• Journal of the Korean Society of Food Science and Nutrition
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• v.15 no.1
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• pp.69-74
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• 1986

In order to examine the effect of 'Lactobacillus plantarum' inoculation on the maturation of cured loin ham, bacteriological and biochemical changes in meat were investigated during curing periods. The results were summarized as follow; On the bacteriological changes of cured ham, during curing periods, the number of coliform group were decreased. while psychrotrophic and halo-tolerant bacteria were increased until the 4 days. In the brine solution after the 7days of the curing, the number of coliform group were decreased the 7 days, but psychrotophic and halo-tolerant bacteria were increased until the 7 days of curing. The pH value of the meat and curing solution were sharply decreased at the one day, since these were slightly increased from 4 days. The color development of cured meat was showed 84.05 % development of within the 7 days of curing. Glutamic acid contents among the 17 kinds of amino acid were the highest at the 7 and 10 days of curing. The 13 kinds of fatty acids detected from at the all sample and total contents of unsaturated fatty acid were slightly decreased during curing.

• Microbiology and Biotechnology Letters
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• v.24 no.3
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• pp.268-273
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• 1996

An extremely cadmium tolerant yeast, Hansenula anomala B-7 used to determine the modification of the intracellular enzyme activities by cadmium ion. The activities of alcohol dehydrogenase, phosphofructokinase, and cytidine deaminase were decreased up to 90%, 40%, and 86% compa- red with the control by 1 mM cadmium nitrate respectively, but the activities of malate dehydrogenase, 6- phosphogluconate dehydrogenase, cytochrome c oxidase, and alkaline phosphatase were increased up to 440%, 136%, 260% and 155% compared with the control by 1 mM cadmium nitrate respectively. These results show that the activities of the enzymes participating in Embden-Mayerhof pathway (e.g. anaerobic metabolism) were reduced by cadmium, but those involved in hexose monophosphate pathway and tricarboxylic acid cycle (e.g. aerobic metabolism) were stimulated in contrast. It has been suggested that the diminished activity of cytidine deaminase in pyrimidine nucleotide dissimilation occured due to the inhibited nucleotide dissimilation by cadmium ion; the enhanced activity of cytochrome c oxidase was specifically required in order to oxidize a raised amount of NADH and NADPH due to the increased aerobic metabolism.

• Journal of Microbiology and Biotechnology
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• v.16 no.3
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• pp.431-437
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• 2006

Aero-tolerant microorganisms were isolated from healthy Koreans over the age of 95 years. The microorganisms were then identified based on their morphological and biochemical characteristics and 16S rDNA sequences. The growth properties of the isolated strains were investigated in kimchi. The characteristics of kimchi containing the microorganisms were studied microscopically, physicochemically, and organoleptically. Among 7 aero-tolerant strains, a strain with a 16S rDNA sequence exhibiting 99% homology with Bifidobacterim animalis strain B83 was selected and named B. animalis DY-64. The new strain showed a better acid resistance and salt resistance (p<0.05) than B. animalis ATCC 25527. After 15 days of fermentation in kimchi, the viability of B. animalis DY-64 was about 10%, and the kimchi had a better overall edible quality than conventional kimchi. Thus, it was found that the application of B. animalis DY-64 to kimchi preparation produced a good overall edible quality.

• Journal of the Korean Chemical Society
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• v.52 no.1
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• pp.23-29
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• 2008

Simple Keggin type tungsten and molybdenum heteropoly acids, H3PW12O40 and H3PMo12O40, were usedas water-tolerant catalysts for the oxidation of alcohols with 34% hydrogen peroxide in normal drinking water. Accordingto our findings, H3PW12O40 may be used as a simple, effective, and cheap catalyst for this type of transformation in nor-mal drinking water with excelent yields. Efects of diferent solvents at 25-80oC and changing concentration of catalystand substrate on the reaction progress were also studied.

