• Journal of Life Science
• /
• v.32 no.1
• /
• pp.36-43
• /
• 2022

Mucosal immunity is a well-designed defense system that builds precise and dynamic relationships against pathogens, and the gastrointestinal tract is the most important organ with this system, acting as a guardian at the forefront of its activity. Salmonella spp. cause food poisoning, entering the body orally and mainly invading the Peyer's patches of the small intestine. Although Salmonella strains share similar mechanisms for inducing innate immunity, different serotypes may have different effects on the intestinal mucosa due to host specificities and pathogenicity. In this study, we evaluated the effects of Salmonella enteritidis infections in mouse intestine and observed significantly reduced dose-dependent survival rates in a challenge test. Flow cytometry data showed no significant differences in intestinal immune cell populations, although histology indicated increased mucin production and decreased goblet cell counts in the Salmonella-treated groups. Furthermore, Claudin expression was significantly decreased in the samples with Salmonella. To investigate the relationship between S. enteritidis infection and inflammatory response, dextran sodium sulfate (DSS) was administered after infection and the results indicate lower survival rate after DSS treatment. In conclusion, we were able to identify the optimal concentration of S. enteritidis to modulate the intestinal mucosal immunity of mice and inflammatory response.

• Korean Journal of Environmental Biology
• /
• v.35 no.2
• /
• pp.116-122
• /
• 2017

Basic dyes such as malachite green and methylene blue have been used as disinfectants to control water fungal infections since the 1930s. However, after succeeding reports of carcinogenicity and bioaccumulation of the dye, their use was forbidden in lieu of public health. This study undertook to evaluate the therapeutic effect of sulfur solution processed by effective microorganisms (EM-PSS) against Saprolegnia parasitica infection, and its safety in fish. In vitro antifungal evaluation of EM-PSS inhibited the growth of S. parasitica mycelia at concentrations of 50 ppm or higher. The acute toxicity test of EM-PSS to the mud fish (Misgurnus mizolepis) measured a no effect concentration (NOEC) at 100 ppm, the lowest effect concentration (LOEC) at 125 ppm, and the half-lethal concentration ($LC_{50}$) at 125 ppm in juvenile and 250 ppm in the immature stage. In addition, the ecotoxicity test of EM-PSS using Daphnia magna inhibited swimming of D. magna at concentrations of 100 ppm or less. Lastly, the EM-PSS prevented infection of S. parasitica to mud fish, at concentrations of 50 ppm. Furthermore, at 100 ppm concentration, the EM-PSS showed no acute toxicity on mud fish, nor any eco-toxic effects on D. magnano. Therefore, we conclude that carcinogenic disinfectants such as malachite green and methylene blue could be replaced by EM-PSS to remove S. parasitica in mud fish farming, and might be a potential eco-friendly disinfectant in aquaculture.

• Korean Journal of Ichthyology
• /
• v.10 no.1
• /
• pp.98-105
• /
• 1998

The effect of ammonia on survival and growth of the larval rockfish, Sebastes schlegeli was examined by a static renewal bioassay method. The tolerance of larvae to ammonia toxicity was more sensitive at the early larvae, but increased with the development of larvae. In 14 day-old-larvae after parturition, the mortality with treatment of each concentration of ammonia was 5% at control group and 0.0112 $NH_3$mg/l, whereas it was increased up to 27.5% at exposure group of 0.1230 $NH_3$mg/l with higher concentration. Regression equation between ammonium concentration(X) and mortality(Y) was followed; Y=0.516+3.482 X($r^2=0.4737$, P<0.01). The NOEC(no-observable-effect concentration) and LOEC (lowest-observable-effect concentration) to mortality compared to control group were 0.100 $NH_3mg/l$ and 0.1230 $NH_3$mg/l, respectively and chronic value(ChV) which is the geometric mean of the NOEC and LOEC was 0.1110 $NH_3$mg/l. Body length after 7-days exposure in control group, 0.0112 $NH_3$mg/l and 0.1230 $NH_3$mg/l were 7.8325mm, 7.700mm and 7.05mm, respectively. The NOEC, LOEC and chronic value(ChV) were 0.0335 $NH_3$mg/l, 0.0558 $NH_3$mg/l and 0.0432 $NH_3$mg/l, respectively.

