• Journal of Microbiology and Biotechnology
• /
• v.17 no.5
• /
• pp.812-821
• /
• 2007

The ecosystems of certain abandoned mines contain arsenic-resistant bacteria capable of performing detoxification when an ars gene is present in the bacterial genome. The ars gene has already been isolated from Pseudomonas putida and identified as a member of the membrane transport regulatory deoxyribonucleic acid family. The arsenite-oxidizing bacterial strains isolated in the present study were found to grow in the presence of 66.7 mM sodium arsenate($V;\;Na_2HAsO_4{\cdot}7H_2O$), yet experienced inhibited growth when the sodium arsenite($III;\;NaAsO_2$) concentration was higher than 26 mM. Batch experiment results showed that Pseudomonas putida strain OS-5 completely oxidized 1 mM of As(III) to As(V) within 35 h. An arsB gene encoding a membrane transport regulatory protein was observed in arsenite-oxidizing Pseudomonas putida strain OS-5, whereas arsB, arsH, and arrA were detected in strain OS-19, arsD and arsB were isolated from strain RW-18, and arsR, arsD, and arsB were found in E. coli strain OS-80. The leader gene of arsR, -arsD, was observed in a weak acid position. Thus, for bacteria exposed to weak acidity, the ars system may cause changes to the ecosystems of As-contaminated mines. Accordingly, the present results suggest that arsR, arsD, arsAB, arsA, arsB, arsC, arsH, arrA, arrB, aoxA, aoxB, aoxC, aoxD, aroA, and aroB may be useful for arsenite-oxidizing bacteria in abandoned arsenic-contaminated mines.

• Korean Journal of Pharmacognosy
• /
• v.29 no.4
• /
• pp.379-383
• /
• 1998

Sodium arsenate and Paljin-Tang extract (PJT), a herbal restorative were treated p.o. 20 mg/kg and 500 mg/kg, respectively, and concurrently to rats, and examined the biochemical parameters in blood. The values of white blood cell (WBC), red blood cell (RBC), hemoglobin (Hgb) and hematocrit (Hct) in each group did not show significant variance. The value of aspartate aminotrasferase(AST) of arsenic-treated group was increased for 2 weeks significantly while that of the group of concurrent administration with PJT became low significantly compared with arsenic-treated group and the value of alkaline phosphatase (ALP) of arsenic-treated group was decreased while that of the group of concurrent administration with PJT was increased significantly compared with arsenic-treated group. The value of glucose (Glu) was increased and those of lactic dehydrogenase (LDH), blood urea nitrogen (BUN) and triglyceride (TG) were decreased at first but increased later while the group of concurrent administration with PJT showed significant recovery from the toxicity of arsenic.

• Korean Journal of Food Science and Technology
• /
• v.12 no.1
• /
• pp.13-17
• /
• 1980

A Streptomyces spp. strain SY 79-1 which was capable of producing metal protease was isolated from soil. The optimal pH and temperature of the protease were around pH 8.0 and $45^{\circ}C$, respectively. The stable pH range of the enzyme was between pH 6.0 to 8.0. The enzyme was stable at $45^{\circ}C$, but it lost the activity about 75 % for 5 min and completely for 30 min when it was treated at $60^{\circ}C$. The activity of the enzyme was inhibited by $Hg^{++},\;Cu^{++},\;Ag^{+}$ and activated by $Mg^{++},\;Mn^{++},\;Co^{++},\;but\;Fe^{++},\;Ca^{++},\;Pb^{++}\;and\;Al^{3+}$ did not affect enzyme activity. This enzyme was strongly inhibited by EDTA, but was not inhibited by 2, 4-DNP, ${\rho}$-CMB, ${\varepsilon}$-aminocaproic acid, cysteine, thiourea, citric acid, oxalic acid and sodium arsenate. When cobalt was added to the EDTA-denatured enzyme, the activity of the enzyme was restored.

• Korean Journal of Veterinary Research
• /
• v.30 no.2
• /
• pp.203-214
• /
• 1990

