[Effect of introduced microorganisms on copper and cobalt mobility in soil].

The paper deals with the change of copper and cobalt mobility in contaminated soil when activating microbiological processes by introduction of sources of carbon, nitrogen, phosphorus, metal-resistant microorganisms. When Bacillus cereus BKM 4368 growing in soil fertilized with glucose one can observe a 5-fold increase of cocentration of heavy-metal mobile forms as compared with sterile soil. The use of acetate as a carbon source and Alcaligenes euthrophus CH 34 culture as inoculum will provide a 3-fold decrease of concentration of copper and cobalt mobile forms in the process of microorganisms growth.

[Degradation of alkylsulfates by a Pseudomonas aeruginosa culture immobilized on a polyvinyl alcohol fiber].

Pseudomonas aeruginosa cells capable of destroying alkyl sulfates, anionic surfactants, were immobilised on activated polyvinyl alcohol fibres. The immobilised cells could decompose SDS. When the immobilised cells were used repeatedly, their biomass increased but the activity hardly changed.

[Hydrophilic-hydrophobic properties of microorganisms under various culturing conditions].

The index of hydrophobicity and the hydrophilic-hydrophobic properties of seven microbial cultures were determined by studying their adhesion to n-hexadecane. The index of hydrophobicity was shown to be a stable characteristic of a culture grown in media with different carbon sources. As was found for Escherichia coli K-12 and Acinetobacter calcoaceticus K-9 whose hydrophobicity indicates were quite different, the character of cell hydration was virtually independent of the growth phase and did not change upon either submerged or superficial cultivation.

[Coagulation of bacteria by the action of montmorrillonite].

Conditions were studied for the coagulation of aggregation-stable Bacillus subtilis, Flavobacterium rigens and Escherichia coli cell dispersions. Their aggregative stability decreased when montmorillonite, a clay mineral, was added to a weakly acid medium or in the presence of Al3+ ions. Bacterial heterocoagulation under the action of montmorillonite can be used as a universal strategy for biomass isolation from aqueous dispersion media.

[Sorption of microorganisms by fiber materials].

Candida guilliermondii and Escherichia coli cells were adsorbed on glass and basalt fibres with a similar specific surface, but with a different charge. The quantity of adsorbed microorganisms did not depend on the type and charge of a fibre surface. However, cells were adsorbed faster and more firmly on positively charged and uncharged fibres than on negatively charged fibres.