• Animal Bioscience
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• v.34 no.6
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• pp.1029-1037
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• 2021

Objective: This study was conducted to investigate effects of antifungal substance and carboxylesterase-producing inoculant on fermentation indices and rumen degradation kinetics of whole crop rice (WCR) silage ensiled at different dry matter (DM) contents. Methods: Dual-purpose inoculants, Lactobacillus brevis 5M2 and Lactobacillus buchneri 6M1, confirmed both activities of antifungal and carboxylesterase in the previous study. The WCR at mature stage was chopped, and then wilted to obtain three different DM contents consisting of 35.4%, 43.6%, and 51.5%. All WCR forages were applied distilled water (CON) or mixed inoculants with 1:1 ratio at 1×105 colony forming unit/g (INO), and ensiled into 20 L mini silo (5 kg) in quadruplicates for 108 d. Results: The INO silages had lower lactate (p<0.001) and butyrate (p = 0.022) with higher acetate (p<0.001) and propionate (p<0.001) than those of CON silages. Ammonia-N (p<0.001), lactate (tendency; p = 0.068), acetate (p = 0.030), and butyrate (p<0.001) concentrations of INO silages decreased linearly with increasing DM content of WCR forage. The INO silages presented higher lactic acid bacteria (p<0.001) with lower molds (p<0.001) than those of CON silages. Yeasts (p = 0.042) and molds (p = 0.046) of WCR silages decreased linearly with increasing DM content of WCR forage. In the rumen, INO silages had higher the total degradable fraction (p<0.001), total volatile fatty acid (tendency; p = 0.097), and acetate (p = 0.007), but lower the fractional degradation rate (p = 0.011) and propionate (p<0.001) than those of CON silage. The total degradable fraction (p<0.001), total volatile fatty acid (p = 0.001), iso-butyrate (p = 0.036), and valerate (p = 0.008) decreased linearly with increasing DM content of WCR forage, while the lag phase (p<0.001) was increased linearly. Conclusion: This study concluded that application of dual-purpose inoculants on WCR silage confirmed antifungal and carboxylesterase activities by inhibiting mold and improving rumen digestibility, while increase of wilting times decreased organic acids production and rumen digestibility.

• Animal Bioscience
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• v.36 no.5
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• pp.720-730
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• 2023

Objective: This study investigated the effects of corn silage as a source of microbial inoculant containing antifungal and carboxylesterase-producing bacteria on fermentation, aerobic stability, and nutrient digestibility of fermented total mixed ration (FTMR) with different energy levels. Methods: Corn silage was used as a bacterial source by ensiling for 72 d with an inoculant mixture of Lactobacillus brevis 5M2 and L. buchneri 6M1 at a 1:1 ratio. The corn silage without or with inoculant (CON vs MIX) was mixed with the other ingredients to formulate for low and high energy diets (LOW vs HIGH) for Hanwoo steers. All diets were ensiled into 20 L mini silo (5 kg) for 40 d in quadruplicate. Results: The MIX diets had lower (p<0.05) acid detergent fiber with higher (p<0.05) in vitro digestibilities of dry matter and neutral detergent fiber compared to the CON diets. In terms of fermentation characteristics, the MIX diets had higher (p<0.05) acetate than the CON diets. The MIX diets had extended (p<0.05) lactic acid bacteria growth at 4 to 7 d of aerobic exposure and showed lower (p<0.05) yeast growth at 7 d of aerobic exposure than the CON diets. In terms of rumen fermentation, the MIX diets had higher (p<0.05) total fermentable fraction and total volatile fatty acid, with lower (p<0.05) pH than those of CON diets. The interaction (p = 0.036) between inoculant and diet level was only found in the immediately fermentable fraction, which inoculant was only effective on LOW diets. Conclusion: Application of corn silage with inoculant on FTMR presented an antifungal effect by inhibiting yeast at aerobic exposure and a carboxylesterase effect by improving nutrient digestibility. It also indicated that fermented feedstuffs could be used as microbial source for FTMR. Generally, the interaction between inoculant and diet level had less effect on this FTMR study.

• Korean Journal of Food Science and Technology
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• v.44 no.4
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• pp.460-466
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• 2012

Through an analysis of T-2 and HT-2 toxins in corn and brown rice, the effect of enzymatic deacetylation of T-2 toxin on HT-2 toxin was investigated. Gas chromatography (GC) with electron capture detection and high-performance liquid chromatography (HPLC) with fluorescence detection were used for quantitative determination. T-2 toxin was converted into HT-2 (84-86%) within 15 min in the presence of crude protein extracts from corn and brown rice. The absence of T-2 conversion was observed for autoclaved samples, in which the enzymes were inactivated. When phosphate buffered saline, followed by methanol, was used as the extraction solvent, recoveries of T-2 toxin spiked at 50 and 200 ${\mu}g/kg$ were from 60 to 87%, whereas those of HT-2 in the autoclaved samples were 0%. In non-autoclaved samples, recoveries of HT-2 were 37-66%, whereas those of T-2 were negligible. However, the conversion of T-2 into HT-2 was not observed when samples were extracted by methanol/water.

