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The content of heavy metals in the water bodies increases as a result of anthropogenic effects. Heavy metals exert toxical effect on hydrobionts. Involved into the trophic chain they can be the cause of grave human diseases. Microorganisms possess a capacity to accumulate heavy metals in their body, evoke the process of their enzymatic transformation into nontoxical compounds and adsorb them on the cell surface. When breeding bacterial strains for the biological treatment of sewage from the metal-working plants the authors recommend to choose the cultures from econiches containing heavy metal compounds and to establish their resistance to high concentrations of metals. This resistance correlates with high biological activity. The bacterial strains of Pseudomonas genus possessing a capacity to sulphate reduction have been selected. As a result of their activity the high-solvable toxical sulphates are restored to practically unsolvable precipitating forms. A new species Aeromonas dechromatica transforming high-toxical six-valence chromium into low-toxical three-valent ones is described. The grounds of biotechnologies of the use of the breeded cultures for treatment of industrial sewage are stated.

Lactic bacteria predominate in the microflora of the digestive tract of chicken and turkey. They are represented mainly by Lactobacillus acidophilus, L. salivarius, L. fermentum and L. buchneri. Streptococcus faecium is always isolated. L. ruminis, L. vitulinus, L. delbrueckii, L. coryniformis and L. viridescens were found in this ecological niche for the first time. S. faecium and S. faecalis prevail in the digestive tract of geese and ducks, while lactobacilli are detected in a lesser amount and are represented mainly by L. plantarum. L. salivarius cells isolated from the digestive tract of poultry are highly polymorphous. Most of the lactic acid bacteria found in the digestive tract of poultry can grow at 45-50 degrees C whatever is the species they belong to.

A large number of bacterial strains assimilating chemical ethanol has been isolated using an original technique. Active growth of strains belonging to the genera Pseudomonas and, particularly, Acinetobacter was registered on mineral media containing ethanol. A mathematical model was constructed select a strain of Acinetobacter calcoaceticus K-9 during its continuous cultivation on media containing ethanol. The model makes it possible to determine conditions for producing a present amount of the biomass, the percentage of its yield, and the produc;iveness as a function of the dilution rate, temperature, and the concentration of ethanol and phosphoric acid in the medium. The main characteristics of the growth process in the studied factor space were established. The optimum conditions were calculated for growth of the strain with respect to each of the criteria. Under various conditions of bacterial growth, changes in the morphology and ultra-fine structure of the cells correlated with their physiological activity. The volume of the cells increased with the rate of dilution of the medium: the process can be described by a saturation curve. The presence of mesosomal structures is typical of the cells growing at low flow rates.

Bacteria capable of hexavalent chromium (Cr6+) reduction can be found in Cr6+-containing sewage and sediments of purification tanks of industrial plants. They cannot be detected in water and soil samples containing no chromium compounds. Bacteria reducing chromium belong to the genera Aeromonas, Escherichia, Pseudomonas and Enterobacter. Their activity of Cr6+ reduction correlates with the high resistance to the elevated content of this ion in the medium. The fine cell structure of these bacteria is described.

Normal microflora in the intestinal tract of fishes inhabiting fresh-water reservoirs includes lactic bacteria. The number of the bacteria depends on the animal species, the composition of food, the age, and the season. The highest number of these microorganisms (hundreds of millions per gram of the intestinal content) is found in carps. Enterococci are most often encountered in fishes inhabiting ponds: Streptococcus faecalis Andrewes a. Horder, Str. faecium Orla-Jensen, Str. bovis Orla-Jensen. Lactobacilli are more typical of fishes in water reserviors: Lactobacillus plantarum (Orla-Jensen) Bergey et al., L. casei (Orla-Jensen) Hansen a. Lessel, L. casei var. casei, L. casei var. rhamnosus, L. Casei var. alactosus, L. leichmannii (Henneberg) Bergey et al., L. acidophillus (Moro) Hansen a. Mocquot, L. Fermenti Beijerinck, L. cellobiosus Rogosa et al., L. Buchneri (Henneberg) Bergey et al. The content of lactic bacteria varies in water reservoirs; their highest content is found in ooze (tens of thousands per gram).

From soils of the Ukrainian SSR bearing oil and without it, 241 strains of Nocardia were isolated on mineral media containing n-alkanes C12-C22. The strains were divided into two groups: actinoid (N. asteroides, N. flavescens) and bacterium-like (N. rubropertincta, N. flava, N. ucrainica, N. salmonicolor, N. rubra, N. erythropolis, Nocardia ssp). Chemotaxonomic characteristics (the presence in the cells of galactose, arabinose, mesodiaminopimelic acid, lipid LCN-A) were used to differentiate Nocardia from other genera of actinomycetes and coryneforms and to confirm the taxonomy of museum strains. The majority of the Nocardia cultures belongs to the groups "asteroides" and "rhodochrous" according to location of spots of lipid LCN-A on chromatograms. The strains of N. asteroides and complex "M." rhodochrous may belong to both groups. A small number of strains belongs to the group which is represented by N. calcarea 41 (NCIB 8863).

In the C. tropicalis K-41 cells fixed by glutaraldehyde and osmium most membranes consisted of two electron-transparent and one electron-dense layer. Morphologo-structural peculiarities of the cell fraction grown at 39 degrees testify to a certain disconnection of energetic and constructive metabolism, inhibition of synthetic processes. Cell division was more active at 29 degrees.

The composition of free mycolic acids was studied in the cells of Brevibacterium ammoniagenes ATCC 6871, B. flavum 22, B. stationis ATCC 14403, Corynebacterium divaricatum ATCC 14020 and Rhodococcus maris IMV 195. The acids are a mixture of saturated and unsaturated compounds with the total number of carbon atoms from 32 to 36 and the number of C atoms in the alpha-chain from 10 to 15.

Chemotaxonomic characters (the monosaccharide composition and diaminopimelic acid (DAP) of cell hydrolysates, the type of lipid LCN-A) were studied with bacteria of the "rhodochrous" complex and the Arthrobacter genus isolated from natural substrates as well as with collection strains of the genera Arthrobacter, Brevibacterium and Corynebacterium. If arabinose, galactose and meso-DAP were present in cell hydrolysates of these bacteria, they always contained lipid LCN-A. Bacteria of the "rhodochrous" complex can be differentiated from Corynebacterium sensu stricto by location of lipid LCN-A spots on chromatograms, and from the genera Brevibacterium (B. linens) and Arthrobacter, by the presence of arabinose, meso-DAP and lipid LCN-A in the cells. The representatives of two latter genera do not contain arabinose and lipid LCN-A in their cells.

The effect of biotin on the specific growth rate of Candida tropicalis was studied on media with various sources of carbon nutrition at temperatures of 29 and 39degreesC. The yeast was found to require 3--5 times less biotin on the medium with paraffin than on the medium with glucose and hexodecane, and 3--4 times more biotin on the same substrate with an increase in temperature. The growth rate increased by 36--40% on liquid paraffins containing 0.5 mcg/litre of biotin at 29degreesC and 1.5--2.0 mcg/litre of biotin at 39degreesC. The saturation constant of biotin increased from 0.033 to 0.063 mcg/litre on the medium with paraffin, and more by an order on the medium with glucose and hexadecane, at a rise of growth temperature from 29 to 39degreesC.