Occurrence of collagen-degrading microorganisms in associations of mesophilic heterotrophic bacteria from various soils.

A total of 437 bacterial cultures was isolated from various soils and sewage water that were tested for the ability to decompose reconstituted collagen. This activity was found in 6.6% of the cultures isolated from sewage water, 15% of the cultures from organic horizons of the spruce growth soil, 30% of the cultures from the meadow soil, 29% of the cultures from the vegetable field soil and in 37% of those isolated from garden soil. The capability to produce collagenolytic enzymes does not appear to be rare among soil bacteria.

Production of toxic antigens in dialyzed cultures of microorganisms.

Data on the production of clostridial toxins in dialyzed cultures are summarized. Principal modifications of this cultivation technique suitable for both research and production are shown. If toxins are released from the cells by autolysis (neurotoxins of Clostridium tetani, C. botulinum; lethal factors of C. novyi and C. sordellii), a 10-fold increase of the antigen concentration in filtrates of dialyzed cultures is found in comparison with normal cultures. If toxins are excreted already during growth (lethal factors of C. perfringens type A, C. septicum), the positive effect of the technique is less significant. A dialyzed culture ensures a well-balanced production of toxic filtrates that contain highly concentrated, relatively pure and strongly immunogenic antigens.

Preparation of Clostridium septicum antigen for hyperimmunization of horses using a dialyzed culture.

The preparation of toxic cultures of Clostridium septicum is described, using an apparatus with a straight dialysis tubing, where the medium is filled both into the nutrition and cultivation space of the apparatus. Using the cultivation to nutrition volume rate 1:2, mean titre of lethal antigen in filtrates 3.86 limes mortis per mL and 300 dosis lethalis minima per Lm was obtained in comparison with the values of 2.22 and 150 respectively in flask filtrates. Native filtrates of dialyzed cultures were better antigens for hyperimmunization of horses than the culture filtrates from flasks.

The role of microorganisms in transformations of sulphite in spruce forest soil.

Transformations of sulphite and the participation of microorganisms were investigated in samples of fermentative (A02) and humus (A03) horizons from a spruce forest. About 80% of sulphite were almost immediately oxidized abiotically to sulphate, less than 1% persisted in the soil for several days and almost 20% were converted to a form not demonstrable as sulphite or sulphate. Microorganisms accelerated the disappearance of less than 10% of the added sulphite.

Effect of industrial emissions with high sulphur dioxide content on thiobacilli and oxidative activity of spruce forest soils towards inorganic sulphur compounds.

Effect of industrial emissions with high sulphur dioxide content on the upper horizons of spruce forest soils in NW Bohemia was investigated. The content of sulphates, oxidative activity towards sulphide, elemental sulphur, thiosulphate and sulphite, concentration and species representation of thiobacilli in horizons F, H and A in regions highly affected by emissions (two localities) and in regions relatively less influenced (three localities) were followed. In the affected areas the sulphur content in the soil was higher, the species representation of thiobacilli was similar and their concentration was higher, the ability of the soil to oxidize thiosulphate was inhibited and oxidation of elemental sulphur was stimulated. The oxidation of sulphide and sulphite was not significantly affected by the emissions. Changes caused by emissions could be observed only in horizons F and H and did not involve horizons A.

Effect of some sulphur compounds on soil microflora of spruce rhizosphere.

The effect of a long-term application of sulphite, thiosulphate and sodium sulphate on the soil microflora and spruce seedlings was investigated in a pot experiment. Sulphur compounds decreased the concentration of bacteria, including thiobacilli, increased the concentration of microscopic fungi and sulphate-reducing bacteria; they inhibited respiration, nitrification and oxidation of thiosulphate, stimulated ammonification and oxidation of elemental sulphur. In certain cases the spruce rhizosphere exhibited just the opposite effect. In the rhizosphere the sulphate-reducing bacteria was suppressed together with thiobacilli, whose unit oxidative activity increased substantially. Growth of seedlings was inhibited by sulphite and stimulated by thiosulphate and sulphate. Sulphite, the effects of which were similar to those of sulphur dioxide immissions, was the most effective compound. In regions influenced by immissions the soil is apparently intoxicated by the absorbed sulphite.