• The Korean Journal of Malacology
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• v.12 no.1
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• pp.39-45
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• 1996

Polyacrylamide gel electrophoresis was used to reveal the esterase isozyme patterns of a freshwater snail, Semisulcospira gottschei, in the lake Uiam. From the result with inhibitors, it is tentatively concluded that four types (arylesterase, carboxylesterase, acethylesterase, acethylcholinesterase)of the adult(means of allele per locus=1.16, %polymorphism=16.7, heterozygosity=0.082)was lower than the juveniles(A=1.7, %P=16.7, H$\sub$D/=0.2215).

• Environmental Analysis Health and Toxicology
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• v.6 no.3_4
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• pp.105-121
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• 1991

The object of this study is to investigate the toxicity of fenvalerate [(RS)-$\alpha$-cyano-3 -phonoxybenzyl-(RS)-2-(4-ch1orophenyl)-3-methylbutyrate] and the effect of carbaryl on the toxicity of fenvalerate. Rats were treated with fenvalerate (50 mg/kg, 100 mg/kg), carbaryl (50 mg/kg, 100 mg/kg) or mixtures of the two compounds (fenvalerate+carbaryl: 50 mg/kg+50 mg/kg, 50 mg/kg+100 mg/kg) by oral administration for 1~3 weeks. Control groups were treated with corn oil. The experimental results were summarized as follows. 1. LD$_{50}$ values of fenvalerate and carbaryl in male rats were 385 mg/kg and 625 mg/kg respectively. When 50 mg/kg and 100 mg/kg of carbaryl were administratrd, LD$_{50}$values of fenvalerate were 265 mg/kg and 225 mg/kg respectively. 2. Biochemical parameters such as ALT, LDH and glucose in serum were much more increased in the groups treated with mixture than the groups treated with either one of fenvalerate or carbaryl. 3. The groups treated with carbaryl and mixture for 3 weeks, the contents of cytochrome P-450 in the liver were significantly increased. In renal microsomal fractions, however, no significant changes of drug metabolizing enzyme activities were observed. 4. The activities of aniline hydroxylase in hepatic microsomal fractions were increased in the groups treated with fenvalerate and mixture and activity was much more increased in the groups treated with mixture. 5. The activities of ATPase in the groups treated with fenvalerate were decreased than that of groups treated with mixture. TBA values and the activity of glucose-6 -phosphatase in the liver were not significantly changed. 6. In mixture treated groups, the activities of cholinesterase in serum and in the liver were more decreased than those of carbaryl treated groups. The activities of carboxylesterase in serum in the liver were slightly increased in mixture treated groups, but in fenvalerate treated groups, the activities of carboxylesterase were much more increased than those of control groups. 7. As a result of this study, when carbaryl was as the synergist of fenvalerate, carbaryl inhibited the activities of esterases, so the toxicity of fenvalerate was increased.sed.

• Journal of the Korean Society of Tobacco Science
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• v.21 no.1
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• pp.49-56
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• 1999

Classification of esterase isozymes of the apterous green peach aphids (Myzus persicae Sulzer) collected in tobacco fields were investigated by the native polyacrylamide gel electrophoresis (PAGE). A total of twelve esterase bands were identified in adult apterous aphid, and the difference of enzyme band activity in the clones was observed at the first and second bands group. Esterases of green peach aphids reacted with specific substrate were more stained $\alpha$-naphthyl acetate than $\alpha$-naphthyl propionate, and $\alpha$-naphthyl acetate more than $\beta$-naphthyl acetate. Twelve esterases on the basis of inhibition by the three types of inhibitors (organophosphates: 2.5$\times$10$^{-3}$ M paraoxon, 4$\times$10$^{-3}$ M DFP; eserine sulfate : 2$\times$10$^{-3}$ M eserin; sulfhydryl reagents: 2$\times$10$^{-3}$ M p-HMB) were classified into three class, namely, cholinesterase (ChE) I, II, carboxylesterase (CE) and arylesterase (ArE), and these classes contained 3, 4, 3 and 2 isozymes, respectively.

