• Korean Journal of Environmental Agriculture
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• v.42 no.4
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• pp.259-268
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• 2023

Rhodococcus sp. 3-2 strain has been reported to degrade benzimidazole-based pesticides, such as benomyl and carbendazim. Therefore, this study aimed to optimize culture medium composition and culture conditions to achieve cost-effective and efficient large-scale production of the Rhodococcus sp. 3-2 strain. The study identified that the optimal media composition for mass culture comprised 0.5% glucose, 0.5% yeast extract, 0.15% NaCl, 0.5% K₂HPO₄, 0.5% sodium succinate, and 0.1% MgSO₄. Additionally, a microbial agent was developed using a 1.5-ton fermenter, with skim milk (20%), monosodium glutamate (15%), and vitamin C (2%) as key components. The storage stability of the microbial agent has been confirmed, with advantages of low temperature conservation, which helps to sustain efficacy for at least six months. We also assessed the benomyl degradation activity of the microbial agent within field soil. The results revealed an over 90% degradation rate when the concentration of viable cells exceeded 2.65 × 10⁶ CFU/g after a minimum of five weeks had elapsed. Based on these findings, Rhodococcus sp. 3-2 strain can be considered a cost-effective microbial agent with diverse agricultural applications.

• Journal of fish pathology
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• v.36 no.2
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• pp.251-261
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• 2023

Photobacterium sp. YW2207 was isolated from rainbow trout raised in a fish farm located in Yeongwol-gun, Gangwon Province, South Korea. Based on 16S rRNA sequence analysis and phylogenetic analysis, it was confirmed that Photobacterium sp. YW2207 showed 100% similarity with Photobacterium piscicola and Photobacterium phosphoreum, and 94.6% similarity with P. damselae subsp. damselae. Biochemical analysis revealed that Photobacterium sp. YW2207 is a Gram-negative, motile bacterium with a cell size of 1.5~3×3~5 ㎛. The bacteria were cultured on nutrient agar, brain heart infusion agar, Muller-Hinton agar, tryptic soy agar, and thiosulfate citrate bile sucrose agar with NaCl concentrations ranging from 0 to 2.5%. The API50CHE and API20E tests indicated lower utilization capabilities compared to the P. damselae strains provided in the API database. Furthermore, unlike most Photobacterium species, Photobacterium sp. YW2207 presented negative for catalase test. Results from the flow cytometric measurement indicated that Photobacterium sp. YW2207 exhibited a more diverse distribution of cell sizes and had larger cell sizes compared with P. damselae subsp. damselae. Minimum inhibitory concentration tests showed that Photobacterium sp. YW2207 had low susceptibility to β-Lactam and aminoglycoside antibiotics, while having high susceptibility to tetracycline, doxycycline, and quinolone antibiotics. Pathogenicity on rainbow trout revealed that an immersion of 1×10⁵ CFU/ml did not cause mortality or clinical symptoms.

• Korean Journal of Plant Resources
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• v.9 no.2
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• pp.105-112
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• 1996

Physicochemical properties of Youngia sonchifolia were compared according to harvesting time and brine methods for its Kimchi preparation. Moisture contents in the roots and the leaves of Y. sonchifolia grown for 5 weeks was more than those grown for 11 weeks. 5-week-grown Y. sonchifolia contained more total free sugar than 11-week-grown ones, and among total free sugar the content of fructose was the most, and the contents of glucose and sucrose were rather high. The roots of 11-week-grown Youngia sonchifolia were harder than those of 5-week grown ones. When the roots were soaked in NaCl solution, the hardness decreased with time. Salt concentration of the Kimchi of Y. sonchifolia increased by the brined material of the Kimchi with soaking time.Salt concentration of the Kimchi was higher in the leaves than in the roots.The roots and leaves of Y.sonchifolia grown for 11 weeks contained organic acids such as malic acid, oxalic acid, succinic acid,lactic acid, and citric acid,among which major organic acids were malic acid, oxalic acid, succinic acid, whereas lactic acid and citric acid were minor organic acids.