• Korean Journal of Weed Science
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• v.17 no.3
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• pp.325-333
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• 1997

Selection of pepper (Capsicum sp.) cultivars tolerant to acetolactate synthase (ALS)-inhibiting herbicides {imazethapyr, 2-[4,5-dihydro-4-methyl-4-(1-methylethyl)-5-oxo-1H-imidazol-2-yl]-5-ethyl-3=pyridine-carboxylic acid, and primisulfuron methyl 2-[[[[[4,6-bis(difluoromethoxy)-2-pyrimidinyl]amino] carbonyl]amino]sulfonyl]benzoate} was investigated. Pepper cultivars such as Red Top, Happy Dry, Golden Tower, and Hagyeorae showed relatively tolerant response to imazethapyr, while cultivars; Korea, Cheongyang, Oriental Glory, and Hanam were susceptible. Red Horn, Jopoong, Kwangbok, and Wangcho cultivars were tolerant to primisulfuron whereas Korea, Dahhong, Chamjoah, and Poongchon cultivars were susceptible. Determination of growth inhibition by ALS-inhibiting herbicides showed that the $I_{50}$ estimates of growth from the susceptible- and tolerant-cultivars were 0.075 and 0.20kg ai/ha for imazethapyr; 0.06 and 0.16kg ai/ha for primisulfuron, respectively. Furthermore, the $GR_{50}$ estimates of growth from the susceptible and tolerant cultivars were 0.05 and 0.20kg ai/ha for imazethapyr; 0.07 and 0.16kg ai/ha for primisulfuron, respectively. This result, based on the $GR_{50}$ and $I_{50}$ values, indicates that responses of pepper to ALS-inhibiting herbicides between tolerant- and susceptible-cultivars were different about 3- to 4-fold to imazethapyr, and 2- to 3-fold to primisulfuron.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.11
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• pp.1612-1617
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• 2009

Aspergillus sp. 101 was isolated from the Korean traditional soybean paste for the production of a salt-tolerant protease. The optimal condition for the production of a salt-tolerant protease was determined with various energy sources such as carbon, nitrogen, and protein, and at different culture conditions such as temperature, pH, incubation time and NaCl concentration. The most favorable organic nitrogen sources were 2% defatted soybean flour (DSF) and soy protein isolate (SPI). Optimal pH and temperature were pH 6.0 and $25{\sim}27^{\circ}C$, respectively. Therefore, Aspergillus sp. 101 protease was a mild acid (or neutral) protease. Protease production was the highest at 0.1% concentration of $CaCO_3,\;K_2HPO_4$ and Arabicgum. Aspergillus sp. 101 could grow in culture medium at 15% NaCl concentration and produce a salt-tolerant protease even at 7% NaCl. The cell mass and protease activity of Aspergillus sp. 101 cultured in a modified medium was comparatively higher in Czapek dox and protease producing media. Hence, Aspergillus sp. 101 protease can be utilized in soy or fish sauce industry as a salt-tolerant protease starter.

• Journal of Microbiology and Biotechnology
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• v.30 no.10
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• pp.1500-1509
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• 2020

Drought is a major abiotic factor and has drastically reduced crop yield globally, thus damaging the agricultural industry. Drought stress decreases crop productivity by negatively affecting crop morphological, physiological, and biochemical factors. The use of drought tolerant bacteria improves agricultural productivity by counteracting the negative effects of drought stress on crops. In this study, we isolated bacteria from the rhizosphere of broccoli field located in Daehaw-myeon, Republic of Korea. Sixty bacterial isolates were screened for their growth-promoting capacity, in vitro abscisic acid (ABA), and sugar production activities. Among these, bacterial isolates YNA59 was selected based on their plant growth-promoting bacteria traits, ABA, and sugar production activities. Isolate YNA59 highly tolerated oxidative stress, including hydrogen peroxide (H₂O₂) and produces superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) activities in the culture broth. YNA59 treatment on broccoli significantly enhanced plant growth attributes, chlorophyll content, and moisture content under drought stress conditions. Under drought stress, the endogenous levels of ABA, jasmonic acid (JA), and salicylic acid (SA) increased; however, inoculation of YNA59 markedly reduced ABA (877 ± 22 ng/g) and JA (169.36 ± 20.74 ng/g) content, while it enhanced SA levels (176.55 ± 9.58 ng/g). Antioxidant analysis showed that the bacterial isolate YNA59 inoculated into broccoli plants contained significantly higher levels of SOD, CAT, and APX, with a decrease in GPX levels. The bacterial isolate YNA59 was therefore identified as Variovorax sp. YNA59. Our current findings suggest that newly isolated drought tolerant rhizospheric Variovorax sp. YNA59 is a useful stress-evading rhizobacterium that improved drought-stress tolerance of broccoli and could be used as a bio-fertilizer under drought conditions.

