StatusThe thesis was presented on the 27 October, 2006
Approved by NCAA on the 21 December, 2006
Abstract– 0.35 Mb / in romanian
This work contains the results of scientific researches in the field of selection and characterization of new fungal strains producers of pectinases, establishment of optimal biosynthesis conditions, emphasizing of some economical and efficient methods for amelioration of biosynthetic potential in the aim to obtain pectolytic enzymatic preparations with multiple implications in different domains of national economy.
The screening researches are permitted to select a new strain of filamentous fungi Penicillium viride CNMN FD 04 P, isolated from Moldova soils, which has a high capacity of exocellular pectolytic enzymes synthesis. There have been studied the morphologo-cultural and physiology-biochemical peculiarities of strain, as well as the nutritive exigencies, optimal conditions for pectinases biosynthesis.
The significant stimulator and stabilizator effect of coordinative compounds of nickel and cuprum joining with thiosemicarbasones on pectolytic activity of producer was determined. There was demonstrated the correlation between the type of coordinative compound added to nutritive medium, pectolytic activity and growth phases of micromycete Penicillium viride CNMN FD 04 P. It was established that qualitative and quantitative composition of pectolytic enzimatic complex depends on the origin of chemical biostimulators, fact which permit to obtain some pectolytic enzimatic complexes with prognosed containing. Based on obtained results, new compositions of nutritive media, which ensure the considerable increasing of exocellular pectinases activity and reduction of cultivation duration of producer, were proposed.
The benefic influence of low intensity millimetric waves on biosynthesis of pectolytic enzymes by strain Penicillium viride CNMN FD 04 P was established. There was determined that the effect exercised by millimetric waves vary in dependence on the exposure duration, type of irradiated inoculums, phases of culture growth. The obtained data have been used for the elaboration of two original proceedings of pectolytic activity increasing.
The optimal parameters of the pectolytic enzymatic complex recovery from culture filtrate of Penicillium viride CNMN FD 04 P have been established. In order to recommend the pectolytic preparation for practical application, the optimal conditions of complex action have been determined.