• Journal of Applied Biological Chemistry
• /
• v.61 no.2
• /
• pp.151-155
• /
• 2018

In this study, cinnamon essential oil (CEO) was formulated as emulsifiable concentrate (EC) and a granule. For the evaluation of their negative effects on the ecosystem, acute toxicities against Cyprinus carpio was determined in a static condition. The formulations were made using CEOs extracted by 3 different methods (steam distillation (SD), solvent extraction and supercritical fluid extraction (SFE)) and were tested to obtain $LC_{50}$ values. Among the ECs, EC including CEO extracted by SFE showed highest acute toxicity against C. carpio. Among the granules, a granule including CEO extracted by SD showed highest acute toxicity against C. carpio. Nevertheless, $LC_{50}$ of EC and a granule formulation with CEOs was higher than toxicity level III of pesticide standardized by Korea rural development administration. These results were similar to those using zebrafishes. Chronic toxicities were not found for 45 days in zebrafishes until $500{\mu}gL^{-1}$ level of EC formulation including CEO obtained by the SD. Based on these results, EC formulation of CEOs may be considered to be used as environmental-friendly natural insecticides in accordance with the standards.

• The Korean Journal of Pesticide Science
• /
• v.18 no.2
• /
• pp.104-114
• /
• 2014

Scale insects heavily damaged many agricultural crops and trees in urban and forest areas. This study was conducted to carry out alternative control methods for environmentally friendly control of scale insects. Hot water extract of Quisquali indica produced high mortality against the black pine bast scale, Matsucoccus thunbergianae in previously experiment. Methanol extract obtained from fruit of Q. indica was successively fractionated using hexane, chloroform, ethyl acetate, buthanol and water which were examined by exposing for their insecticidal activity against four Cocoidea species (Eriococcus lagerstroemiae, Ceroplastes japonicus, Crisicoccus pini and Planococcus citri) in laboratory. Hexane fraction gave the highest insecticidal activity against scale insect pest. GC-mass analysis confirmed that the main compounds of Q. indica were alpha-pinene, methyl palmitate, eugenol, methyl myristate, phthalic acid mono(2-ethylhexyl)ester and palmitic acid. Among those compounds, ${\alpha}$-pinene was included 10 hexane subfractions. $LC_{50}$ of ${\alpha}$-pinene was 0.0114 ppm against 2nd instar of E. lagerstroemiae. These results suggest that Q. indica extracts might be used as an alternative control agent of scale insects.

• Korean Journal of Environmental Biology
• /
• v.26 no.3
• /
• pp.138-144
• /
• 2008

The effects of salinity on oxygen consumption, operculum movement number and ammonia nitrogen excretion were examined in cultured tilapia, Oreochromis mossambicus (total length 10$\pm$1.0 cm, total weight 17.3$\pm$4.2 g). The fish were exposured to certain salinities (0, 3, 9, 15, 21, 27 and 32 psu) step by step with 3 psu$\cdot$d$^{-1}$ and changed rapidly from certain salinity to another salinity. The oxygen consumption of the fish which was transferred step by step showed increasing tendency in the range of 3 $\sim$ 27 psu, but markedly appeared very low value at 32 psu. The tolerance limit in tilapia by salinity change without acclimation was shown 23.3 psu from 96-h TL$_{50}$. The oxygen consumption, operculum movement and ammonia nitrogen excretion of fish which was transferred rapidly from certain salinity to each salinity (0, 9, 15, 21 and 32 psu) showed a changing point at 15 psu; they showed increasing and/or decreasing pattern before 15 psu, and showed decreasing pattern after 15 psu. From these results, it was concluded that the appropriate salinity without physiological change for Java tilapia was below 15 psu.

• Korean Journal of Environmental Biology
• /
• v.36 no.4
• /
• pp.659-664
• /
• 2018

In this study, two essential oils (EOs) extracted from Aleriana fauriei and Alpinia galangal were formulated as an emulsifiable concentrate (EC) and a granule. In the evaluation of their acute toxicity on fishes, Cyprinus carpio adults were used and the toxicities were determined in a static condition. The formulations were prepared from the essential oil extracted by three different methods namely steam distillation (SD), solvent extraction (SE) and supercritical fluid extraction (SFE). The acute toxicities were calculated using $LC_{50}$ values. Among EOs, only the EO extracted by solvent showed acute toxicities on carps. Some of the EC, EOs of Aleriana fauriei did not exhibit toxicity, while EOs from Alpinia galangal showed potent acute toxicities on carps. Among the granules, granules formulated with Aleriana fauriei EO extracted by SD method and Alpinia galangal EO extracted by SFE method showed acute toxicities on fishes. Nevertheless, $LC_{50}$ of ECs and granules formulated with all types of EOs in this study was higher than the fish toxicity level III for pesticides suggested by Korea Rural Development Administration. Furthermore, cytochrome P450 1A and glutathione S-transferase were confirmed as biomarkers in carps in response to the exposure to Alpinia galangal EO extracted by SD and SFE method, tracking Alpinia galangal EO in the aquatic environment.