A total of 166 strains of Salmonella (S) typhimurium var copenhagen isolated from pigeons (164 strains) and aquatic birds (2 strains) were examined for the biochemical characteristics and plasmid profiles. All the strains were sensitive to ampicillin, chloramphenicol, gentamicin, kanamycin and sulfadimethoxine. But 13 strains(7.8%) were resistant to streptomycin (Sm), 2 (1.2%) to tetracycline, 2 (1.2%) to rifampicin, and 1 (0.6%) to nalidixic acid. Among drug resistant strains, only one strain resistant to Sm contained conjugative R plasmid which was fertility inhibition and incompatibility group $I_{\alpha}$. All the strains were sensitive to cobalt chloride, cupric sulfate, lead nitrate, mercuric chloride and silver nitrate. Of 166 isolates, 6 (3.6%) were resistant to sodium arsenate and 1 (0.6%) to potassium tellurite. Among 166 isolates, 1 (0.6%) was colicinogenic, 12 (7.2%) sucrose fermenters, and 166 (100%) maltose fermenters. Plasmid profiles were confirmed as being 4 or 5 plasmids, and their molecular weight ranged 3.2 to 60 megadalton (MD). All the strains harbored 60 Md plasmid. There are three patterns by the plasmid profile, 150 isolates (90.4%) were pattern I (3.2, 3.5, 33, 60Md), 14 (8.4%) pattern II (3.2, 3.5, 29, 60Md), and 2 (1.2%) pattern III (4.2, 7.8, 8.5, 15, 60Md). S typhimurium var copenhagen strains containing 60Md plasmid were resistant to killing by 90% normal guinea pig serum.

• Asian-Australasian Journal of Animal Sciences
• /
• v.15 no.1
• /
• pp.19-25
• /
• 2002

The objectives of this study were to understand the possible mechanism of duck sperm toxicity induced by arsenic exposure in vivo, and to investigate the roles of the antioxidant L-ascorbic acid in ameliorating the arsenic-induced sperm impairment. To test the acute toxicity, the percentages of mortality of mature drakes treated with different concentrations of trivalent sodium arsenite, As (III), and pentavalent sodium arsenate, As (V) were measured. The LD50 value of As (III) for mature drakes was $4.89{\pm}1.49$ ppm. Although As (V) didn't cause any deaths even at a concentration of 40 ppm, the chronic toxicity of As (V) on sperm quality was shown by a decreased fertilization rate. When the concentrations of As (V) were above 0.4 ppm, fertilization rates were lower than those of 0.04 ppm and control. Drakes treated with 40 ppm of As (V) had the highest malondialdehyde (MDA) level in the testis tissue, $3.100{\pm}0.218{\mu}mole/g$ testis. This showed that 40 ppm of As (V) significantly induced lipid peroxidation in testis tissue. For the 1.2 ppm As (III) treatment, several significant effects were observed: (1) sperm motility was decreased most dramatically by $52.0{\pm}9.1$% after three days of incubation; (2) fertilization rate of artificially inseminated semen was the lowest, $26.4{\pm}15.4$; (3) the MDA concentration in testis tissue, $7.846{\pm}0.246{\mu}mole/g$ testis, was significantly higher than the others (p<0.05); (4) the sperm number, $1.17{\pm}0.40({\times}10^9)$, was significantly lower than with the 60 ppb and control treatments (p<0.05); (5) a black appearance and soft texture was observed in the testis tissue. The antioxidant L-ascorbic acid administered along with 1.2 ppm As (III) decreased the toxicity of arsenic. The ameliorating effects included: improved sperm motility, increased sperm number and fertilization rate, and decreased MDA concentration in the testis tissue. This study suggests that the toxicity of the trivalent arsenic on sperm quality is partly from free radicals generated by its metabolic pathway, and the antioxidant ascorbic acid ameliorates arsenic-caused sperm impairment.

• Korean Journal of Environmental Agriculture
• /
• v.6 no.2
• /
• pp.39-45
• /
• 1987

A water culture experiment was conducted to investigate the effect of As content in a culture solution on the water status and growth of rice plants. Rice (Oryza sativa L. Line. Iri 316) seeds were germinated in bentonite and cultivated there for 30 days. Rice seedlings were transplanted into 3.5l pots containing the culture solution on May 1, 1985 and allowed to grow without As treatment for one month. Afterwards, they were grown in a culture solution maintaining the final concentration of As, 0, 1, 5, 10 and 15mg/1 renewing in the solution dissolved sodium arsenate at intervals of 3 to 7 days. Plants were cultivated in the green house during the growing period and harvested 60 days after As treatment. The results obtained were as follows: Transpiration of rice plants was decreased with the increase of the As level in the culture solution. Stomatal diffusive resistance and leaf temperature increased with increase of As levels though the humidity and the air flow rate in leaf decreased. Air flow rate, transpiration and stomatal diffusive resistance showed a highly significant correlation with As contents in shoots and roots of rice plants: Espally The air flow rate and transpiration revealed a significantly higher correlation with As contents in the root than that in the shoot, but diffusive resistance showed adverse tendency. High levels of As in the culture solution depressed plant height, no. of tillers, leaf width and dry weight of plant remarkably. Typical symptoms of As toxicity were root discoloration, and necrosis of leaf tips and margins, and leaf rolling during the sunny daytime were also another symptoms.