• The Korean Journal of Mycology
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• v.17 no.3
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• pp.114-118
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• 1989

The transfer of isolated nuclei from Agrocybe aegerita mycelia of wild type into Pleurotus florida protoplasts of auxotroph was induced with polyethylene glycol. The type 1 of nuclear transfer products was spontaneous segregants of both parental morphology of colony. Hyphae of A. aegerita type had clamp connections while that of P. florida type lacked. Type 2 was main products of nuclear transfer which formed true clamp connections. Type 3 was clampless products. They all produced primordia and developed basidiocarps similar to Agrocybe aegerita. A comparison of nuclei transfer products was made using isozyme analyses of alcohol dehydrogenase, esterase, lactate dehydrogenase and peroxidase. Isozyme band patterns of some type 2 strains produced a new band. Band patterns from mycelial extracts of the other strains could be characterized by parental bands.

• Korean journal of applied entomology
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• v.38 no.1
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• pp.53-57
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• 1999

Simple diagnostic kits for monitoring insecticide susceptibility of beet armyworm, Spodoptera exigua (Hiibner) were developed and applied to the field populations. The operation of the kits was based on the correlations between enzyme activities of esterase (EST) and acetylcholinesterase (AChE) and the insecticide susceptibilities. Four different kinds of diagnostic kits (ED, EM, AD, and AM) were designed and classified by diagnostic enzymes (E for esterases and A for acetylcholinesterase) and inhibitors (D for dichlorvos and M for monocrotophos). Diagnostic inhibitor concentrations were 1 mM for ED, 10 mM for EM, 100 mM for AD, and 100 mM for AM. Resistant larvae which were not inhibited by the diagnostic amounts of insecticides developed positive staining (red color), but susceptible~ s howed negative (no color). An insect was used for both EST and AChE diagnostic kits, but different in their samples: hemolymph for EST and the head for AChE. These four diagnostic kits were applied to 1 1 different populations which showed variations of insecticide susceptibilities. Four kits were different in the capability discriminating the insecticide susceptibilites according to insecticides: ED to bifenthrin, AD to methomyl, and ED and AM to chlorpyrifos-methyl. These diagnostic devices can be used for insecticide-resistance management program for this insect pest. It also provide a technical guide to insect pest management for farmers, directors, and researchers.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.1
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• pp.127-131
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• 2020

Objective: This study was conducted to determine catalytic properties of wheat phytase with exopolyphosphatase activity toward medium-chain and long-chain inorganic polyphosphate (polyP) substrates for comparative purpose. Methods: Exopolyphosphatase assay of wheat phytase toward polyP75 (medium-chain polyP with average 75 phosphate residues) and polyP1150 (long-chain polyP with average 1150 phosphate residues) was performed at pH 5.2 and pH 7.5. Its activity toward these substrates was investigated in the presence of Mg²⁺, Ni²⁺, Co²⁺, Mn²⁺, or ethylenediaminetetraacetic acid (EDTA). Michaelis constant (K_m) and maximum reaction velocity (V_max) were determined from Lineweaver-Burk plot with polyP75 or polyP1150. Monophosphate esterase activity toward p-nitrophenyl phosphate (pNPP) was assayed in the presence of polyP75 or polyP1150. Results: Wheat phytase dephosphorylated polyP75 and polyP1150 at pH 7.5 more effectively than that at pH 5.2. Its exopolyphosphatase activity toward polyP75 at pH 5.2 was 1.4-fold higher than that toward polyP1150 whereas its activity toward polyP75 at pH 7.5 was 1.4-fold lower than that toward polyP1150. Regarding enzyme kinetics, K_m for polyP75 was 1.4-fold lower than that for polyP1150 while V_max for polyP1150 was 2-fold higher than that for polyP75. The presence of Mg²⁺, Ni²⁺, Co²⁺, Mn²⁺, or EDTA (1 or 5 mM) exhibited no inhibitory effect on its activity toward polyP75. Its activity toward polyP1150 was inhibited by 1 mM of Ni²⁺ or Co²⁺ and 5 mM of Ni²⁺, Co²⁺, or Mg²⁺. Ni²⁺ inhibited its activity toward polyP1150 the most strongly among tested additives. Both polyP75 and polyP1150 inhibited the monophosphate esterase activity of wheat phytase toward pNPP in a dose-dependent manner. Conclusion: Wheat phytase with an unexpected exopolyphosphatase activity has potential as a therapeutic tool and a next-generational feed additive for controlling long-chain polyP-induced inappropriate inflammation from Campylobacter jejuni and Salmonella typhimurium infection in public health and animal husbandry.

