Attestation committee
Accreditation committee
Expert committee
Dispositions, instructions
Normative acts
Scientific councils
Scientific advisers
Doctoral students
Postdoctoral students
CNAA logo

 română | русский | english

The modification of cultural and biochemical properties of some strains of streptomycetes after long time storage

Author: Postolachi Olga
Degree:doctor of biology
Speciality: 03.00.07 - Microbiology
Scientific adviser: Svetlana Burţeva
doctor habilitat, professor, Institute of Microbiology and Biotechnology of the ASM
Institution: Institute of Microbiology and Biotechnology of the ASM
Scientific council:


The thesis was presented on the 18 September, 2009
Approved by NCAA on the 5 November, 2009


Adobe PDF document0.32 Mb / in romanian


streptomycetes, variability, long storage, lipids, aminoacids, antimicrobial activity, millimeter waves


The aim the work was to investigate the modification of cultural and biosynthetic properties of the some streptomycetes strains, after long storage in the laboratory conditions on solid media and under the influence of millimeter waves and to select of cultivation media, which would provide the maximal productivity of the bioactive substances offered for use in aviculture and beekeeping.

Methodology of scientific research is based on fundamental data, exposed in scientific works by Jukova R. (1978), Keyts Е. (1985), Таranov G. (1986), Zenova G. (1992), Zarnea G. (1992), Burţeva S. (1996), Usatîi A. (1999), Toderaş A. (2000), Egorov N. (2004).

Scientific inovation. The cultural properties and biosynthetic activity of streptomicetes strains had been store for a long time in the laboratory were studied. Research has shown that the strain, obtained after combined irradiation of γ and UV rays had a higher level of stability of the mentioned properties in compare with the initial strain. Were determined that millimeter waves of low intensity induced the changes in quantity and quality content of exo- and endometabolites of streptomycetes. The effect depended on the power density and the time of treatment. For the first time was shown that the millimeter waves intensify the antimicrobial activity of streptomicetes.

The theoretical significance. The natural variability of streptomicetes strains, obtained after γ and γ + UV irradiation, was studied. It was established posibility to increase the streptomicetes productivity by cultivation on complex media and by irradiation with millimeter waves of low intensity.

The practical importance. Were selected nutrient media that ensures a high level of sporulation and maximal homogenety in populations of streptomicetes strains. Have been proposed media for submerged cultivation of streptomicetes, which increasead the economic efficiency by significantly increasing of biomass quantity (2-3,5 times) with biologically active substaces of different chemical nature. An investigation was showed the perspective to use streptomicetes in elaboration of biopreparation for aviculture and beekiping.