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Abstract:Purpose -Preservation environments such as repositories need scalable and context-aware preservation planning and monitoring capabilities to ensure continued accessibility of content over time. This article identifies a number of gaps in the systems and mechanisms currently available, and presents a new, innovative architecture for scalable decision making and control in such environments.Design/methodology/approach -The paper illustrates the state of the art in preservation planning and monitoring, highlights the key challenges faced by repositories to provide scalable decision making and monitoring facilities, and presents the contributions of the SCAPE Planning and Watch suite to provide such capabilities.Findings -The presented architecture makes preservation planning and monitoring context-aware through a semantic representation of key organizational factors, and integrates this with a business intelligence system that collects and reasons upon preservation-relevant information.Research limitations/implications -The architecture has been implemented in the SCAPE Planning and Watch suite. Integration with repositories and external information sources provide powerful preservation capabilities that can be freely integrated with virtually any repository.Practical implications -The open nature of the software suite enables stewardship organizations to integrate the components with their own preservation environments and to contribute to the ongoing improvement of the systems.Originality/value -The paper reports on innovative research and development to provide preservation capabilities. The results enable proactive, continuous preservation management through a context-aware planning and monitoring cycle integrated with operational systems.

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-Sterilization of fermentation medium involving heat may result in undesirable chemical reactions that alter nutrient concentration and yield products, which interfere in the fermentation performance. Sterilization of heat-sensitive compounds usually involves separate sterilizations of carbon source and nutrient solution. Membrane separation processes are an alternative to thermal processes, as they have many advantages such as the possibility of continuous and modular operation and the use of moderate temperatures. In this context, the objective of this work was the preparation of hollow-fiber membranes and the design of modules suitable for continuous sterilization of fermentation medium. The membrane with the best performance had a maximum pore diameter of 0.2 µm and a permeability of 42.9 L/m 2 .bar.h for a glucose/peptone/yeast extract medium. A module with 0.26 m 2 of permeation area was built with these membranes. This module was able to provide a permeate flow rate of 2.2 L/h using a pressure difference of 0.2 bar. The collected permeate was completely sterile, thus confirming the efficiency of this process.

Oxygen availability is the most important environmental parameter in the production of xylitol by yeasts, directly affecting yields and volumetric productivity. This work evaluated the cell behavior in fermentations carried out with different dissolved oxygen concentrations (0.5-30.0% of saturation), as well as a limited oxygen restriction (0% of saturation), at several oxygen volumetric transfer coefficients (12 < or = kLa < or = 70 h(-1)). These experiments allowed us to establish the specific oxygen uptake rate limits to ensure high yields and volumetric productivity. When oxygen availability was limited, the specific oxygen uptake rate values were between 12 and 26 mg of O2/of g cell x h, resulting in a yield of 0.71 g of xylitol/xylose consumed, and 0.85 g/[L x h] for the volumetric productivity. According to the results, the effective control of the specific oxygen uptake rate makes it possible to establish complete control over this fermentative process, for both cell growth and xylitol production.

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