ACTIVITY OF CATALASE OF MICROMYCETES FROM MOLDOVAN SOILS

Abstract

The catalase is found out in all aerobic organisms. At catalyses significant metabolic reaction of decomposition of Н2О2 intomolecular oxygen and water. Catalase is applied in medicine as antioxidizer at various diseases, to remove the peroxide of the hydrogen, to sterilize products and bleach materials in the various research centers of many countries of the world. Among the sources of commercial preparations of catalase are animals liver and microorganisms, mainly microscopic fungi of various taxonomically groups. Microscopic fungi are capable of synthesizing extracellular enzymes with activity that many times exceeds the activity of endocellular ones. Taking into account high cost and requirement for fermental preparations, the search of perspective producers of extracellular catalase is rather actual. The main source of microscopic fungi is the soil. In our work we used strains of microscopic fungi isolated from various types of soils and zones of Moldova and also from root zones of plants. 158 strains of microscopic fungi of various taxonomically groups (30 from National Collection of Nonpathogenic Microorganisms (NCNM)) were investigated Among researched strains of microscopic fungi the higher activity of extracellular catalase was found in the strains of genus Penicillium and Aspergillus, whereas in others strains the activity was very low. It is established that new isolated strains in comparison with strains from the NCNM are more active. 5 strains of genus Penicillium theactivity was more than 100 un./ml. For the further work as the potential producer of catalase the strain Penicillium sN€.6 with activity of 244 un./ml was chosen. Investigation activity of extracellular catalase in the strain of Penicillium sN€.6, after the change of composition of the medium, established, that among the best source of carbon are glucose, fructose, then saccharose and starch. Maximal production of extracellular catalase is established on medium with yeasts and corn extract, and also with potassium and sodium nitrate as sources of nitrogen. Formation of catalase on medium with NH4NO3; NaNO2; C6H11O7N and urea was considerably decreased. Production of catalase by this fungi was considerably higher at increased of concentrations of ÐsH2PO4 from 0,25 up to 1,5 % with simultaneous increase of ÐsNO3 up to 2,0 % and a yeasts extract up to 3,0 %. Addition into the medium of a solution of microelements has considerably increased formation of extracellular catalase for the strain Penicillium sN€.6. As a result, a new strain of genus Penicillium was isolated from Moldovan a soil, that was able to produce under the determined conditions 300-500un/ml of extracellular catalase.