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The effect of cations and anions on the activity of Aspergillus flavus var. oryzae and Bacillus subtilis α-amylases showed that the tested enzymes are sensitive to most of cations and resistant to anions. The most significant inhibitory effects on the activity of A. flavus var. oryzae α-amylase have been demonstrated by Al3+ and Fe3+ ions, while on the activity of B. subtilis α-amylase - Hg2+, Cu2+ and Fe3+ ions. Inactivation of A. flavus var. oryzae and B. subtilis α-amylases in the presence of EGTA is indicated on the presence within their structure of metal ions. An important role in the enzymatic catalysis of both enzymes play carboxyl groups as evidenced by their inhibition of 1-[3-(dimethylamino)propyl]-3-ethylcarbodiimide methiodide. Inhibition of B. subtilis α-amylase by p-chloromercuribenzoate, N-ethylmaleimide and sodium sulfite is indicated on the probable involvement of the sulfhydryl groups in the functioning of the enzyme. Unlike most studied glycosidases the tested enzymes do not contain histidine imidazole group in the active center.

Screening of protease producers with specificity to insoluble and hard soluble protein substrates of animal origin (collagen, fibrin, elastin and keratin) was carried out. It was studied the bacterial cultures (24 strains) isolated from water and periphyton of enclosures with dolphins, and also from exhalations, oral cavity and skin of dolphins. Some bacterial strains isolated from water and periphyton of enclosures hydrolyzed collagen (5-23 U/ml) and elastin (20-32 U/ml). Thus all tested cultures did not possess the property of extracellular keratinases synthesis. The streptomycetes (48 strains) were isolated from the soil of Black Sea coastal strip near Odessa and Saky, from parkland and the shores of freshwater lake in Saky and from the soil of Atlantic Ocean coastal strip near Albufena (Portugal). Several streptomycetes have been found to appeare the perspective producers of extracellular keratinase and collagenase. The strains isolated from the soil of the coastal strip area both sea and freshwater lake in Saky possessed the highest activity (up to 5 U/mg).

Support of optimum redox-homeostasis in the cells of microorganisms plays a substantial role in the processes of DNA synthesis, respiration, providing of immune and protective reactions, activity of enzymes, etc. The changes of the redox-status can be accompanied by the increase of the level of reactive oxygen species (ROS) which predetermine the damage of biologically active molecules. Adjusting of ROS concentrations is a very important process in development of microorganisms. Low-molecular antioxidants are effective inhibitors of free-radical processes. The authors of the review present the description of oxidants and consider the ways of origin and consequences of their influence on the living cells. An accent is done on phenomenological description of low-molecular antioxidants. The basic mechanisms of their action are considered. Special attention is given to the question of synergism between these protectors. The detailed study of mechanisms of functioning of low-molecular antioxidants in the cells of microorganisms will allow using these living objects in different spheres of human activity.

The mechanisms of electron transfer of association of chemoorganotrophic bacteria to the anode in microbial fuel cells are summarized in the survey. These mechanisms are not mutually exclusive and are divided into the mechanisms of mediator electron transfer, mechanisms of electron transfer with intermediate products of bacterial metabolism and mechanism of direct transfer of electrons from the cell surface. Thus, electron transfer mediators are artificial or synthesized by bacteria riboflavins and phenazine derivatives, which also determine the ability of bacteria to antagonism. The microorganisms with hydrolytic and exoelectrogenic activity are involved in electron transfer mechanisms that are mediated by intermediate metabolic products, which are low molecular carboxylic acids, alcohols, hydrogen etc. The direct transfer of electrons to insoluble anode is possible due to membrane structures (cytochromes, pili, etc.). Association of microorganisms, and thus the biochemical mechanisms of electron transfer depend on the origin of the inoculum, substrate composition, mass transfer, conditions of aeration, potentials and location of electrodes and others, that are defined by technological and design parameters.