• Food Science of Animal Resources
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• v.28 no.5
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• pp.587-595
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• 2008

In order to develop a new starter for fermented milk, 1037 bacterial strains were isolated from raw milk. The strain that showed excellent acid producing and angiotensin converting enzyme (ACE) inhibitory activity (88.6%) was selected and identified as a Lactobacillus zeae based on the result of API carbohydrate fermentation pattern and 16S rDNA sequence. Lactobacillus zeae RMK354 was investigated further to study its physiological characteristics. It showed strong ACE inhibitory activity compared with commercial LAB starters tested. The optimum growth temperature of L. zeae RMK354 was $40^{\circ}C$ and it took 10 hr to reach pH 4.3 under this condition. L. zeae RMK354 showed more sensitive to penicillin-G, bacitracin, novobiocin, in a comparison of 14 different antibiotics, and showed most resistance to polymyxin B and vancomycin. It showed higher esterase and leucine arylamidase activities compared with 16 other enzymes. It was comparatively tolerant to bile juice and able to survive at pH 2 for 3 hr. It showed inhibitory activity against Salmonella Typhimurium with the rate of 60%. Based on these and previous results, L. zeae RMK354 could be an excellent starter culture for fermented milk with high level of ACE inhibitory activity.

• Korean Journal of Medicinal Crop Science
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• v.4 no.1
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• pp.52-57
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• 1996

This study was carried out to compare isozyme band pattern, growth characteristics and tuber yield of Dioscorea batatas to get basic information for varietal classification. It could be identify clearly by protein and esterase band pattern of leaf, petiole and stem tissue in three cultivar but with peroxidase band it was difficult to identify because of similar pattern in leaf and petiole tissue. Three cultivars has different leaf shape as Dan-ma and Jang-ma were lanceolate, Sukunea was long-heart shape in upper part of plants. In phyllotaxis, Dan-ma and Jang-ma shows alternate and opposite but Suwon 2 shows opposite in upper parts of stem. Root length shows significant difference from 9.7cm to 51cm respectively as 30cm, 51cm and 9.7cm in Dan-ma, Jang-ma and Sukunea. Tuber yield of three cultivars were 27.5M/T in Dan-ma, 22.8M/T in Jang-ma and 22.8M/T/ha in Sukunea.

• Korean journal of applied entomology
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• v.53 no.2
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• pp.149-156
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• 2014

The resistance levels of the green peach aphid, Myzus persicae (Sulzer), against 10 insecticides was checked and selected the applicable insecticide resistance markers. We conducted our study in 5 cabbage cultivation regions (Pyeongchang, Hongcheon, Bongwha, Muju, and Jeju) of Korea, over 3 successive years (2009-2011). We selected a multi-resistant (MR) strain from among the 5 field-collected populations. We analyzed esterase over-expression and mutation(s) in the target sites, by using native isoelectric focusing (IEF) and quantitative sequencing (QS). We detected esterase over-expression and StoF mutation in the acetylcholinesterase 1 gene (ace1) in all of the field-collected populations, including the MR strain. We did not detect the LtoF mutation, which is a well-known knockdown resistance (kdr) mutation in the para-type sodium channel gene (para), in the MR strain; however, the value of the MR strain for bifenthrin was 3,461-fold higher than that of the susceptible strain. Our results indicate that insecticide resistance is more effectively evaluated using molecular markers than by conducting a bioassay. The molecular markers StoF in ace1 and MtoL in para can easily be applied in diagnostic methods such as QS or PCR amplification of specific alleles (PASA). These methods may be extended to management of M. persicae resistance in the field.