• Korean journal of applied entomology
• /
• v.63 no.1
• /
• pp.53-61
• /
• 2024

The susceptibility of Aphis gossypii populations collected from three fields (WJ, CC, and GS) was evaluated to three insecticides (afidopyropen, chlorfenapyr and cyantraniliprole) and three binary mixtures. Three field populations showed resistance ratios of over 100 to all insecticides. The Combination Index (CI), %M_(synergism), Co-Toxicity Coefficient (CTC), Wadley Ratio (WR), Synergism Ratio (SR) and Abbott Ratio (AR) were used to evaluate combined effect of the insecticides. Afidopyropen + chlorfenapyr (CI ≤ 0.16; %M_(synergism) ≥ 94; CTC ≥ 764.5; WR ≥ 6.4; SR ≥ 6.9 and AR ≥ 1.1) showed a synergism in all filed populations. WJ and CC populations showed a synergism in all binary mixtures of insecticides, but GS population showed an antagonism for chlorfenapyr + cyantraniliprole (CI, 1.63; %M_(synergism), 30; CTC, 64.0; WR, 0.6 and AR, 0.54) and afidopyropen + cyantraniliprole (CI, 6.7; %M_(synergism), 1; CTC, 19.8; WR, 0.2 and AR ≤ 0.55). All mixtures (afidopyropen + chlorfenapyr, chlorfenapyr + cyantraniliprole and afidopyropen + cyantraniliprole) showed a control value of over 99% after 21 days of treatment in the field. This study highlights that binary mixtures of three insecticides serve as an effective control strategy for A. gossypii.

• Korean journal of applied entomology
• /
• v.49 no.1
• /
• pp.37-42
• /
• 2010

As an environment-friendly phytosanitary measure, CATTS (controlled atmosphere temperature treatment system) has been developed to kill several quarantine insect pests infesting subtropical agricultural commodities. This study tested any possibility to apply CATTS to apples to effectively eliminate the peach fruit moth, Carposina sasakii, which has been regarded as a quarantine insect from the imported countries. When the larvae of C. sasakii were directly exposed to $46^{\circ}C$ (an installed lethal temperature of CATTS), they showed a median lethal time at 14.66 min. Addition of high carbon dioxide to the temperature treatment enhanced the thermal limit susceptibility of C. sasakii to $46^{\circ}C$. CATTS device was constructed to automatically control $CO_2$ concentration and temperature with real-time monitoring both in the chamber and in the fruit. The larvae internally infesting apples were tested using the CATTS device and showed 100% lethality after 60 min exposure to a treatment of $46^{\circ}C$ under 15% $CO_2$ in the chamber. Relatively long exposure may be due to the deviation between the ramping temperature ($0.35^{\circ}C$/min) of the chamber and the ramping temperature (0.12-$0.23^{\circ}C$/min) inside apple fruit, where the tested larvae were located. This study suggests a possibility that CATTS can be applied as a quarantine measure to kill the larvae of C. sasakii locating inside the apples.

• Korean journal of applied entomology
• /
• v.46 no.2
• /
• pp.313-318
• /
• 2007

Entomopathogenic nematode, Steinernema carpocapsae GSN1 strain was evaluated for the environmentally sound control of Tebenna issikii (Lepidoptera: Choreutidae) in the laboratory. The corrected mortality of Tebenna issikii larvae was 100% at the 40 infective juveniles (Ijs)/larva 3 days after treatment with S. carpocapsae GSN1 strain in Petri dish. $LC_{50}$ value of S. carpocapsae GSN1 strain against Tebenna issikii was 5.7 Ijs. The mean penetration numbers of Ijs of S. carpocapsae GSN1 strain at the 5, 10, 20, 40 and 80 Ijs/larva in a Tebenna issikii larva were 1.4, 1.4, 3.2, 5.6 and 11.9 Ijs/larva, respectively. However penetration rate of Ijs of S. carpocapsae GSN1 strain at 5 Ijs/larva was the highest among other nematode concentrations. Progeny of S. carpocapsae GSN1 strain in a Tebenna issikii larva was higher with increasing nematode concentration.