The Role Of Thermodynamics In Biochemical Engineering

Abstract

This article is an adapted version of the introductory chapter of a book whose publication is imminent. It bears the title "BiothermodynamicsThe role of thermodynamics in biochemical engineering." The aim of the paper is to give a very short overview of the state of biothermodynamics in an engineering context as reflected in this book. Seen from this perspective, biothermodynamics may be subdivided according to the scale used to formalize the description of the biological system into three large areas: (i) biomolecular thermodynamics (most fundamental scale), (ii) thermodynamics of metabolism (intermediary scale), and (iii) whole-cell thermodynamics ("black-box" description of living entities). In each of these subareas, the main available theoretical approaches and the current and the potential applications are discussed. Biomolecular thermodynamics (i) is especially well developed and is obviously highly pertinent for the development of downstream processing. Its use ought to be encouraged as much as possible. The subarea of thermodynamics of live cells (iii), although scarcely applied in practice, is also expected to enhance bioprocess research and development, particularly in predicting culture performances, for understanding the driving forces for cellular growth, and in developing, monitoring, and controlling cellular cultures. Finally, there is no question that thermodynamic analysis of cellular metabolism (ii) is a promising tool for systems biology and for many other applications, but quite a large research effort is still needed before it may be put to practical use. IntroductionThermodynamics has had an enormous impact on a very wide variety of fields, including chemistry, biology, physics, geology, and in particular on applied engineering sciences such as chemical engineering [1]. Systematic application of chemical thermodynamics to process technology is one of the reasons why petrochemical plants can often be designed and petrochemical processes be developed with a bare minimum, if any, of experimental work.In biochemical engineering, the situation is radically different. The need for experimental trials is so overwhelming in bioprocess development that more often than not, extensive use is made of massively parallel experimentation involving such tools as microtiter plates, minireactors, robotic set-ups, and statistical experimental design. Therefore, the development of high-throughput systems and analytical equipment is now pursued at a very high pace. It can be speculated, however, that rigorous application of thermodynamics in biochemical engineering may be able to rationalize greatly bioprocess development and obviate a substantial fraction of this need for tedious experimental work [2].It was this vision that motivated a number of scientists about twenty years ago to organize an advanced course in thermodynamics for biochemical engineers to stimulate them to use thermodynamics more systematically in their work, and also to encourage further research in this area [2]. In the last 20 ye...