Changes in Streptomyces hygroscopicus 155 endopeptidase and aminopeptidase activity and heat resistance under starvation and increased temperature

The influence of temperature stress and starvation for amino acids, glucose and phosphates, on the heat resistance of mycelium and endo- and aminopeptidase activity of Streptomyces hygroscopicus   155, was studied. The strongest growth inhibition was determined at temperature elevation from 30° to 39°C and at starvation for amino acids. Also these stress treatments mostly induce the heat resistance of the mycelium. A correlation between the intracellular endo- and aminopeptidase activity and decrease in biomass yield was registered. The process of catabolization of proteins, during the adaptation to stress treatments, depends on energy and is stimulated by the presence of Mg2+ ions

CHANGES IN STREPTOMYCES HYGROSCOPICUS 155 ENDOPEPTIDASE AND AMINOPEPTIDASE ACTIVITY AND HEAT RESISTANCE UNDER STARVATION AND INCREASED TEMPERATURE

The influence of temperature stress and starvation for amino acids, glucose and phosphates, on the heat resistance of mycelium and endo- and aminopeptidase activity of Streptomyces hygroscopicus 155, was studied. The strongest growth inhibition was determined at temperature elevation from 30\ub0 to 39\ub0C and at starvation for amino acids. Also these stress treatments mostly induce the heat resistance of the mycelium. A correlation between the intracellular endo- and aminopeptidase activity and decrease in biomass yield was registered. The process of catabolization of proteins, during the adaptation to stress treatments, depends on energy and is stimulated by the presence of Mg2+ ions

ELECTROPHORETIC DIFFERENTIATION OF SOME TOBAMOVIRUSES

Purified preparations of 16 tobamoviruses including 3 strains of tobacco mosaic virus (TMV) and 13 strains of tomato mosaic virus (ToMV) were investigated by the means of horizontal polyacrylamide gel electrophoresis (PAGE). Among the representatives of ToMV, the strains from group "2" after Pelham demonstrated the highest particle mobility and the ones from group "1", causing yellow mosaic, migrated most slowly in electric field. Besides that all the ToMV strains differed among each other, all they moved significantly quicker than the TMV strains. The horizontal PAGE was applied for virus detection in plant saps and for identification of unknown isolates. The electrophoretic analysis of viral particles had a good reproducibility and reliability of the results and proved a possibility for fast screening of a large number of isolates

AN INVESTIGATION OF THE TREHALOSE ACCUMULATION DYNAMICS BY YEASTS FROM GENUS SACCHAROMYCES

The trehalose accumulation by 77 superficially cultivated yeast strains from genus Saccharomyces   was investigated in dynamics. The conditions were determined for the maximal achievement of the storage carbohydrate in the cells. Experiments with optimal duration of 120 - 144 hours were performed on two nutrient media. The brewery yeasts produced significantly more trehalose (10 - 13%) when compared with the wine and baking ones

SCREENING OF ANTIMICROBIAL ACTIVITIES AMONG BULGARIAN LACTOBACILLI STRAINS

Forty-six strains of genus Lactobacillus from the collection of the National Bank for Industrial Microorganisms and Cell Cultures (NBIMCC) were screened by the use of the agar drop diffusion test, for antibacterial activity against nine test-microorganisms. Lactobacillus casei 300 exhibited activity against eight lactic acid bacteria and one yeast strains. The substance with antibacterial activity, produced by the NBIMCC 300 strain, was inactivated by proteolytic enzymes and possessed thermostability when heated to 80°C. This gave us a reason to conclude that this substance belonged to the bacteriocins' group

APPLICATION OF MOLECULAR BIOLOGICAL METHODS IN TAXONOMY OF GENUS STREPTOMYCES

An extensive literature review concerning the taxonomic status of the species of genus Streptomyces   has been made. The classical microbiological and chemo taxonomical methods which form the base of the present classification of the species of this genus, as well as, the modern molecular biological approaches - analysis of protein patterns, multilocus enzyme electrophoretical (MLEE) analysis, restriction analysis, analysis of the nucleotide sequences of 16S and 23S RNA, RNA/DNA sequencing, DNA finger-printing with different probes or polymerase chain reaction (PCR) primers were described. The profound analysis showed the advantages of the molecular biological methods for streptomyces taxonomy and indicated that none of these methods applied independently could solve the existing problems in the taxonomy of genus Streptomyces. A wider application of the molecular genetic approaches is necessary in order to specify the taxonomic status of the species included in category III and IV according to Bergey and to find a criterion for distinguishing between the closely related species, as well as, to e evaluate the homogeneity of some streptomyces species

APPLICATION OF MOLECULAR BIOLOGICAL METHODS IN TAXONOMY OF GENUS STREPTOMYCES

An extensive literature review concerning the taxonomic status of the species of genus Streptomyces has been made. The classical microbiological and chemo taxonomical methods which form the base of the present classification of the species of this genus, as well as, the modern molecular biological approaches - analysis of protein patterns, multilocus enzyme electrophoretical (MLEE) analysis, restriction analysis, analysis of the nucleotide sequences of 16S and 23S RNA, RNA/DNA sequencing, DNA finger-printing with different probes or polymerase chain reaction (PCR) primers were described. The profound analysis showed the advantages of the molecular biological methods for streptomyces taxonomy and indicated that none of these methods applied independently could solve the existing problems in the taxonomy of genus Streptomyces. A wider application of the molecular genetic approaches is necessary in order to specify the taxonomic status of the species included in category III and IV according to Bergey and to find a criterion for distinguishing between the closely related species, as well as, to e evaluate the homogeneity of some streptomyces species

AN INVESTIGATION OF THE TREHALOSE ACCUMULATION DYNAMICS BY YEASTS FROM GENUS SACCHAROMYCES

The trehalose accumulation by 77 superficially cultivated yeast strains from genus Saccharomyces was investigated in dynamics. The conditions were determined for the maximal achievement of the storage carbohydrate in the cells. Experiments with optimal duration of 120 - 144 hours were performed on two nutrient media. The brewery yeasts produced significantly more trehalose (10 - 13%) when compared with the wine and baking ones

ELECTROPHORETIC DIFFERENTIATION OF SOME TOBAMOVIRUSES

Purified preparations of 16 tobamoviruses including 3 strains of tobacco mosaic virus (TMV) and 13 strains of tomato mosaic virus (ToMV) were investigated by the means of horizontal polyacrylamide gel electrophoresis (PAGE). Among the representatives of ToMV, the strains from group "2" after Pelham demonstrated the highest particle mobility and the ones from group "1", causing yellow mosaic, migrated most slowly in electric field. Besides that all the ToMV strains differed among each other, all they moved significantly quicker than the TMV strains. The horizontal PAGE was applied for virus detection in plant saps and for identification of unknown isolates. The electrophoretic analysis of viral particles had a good reproducibility and reliability of the results and proved a possibility for fast screening of a large number of isolates

SCREENING OF ANTIMICROBIAL ACTIVITIES AMONG BULGARIAN LACTOBACILLI STRAINS

Forty-six strains of genus Lactobacillus from the collection of the National Bank for Industrial Microorganisms and Cell Cultures (NBIMCC) were screened by the use of the agar drop diffusion test, for antibacterial activity against nine test-microorganisms. Lactobacillus casei 300 exhibited activity against eight lactic acid bacteria and one yeast strains. The substance with antibacterial activity, produced by the NBIMCC 300 strain, was inactivated by proteolytic enzymes and possessed thermostability when heated to 80\ub0C. This gave us a reason to conclude that this substance belonged to the bacteriocins' group