• Journal of Microbiology and Biotechnology
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• v.12 no.6
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• pp.901-908
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• 2002

The relationship between the layered structure of granules in UASB reactors and microbial resistance to toxicity was investigated using disintegrated granules. When no toxic materials were added to the media, the intact and disintegrated granules exhibited almost the same ability to decrease COD and to produce methane. However, when metal ions and organic toxic chemicals were added to a synthetic wastewater, he intact granules were found to be more resistant to toxicity than the disintegrated granules, as determined by the methane production. The difference in resistance between the intact and disintegrated granules was maximal, with toxicant concentrations ranging from 0.5 mM to 2 mM for trichloroethylene with toluene and 5 mM to 20 mM for metal ions (copper, nickel, zinc. chromium, and cadmium ions). The augmented COD removal rate by granulation compared to disintegrated granules was also measured in the treatment of synthetic and real wastewaters; synthetic wastewater, $-2.6\%$; municipal wastewater, $2.8\%$; swine wastewater, $6.4\%$; food wastewater, $25.0\%$; dye works wastewater, $42.9\%$; and landfill leachate, $61.8\%$. Continuous reactor operation also demonstrated that the granules in the UASB reactor were helpful in treating toxic wastewater, such as landfill leachate.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.32 no.3
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• pp.253-267
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• 2022

Objectives: This study was performed to check whether the CRS (Chemical Ranking and Scoring) system is appropriate as a method to determine substances as candidates for substances subject to permission and to apply this system to the selection of candidates for substances subject to permission. Methods: A risk score was obtained by multiplying the hazard score and the exposure score and then ranking them. The hazard sub-indicators are carcinogenicity, germ cell mutagenicity, reproductive toxicity, specific target organ toxicity-repeated exposure, respiratory sensitization and endocrine disrupting chemicals. Exposure sub-indicators are persistence, bioaccumulation and emission volume. Sensitivity analysis was performed for missing values. Correlation analysis and multivariable linear regression analysis were performed among hazard, exposure and risk in order to confirm that CRS was an appropriate method. Results: As a result of the sensitivity analysis on missing values, it was confirmed that the effect on the risk ranking was not sensitive. Correlation and regression analysis confirmed that exposure had a greater effect on risk than hazard. Conclusions: The CRS system, which derives a risk score using a hazard and exposure score, is judged to be appropriate as a method for the selection of preliminary of candidates for substances subject to permission. Benzene, cadmium, nickel, and cobalt were selected as priority candidates for substances subject to permission.

• Microbiology and Biotechnology Letters
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• v.47 no.2
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• pp.269-277
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• 2019

In the present study, we have studied the bioremediating capability of bacterial strain against six heavy metals. The strain was isolated from river Yamuna, New Delhi which is a very rich repository of bioremediating flora and fauna. The strain was found to be Gram positive as indicated by Gram staining. The strain was characterized using 16s rRNA gene sequencing and the BlastN result showed its close resemblance with the Cellulosimicrobium sp. As each treatment has its own toxicity eliciting expression of different factors, we observed varied growth characteristics of the bacterial isolate and its protein content in response to different heavy metals. The assessment of its bioremediation capability showed that the strain Cellulosimicrobium sp. has potential to consume or sequester the six heavy metals in this study in the following order iron > lead > zinc > cooper > nickel > cadmium. Thus, the strain Cellulosimicrobium sp. isolated in the present study can be a good model system to understand the molecular mechanism behind its bioremediating capabilities under multiple stress conditions.

