Adenosine-5'-Phosphosulfate- and Sulfite Reductases Activities of Sulfate-Reducing Bacteria from Various Environments.

A comparative study of the kinetic characteristics (specific activity, initial and maximum rate, and affinity for substrates) of key enzymes of assimilatory sulfate reduction (APS reductase and dissimilatory sulfite reductase) in cell-free extracts of sulphate-reducing bacteria (SRB) from various biotopes was performed. The material for the study represented different strains of SRB from various ecotopes. Microbiological (isolation and cultivation), biochemical (free cell extract preparation) and chemical (enzyme activity determination) methods served in defining kinetic characteristics of SRB enzymes.

ATP sulfurylase activity of sulfate-reducing bacteria from various ecotopes.

Sulfate-reducing bacteria (SRB) are widespread in various ecotopes despite their growth and enzymatic features not compared. In this study, the enzymatic parameters of ATP sulfurylase in cell-free extracts of sulfate-reducing bacteria isolated from various ecotopes such as soils, corrosion products and human large intestine were determined. Comparative analysis of both enzyme characteristics and growth parameters were carried out and similar research has not been reported yet.

[Biodiversity of sulfate-reducing bacteria growing on objects of heating systems].

It was shown that sulfate-reducing bacteria developed on the sections of Kyiv municipal heating systems, which are exploited in conditions of different temperatures. The bacteria were different as to their morphological and physiological properties. The bacteria of Desulfovibrio genus were revealed on the sections, which were exploited at a temperature of 35-40 degrees C and bacteria of Desulfomicrobium and Desulfotomaculum genera were revealed on the sections with a higher temperature such as 60 degrees C.

[Possibility of the plasmid transfer within bacteria - compounds of the sulfidogenic microbial community].

Extrachromosomal elements have been found within the isolates of ammonifying and iron-reducing bacteria obtained from the natural sulfidogenic community. These elements were small with size approximately 5-9 kb. Transconjugant strains Pseudomonas aeruginosa 27, P aeruginosa 28, P mendocina 29, Aeromonas hydrophila/caviae 30, harboured plasmids RP4 and R68.

[Lectin-binding analysis of the biofilm exopolymeric matrix carbohydrate composition of corrosion-aggressive bacteria].

The carbohydrate components of biofilms of corrosion-aggressive bacteria were studied by transmisstion electron microscopy using lectins labeled with colloidal gold. N-acetyl-D-glucosamine, N-acetyl-D-galactosamine, and neutral carbohydrates D-glucose and D-mannose were found within the exopolymeric matrix. Lectins with equal carbohydrate specificity demonstrated different degrees of interaction with the carbohydrate components of bacterial biofilms.