Investigations of physico-chemical properties of the Bacillus thuringiensis IMV B-7324 fibrinolytic peptidase showed that optimal activity of enzyme displayed at pH 10.0 and temperature 60 degrees C. Stability of peptidase retained in the range of pH from 6.0 to 11.0 and temperature from 20 to 50 degrees C over 1 h. Inhibition of fibrinolytic peptidase activity by ethylene glycol tetraacetic acid (EGTA) and tetrasodium salt of ethylenediaminetetraacetic acid (trilon B) indicates the belonging of this enzyme to the group of metallopeptidases. It was established that cations Ag+, Mg2+ and Ba2+ increased the fibrinolytic activity by 40 %, 25 % and 30 %, respectively, but Ca2+, Zn2+, Cu2+, Pb2+ and Hg2+ reduced it by 30-60%. Several of studied anions (F-, Br-, SO2-, S2O(2-)3, AsO(3-)4, NO-(3) and NO2(-) inhibit the activity of B. thuringiensis IMV B-7324 fibrinolytic peptidase by 25-100%.

The current literature data on producers, physico-chemical properties and substrate specificity of a-amylases produced by microbes from different taxonomic groups such as bacteria, fungi and yeasts are discussed in the survey. Synthesis of alpha-amylase majority is an inducible process which is stimulated in the presence of starch or products of its hydrolysis. It is possible to increase enzymes activity level by optimization of cultivation conditions of strains-producers. alpha-Amylases, isolated from different sources are distinguished in their physico-chemical properties, particularly in their molecular weights, pH- and thermooptimums, inhibitors and activators. The enzymes hydrolyse soluble starch, amylose, amylopectin, glycogen, maltodextrins, alpha- and beta3-cyclodextrins and other carbohydrate substrates. It is well known that alpha-amylases belong to GH-13 family of glycosyl-hydrolases, which contain the catalytic domain A as (beta/alpha)8-barrel. In addition to domain A, alpha-amylases contain two other domains: B and C, which are localized approximately on opposite sides of (beta/alpha)8-barrel. Most of the known alpha-amylases contain calcium ion, which is located on the surface between domains A and B and plays an important role in stability and activity of the enzyme.

The scheme of isolation and purification of Bacillus thuringiensis IMV B-7324 peptidase has been developed. This scheme includes ammonium sulfate precipitation and chromatography on neutral and charged TSK-gels. It was found that the enzyme hydrolyzes elastin and fibrin. The molecular weight is 26 kDa. It was shown that the enzyme is an alkaline serine peptidase. The optimal pH of hydrolysis of elastin and fibrin were 9.0 and 10.0, respectively. The optimal temperature of elastin and fibrin hydrolysis are 40 and 50 degrees C, respectively. The high stability of the purified preparation in the studied range of pH and temperature was shown. The stabilizing effect of zinc at a concentration of 1 mM on the elastase activity, and the inhibitory effect of other divalent cations under study have been established. The investigated chloride and acetate anions reduced activity by 20%, while phosphate anions increased activity by 15-30%.

Fibrinolytic peptidase of Bacillus thuringiensis IMV B-7324 was isolated by ammonium sulfate fractionation, gel-filtration and ion exchange chromatography on TSK-gels--Toyopearl HW-55 and DEAE 650 (M). Fibrinolytic activity of the purified enzyme was 87.9 U/mg of protein that was 19.9 times higher compared with the supernatant cultural liquid, the yield on its activity reached 31%. The gel-filtration on Sepharose 6B and by SDS-PAGE electrophoresis demonstrated the homogeneity of the purified fibrinolytic peptidase, which molecular weight was approximately 24 kDa.

The chemical synthesis of a modified gene fragment that codes IgG-binding domain of protein G of Streptococcus sp. (SPG) was done. Two copies of gene fragmentes SPG were cloned into plasmid vector pET-24(a), for expression of recombinant truncated protein G (rSPG) in the culture of Escherichia coli. IgG-binding capacity and specificity for rSPG was confirmed by model assay such interaction in vitro. Basing on the obtained data we affirm that truncated recombinant protein G is able to bind immunoglobulin G in mammalians and can be used for purification of IgG from sera by affinity chromatography or for synthesis of immunoassay conjugates with broad range specificity.