Stresses which arise in bioreactors can influence process performance considerably. Recent molecular biological investigations indicate that stress caused by fluid dynamical effects and extreme values of process variables and toxic substances cause similar responses in the cells. These molecular fundamentals, as well as quantitative evaluation of fluid dynamical stresses and, their effects on microorganisms, animal and plant cells and proteins are treated in this volume.

Solvent Extraction in Biotechnology deals with the reco- very and purification of primary and secondary metabolites by solvent extraction. In the first part the reaction engineering principles: definitions, thermodynamic fundamentals, and system models, the kinetics of mass transfer between two phases without and with chemical reaction as well as extraction equipment, which are important for downstream processing in biotechnology, are considered in detail. The special part of the book describes the recovery of low-molecular metabolites: alcohols, acids and antibiotics with organic solvents, carrier-modifier-solvent systems, supercritical gases as well as with liquid membrane techniques. Several practical examples are given for the recovery of different metabolites as well as for the calculation of the extraction processes necessary for equipment design. Besides solvent extraction, novel separation techniques with liquid membrane, microemulsion and reversed micelles are also presented. This book will introduce the biochemical engineer and process engineer to the recovery of products from complex cultivation broths by modern techniques of solvent extraction and help them with process design.

The state of the art of the bioengineering aspects of the morphology of microorganisms and their relationship to process performance are described in this volume. Materials and methods of the digital image analysis and mathematical modeling of hyphal elongation, branching and pellet formation as well as their application to various fungi and actinomycetes during the production of antibiotics and enzymes are presented.

Solvent Extraction in Biotechnology deals with the reco- very and purification of primary and secondary metabolites by solvent extraction. In the first part the reaction engineering principles: definitions, thermodynamic fundamentals, and system models, the kinetics of mass transfer between two phases without and with chemical reaction as well as extraction equipment, which are important for downstream processing in biotechnology, are considered in detail. The special part of the book describes the recovery of low-molecular metabolites: alcohols, acids and antibiotics with organic solvents, carrier-modifier-solvent systems, supercritical gases as well as with liquid membrane techniques. Several practical examples are given for the recovery of different metabolites as well as for the calculation of the extraction processes necessary for equipment design. Besides solvent extraction, novel separation techniques with liquid membrane, microemulsion and reversed micelles are also presented. This book will introduce the biochemical engineer and process engineer to the recovery of products from complex cultivation broths by modern techniques of solvent extraction and help them with process design.

Stresses which arise in bioreactors can influence process performance considerably. Recent molecular biological investigations indicate that stress caused by fluid dynamical effects and extreme values of process variables and toxic substances cause similar responses in the cells. These molecular fundamentals, as well as quantitative evaluation of fluid dynamical stresses and, their effects on microorganisms, animal and plant cells and proteins are treated in this volume.

Der wichtigste Unterschied zwischen der Biotechnologie und ihrer Vorgangerin, der Fermentationstechnologie, ist, daB die Fermentationstechnologie eine Samm- lung kaum quantifizierbarer empirischer Erfahrungen darstellt, wahrend die Biotechnologie eine Sammlung immer noch empirischer aber quantitativ darstellba- rer Beziehungen ist. Sie ist auf bestem Wege, Biotechnik zu werden, die in der Lage ist, mit Hilfe aligemeingOltiger Gesetze quantitative Voraussagen zu machen. Dies gilt sowohl fUr die Mikroorganismen als auch fUr Zell-Linien. FrOher wurden Produktionsstamme ausschlieBlich durch langwieriges Screening ausgewahlt und durch herbeigefUhrte Mutation und Screening mOhsam verbessert, jetzt werden sie zunehmend mit Hilfe der Gentechnologie gezielt verandert. Das Protein-Design ermoglicht eine ortlich gezielte Anderung der Proteine durch ent- sprechende genetische Modifikation der MikroorganismenjZelien. Durch das Me- tabolit-Design lassen sich die fUr die Produktion nachteiligen Stoffwechselwege eli- minieren und erwOnschte Wege verstarken. Bei der industriellen Nutzung des vollen biologischen Potentiales der so gewon- nenen Mikroorganismen und Zellen spielt die Analytik eine wichtige Rolle. Sie er- moglicht, die Physiologie der Zellen genau zu erforschen und die Regulation des Stoffwechsels quantitativ zu erfassen. Weiterhin lassen sich durch die ProzeBanaly- tik die fUr das Wachstum und fUr die Produktbildung optimalen ProzeBbedingungen einstellen und aufrechterhalten. Will man diese Informationen bei der Produktion zur ProzeBregelung nutzen, so ist eine On-line-ProzeBanalytik notwendig. Neben der On-line-Probeentnahme werden Verfahren mit kurzen Analysenzeiten, geringer Storanfalligkeit und groBer Zuverlas- sigkeit benotigt.