The solubilization of silicates was investigated using kaolin and quartz sand as model substances. The mineral solubilization was studied in the concentration of solubilized Si and Al. The chemical leaching of the silicates was carried out using inorganic and organic acids as well as sodium hydroxide. The process was more effective in the alkine than in the acid p H range. In the acid medinm, oxalic acid showed maximum acidity and a tendency to form complex structures, especially with aluminium, and was most effective in leaching. The microbiological influence on solubilization reactions was tested using a number of microorganisms among them acid, alkali and slime-forming species. The highest. leaching activity was observed in the case of Thiobucillus thiooxiduns, whereas the heterotrophic microorganisms (among them Bacillus muciluginosus) did not exercise D solubilizing effect on the silicates. X-ray phase analysis of leached kaolin samples did not show any differences from the non-leached mineral.

The relationship between love/care and justice was one of the key tensions from which care ethics originated; to this very day it is subject of debate between various streams of thought within care ethics. With some exceptions (e.g. Christa Schnabl) most approaches have in common the belief that care and justice are mutually exclusive concepts, or at least as so different that their application is situated on different levels. Hence, both are complementary, but distinct, so that there is no real interaction. This paper aims to investigate whether, and if so, how, a deeper understanding of Ricoeur's thoughts on this matter enriches the relationship between care and justice with respect to care ethics. This connection suggests itself from Ricoeur's interpretation of the relationship as a dialectical one in which the logic of superabundance (love) and the logic of equivalence (justice) meet. Care enables people to see the face and individuality of the one, 'le chacun,' within the anonymous structures of justice that tend to reduce all human beings to the anonymous each, 'le on'; justice in its turn is the precondition for love to become incarnated and made real. What may this view--of care and justice standing in close connection, in which they correct and strengthen each other--add to the understanding of concrete practices of care?

Fermentation kinetic, thermokinetic and morphological investigations of biological carbonsource conversions into microbial biomass and other reaction products can be used for improving the efficiency of biotechnical processes. In this way biorhythmic processes on a macroscopic scale could be found in transitional stages of microorganism cultivation. These biorhythmic processes can be explained by the occurence of different cell states in the cell cycle. I n order to characterize these cell states synchronized microorganism growth was investigated with the aid of the phased culture method. Two states could be observed in the case of yeast growth: the single ccll state and the budding cell state. The duration and efficiency of the single cell state is dependent on the growth limitation and the carbon substrate feeding. Thus the reduction of carbon substrate feeding in states of synchronized populations which are characterized by a high percentage of single cells and by energy metabolite production which, in turn, is influenced by carbon substrate concentration can cause increased material and energetic efficiencies of biological carbon-source conversions.

The influence of perturbations on continuous yeast cell cultivations on hydrocarbons of crude oil is described.Due to such perturbations the fermentation system leaves its steady state, passes through transitional stages and reaches a new steady state. In the transitional stages a damped oscillation of biomass concentration, percentage of budding cells, oxygen consumption rate, and heat flow is observed. These results can be explained by partial synchronization of yeast cell functions in microorganism populations. I n phases of partial synchronization the cell cycle of a single cell is reflected by the behaviour of the microorganism population. The adaptationof the carbon substrate feeding rate to the state of partially synchronized microorganism population makes possible lower specific substrate consumption in biomass production.

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