Styrene oxide and 2-phenylethanol metabolism in the styrene-degrading Xanthobacter sp. strain 124X was shown to proceed via phenylacetaldehyde and phenylacetic acid. In cell extracts 2-phenylethanol was oxidized by a phenazine methosulfate-dependent enzyme, probably a pyrroloquinoline quinone enzyme. Xanthobacter sp. strain 124X also contains a novel enzymatic activity designated as styrene oxide isomerase. Styrene oxide isomerase catalyzes the isomerization of styrene oxide to phenylacetaldehyde. The enzyme was partially purified and shown to have a very high substrate specificity. Of the epoxides tested, styrene oxide was the only substrate transformed. The initial step in styrene metabolism in Xanthobacter sp. strain 124X is oxygen dependent and probably involves oxidation of the aromatic nucleus.

The activities of hexokinase, phosphofructokinase, aldolase, enolase and pyru-vate kinase were studied in breast cancer tissues, in comparison to benign breast disease and normal breast tissues. The enzyme activities in breast cancer were significantly increased compared to normal and benign breast tissues (p < 0.001). Also the increase in activity in benign disease compared to normal was statistically significant (p < 0.001). Within the group of benign diseases, fibroadenomas could be distinguished from fibrocystic disease, the former generally showing higher activities compared to the latter (p ≤ 0.05). Carcinoma subgroups, classified according to their histology, could not be recognized enzymologically. In addition, isozyme composition of pyruvate kinase and enolase was studied. We did not find a significant shift towards K type pyruvate kinase expression in benign disease compared to normal breast tissues. Also fibroadenomas did not differ from fibrocystic disease. However, the amount of K type pyruvate kinase in carcinomas proved to be significantly higher in comparison to benign disease and normal breast tissues (p < 0.001). Expression of αγ-enolase in normal breast tissue was virtually absent. In benign disease only a minority of specimens did show the hybrid αγ-enolase. Nearly all carcinomas had αγ-enolase expression and in 20% of the carcinomas γγ-enolase could be detected (so-called neuron-specific enolase). By discriminant analysis, the function giving the best discrimination compared to the histological data was based on natural logarithm aldolase and the total of γ-enolase subunits. Contrary to expectation, the regulator enzymes of glycolysis; i.e., hexokinase, phosphofructokinase and pyruvate kinase were not included in this discriminant function. The best fit produced a 90% correct classification in both benign and malignant disease. If these findings are confirmed to a larger series, the discrimination is sufficiently strong to form the basis of a clinically useful tool.

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This paper investigates the role of intellectual property rights (IPRs) in the process of standardization in the telecommunications industry. We take the global system for mobile communications (GSM) case as a highly relevant example, being part of a high-tech industry in which standards play a large role. In the process of designing the GSM standard, a lot of attention has been given to IPRs, mainly to avoid a situation in which a single IPR holder could hamper or even totally block the development of the standard. Nevertheless, the ultimate GSM standard contains a large amount of so-called 'essential IPRs', i.e., IPRs without which the implementation of GSM products is impossible.The paper provides a general discussion of the development of GSM and presents a database on the essential IPRs in the GSM standard. This database has been compiled on the basis of international patent statistics, and the data that manufacturers have supplied to European Telecommunications Standards Institute, the European standardization body responsible for defining the GSM standard. We use this database to assess the dynamic IPR position of firms in the original GSM standard and its subsequent development.We use the GSM case to underline the importance of a general European policy with regard to IPRs and standardization, and derive several concrete recommendations for such a policy. r

The activities of hexokinase, phosphofructokinase, aldolase, enolase and pyru-vate kinase were studied in breast cancer metastases occurring at various sites and compared with the enzyme activities in a series of primary breast cancers. The activities of all enzymes studied were significantly higher in the metastases compared to the primary tumors (p ≤ 0.05). However, no changes in the isozyme patterns of enolase and pyruvate kinase were observed when the metastases were compared with primary breast cancers. Differences in location of the metastases did not lead to differences in enzyme activities. Our data suggest an association of an increasing rate of glycolysis with tumor progression.

The theoretical mathematical models described in this paper are used to evaluate the effects of fungal biomass inactivation kinetics on a non-isothermal tray solid-state fermentation (SSF). The inactivation kinetics, derived from previously reported experiments done under isothermal conditions and using glucosamine content to represent the amount of biomass, are described in different ways leading to four models. The model predictions show only signi®cant effects of inactivation kinetics on temperature and biomass patterns in the tray SSF after long fermentation periods.The models in which inactivation is triggered by low speci®c growth rates can predict restricted biomass evolution in combination with a fast temperature increase followed by a slower temperature decrease. Such inactivation might occur when substrate is limiting or products are formed in toxic concentrations.Temperature is predicted to be the key parameter. Oxygen concentration is predicted to become limiting only at high heat conduction and low oxygen diffusion rates. Desiccation of the substrate is predicted not to occur. IntroductionSolid-state fermentations (SSF) are applied for the production of, for example, enzymes, biopesticides, food, feed and ®ne chemicals. In SSF, microorganisms grow on a moist solid substrate without free-¯owing water. The chemical reactions necessary for growth are exothermic and thus temperature control is necessary. It depends strongly on the type of fermenter system used (tray, packed bed, rotating drum) what the effect of heat production is on temperature in the fermenter bed and thus on the results of the fermentation. A typical temperature course during fermentation in a tray system shows a steep increase to 40±45 C after a short lag phase, followed by a decline at a rate of 0.1 [5]±0.5 C [6] per hour, depending on the microorganism and type and size of system used.Simulation models can provide insight into the complex interaction between microbial growth, oxygen consumption and concomitant heat production, and oxygen and heat transport. Ideally, these models should take into account the effects of growth, maintenance and decay on respiration activity, each as functions of, for instance, time, temperature, nutrient and water availability.Several examples of models for fungal SSF processes can be found in the literature, describing different fermentation systems [7±12]. These reports focus on the biomass production phase of the fermentation and do not properly consider the period after growth has virtually stopped. Especially for secondary metabolite production, the latter period may be very important. Besides, in most SSF systems fungal biomass is present growing at different rates, depending on combined effects of several parameters, such as temperature, water activity, and oxygen and carbon dioxide concentration. Thus, all biomass is not necessarily in the same growth phase. This emphasizes the need for considering description of the post-growth stage in modelling SSF.In our models we describe the respiration ...

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A novel solid-state fermentation method using polyurethane foam as inert carrier impregnated with a synthetic liquid medium was developed simulating the nutritional composition and culture conditions of solid-state fermentation on wheat bran. With this system, biomass, the important parameter involved in solid-state fermentation processes, can be measured directly. Some other superiorities of this system over conventional solid-state fermentation systems are discussed.