provide a reasonable estimate of mass balance and chemistry in a neutralization facility for acid mine drainage.

The Dependency of the Expression Level of Recombinant Protein by the Drop of Alkali Consumption Rate after Induction (발현유도에 의한 알칼리 소비속도의 감소가 재조합 단백질 생산에 미치는 영향)

  • Hur, Won
    • KSBB Journal
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    • v.21 no.4
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    • pp.236-240
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    • 2006
  • IPTG induction caused a sudden drop of alkali consumption rate during cultivation of a recombinant E. coli with ${\beta}$-galactosidase structural gene under T7 promoter on a plasmid. A series of batch cultivations showed the positive correlation of the decrease of alkali consumption and the level of expression. However, repeated IPTG induction did not cause any variation of alkali consumption rate. Supplementation of medium even at stationary phase enhanced the level of ${\beta}$-galactosidase expression. These results suggests that the drop of alkali consumption rate by IPTG induction represents the rate of expression.

Effect of Blanching Condition, Acid and Alkali Treatments on the Qualities of Carrot Juices (Blanching 조건(條件) 및 산(酸)·알칼리 처리(處理)가 당근주우스의 품질(品質)에 미치는 영향(影響))

  • Kim, Woon Sung;Kim, Seung Yeol
    • Korean Journal of Agricultural Science
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    • v.10 no.1
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    • pp.135-145
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    • 1983
  • This study was conducted to obtain the fundamental data for the processing of carrot juices and know the effects of blanching conditions, acid and alkali treatments and sterilization on the quality factors of carrot juices. The result obtained was as follows. 1. Blanching condition, $100^{\circ}C$, 5min. was the most effective for the Brix, amino-N content, suspended solid, light transmittance and yield of carrot juices among $90^{\circ}C$, 15min., $95^{\circ}C$, 10 min., and $100^{\circ}C$, 5min. 2. 0.05N-acetic acid solution was the most effective blanching solution for the suspended solid, light transmittance, viscosity and yield of the juices compared to 0.05N-citric acid and 0.03N-hydrochloric acid solution. 3. The color changes during the processing of carrot juices caused by blanching process rather than sterilization process. 4. The ${\beta}$-carotene in carrot juices was very stable and about 80 % of it was remained in the carrot juice which had been blanched, extracted and sterilized at $115^{\circ}C$ for 30min. 5. Alkali treatment for the juice from acid - blanched carrots formed discoloration after sterilization. 6. Relative content (%) of sugars in raw carrot juice we re ribose, 8.51%; fructose. 10.15%; glucose, 12.25%; sucrose, 49.53% and oligosaccharide, 19.56%. When the carrots were blanched in boiling water, the contents of monosaccharide and disaccharide decreased slightly but that of oligosaccharide increased slightly, however, when the carrots were blanched in acid solution, and then neutralized and sterilized, relative contents of ribose and sucrose decreased remarkably but that of oligosaccharide increased considerably and those of glucose and fructose increased slightly. 7. Nineteen sorts of free amino acid were detected from the carrot juices and the mains of them were threonine+asparagine, alanine, serine+glutamine, aspartic acid, arginine, and glutamic acid.

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Isolation and Physiological Characteristics of Rhizobia with Good Nitrogen Fixation Ability (우량질소고정균(優良窒素固定菌)의 탐색분리(探索分離) 및 생리적(生理的) 특성(特性))

  • Park, Woo-Churl;Lee, Kwang-Hee;Kim, Jin-Ho;Rhee, In-Koo;Jo, Jin-Ki
    • Current Research on Agriculture and Life Sciences
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    • v.5
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    • pp.40-51
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    • 1987
  • This experiment was conducted to search for Rhizobia with good nitrogen fixation abilities and to investigate their physiological characteristics isolated from 12 soybean cultivars and the affinities of root nodule bacteria with soybeans. The results obtained were as follows; Based on colors, Rhizobia grown on YMA medium were divided into 3 groups, i. e., white, translucent and transparent, amounting to 60, 30 and 10%, respectively. In litmus milk reaction, the strains which produced alkali, acid serum, alkaline serum and acid reached to 51, 29, 9 and 11%, respectively. Strains, S022, and S096 were slow-growers and produced alkaili, while strains, S080, S-090, and S118 were fastgrowers and produced acid. The growth of root nodule bacteria on YMA medium was favorable between the initial pHs of 6.0~7.0. Glutamine, asparagine and al1antoin as nitrogen sources enhanced the growth of root nodule bacteria. All the strains tested formed nodules on the soybean roots, and the strains with good symbiotic nitrogen fixation abilities that had white color, small colony, nitrate reduction abilities and no nitrite reduction abilities showed comparatively high nitrogen fixing activities. Some strains varied in nitrogen fixing activities according to soybean cultivars, and a few strains fanned ineffective nodules which showed no nitrogen fixing activity.

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Antitumor and Antioxidant Activities of the Extracts from Fruiting Body of Phellinus linteus

  • Lee, June-Woo;Baek, Seong-Jin;Bae, Woo-Chul;Park, Jeong-Min;Kim, Yong-Seok
    • Mycobiology
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    • v.34 no.4
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    • pp.230-235
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    • 2006
  • Fruiting bodies of Phellinus linteus were extracted by hot water and alkali methods. Sugar contents of PL-H (hot water extract) and PL-A (alkali water extract) were 81.1%, 37.4% and protein contents were 6.2%, 21.8%, respectively. Amino acid pattern showed that two extracts contained large amount of aspartic acid and alanine. Two extracts showed characteristic IR absorption pattern for glycosidic bond at $890\;cm^{-1}$. PL-H was divided two fractions by gel filtration chromatography and the molecular weights of each fraction were estimated to be about 10 kD and 225 kD, respectively and also PL-A was estimated 10 kD. Two extracts showed strong antitumor, immunomodulating and antioxidant activities, and were compared with commercialized glycopeptide anticancer drugs.