• Mycobiology
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• v.49 no.4
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• pp.421-433
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• 2021

Morchella is a genus of fungi with the ability to concentrate Cd both in the fruit-body and mycelium. However, the molecular mechanisms conferring resistance to Cd stress in Morchella are unknown. Here, RNA-based transcriptomic sequencing was used to identify the genes and pathways involved in Cd tolerance in Morchella spongiola. 7444 differentially expressed genes (DEGs) were identified by cultivating M. spongiola in media containing 0.15, 0.90, or 1.50 mg/L Cd²⁺. The DEGs were divided into six sub-clusters based on their global expression profiles. GO enrichment analysis indicated that numerous DEGs were associated with catalytic activity, cell cycle control, and the ribosome. KEGG enrichment analysis showed that the main pathways under Cd stress were MAPK signaling, oxidative phosphorylation, pyruvate metabolism, and propanoate metabolism. In addition, several DEGs encoding ion transporters, enzymatic/non-enzymatic antioxidants, and transcription factors were identified. Based on these results, a preliminary gene regulatory network was firstly proposed to illustrate the molecular mechanisms of Cd detoxification in M. spongiola. These results provide valuable insights into the Cd tolerance mechanism of M. spongiola and constitute a robust foundation for further studies on detoxification mechanisms in macrofungi that could potentially lead to the development of new and improved fungal bioremediation strategies.

• Korean Journal of Environmental Agriculture
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• v.35 no.2
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• pp.152-157
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• 2016

BACKGROUND: Since bottom ash (BA) contains considerable amounts of CaO and MgO, it could be a useful amendment to increase soil pH and to immobilize cadmium (Cd). This study was conducted to evaluate effect of BA application in reducing Cd phytoavailability.METHODS AND RESULTS: Bottom ash was applied at the rate of 0, 20, 40, and 80 Mg/ha to Cd contaminated soil, and then lettuce was cultivated under field condition. soil pH and net negative charge increased slightly with increasing BA application; however, there was no statistical difference among the rates. Water soluble, exchangeable+acidic, reducible, and oxidizable fraction of Cd decreased with increasing bottom ash application rate, whereas residual fraction of Cd increased with increasing bottom ash application rate. Lettuce yield increased with rate of bottom ash up to 40 kg/ha. Visual evidences of cadmium toxicity and growth inhibition were not found during lettuce cultivation.CONCLUSION: Bottom ash was effective to reduce phytoextractability of Cd and to increase lettuce yield. Conclusively, BA could be a good soil amendment to reduce Cd phytoavailability in contaminated arable soil.

• Korean Journal of Environmental Biology
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• v.42 no.1
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• pp.54-61
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• 2024

The ecosystem provides a diverse array of environmental conditions for organisms, and only those that are capable of successfully adapting to these conditions within their habitats can endure, thrive, and proliferate. Further, the environmental conditions within these habitats can significantly affect the bioavailability of chemicals that are introduced therein, thus resulting in varied adverse impacts on the organisms. The present study aims to evaluate the sensitivity of Yuukianura szeptyckii - a species adapted to riparian - to heavy metals following ISO guideline 11276, with the objective of assessing its potential as an indicator species for ecotoxicological evaluations in riparian habitats. The findings revealed that cadmium and copper both had significant toxic effects depending on their concentrations. For cadmium, the LC₅₀ was 280 mg kg^-1, EC₅₀ was 66 mg kg^-1, and NOEC and LOEC were 25 and 50 mg kg^-1, respectively. For copper, the LC₅₀ was 911 mg kg^-1, EC₅₀ was 151 mg kg^-1, and LOEC was 50 mg kg^-1. Comparative analysis with previous results for the international standard species Folsomia candida and the domestic standard species Allonychiurus kimi indicated that Y. szeptyckii exhibited even greater sensitivity to toxicity values. The adverse effects on survival and reproduction were closely associated with the influx concentration of heavy metals in their bodies. Altogether, the results suggest that Y. szeptyckii is a sensitive species for ecotoxicological assessments in riparian habitats, thus making it suitable as an indicator species, particularly in riparian ecosystems that are characterized by relatively high humidity conditions.