• Toxicological Research
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• v.14 no.3
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• pp.435-441
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• 1998

Alginase$Alginase^{ⓡ}$ (Arginine esterase) is one of the snake venoms which is mainly consisted of arginine esterase and acts as a thrombus -forming inhibitor/thrombus-lysin. These present studies were performed to investigate of the acute and subacute toxicity of the Alginase$Alginase^{ⓡ}$ in rats. In acute toxicity study, rats were single administered intravenously with dosages of 0.001, 0.01. 0.1, 1 and 10U/kg B.W. and examined the number of death, clinical sign, body weight and pathological change for 7days after administration of Alginase$Alginase^{ⓡ}$. At maximum dose level (10U/kg B.W.), Alginase$Alginase^{ⓡ}$ induced symptoms of shock with cyanosis and dyspnea. But these symptoms dissappeared after 30~50 minutes and we could not find any other toxic effect in rats. Therefore, $LD_{50}$ Value of Alginase was over 10U/kg B.W. in rats. In four-week intravenous toxicity study of Alginase$Alginase^{ⓡ}$, rats were administered intravenously seven days per week for 28 days, with dosages of 0, 0.0125, 0.125 and 1.25U/kg B.W./day, respectively. Alginase$Alginase^{ⓡ}$ did not caused any death and showed any clinical signs in rats. No significant Alginase$Alginase^{ⓡ}$ -related changes were found in feed uptake, water consumption, hematology, serum biochemistry, urinalysis, ocular examination, organ weight and histopathological examination. From the results, Alginase$Alginase^{ⓡ}$ seems not to have any toxic effect in rats when it were given daily intravenous injections below the dosage 1.25U/kg B.W./day for four weeks.

• The Korean Journal of Pesticide Science
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• v.11 no.4
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• pp.320-330
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• 2007

Mitochondrial 16S DNA sequences of Bemisia tabaci which were collected on rose greenhouse of Iwol and Jinchen in Chungbuk and red pepper field of Miryang, Gyeongnam, were analyzed. The mtCOI PCR product of B. tabaci collected on red pepper field of Miryang were digested with EcoT14I (Sty I) into two fragments 555bp and 311bp, while the PCR product of B. tabaci collected on rose greenhouse of Iwol were digested with Sty I into two fragments of 560bp and 306bp. As a result, B. tabaci collected on red pepper reveal biotype Q and those on rose greenhouse was biotype B. These was difference between two biotypes in insecticide susceptibility, and the biotype B was more susceptible than biotype Q. As a result of foliar systemic test, root-uptake systemic test and residual effect, the biotype B was more susceptible. In case of inhibition effect on enzyme activities of fenitrothion (organophosphorous) and fenothiocarb (carbamate), those of biotype Q was higher than those of biotype B. These results indicate that biotype Q was more resistant than biotype B against 12 insecticides.

• The Korean Journal of Pesticide Science
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• v.10 no.1
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• pp.50-55
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• 2006

A field-resistant strain of the diamondback-moth(Plutella xylostella L.), collected from Chinese cabbage alpine farmland at Gangwon-do, Korea, was used for determination of the characteristics of resistance to chlorpyrifos using the activities of esterases and glutathione-S-transferase(GST), protein sequestration and AChE insenstivity. Although the activities of esterases extracted from resistant strain and susceptible strain were not significantly different, isozyme bands shown on the electrophoresis were different. GST activity from field resistant strain was 1.5-fold higher than that of susceptible. No differences were shown between resistant and susceptible ones in protein sequestration. The insensitivities of AChE to chlorpyrifos, however, extracted from susceptible strain was 460-fold higher than those of resistant. These results indicated that the insensitivity of AChE is the major factor for developing the resistance and activities of GST might be a minor factor.

• Food Science and Preservation
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• v.22 no.6
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• pp.908-914
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• 2015

The objectives of this study were to isolate and characterize low temperature adaptation yeast and to obtain suitable yeasts strains for manufacturing Yakju. In this study, we isolated 482 wild yeasts from fermented foods. Out of these, 5 yeast strains were selected based on increased growth at low temperature ($15^{\circ}C$) and high ${\beta}$-glucosidase activity. To screen the aromatic level of isolates, media containing cerulenin and 5,5,5-trifluor-DL-leucine (TFL) were used. Y297 strain demonstrated tolerance against TFL and produced more than 13% alcohol. Y297 strain was identified a Saccharomyces cerevisiae based on the 26S rDNA gene sequences. Maximum cell growth was observed after 19 hr and 38 hr of incubation at $25^{\circ}C$ and $15^{\circ}C$, respectively. The exponential phase was followed by a lengthy stationary phase, at $15^{\circ}C$, when the cells remained high viable. Y297 strain demonstrated tolerance against alcohol (10%), glucose (60%) and salt(NaCl, 8%). ${\beta}$-glucosidase and esterase activity in Y297 were higher than those of controls at $15^{\circ}C$. Overall, these results indicated that using wild yeast strain, isolated from fermented food, affects the chemical characteristics of the brewed Yakju.