Biochemical Engineering Journal - Preface

Abstract:
In 2001, the Biochemical Engineering Journal dedicated a first special issue to the field of shaking bioreactors (vol. 7, issue 2). Due to the significance of this topic at the early steps of bioprocess development, a second special issue was arranged to address the new biochemical engineering aspects of this versatile and easy-to-use bioreactor. Substantial progress has been made since the previous special issue. The mechanistic understanding of basic physical phenomena in shaking bioreactors has increased. Furthermore, new devices for on-line analysis are now available. As a result, some of the experimentally observed peculiarities obtained with biological systems can now be explained. This progress is represented by the eight full papers of this special issue. However, there are still many unsolved problems associated with shaking bioreactors. These are, for example, the control of microbial growth on the reactor walls, the impact of shaking conditions on the morphology of filamentous microorganisms or the influence of foam on the maximum oxygen transfer capacity in baffled flasks. Besides, easily applicable techniques for feeding nutrients to cultures in shaking bioreactors are strongly desired. In the field of shaking bioreactors, a clear trend is visible leading to smaller culture volumes by utilising test tubes and micro titre plates. A complete automation of the whole screening process ranging from colony picking from large agar plates to readily processed supernatants or cell extracts seems to be feasible in the near future. Such systems will potentially handle more than 10,000 individual shaking bioreactors at the same time under the control of on-line measurement. Thus, it seems that the area of shaking bioreactors will keep biotechnologists and biochemical engineers heavily engaged and therefore, new advances in terms of understanding, devices and technologies will be assured for in the future.