• Journal of Life Science
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• v.18 no.10
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• pp.1377-1383
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• 2008

A bacterium producing non- or partially digestible dextran was isolated from kimchi broth by enrichment culture technique. The bacterium was identified tentatively as Leuconostoc sp. strain SKY. We established the response surface methodology (Box-Behnken design) to optimize the principle parameters such as culture pH, temperature, and yeast extract concentration for maximizing production of dextran. The ranges of parameters were determined based on prior screening works done at our laboratory and accordingly chosen as 5.5, 6.5, and 7.5 for pH, 25, 30, and $35^{\circ}C$ for temperature, and 1, 5, and 9 g/l yeast extract. Initial concentration of sucrose was 100 g/l. The mineral medium consisted of 3.0 g $KH_2PO_4$, 0.01 g $FeSO_4{\cdot}H_2O$, 0.01 g $MnSO_4{\cdot}4H_2O$, 0.2 g $MgSO_4{\cdot}7H_2O$, 0.01 g NaCl, and 0.05 g $CaCO_3$ per 1 liter deionized water. The optimum values of pH and temperature, and yeast extract concentration were obtained at pH (around 7.0), temperature (27 to $28^{\circ}C$), and yeast extract (6 to 7 g/l). The best dextran yield was 60% (dextran/g sucrose). The best dextran productivity was 0.8 g/h-l.

• Journal of Preventive Medicine and Public Health
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• v.21 no.1 s.23
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• pp.183-194
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• 1988

This study was carried out to investigate for resistance of V. parahaemolyticus that isolated from patients of food poisoning and fish and shellfish, captured in east coast of Kyungpook province of Korea from 1985 to 1986. VP ATCC 17802 and NAG V. ATCC 6538 were used as control. In fish, shellfish and seaweed, the more temperature increased, the shorter survival time was. In case of sea-water, the more temperature rose up, the longer survival time was, particularly in $37^{\circ}C$ and $25^{\circ}C$, the strains had survived after 6 months. And in tapwater, it was sterilized in 150 mins. and survived for 11.5 days on maximum in ground water. In kimchi, at room temperature, germicidal time was shorter more than 6 times compared with that which had been kept in refrigerator. It survived for 57.1 days in milk, 49.2 mins. in yougurt. Strains had been surviving in frozen condition at $-70^{\circ}C$ even after 6 months, present study time. In resistance test in water bath at several degrees of temperature, all the strains were sterilized in 20 mins. with $60^{\circ}C$. In resistance test to driness, number of surviving strains dropped rapidly in 10-11%) water contents. In UV $2538{\AA}$, strains were sterilized in 20 mins. In resistance test to alcohol, strains had survived for 0.1-4 mins. in fermentative wine of below than 25% and distilled wine of over than 25% in alcohol concentration. The bactericidal concentration of disinfectant was 1% in phenol and 3% in cresol. In 0.1M acetic acid and 0.1M lactic acid, number of surviving colonies decreased rapidly but not in citric acid. The more NaCl concentration rose up, the lower decreasing rate of number of surviving colonies was. The strains had showed sensitive response to vancomycin, chloramphenicol, gentamicin, and resisted to carbenicillin, ampicillin and kanamycin. When one day culture strain was cultured till 25th day, resistant strains to tetracycline and cephalothin were changed to sensitive.

• Journal of Food Hygiene and Safety
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• v.35 no.4
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• pp.382-390
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• 2020

This study was carried out to evaluate the antimicrobial effect of red ginseng (Panax ginseng C.A. Meyer) against several foodborne pathogens including Staphylococcus aureus, Escherichia coli, Candida albicans and Aspergillus niger. The antimicrobial effect was determined by agar diffusion method using red ginseng extract, crude saponin and non-water-soluble fractions. Red ginseng extract showed antimicrobial effect against S. aureus, but not C. albicans or A. niger. The extract showed anti-bacterial activity at concentration above 30% against S. aureus, which cause both food poisoning and atophic dermatitis. Crude saponin showed antibacterial activity above 7.5% against the bacterium. However, the ginsenosides purified from crude saponin showed no antimicrobial activities at 100-200 ㎍/mL. To investigate the mode of growth inhibition, red ginseng extract and crude saponin were added to 0.85% NaCl solution containing S. aureus and then incubated at 35℃ for 12 h. The results showed that viable cells were rapidly reduced in above 10% concentration of red ginseng extract and above 2% of crude saponin, respectively. However, the crude saponin and red ginseng extract did not inhibit the bacterial cells completely at those same concentrations. On the other hand, whereas all non-water-soluble fractions showed inhibition zones above 10 mm against S. aureus, they showed no inhibition effects against E. coli, C. albicans or A. niger. The methanol fraction-1 (MF-1) showed the highest antibacterial activity against S. aureus, and the MIC (minimal inhibitory concentration) was 0.625 mg/mL. These results suggest that red ginseng extract, crude saponin and non-water-soluble fractions show selective antibacterial activity against S. aureus, and non-water-soluble fractions might be used as natural antibacterial agents.

