3 - Microbial Physiology

Summary

Introduction

Microbial physiology is the study of the manner in which cells grow and live. It is concerned with their metabolism, growth, reproduction, and response to the environment. In the case of the production of antibiotics, the formation of these substances must be added to these functions. The environment becomes that of submerged fermentation systems, which are affected by the physical conditions used and the effect that the presence of the organism has upon these physical conditions.

Chapter 2 gives a general account of the behaviour of the streptomyces and fungi. In the present chapter a more-detailed account of the behaviour of antibiotic-producing strains is given. The subject is a large one, and it is only possible to give those aspects which are of practical interest. The discussion will also be based on the behaviour of relatively high-yielding strains, stressing features of this behaviour that are important in commercial production of antibiotics and that can be used as a basis for a consideration of advanced development work.

The chemical and biological behaviour of the microorganisms is very complex, involving many reactions, within and without the cells. To attempt to describe such a multi-dimensional system is almost impossible. Workers in the field, therefore, adopt the physiologist's view and consider the cell as a mechanism through which material flows, giving rise to cells and products. The interaction between these flows, the properties of the cells, the conditions used, and the regulatory systems involved can then be considered in terms of systems engineering, without going into too much detail about the biochemical and other mechanisms involved, so as to produce a relatively simple model.