• Journal of Microbiology and Biotechnology
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• v.13 no.1
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• pp.90-98
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• 2003

In vivo $^31p$ Nuclear Magnetic Resonance ($^31p$NMR) and metabolic studies were carried out on an acetic acid tolerant mutant, Zymomonas mobilis $ZM4/Ac^R$, and compared to those of the parent strain, Z. mobilis ZM4, to evaluate possible mechanisms of acetic acid resistance. This investigation was initiated to determine whether or not the mutant strain might be used as a suitable recombinant host far ethanol production from lignocellulose hydrolysates containing various inhibitory compounds. $ZM4/Ac^R$ showed multiple resistance to other lignocellulosic toxic compounds such as syringaldehyde, furfural, hydroxymethyl furfural, vanillin, and vanillic acid. The mutant strain was resistant to higher concentrations of ethanol or lower pH in the presence of sodium acetate, compared to ZM4 which showed more additive inhibition. in vivo $^31p$ NMR studies revealed that intracellular acidification and de-energization were two mechanisms by which acetic acid exerted its inhibitory effect. For $ZM4/Ac^R$, the internal pH and the energy status were less affected by sodium acetate compared to the parent strain. This resistance to pH change and de-energization caused by acetic acid is a possible explanation for the development of resistance by this strain.

• Korean Journal of Soil Science and Fertilizer
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• v.22 no.1
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• pp.72-77
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• 1989

A study was conducted to obtain acid tolerant and superior Rhizobium meliloti strain for alfalfa on hilly acid soils. With host plant, eight isolates of R, meliloti selected in the vicinity of Milyang were evaluated for their ability to establish symbiotic effectiveness in acidified tube culture medium and vermiculite pot with different urea levels. Among isolates "YA03" was characterized for the ability to manifest to acid tolerance in three different soils of which pH were 5.0, 6.0, and 7.5. The results obtained were summarized as follows: 1. Of eight isolates "YA03" and "YA09" performed nodule in the tube medium of pH5.0, and in the symbiotic effectiveness YA03 was superior to others. 2. Alfalfa growth and $N_2-fixing$ activity by the inoculation of "YA03" isolate were better than others at the level of urea 1.25mM as well as nonurea. 3. Application of urea with inoculation of "YA03" islate to alfalfa was one of the effective factors for symbiotic effectiveness. 4. In infertile soil of pH5.0 inoculation of R. meliloti "YA03" to alfalfa caused the increase of shoot dry matter of 320% as compared to the control, and the total amount of yield was 131% as much yield in moderate fertile soil of pH7.5. Finally R. meliloti "YA03" isolate was selected as an acid tolerant strain.

• Archives of Pharmacal Research
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• v.16 no.1
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• pp.57-61
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• 1993

Based on the turbidimetric response of protein with 50% trichloroacetic acid (TCA), this study aims to introduce an assay method for protein in solution. The standard procedure consists of mixing equal volume of sample solution (standard or unknown) with 50%-TCA solution and measuring the absorbance at 450 nm after 20 min. The absorbances of the solutions were almost stable over 120 min at room temperature. This assy method is simple, reproducible, and tolerant to many interfering substances. It can detect less amount than $10\mu$g/ml of bovin serum albumin. The assay method has low protein-to-protein variability over wide range of molecular weight.