• Korean Journal of Agricultural and Forest Meteorology
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• v.8 no.1
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• pp.15-21
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• 2006

This study was conducted to understand the regulation mechanism of carbohydrate allocation and partitioning of one-year-old seedlings of Betula schmidtii with Cd treatment, and to assess tolerance against Cd toxicity among five half-sib families on the basis of carbon allocation and partitioning. Seedlings were treated with $CdSO_4$ solution of 0, 0.2, 0.4, and 0.6 mM for two months. After harvesting, carbohydrate concentrations were analyzed for leaves, stems and roots of seedlings. Carbohydrate concentration for Cd-treated seedlings decreased in comparison with control plants, even though Cd effects were significantly different among five families. Meanwhile, Cd treatment decreased carbohydrate allocation in leaves and increased allocation in roots. In addition, partitioning of glucose in leaves was increased by Cd treatment, but partitioning of sucrose and starch in leaves decreased. In Cd-treated roots, partitioning of glucose, sucrose and starch increased. On the basis of carbohydrate allocation patterns, 'Family No. 7' (of the five families studied) was considered as the most sensitive family to Cd toxicity because the decrease of carbohydrate concentration and the change of carbohydrate allocation pattern after Cd treatment were relatively greater.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.11
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• pp.1759-1766
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• 2013

In this study, the optimal conditions for salmon hydrolysate using squid liver and compositional properties of hydrolysate were investigated. The optimal conditions were $55^{\circ}C$, pH 5.5 and 0.66~0.67% (w/w) in the ratio of squid liver to acidic and thermal treated salmon muscle. The free amino acid of hydrolysate from the acidic treated salmon muscle was higher than that of hydrolysate from the thermal treated salmon muscle, while the total amino acid and mineral were high in the acidic treated salmon muscle. Furthermore, cadmium of hydrolysate from the thermal denatured salmon muscle was below 2 ppm, and has an acceptable level as potential ingredient. The distribution of peptide molecular weight was 40.0% for 1.0~9.5 kDa, 6.7% for 0.5 kDa, and 47.4% of others in hydrolysate from the thermal treated salmon muscle. Both hydrolysates did not show any toxicity against the HepG2 cell line for up to $200{\mu}g/mL$.

• Korean Journal of Clinical Laboratory Science
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• v.48 no.1
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• pp.1-7
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• 2016

The aim of this study was to evaluate the cytotoxicity of cadmium chloride ($CdCl_2$), toxicant, and the protective effect of Chelidonium majus (CM) extract on $CdCl_2$-induced cytotoxicity in cultured NIH3T3 fibroblasts. Cell viability, the effect of butylated hydroxytoluene (BHT) against $CdCl_2$, and the antioxidative effects including DPPH-free radical scavenging activity, superoxide anion-radical scavenging activity (SSA), and lactate dehydrogenase (LDH) activity were assessed. $CdCl_2$ caused a significant dose-dependent decrease in cell viability, and $XTT_{50}$ value was determined at 38.7uM of $CdCl_2$. It was determined as highly-toxic by Borenfreund and Puerner' toxic criteria. BHT of antioxidant significantly increased cell viability severely damaged by $CdCl_2$-induced cytotoxicity in these cultures. In the protective effect of CM extract on $CdCl_2$-induced cytotoxicity, CM extract significantly increased cell viability, DPPH-free radical scavenging activity, SSA and inhibitory activity of LDH. From these results, it is suggested that oxidative stress is involved in the cytotoxicity of $CdCl_2$, and CM extract showed protective efficacy on $CdCl_2$-induced cytotoxicity via antioxidative effects. Conclusively, natural resources like CM extract may be a putative antioxidative agent for the detoxification or diminution of toxicity correlated with oxidative stress.

• Journal of Society of Preventive Korean Medicine
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• v.3 no.2
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• pp.79-89
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• 1999

This study was conducted to investigate the antitoxic component in aqueous extract of Houttuynia cordata $T_{HUNB}$. The results were as follows: Generally, detoxication effects by Houttuynia cordata $T_{HUNB}$ extract increased in proportion to the extract concentrations. When 40mg/kg dosage of Houttuynia cordata $T_{HUNB}$ extract was administered, it showed the highest antitoxic effects in metallothionein induction. After the extract treatment, body weights increased in proportion to the extract concentration. However, after 3 weeks, the body weight decreased insignificantly. From the above results, Houttuynia cordata $T_{HUNB}$ extract increased metallothionein concentration and decreased the toxicity of cadmium in rats.