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I Savvaidis

Publications and source records attributed to I Savvaidis.

5 recordsLinked to original sources

Recovery of gold from thiourea solutions using microorganisms.

The recovery of gold from gold-thiourea solutions using various types of waste biomass was investigated. All organisms tested, namely, Saccharomyces cerevisiae, Spirulina platensis and Streptomyces erythraeus removed gold rapidly from gold-thiourea solutions. The process of gold accumulation was pH-dependent for Saccharomyces ceresvisiae and Streptomyces erythraeus and independent of pH in the case of Spirulina platensis. Of all strains of microorganisms examined, Spirulina platensis had the highest affinity and capacity for gold even at low pH values. Thus, all three microorganisms tested for their ability to recover gold from gold-thiourea solutions can therefore be used in biotechnological applications, especially Spirulina platensis which has the highest binding capacity for gold at low pH values.

Bacterial Proteins↗

A relationship between serum gentamicin concentrations and minimal inhibitory concentration.

Since there are few widely accepted guidelines upon which to base therapeutic decisions and adjust for the many variables which may influence the ultimate therapeutic outcome, and few studies have evaluated what the optimal peak concentration-to-MIC ratio should be, pharmacokinetic parameters were estimated from pre- and post-dose concentrations measured in 30 orthopaedic patients, receiving gentamicin. The fluorescence polarization method was used, and simultaneous determination of the MIC (minimal inhibitory concentration) has been made. When Gram(-) microorganisms were incriminated for the infection, the optimal peak concentration exceeded the MIC by more than 3-fold in our serum samples. In Gram(+) bacteria, the peak antibacterial activity usually obtained tended to be lower (between 1.5 and 2). No correlation was found for the nadir bacteriostatic level. Our investigations showed that the peak bacteriostatic activity correlated well with response to therapy. Based on these findings, the peak antibacterial activity should therefore be between 1.5 and 2 for Gram(+) and greater than 3-fold for Gram(-) microorganisms, and these values seem to be effective for eradication of the infection.

Anti-Bacterial Agents↗

Distribution of Clostridium perfringens in polluted lake environments.

Many of the directives that relate to the prevention of pollution or the improvement of fresh water also relate to lake waters since lake waters ultimately inherit much of the pollution that enters into fresh water. In order to determine the influence of the water depth on Clostridium perfringens, we utilised a new medium, lactose-sulfite (LS) broth, suggested for rapid enumeration and identification of C. perfringens. Duplicate samples were collected at each one of the following sites of the polluted station: surface, 60 cm, 90 cm and bottom (1.18 cm). Membrane filtration equipment was used. All samples were alternatively passed through two membrane filters, the first (20-25 microm pore size) was used for retention of the abundant phytoplankton and the second (porosity 0.45 microm) for C. perfringens. Membranes were placed into the first tube of ten-fold dilutions from 10(1) to 10(4) and incubated aerobically in a waterbath at 46 degrees C for 24 h. The numbers of C. perfringens fluctuated depending on the water depth. Vegetative forms were found only in the bottom sampling; they were never found in surface, 60 cm and 90 cm sampling sites. Sporulated forms were found in all sampling sites with the exception of the surface sampling. Clostridium perfringens as an anaerobic bacterium never occurred in the surface waters in vegetative or spore forms, even if the waters were extremely polluted by domestic or industrial activities. Vegetative forms occurred only in the bottom samples but spore forms which are more resistant to various environmental effects occurred in all depths except for the surface.

Journal Article↗