Some factors influencing production of sulphate by oxidation of elemental sulphur and thiosulphate in upper horizons of spruce forest soils.

Some factors influencing the oxidative activity of upper horizons of spruce forest soils (a mixture of fermentative and humus layers) toward intermediates of the oxidative part of the sulphur cycle were investigated. Preincubation of the soil with added cysteine, sulphide, elemental sulphur or thiosulphate was found to stimulate enzyme systems oxidating any of these compounds. Sulphite and sulphate were ineffective in this respect. The oxidation of elemental sulphur was stimulated by CaCO3, technical urea and high doses of superphosphate and potassium sulphate. It was inhibited by KH2PO4, pure urea, 40 % potassium salt, ammonium nitrate with calcium carbonate and the fertilizer NPK I. It proceeded at the highest rate at approximately 60 % capillary capacity (61 % of mass water content). Oxidation of thiosulphate was stimulated by KH2PO4, pure urea, superphosphate, potassium sulphate and only slightly by the fertilizer NPK I. It was inhibited by CaCO3, 40 % potassium salt and only slightly by ammonium nitrate with calcium carbonate. Potassium chloride, glucose and technical urea were without effect. The oxidation proceeded at the highest rate at 35 % maximal capillary capacity (48 % mass water content).

Dynamics of oxidation of inorganic sulphur compounds in upper soil horizons of spruce forests.

Dynamics of oxidation of inorganic sulphur compounds to sulphate by the soil of spruce forests was investigated. Sulphide, sulphite and thiosulphate are oxidized to sulphate at a maximal rate at the beginning of the reaction, oxidation of elemental sulphur exhibits a lag phase. Linear relationships between the amounts of the produced sulphate and concentrations of substrates in the soil could be detected. On the basis of ;this finding a method for comparison of the oxidative activity of various soils was proposed.

Thiobacilli and sulphate production from inorganic sulphur compounds in upper horizons of spruce forest soils.

The species representation of Thiobacilli was investigated in horizons F, H and A of spruce forest at ten localities. Concentrations of Thiobacilli in the selected localities and ability of the soils to oxidize sulphur compounds to sulphate were determined. Horizons F exhibited a high oxidative activity, a lower activity was found in horizon H and the lowest one was detected in horizon A. The activities showed spring and autumn maxima. Horizons F, H and A contained 10(4)--10(5), 10(2)--10(3) and 10(1)--10(3), respectively, Thiobacilli in 1 g dry soil. Thiobacillus thioparus was detected in all three horizons from all localities, T.thiooxidans was found in all horizons F, only in some horizons H and was not detected in horizons A. T.novellus was found only in some samples without any relation to the horizons, T.denitrificans was not detected at all.

Preparation of crude Clostridium histolyticum collagenase for therapeutic purposes.

The production of a freeze-dried enzymatic preparation from the category of crude collagenases has been described. The method is based on the utilization of a highly proteolytic Clostridium histolyticum strain whose products have more advantageous properties for therapeutic purposes than the products of the strain commonly used as yet.

Production of toxic enzymes of Clostridium perfringens BP6K on technologically important media including a medium with Tween 80.

The addition of 0.05--0.1% of Tween 80 to casein hydrolysate medium of Adams and Hendee raises and production of Clostridium perfringens BP6K lecithinase by approximately 50%. The use of the silicon antifoam Lukosan makes the medium particularly suitable for cultivation in large volumes. Higher levels of theta haemolysin and lecithinase are formed on the casein hydrolysate medium than on the meat medium. All factors except the theta and lambda components are farily stable during cultivation.