• Journal of Microbiology and Biotechnology
• /
• v.17 no.9
• /
• pp.1452-1459
• /
• 2007

The Dps protein, which is overexpressed in harsh environments, is known to playa critical role in the protection of DNA against oxidative stresses. In this study, the roles of Fur in the expression of the dps gene in Salmonella and the protection mechanisms against oxidative stress in Salmonella cells preexposed to iron-stress were investigated. Two putative Fur boxes were predicted within the promoter region of the S. typhimurium dps gene. The profile of dps expression performed by the LacZ reporter assay revealed growth-phase dependency regardless of iron-status under the culture conditions. The fur mutant, $_X4659$, evidenced a reduced level of ${\beta}$-galactosidase as compared to the wild-type strain. The results observed after the measurement of the Dps protein in various Salmonella regulatory mutants were consistent with the results acquired in the reporter assay. This evidence suggested that Fur performs a function as a subsidiary regulator in the expression of dps. The survival ability of Salmonella strains after exposure to oxidative stress demonstrated that the Dps protein performs a pivotal function in the survival of stationary-phase S. typhimurium against oxidative stress. Salmonella cells grown in iron-restricted condition required Dps for full protection against oxidative stress. The CK24 (${\Delta}dps$) cells grown in iron-replete condition survived at a rate similar to that observed in the wild-type strain, thereby suggesting the induction of an unknown protection mechanism(s) other than Dps in this condition.

• Journal of Korean Society of Environmental Engineers
• /
• v.31 no.10
• /
• pp.839-844
• /
• 2009

This research investigates the importance of the microbial metabolic pathways such as denitrification, iron reduction, and methanogenesis, in the degradation of organic matters of the sediments. There are statistically significant differences( P < 0.05) in the rates of denitrification, iron reduction, and methanogenesis according to the location: Site A has no plant, Site B is dominated by Scirpus, and Site C is dominated by Phragmites. Among them, Site C showed different methanogenesis rate depending on the sediments depth. The organic matter content increased from Site A to Site C. Site A had the smallest organic matter content whereas it showed the largest denitrification rate and iron reduction rate. Site C had the largest methanogenesis rate. Denitrification is the dominant pathways based on the assumption that anaerobic degradation of organic matter is mainly carried out through denitrification, iron reduction, and methanogenesis.

• Proceedings of the Korean Society of Life Science Conference
• /
• 2007.10a
• /
• pp.90.2-90.2
• /
• 2007

See Full Text

• Journal of Nutrition and Health
• /
• v.15 no.4
• /
• pp.258-267
• /
• 1982

This study was performed to investigate the effect of different levels of protein and iron in the diet upon Fe, Cu and Zn metabolism in rat during four weeks of growing period. Forty-five male weanling rats of Sprague-Dawley strain weighing $68.5{\pm}1.1g$ were divided into 9 groups and each group was given with one of the 9 different kinds of diets for four weeks. The three dietary protein levels used were 5, 20 and 40% and Fe levels 0, 35, and 350 ppms. The results obtained were summarized as following ; 1) Food intake and body weight gain in 20%(SP) and 40%(HP) dietary protein groups tended to be significantly higher than 5%(LP) protein groups. Protein efficiency ratio (PER) was higher in LP groups than in HP and SP groups. With dietary Fe levels, there were no significant differences among groups in food intake, body weight gain, and PER. 2) In LP groups, the Fe concentrations in liver, kidney, and hind limb muscle were higher than in SP and HP groups. Regarding with dietary protein levels, the liver Cu concentrations in LP groups were slightly higher, but the liver Zn concentrations were lower in LP groups. The Fe concentrations in liver and kidney tended to decrease with decrease in dietary Fe levels, but Cu and Zn concentrations showed no consistent tendency with dietary Fe levels. 3) The Fe, Cu and Zn concentrations in serum were not different from dietary treatments except that the serum Fe concentrations increased slightly in LP groups. 4) The Fe and Cu concentrations in urine tended to be higher in HP groups. Fecal Cu and Zn concentrations showed no significant differences in dietary protein or Fe levels, but the Fe concentrations tended to increase with increase in dietary Fe levels.