• Microbiology and Biotechnology Letters
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• v.17 no.4
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• pp.392-396
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• 1989

Methylobacterium organophilum, a facultative methylotroph was cultivated on a methanol as a sole carbon and energy source. The cell growth was affected by the various components of minimal synthetic medium and the medium composition was optimized with 0.5% (v/v) methanol at pH 6.8 and at 3$0^{\circ}C$. The maximum specific growth rate of M. organophilum was achieved to 0.26 hr$^{-1}$ in the optimized medium which has following composition: Methanol, 0.5% (v/v):(NH$_4$)$_2$SO$_4$, 1.0g/l:KH$_2$PO$_4$, 2.13g/l:KH$_2$PO$_4$, 1.305g/ι:MgSO$_4$.7$H_2O$. 45g/l and trace elements (CaCl$_2$.2$H_2O$, 3.3mg:FeSO$_4$.7$H_2O$, 1.3mg:MnSO$_4$.4$H_2O$, 130$\mu\textrm{g}$:ZnSO$_4$.5$H_2O$, 40$\mu\textrm{g}$:Na$_2$MoO$_4$.2$H_2O$, 40$\mu\textrm{g}$:CoCl$_2$.6$H_2O$, 40$\mu\textrm{g}$:H$_3$BO$_3$, 30$\mu\textrm{g}$ per liter). By the limitation of nitrogen and deficiency of Mn$^{+2}$ or Fe$^{+2}$, the cell growth was significantly repressed. Methanol greatly repressed the cell growth and the complete inhibition was observed at concentration above 4% (v/v). In order to overcome the methanol inhibition and to prevent the methanol limitation, intermittent feeding of methanol was conducted by a D.O.-stat technique. PHB production by M. organophilum was stimulated by deficiency of nutrients such as NH$_{4}^{+}$, SO$_{4}^{-2}$, $Mg^{+2}$, $K^{+}$, or PO$_{4}^{-3}$ in the medium. The maximum PHB content was obtained as 58% of dry cell weight under deficiency of potassium ion in the optimized synthetic medium.

• The Korean Journal of Pharmacology
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• v.24 no.1
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• pp.103-109
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• 1988

Cyclobuxine D, extracted from Buxus microphylla var. koreana Nakai, is a steroidal alkaloid. Many pharmacological effects of cyclobuxine D were examined in our Lab. Cyclobuxine D showed a significant bradycardic effect in the rat heart and an inhibitory action on acetylcholine and $Ba^{++}-induced$ contraction of the longitudinal muscle isolated from the rabbit jejunum. In this study, we investigated the effect of cyclobuxine D on the contractile response-elicited by acetylcholine, oxytocin and $Ba^{++}$ in rat uterine. In order to analyse the inhibitory action of cyclobuxine D on the smooth muscle, we examined the inhibitory action of cyclobuxine D against the contractile response of the high potassium-depolarized rat ileum to calcium. Concentration-dependent decrease in the peak tension and duration of the acetylcholine, oxytocin and $Ba^{++}-induced$ contraction in the isolated rat uterus was observed when cyclobuxine D was added to the organ bath. The isolated longitudinal muscle from the rat ileum was immersed calcium-depleted potassium-depolarizing solution. Ten minutes after, 1.8 mM $CaCl_2$ was added to muscle bath and elicited a biphasic increase in muscle tension. Cyclobuxine D $(6.2{\times}10^{-5}\;M)$ produced an appreciable inhibition of both components of the mechanical response. In addition, $3.1{\times}10^{-4}\;M$ cyclobuxine D, introduced at a point when the tonic response had reached its maximum level, caused the muscle to exhibit a rapid lose of tension. Based on these experimental results, we propose the possibility that the inhibitory action of cyclobuxine D on the acetylcholine, oxytocin and $Ba^{++}-induced$ contraction in the isolated rat uterus may be due to blocking potassium-activated calcium channels, voltage-sensitive calcium channels.

