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Biomedical subjects

H Chmiel

Publications and source records attributed to H Chmiel.

11 recordsLinked to original sources
PubMed1990

Effects of oxygen supply on the production of nikkomycin with immobilized cells of Streptomyces tendae.

For continuous production of the antibiotic nikkomycin immobilized cells have been used in a fluidized bed bioreactor. Cells of Streptomyces tendae were immobilized on sintered glass particles. Different biomass concentrations on the particles correspond to different thicknesses of mycelial layers because growth occurs only on the outer surface of the particles. The antibiotic productivity decreased with increasing layer thickness. In fermentations with higher concentrations of both biomass on the particles and dissolved oxygen levels of about 70% the productivity was also limited because of limited oxygen diffusion in the layers.

Aminoglycosides↗
PubMed1990

A study of N- and P-dependence of nikkomycin production in continuous culture with immobilized cells.

The influence of nitrogen and phosphate on the biosynthesis of nikkomycin was studied in chemically defined medium. Cells of Streptomyces tendae were immobilized on porous glass particles in a fluidized-bed reactor for continuous production of nikkomycin. Phosphate had no significant influence on the biosynthesis of nikkomycin. However, even a very low concentration of phosphate in the production medium (0.0125 mmol/l) resulted in microbial growth on the particles. The concentration of nitrogen was highly effective in the regulation of the biosynthesis of nikkomycin. A high level of antibiotic production (maximum 3.05 mg/g dry cell weight per hour) was maintained for a period of about 200 h in a medium that contained nitrogen at a concentration of 0.2 g NH4NO3/l.

Aminoglycosides↗
PubMed1979

Theoretical aspects of adsorption of polar substances from polar solvents.

The efficiency of adsorbents for hemoperfusion and dialysate regeneration can be increased if suitable catalysts are fixed on their surface in an appropriate density. Suitable catalysts are oxides and salts of the transition metals. The appropriate surface density of the catalysts depends on the molecular data of both catalyst and toxin to be removed, as well as on the distribution of the adsorption sites on the adsorbent surface area. The distribution of the adsorption sites is determined by means of photoelectron spectroscopy and adsorption and desorption measurements.

Adsorption↗