[Fibrinolytic activity of natural variants of Bacillus mesentericus]. / O fibrinoliticheskoi aktivnosti estestvennykh variantov Bacillus mesentericus.

The natural variability of the ability to synthesize proteinases by Bacillus mesentericus 64 was studied. The population of this strain was shown to be heterogeneous. Three types of variants (S, M and P) differed in the morphology of their colonies and in the culture characteristics from the typical colonies of the parent strain. The caseinolytic activity of the M variant was three times as high as that of the parent strain, and it also had an elevated fibrinolytic activity and a high rate of blood thrombolysis in experiments in vitro. The rate of proteinase synthesis correlated with the morphological types of sporogenic bacteria.

[Fibrinolytic activity of Bacillus mesentericus strains]. / O fibrinoliticheskoi aktivnosti nekotorykh shtammov Bacillus mesentericus.

Two Bacillus mesentericus strains with a high activity of proteolytic enzymes having the thrombolytic action were selected from a group of its collection strains. The effect of different carbon sources on the synthesis of proteases was studied. A growth medium containing potato broth (10%), peptone (0.5%) and lactose (0.5%) allowed one to obtain a cultural broth dissolving human blood clots within 2.5 to 3 hours in experiments in vitro.

[Direct selection of Aspergillus terricola variants having different toxicity on a culture of fibroblasts]. / Priamoi otbor variantov Aspergillus terricola s razlichnoi toksichnost'iu na kul'ture fibroblastov.

A direct method is proposed to select less toxic mutants of Aspergillus terricola on a culture of fibroblasts. The conidia are first irradiated with UV, and then are used to grow colonies on the glass surface of tubes or flasks containing medium 199. The cells of fibroblasts are added thereupon and the two cultures are being grown together for 24--48 hours. The colonies which inhibit the growth of fibroblasts to a less extent are selected using microscopy. The method can be used for primarily selection of experimentally produced mutants of Aspergillus which form fibrinolytic enzymes possessing low toxicity.

[Comparative cytomorphologic study of strains of Aspergillus terricola in the process of biosynthesis of proteolytic enzymes]. / Sravnitel'noe tsitmorfologicheskoe izuchenie shtammov Aspergillus terricola v protsesse biosinteza proteoliticheskikh fermentov.

The cytology and morphology of three strains of Aspergillus terricola were studied in the course of synthesis of proteolytic enzymes. The level of the enzymes in the cultural broth was highest during the growth of the diffused mycelium, and was accompanied with specific cytodifferentiation of the fungal hyphae. The contact between the hyphae of the producing culture and the growth medium is presumed to be important for biosynthesis of the enzymes.

[Cultivation conditions of the Aspergillus terricola mutant producing proteolytic enzyme]. / Izuchenie uslovii kul'tivirovaniia mutanta Aspergillus terricola--produtsenta proteoliticheskogo fermenta

The effect of temperature, aeration and various foam suppressors on the growth of a mutant of Aspergillus terricola H-20 and on its production of proteolytic enzymes was studied. A high level of the proteolytic activity (12-15 PU/ml) was found at 28-30 degree C in conditions of aeration with the rate of oxygen dissolution being 0.38-0.86 g of oxygen per litre per hour. Synthesis of the enzyme was inhibited by a decrease in temperature to 22-24 degree C, a surplass (1.07 g O2 per litre per hour) or insufficient (0.18 g O2 per litre per hour) content of oxygen in the medium, and by addition of animal (sperm-whale) fat as a froth breaker to the medium. The best rate of protease biosynthesis was obtained upon stepwise addition of sunflower oil to the cultural broth. The best synthetic froth breakers for biosynthesis of the proteolytic enzyme are adecanol at a concentration of 0.1-1% and polymethylsiloxane PMS-A 154 as a water emulsion at a concentration of 0.5% of the medium volume.