• Clinical and Experimental Pediatrics
• /
• v.52 no.1
• /
• pp.105-110
• /
• 2009

Purpose : Perinatal asphyxia is an important cause of neonatal mortality and subsequent lifelong neurodevelopmental handicaps. Although many treatment strategies have been tested, there is currently no clinically effective treatment to prevent or reduce the harmful effects of hypoxia and ischemia in humans. Erythropoietin (Epo) has been shown to exert neuroprotective effects in various brain injury models although the exact mechanisms through which Epo functions are not completely understood. This study investigates the effect of Epo on hypoxic-ischemic (HI) brain injury and the possibility that its neuroprotective actions may be associated with iron-mediated metabolism. Methods : HI brain injury was produced in 7-day-old rats by unilateral carotid artery ligation followed by hypoxia with 8% oxygen for 2 h. At the end of HI brain injury, the rats received an intraperitoneal injection of 5,000 units/kg erythropoietin. Random premedication with iron, deferoxamine, iron-deferoxamine, or saline were performed 23 d before HI brain injury. The severity of the brain injury was assessed at 7 d after HI. Results : Single Epo treatment post-HI brain injury reduced the gross and histopathological findings of brain injury. Iron premedication did not increase the incidence or severity of the injury as measured by the damage score. Deferoxamine administration before HI brain injury improved the brain injury as compared to no treatment or Epo treatment. Conclusion : These findings indicate that Epo provides neuroprotective benefits after HI in the developing brain. These findings suggest that Epos neuroprotective actions may involve reducing iron in tissues that mediate the formation of free radicals.

• Journal of Nutrition and Health
• /
• v.44 no.5
• /
• pp.394-405
• /
• 2011

Osteoporosis is a rising problem, as the older age population is increasing due to prolongation of life. Genetic and environmental factors play key roles in bone metabolism, and diet is also an important factor. We investigated the relationship among factors affecting bone mineral density (BMD), including daily food intake and nutrient intake in men aged >50 years. Seventy-eight men, who visited the health promotion center at one of the university medical centers, were divided into normal and osteopenia groups according to their BMD. The body weight of the normal group was significantly higher than that of the osteopenia group. The osteopenia group showed significantly higher carbohydrate intake and lower calcium and vegetable calcium intake compared to those in the normal group. Lumbar spine BMD was negatively correlated with energy, fat, vitamin B1, and sodium intake in the normal group. Additionally, femoral neck BMD was negatively correlated with total animal protein, energy, protein, fat, phosphorous, iron, animal iron, potassium, vitamin B1, B2, B6, and niacin intake. Lumbar spine BMD was positively correlated with fruit, calcium, vegetable calcium, animal calcium, and vitamin C intake in the osteopenia group. Femoral neck BMD was negatively correlated with meat, dairy product, total animal protein, plant protein, animal protein, vitamin A, and cholesterol intake. A stepwise multiple regression analysis revealed that several dietary factors affected BMD, including energy, fat, vitamin B1, B2, B6, niacin, sodium, protein, iron, animal iron, phosphorous, potassium, and animal protein in the normal group and zinc, calcium, vegetable calcium, animal calcium, vitamin C, fruit, protein, animal protein, meat, dairy product, carbohydrates, cholesterol, vegetables, mushrooms, and seasonings in the osteopenia group. These results indicate that adequate nutrient intake plays an important role maintaining optimum bone health in middle aged men.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.40 no.12
• /
• pp.1720-1725
• /
• 2011

Aspartic acid chelated iron (Asp-Fe) was synthesized by a new method using calcium carbonate, aspartic acid, and ferrous sulfate. This study was carried out to investigate the bioavailability of Asp-Fe in iron-deficient rats. We divided the rats into four experimental groups. The first was the normal diet control group, or NC. The second was the no treated control group of iron-deficient (ID) rats, or ID+C. The third was the heme-iron (heme-Fe) treated group of ID rats, ID+heme-Fe. And the fourth was the Asp-Fe treated group of ID rats, or ID+Asp-Fe. There were no differences among any of the experimental groups in diet consumption, change of body weight, or the weight of the livers, kidneys, or spleens. After 7 days of feeding, the iron content in the sera of the ID+Asp-Fe group (175.2 ${\mu}g$/dL) and the ID+heme-Fe group (140.8 ${\mu}g$/dL) were significantly higher than that of the ID-C group (96.1 ${\mu}g$/dL). The total iron binding capacity (TIBC) of the ID+Asp-Fe group (735.4 ${\mu}g$/dL) was significantly normalized compared to the ID+C group (841.9 ${\mu}g$/dL) or ID+heme-Fe group (824.6 ${\mu}g$/dL). The hematocrit level of the ID+Asp-Fe group was increased to normal levels, but there was no statistical difference among ID groups. The absorption ratio of heme-Fe was 21.3% and that of Asp-Fe was 50.2%, which indicates a 2.3 times higher ratio in comparison with heme iron. With the above results we found that Asp-Fe seems to be an efficient form of iron to supply iron deficient rats in order to cure them of anemia. Thus, these findings suggest that aspartic acid chelated iron has the potential to serve as a functional food related to iron metabolism.

