ABSTRACT
Pyruvate and valine have been studied for their effect on avermectin biosynthesis by the mutant strain Streptomyces avermitilis UCM Ac-2179. Valine in concentrations 0.5, 1.0 and 1.5 g/l inhibited the antibiotic synthesis. The same concentrations of pyruvate increased the avermectin production 2-2.5 times. The strain cultivated in the mineral medium produced during trophophase some lipids which were not almost revealed during idiophase when avermectin active synthesis took place. The authors make a supposition about the ways of avermectin synthesis by S. avermitilis UCM Ac-2179: the antibiotic biosynthesis can proceed not only through pyruvate transformation but, to a considerable extent, at the expense of using fatty acids which are produced by the culture.
Subject(s)
Anti-Bacterial Agents/biosynthesis , Ivermectin/analogs & derivatives , Pyruvic Acid/pharmacology , Streptomyces/drug effects , Valine/pharmacology , Anti-Bacterial Agents/isolation & purification , Biomass , Chromatography, Thin Layer , Fatty Acids/metabolism , Fermentation , Ivermectin/isolation & purification , Ivermectin/metabolism , Streptomyces/growth & development , Streptomyces/metabolismABSTRACT
The study of the capacity of 310 strains of microorganisms from different taxonomic groups (40 bacilli, 43 yeast, 105 streptomycetes, 12 micromycetes) to hydrolyze collagen and keratin allowed to establish that the highest level of collagenase (KA) and keratinase (KerA) activity is inherent in representatives of streptomycetes. Two strains of Streptomyces sp.--1349 and 1382 with the highest KA and KerA indices--1.9 and 1.85 un./mg of protein, respectively, have been chosen. It has been established that collagenase activity in the medium without adding the inducers decreases 4.76 times, while that of keratinase--5.71 times, i.e. the above enzymes are inducible. The investigation of the spectrum of activities has demonstrated that the both strains possess low level of the general proteolytic and elastase activities and high level of collagenase and keratinase activities. Partial purification of the enzyme complex of Streptomyces sp. 1349 by the successive precipitation by ammonium sulphate with 30, 60 and 80% saturation and a single precipitation by ammonium sulphate with 80% saturation helped to increase the level of KA 5.6-5.9 times, and that of KerA--4.2-4.5 times.
Subject(s)
Collagenases/biosynthesis , Gram-Positive Endospore-Forming Bacteria/metabolism , Mitosporic Fungi/metabolism , Peptide Hydrolases/biosynthesis , Ammonium Sulfate , Chemical Precipitation , Collagenases/analysis , Collagenases/isolation & purification , Gram-Positive Endospore-Forming Bacteria/enzymology , Peptide Hydrolases/analysis , Peptide Hydrolases/isolation & purification , Streptomyces/enzymology , Streptomyces/metabolismABSTRACT
Streptomyces sp. 1349 is the active producer of collagenase. The dynamics of growth, influence of pH and temperature on collagenase activity and heterogeneity of population were studied. Maxima of the enzyme activity, proteins and biomass reach their highest point on the 3-4th day. The complex of enzymes obtained from culture liquid has pH-optimum of collagenase activity in neutral (pH 6-7) and alkaline (pH 9-10) regions, and thermooptimum at 37 and 60 degrees C. The preparation is stable. Four types of colonies with different level of collagenase activity were revealed during analysis of the heterogeneity of Streptomyces sp. 1349 population. The variant of basic type was selected for further work with activity that exceeds 2-3 times that of the control.
