Zentralblatt fur Bakteriologie, Parasitenkunde, Infektionskrankheiten und Hygiene. Zweite naturwissenschaftliche Abt.: Allgemeine, landwirtschaftliche und technische Mikrobiologie最新文献

The possibilities to influence the decomposition of straw and lucerne by fungicidal, bactericida and total acting microbiocides, respectively, were tested comparatively. Total or fungicidal acting substances caused the heaviest inhibition of decomposition at both the organic matters. The efficiency of active ingredients was greater at straw than at lucerne. The reason of the different inhibiting effects is that the lucerne which is easy to decompose and rich in protein can be decomposed alone by the physiologically active bacteria, which are resistant to active ingredients. That means the decomposition of lucerne takes place without the help of fungi. However, the fungi sensible to the active ingredients play a more important role in the straw decomposition. Therefore substances with permanent fungicidal effects are sufficient for the inhibition of straw decomposition. Inhibiting the decomposition of greenmanure presumes permanent acting fungicidal and bactericidal substances. Such substances are not available at present. Systemic fungicides did not influence the decomposition of plants for green-manure due to their limited scope of activity.

The biological activity of the soil under a beech forest and a spruce forest was examined in respect to the CO2-production of the soil samples, the speed of vanillin decomposition, as well as the activity of the soil enzymes catalse, saccharase and phosphatase. Both soils indicated an indentical course of seasonal activity.

The present publication is the first of a series on the enzymatic urea tranformation in soil. With about 2,000 pure cultures of micro-organisms it was possible to prove the very good urea utilization by the soil micro-organisms (bacteria, actinomycetes, and fungi). Above all the fungi showed an excellent utilization of urea, while bacteria and actinomycetes were somewhat poorer. Contrary to this is the urease activity of these organisms, and that is the reason why fungi in soil may be regarded as short-time accumulators for urea nitrogen and must not be suppressed by inhibitors.

An electron microscope study has shown that the spread of Fusarium sulphureum through potato tuber tissue occurs not only intracellular but also intercellular. The spread of hyphae effected both mechanical and enzymatical. The study of cells neighbouring hyphae shows degeneration of protoplasm. Intercellular spaces of infected tissue are filled with a dark substance. It seems that these substances are fragments of cell walls which are macerated by Fusarium enzymes.

The biological nutrient cycle was activated by applying KMg in relatively young and older pine stands growing in the plain of the GDR on former agricultural sandy soils with substrats from the Younger Pleistocene. Application of KMg stimulated tree growth and had a persistent effect on the microbiological processes of organic matter conversion in the AO horizon and in the humous mineral soil. The cellulose test proved to be suitable for assessing the formation and conversion processes of soil organic matter caused by fertilization as to their effect on soil fertility.

Several immunsera of rabbit were developed against 8 Fusarium ssp. on the basis of 10 intravenous injections with an increasing dose of the antigen. By means of these it was possible to differentiate several antigen-epitops by using the method of multidimensional double-diffusion. The number and the specificity of these epitops allows to get an insight as well into the reaction-behaviour of the Fusarium-species on test as in there serological relationship. Finally the serological result were discussed in comparison with the classification of the species within the present classification systems of Fusarium.