PubMed Health⌕ Search

Biomedical subjects

B Kos

Publications and source records attributed to B Kos.

6 recordsLinked to original sources
PubMed2005

Heap leaching of lead contaminated soil using biodegradable chelator [S,S]-ethylenediamine disuccinate.

The feasibility of heap leaching Pb contaminated soil using biodegradable chelator [S,S]-ethylenediamine disuccinate ([S,S]-EDDS) in concentrations ranging from 10 to 40 mmol kg(-1) was assessed in a laboratory study. Treatment with 40 mmol kg(-1) [S,S]-EDDS was the most efficient, removing 31.3% of soil Pb and producing a waste washing solution with a peak Pb concentration slightly exceeding 10 mM. The removal of Pb from simulated washing solution containing 10 mM Pb by biodegradation of the Pb-[S,S]-EDDS complex and sorption of the released Pb on a vermiculite/soya meal/Slovakite based permeable bed was completed in 7.5 days. Lead recovery from washing solutions with higher molarity was significantly slower. Lead fractionation and bioavailability were assessed 6-months after soil treatment. Heap leaching removed Pb proportionally from carbonates (approx. 25% Pb) and organic matter (> 50% Pb), the two main Pb-bearing soil fractions,and increased the small pool of Pb soluble in the soil solution. The latter had no effect on Pb phytoavailability. Accumulation of Pb in leaves of the reported hyperaccumulator species Thlaspi goesingense was < 20 mg kg(-1) in all treatments, comparable to the Pb concentration in lettuce (Latuca sativa). Soil treatment with 40 mmol kg(-1) [S,S]-EDDS reduced concentrations of Pb orally-accessible in the stomach and intestine phase from initial 234.0 and 52.5 mg kg(-1) to 157.8 and 29.7 mg kg(-1), respectively, according to Ruby's test. Our results indicate that heap leaching of Pb with [S,S]-EDDS is not a viable remediation option for the tested soil and conditions used.

Biodegradation, Environmental↗
PubMed2005

Importance of S-layer proteins in probiotic activity of Lactobacillus acidophilus M92.

AIMS: To investigate the functional role of surface layer proteins (S-layer) in probiotic strain Lactobacillus acidophilus M92, especially its influence on adhesiveness to mouse ileal epithelial cells. METHODS AND RESULTS: Sodium dodecyl sulphate polyacrylamide gel electrophoresis of cell surface proteins revealed the presence of potential surface layer (S-layer) proteins, ca at 45 kDa in L. acidophilus M92. Southern blot with pBK1 plasmid, containing slpA gene, gave a positive signal, suggesting that L. acidophilus M92 has a slpA gene coding for the S-layer proteins. S-layer proteins of this strain are present during all phases of growth. The S-layer proteins appeared when cells treated with 5 mol l(-1) LiCl were allowed to grow again. Removal of the S-layer proteins reduced adhesion of L. acidophilus M92 to mouse ileal epithelial cells. Furthermore, the viability of cells without S-layer were reduced in simulated gastric juice at low pH range (2, 2.5, 3) and simulated pancreatic juice with bile salts (1.5 and 3 g l(-1)). S-layer proteins of L. acidophilus M92 were resistant to pepsin and pancreatin, in contrast, the treatment with proteinase K led to a significant proteolysis of the S-layer proteins. CONCLUSIONS: These results demonstrated functional role of S-layer; it is responsible for adhesiveness of Lactobacillus acidophilus M92 to mouse ileal epithelial cells and has a protective role for this strain. SIGNIFICANCE AND IMPACT OF THE STUDY: S-layer proteins have an important role in the establishment of probiotic strain Lactobacillus acidophilus M92 in the gastrointestinal tract.

Animals↗
PubMed2004

Washing of Pb contaminated soil using [S,S] ethylenediamine disuccinate and horizontal permeable barriers.

The feasibility of in situ washing of soil contaminated with Pb (6.83 mmol kg(-1)) using biodegradable chelator, [S,S] stereoisomere of ethylenediamine disuccinate ([S,S]-EDDS) and horizontal permeable barriers was examined in soil columns. After 4-cycles of 10 mmol kg(-1) soil [S,S]-EDDS applications, followed by irrigation, 24.7% of total initial Pb was washed from the contaminated soil and accumulated into the barrier. Sequential extractions indicated that washing removed most of the Pb from the organic soil fraction. Barriers were positioned 20 cm deep in the soil and consisted of a 2 cm layer of nutrient enriched vermiculite. Barriers reduced leaching of Pb in the first cycle of [S,S]-EDDS addition by more than 500-times compared to columns with no barrier. After four cycles of chelator addition, a total of 0.24% of the initial Pb was leached from the columns with barriers. Four cycles of in situ soil washing in soil columns were less effective than simulated ex situ soil washing with 40 mmol kg(-1) [S,S]-EDDS, where 51.0% of the Pb was removed after 48-h extraction. Ex situ soil washing with 10 mmol kg(-1) [S,S]-EDDS was equally effective as the first cycle of in situ soil washing (15.5% and 14.5% of removed Pb, respectively).

Chelating Agents↗
PubMed2003

Adhesion and aggregation ability of probiotic strain Lactobacillus acidophilus M92.

AIMS: To investigate aggregation and adhesiveness of Lactobacillus acidophilus M92 to porcine ileal epithelial cells in vitro, and the influence of cell surface proteins on autoaggregation and adhesiveness of this strain. METHODS AND RESULTS: Lactobacillus acidophilus M92 exhibits a strong autoaggregating phenotype and manifests a high degree of hydrophobicity determined by microbial adhesion to xylene. Aggregation and hydrophobicity were abolished upon exposure of the cells to pronase and pepsin. Sodium dodecyl sulphate polyacrylamide gel electrophoresis of cell surface proteins revealed the presence of potential surface layer (S-layer) proteins, approximated at 45 kDa, in L. acidophilus M92. The relationship between autoaggregation and adhesiveness to intestinal tissue was investigated by observing the adhesiveness of L. acidophilus M92 to porcine ileal epithelial cells. Removal of the S-layer proteins by extraction with 5 mol l-1 LiCl reduced autoaggregation and in vitro adhesion of this strain. CONCLUSIONS: These results demonstrate that there is relationship between autoaggregation and adhesiveness ability of L. acidophilus M92, mediated by proteinaceous components on the cell surface. SIGNIFICANCE AND IMPACT OF THE STUDY: This investigation has shown that L. acidophilus M92 has the ability to establish in the human gastrointestinal tract, which is an important determinant in the choice of probiotic strains.

Animals↗
PubMed1994

[Respiratory function in street cleaners and garbage collectors].

The prevalence of chronic impairment of the respiratory system and ventilatory capacity was studied in 81 sanitation workers. In addition, the prevalence of chronic respiratory symptoms was studied in 65 non-exposed control workers. Among the sanitation workers the prevalence of most of the chronic respiratory symptoms was statistically higher than among the controls. The sanitation workers--smokers had a significantly higher prevalence of chronic cough, chronic phlegm and chest tightness than the non-smoking sanitation workers (P < 0.05). The sanitation smokers exposed for more than 10 years had significantly higher prevalences of nasal catarrh (P < 0.01) and sinusitis (P < 0.05) than those with a shorter exposure. FVC and FEV1 were significantly reduced in sanitation workers exposed for more than 10 years in relation to predicted normal values. These differences were not significant for FEF50 and FEF25. Our results suggest that sanitation workers may develop chronic respiratory symptoms and lung function changes, in the first place those of FVC and FEV1.

Adult↗