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The investigation was carried out to study the relation between CO(,2) evolution and the changes in microflora in the case of cellulose-decomposition in soil with special attention to the heterogeneity of soil crumbs. The rates of CO(,2) evolution correlated with the number of Gram-negative bacteria, while the number of cellulose-decomposing microorganisms did not. The Gram-negative bacteria probably contribute directly to CO(,2) evolution by decomposing simple sugars produced from cellulose by cellulose-decomposing microorganisms. Both the Gram-negative bacteria and cellulose-decomposing microorganisms seemed to grow luxuriantly in the surface area of soil crumbs with added cellulose powder. Therefore it is speculated that there is a cooperation between the Gram-negative bacteria and the cellulose-decomposing microorganisms with respect to cellulose decomposition in soil. The main locus where this reaction takes place may be the surface area of soil crumbs

The growth of microorganisms in the nutrient solution of a circulating hydroponic system was suppressed by ultra-violet radiation. Applied for three hours daily (572 Jm('-2)h('-1)) throughout experiments in which tomato and corn were grown, it was effective in reducing the population of microorganisms from between 500-800.10('3) to 10-50.10('3) cells per ml.

Microorganisms are know to play a key role in the turnover of soil phosphorus a major element in plant nutrition. The microbial transformations of phosphorus compounds (solubilization of inorganic phosphates, mineralization of organic phosphates and inmobilization processes) are reviewed in this paper. The types of microorganisms involved and the action mechanisms responsibles for the microbial activity are discussed. The significance of mycorrhizal fungi in the translocation of phosphate from soil solution into plant roots and, hence, in the recycling of this nutrient in the ecosystem is also considered

An in vitro test for the adherence of microorganisms to epithelial surfaces was performed in an attempt to illustrate the initial steps in the establishment of infectious endocarditis. Preparations of fresh heart valves of swine were incubated in suspensions of Erysipelothrix rhusiopathiae. There was a significant difference (P <0.01) in the degree of adherence between the 5 strains of E. rhusiopathiae investigated. The highest degree of adherence was found in an isolate from an endocardial vegetation and in a strain labelled type A(,1), both originating from swine. Scanning electron microscopy showed the microorganisms distributed on the endocardial surface and in large numbers at the base of the chordae tendinae.

The regulation of lactic acid production, the regulation of lactate fermentation and the role of lactate as intermediate in rumen metabolism was studied. The pH had a pronounced effect on all 3 processes and therefore buffer capacity of the rumen contents is also described. Starch gave much less rise to lactic acidosis than soluble sugars, as glucose and fructose. Most bacteria grow faster and therefore produce more lactic acid when amino acids and/or soluble proteins are present in the diet. Activity of LDH (lactate dehydrogenase) of mixed rumen microorganisms is regulated by the NADH/NAD(H) balance and the ATP concentration. About60% of the LDH in mixed rumen microorganisms is fructose-1, 6-diphosphate independent. Megasphaera elsdenii ferments 60 to 80% of the lactate fermented in the rumen of dairy cattle. Lactate accumulates only when the glycolytic flux (hexose units fermented per unit time per microorganism) is high. During adaptation, the glycolytic flux is increased and lactate may accumulate. After adaptation to a certain diet, the number of microorganisms is changed and the glycolytic flux again is normal and lactate is only a minor intermediate in rumen metabolism.