• Journal of Ginseng Research
• /
• v.7 no.2
• /
• pp.102-107
• /
• 1983

The effects of saponin, one of major components (Panax ginseng C.A. Meyer), on the growth of E. coli K-12 and the formation of siderphore was observed The following results were obtained. 1. When E. coli was grown on medium containing 1${\times}$10-5%-11${\times}$10-1% of the saponin, the rate of growth was stimulated at 10-1% of the saponin significantly compared to that of control. 2. When E. coli K-12 was grown on medium containing 1${\times}$10-1% of the saponin, the amount of siderphore was two times as much as the control. 3. The growth of E. coli was observed to be dependent on the concentration of siderophore when siderophore was added to medium. 4. The effect of saponin on the formation of siderophore in vitro was observed to reach maximum at 1${\times}$10-3% of the saponin. Such results suggest that the growth rate of E. coli K-12 could be enhanced by ginseng saponin fraction through stimulation of siderphore formation. We have described the fast growth of E. coli, K-12 and B. subtilis, rapid uptake of 14C-glucose, and high level of other metabolites such as lipids and proteins of E. coli, and B. subtilis in medium containing saponing fraction compared to that of microorganisms without saponin fraction.1∼3Such differences were claimed to be due to rapid uptake of 14C-glucose by widened periplasmic region throught unknown mechanism in the prescence of saponin fraction in medium3 and have raised a question whether there is another possible factor, siderophore4(Greek for iron bears), since microorganisms must secure a sufficient amount of iron for normal growth. These are known to be synthesized by the cells under iron-deficient condition and in most case, excreted into the medium5, where they can complex and solubilize any iron present there. It is generally believed that these complexes are then taken into the cells presumably by specific transport systems, thus providing iron for cell metabolism. Within the group of enteric bacteria, only three species (E. coli, S. typhimurium, and A. aerogense) have, so far, been studied in a ny detail. The main iron-binding compound produced by these species is enterochelin, and its role in iron transport is now well established. And biosynthesis of enterochelin from 2, 3- dihydroxybenzoate and serine in the prescence of magnesium ions and ATP was reported6. 2, 3-dihydroxybenzoate was also shown to involve isochorismate and 2, 3-dihydro-2, 3-dihydroxybenzoate as intermediate.7∼11 The present paper deals with the effect of ginseng saponin fraction on growth, the level of enterochelin formation in vivo and the conversion of 2, 3-dihydroxybenzoate and serine into entrochelin in vitro, and entrochelin obtained on the growth in relation to possible explanation of ginseng saponin fraction on the rapid growth of E. coli, K-12.

• Asian-Australasian Journal of Animal Sciences
• /
• v.18 no.3
• /
• pp.332-339
• /
• 2005

The effect of transinoculation of goat rumen liquor into sheep rumen on mimosine toxicity was studied. One adult Kutchi male goat having higher mimosine degradation capacity than sheep was gradually adapted to Leucaena leucocephala (Leucaena) leaves by feeding increasing level of eucaena leaves supplementation for 1 month. Six Bharat Merino rams (12-18 months of age) were divided into two equal groups with (group I) or without (group II) infusion of 200 ml of goat rumen liquor per animal. The mimosine degradation in groups I and II were 3.04 and 2.31; 3.90 and 3.73 mg per day per 10 ml rumen liquor respectively after 1 and 2 weeks of leucaena feeding leaves. Total rumen bacterial population in RGCA medium and in a selective medium containing iron showed an increasing trend in both groups, while the bacterial population growing in the presence of cellulose showed a decreasing trend. Animal performance data did not show any adverse effect. Results revealed that transinoculation of rumen liquor from leucaena leaves adapted goat to sheep rumen did not help to improve mimosine degradation in the sheep. The sheep transinoculated with goat rumen liquor displayed no in vivo improvements in nutrient utilization vis-a-vis mimosine metabolism.

• Journal of the Korean Society of Food Culture
• /
• v.15 no.5
• /
• pp.413-422
• /
• 2000

This study was undertaken to investigate meal pattern, nutrition knowledge and food preference of 438 rural middle school students living in ChunNam area. As far as nutrition knowledge is concerned, most subjects did not answer correctly on the items of basic five food groups, animal fat and vegetable oil, empty source of soft drink, nutrient requirement and water's role in energy metabolism. However they responded well on the item of iron deficiency and dietary source of Ca. Male students were significantly better in the answering the items of dietary source of energy and nutrient requirement than females, while female students were significantly better on the items of water's role in energy metabolism related to obesity. Generally the respondents did neither consume oil often nor consider consumption of salty food. Furthermore, only 38.6% of subjects drink milk daily in spite of understanding dietary source of Ca, which suggested that they should incorporate nutrition knowledge into dietary behavior. The preferred foods for most subjects were fruit, kimbab and ice cream. Contrastingly the food that they did not prefer was fermented vegetable probably due to strong flavor.