• Journal of the Korean Society of Tobacco Science
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• v.20 no.1
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• pp.80-86
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• 1998

Changes in activity and classification of esterase isozymes during the tire cycle or Plodia inteipunctella (Hiibner) were investigated by the native polyacrylamide gel electrophoresis. The stage specificity in esterase activity and isozyme pattern was observed throughout the larvalpupal-adult transformation. The activity esterase was highest at the 3-day old adult stage, and the lowest level at the prepupal stage. A total of 12 esterase bands were identified throughout the development, and the bands showing high enzyme activity was observed in the middle part of gel. Twelve esterases on the basis of inhibition by the three types of inhibitors (organophosphates, eserine sulfate and sulfhydryl reagents) were classified into three class, namely, carboxylesterase (CE), arylesterase (ArE) and cholinesterase (ChE), and these classes contained 7, 3 and 2 isozymes, respectively.

• Toxicological Research
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• v.17 no.4
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• pp.303-308
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• 2001

The potential for a given anticholinesterase pesticide to exhibit age-related toxicity is essential information for an accurate and proper risk assessment of that compound. This investigation was designed to study the age-related toxicity of active metabolites of four organophosphates using in vitro detoxification measurement. The blood samples were collected from 1 month and 18 months old rats. The $IC_{50}$ values of mouse brain recombinant AChE of chlorpyrifos-oxon, diazoxon, malaoxon and paraoxon were 10.35, 112.84, 151.28 and 18.43 nM, respectively. When the plasma of young rats, and $CaCI_2$were added, the $IC_{50}$ values of mouse brain recombinant AChE of chlorpyrfos-oxon, diazoxon, malaoxon and paraoxon were 31.89, 164.25, 139.94 and 16.36 nM, respectively. The $IC_{50}$ values of mouse brain recombinant AChE of chlorpyrifos-oxon, diazoxon, malaoxon and paraoxon were changed to 136.840, 1244.45, 654.54 and 52.66 nM by A-esterases In adult rats. These results suggest that four organophosphates have a potential toxicity to exhibit age-related sensitivity.

• Microbiology and Biotechnology Letters
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• v.45 no.1
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• pp.63-70
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• 2017

A functional screen of 60,672 fosmid metagenomic clones amplified from marine sediment obtained from the Dokdo islets in Korea identified the gene EstES1, whose product, EstES1, displayed lipolytic properties on tributyrin-supplemented media. EstES1 is a 576 amino acid protein with a predicted molecular weight of 59.4 kDa including 37 N-terminal leader amino acids. EstES1 exhibited the highest sequence similarity (44%) to a carboxylesterase found in Haliangium ochraceum DSM14365. Phylogenetic analysis indicated that EstES1 belongs to a currently uncharacterized family of lipases. Within the conserved domain, EstES1 retains the catalytic triad that consists of the consensus penta-peptide motif, GESAG. EstES1 demonstrated a broad substrate specificity toward the long acyl group of ethyl esters (C2-C12), and its optimal activity was recorded toward p-Nitrophenyl butyrate (C4) at pH 9.0 and $40^{\circ}C$ (specific activity of 255.4 U/mg). The enzyme remained stable in the ranges of $60-65^{\circ}C$ and pH 9.0-10.5 and in the presence of methanol, ethanol, isopropanol, and dimethyl sulfoxide. Therefore, EstES1 has potential for use in industrial applications involving high temperature, organic solvents, and/or alkaline conditions.

• Korean Journal of Environmental Agriculture
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• v.8 no.1
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• pp.47-54
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• 1989

This study was conducted to investigate insecticide toxicities to a honeybee, Apis cerana F. being raised in Korea and its detoxifying enzyme activities. In order to determine the appropriate usage of insecticides, median effective dose and detoxifying enzyme activities to seven insecticides were observed. Various detoxifying enzymes, including microsomal oxidases, glutathione S-transferases, esterases, and DDT-dehydrochlorinase were assayed in the midguts of adult worker bees as the enzyme source. Of the insecticides used, $LC_{50}$ value in DDT treatment was the highest as 19ppm, and that in EPN treatment was the lowest as 0.75ppm. Sublethal exposures of honeybees to various insecticides had some effects on microsomal enzyme activities. Aldrin epoxidase activity was inhibited by malathion and demeton S-methyl treatment. N-demethylase activity was induced by carbaryl treatment. Of the glutathione S-transferases, aryltransferase(DCNB conjugation) activity was significantly induced by diazinon, and moderately induced by malathion. Of the esterases, ${\alpha}-NA$ esterase activity was moderately inhibited by malathion and permethrin. Carboxylesterase and acetylcholinesterase activity were not affected by the sublethal exposure of honeybee to the insecticides. Sublethal exposure of honeybee to the insecticides had no effect on DDT- dehydrochlorinase activity, except carbaryl, malathion and demeton S-methyl were inhibited.