• Korean Journal of Food Science and Technology
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• v.30 no.5
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• pp.1097-1106
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• 1998

Biodegradable edible films were prepared from rice protein concentrates (RPC) made from rice wine meal by alkaline extraction and isoelectric precipitation. The effect of film forming solution pH and plasticizers were studied, and cross-linkers were added to improve mechanical properties and water vapor permeabilities (WVP) of films. Films could be formed within pH $8{\sim}11$ with tensile strength (TS) of 4.3{\sim}5.7\;MPa$. Films produced under pH 11 had the highest TS (5.7 MPa) and the lowest WVP $(0.44\;ng{\cdot}m/m^2{\cdot}s{\cdot}Pa)$. Added glycerol, polyethylene glycol 200 (PEG) and its mixture (GLY:PEG=50:50) as plasticizers also affected the mechanical properties and WVP of films. TS and elongation at break (E) of films at various plasticizer levels were $5.5{\sim}1.0\;MPa$ and $3.6{\sim}24.3%$, respectively. At the same plasticizer concentration, the highest TS was observed when glycerol was used whereas the highest E was measured when mixture was used as plasticizer. WVPs of films with thickness of $60\;{\mu}m$ were $0.39{\sim}0.54\;ng{\cdot}m/m^2{\cdot}s{\cdot}Pa$. WVP of films decreased as the ratio of glycerol/PEG 200 was decreased, and WVP increased as the total amount of plasticizer added to the films increased. Film strength was improved by the addition of small amount of sodium hydrogen sulfate, succinic anhydride, ascorbic acid and citric acid, whereas TS of films containing $0.5{\sim}2.0%$ of NaCl and $CaCl_2$ were lower than those without the salts. The highest TS (6.3 MPa) was achieved with films containing 0.1% of succinic anhydride.

• The Korean Journal of Pharmacology
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• v.30 no.1
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• pp.1-9
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• 1994

It has been shown that there are several subtypes of ${\kappa}$ opioid receptor. We examined ligand binding profiles and the effects of various opioid agonists on high potassium-stimulated release of $[^3H]$ histamine. We have evaluated the properties of $non-{\mu},\;non-{\delta},$ binding of $[^3H]\;DIP\;([^3H]\;diprenorphine),$ anonselective opioid antagonist, in rat cortex membranes. Binding $to\;{\mu}\;and\;{\delta}$ sites was inhibited by the use of an excess of competing selective agonists (DAMGO, DPDPE) for these sites. (-) Ethylketocyclazocine (EKC), DIP and bremazocine inhibited $[^3H]$ DIP binding. However, arylacetamides (U69593 and U50488H) gave little inhibition Replacement of sodium by NMDG and the addition of guanine nucleotide influenced the inhibitory potency of (-) EKC, an agonist for {\kappa}_1-and-{\kappa}_2-binding site, but not of bremazocine. This result suggests that bremazocine can be an antagonist at this binding site. Also, we have examined the opioid modulation of $K^+(30mM)-induced\;[^3H]\;histamine$ release in rat frontal cortex slices labeled with $1-[^3H]\;histidine$. The $[^3H]\; histamine$ release from cortex slices was inhibited by EKC in a concentration-dependent manner. However, the ${\delta}$ receptor selective agonists, DPDPE and deltorphine II, ${\mu}$ receptor agonists, DAMGO and TAPS, ${\kappa}_1-agonists$, U69593 and U50488H, and ${\varepsilon}-agonist,\;{\beta}-endorphin,$ did not. The concentration-response curve of EKC was shifted to right in the presence of naloxone, nor-binaltorphimine and bremazocine, respectively. These results suggest that ${\kappa}_2$ opioid receptor regulates histamine release in the fromtal cortex of the rat.