MICROBIAL METABOLISM AND ITS INDUSTRIAL IMPLICATIONS 



sulphate-reducing bacteria in order to cope with the menace of the 

 world sulphur shortage. 



The question which should occupy us now is, what are the prospects 

 in a not too far distant future for a bulk production of relatively simple 

 organic compounds by micro-organisms? 



I regret that my answer can only be that in my opinion these pros- 

 pects are not bright. 



Without decrying the great merits of many industrial microbiolo- 

 gists, it appears difficult to escape the conclusion that the enormous 

 progress which synthetic organic chemistry has made in later years 

 almost inevitably leads to some cheap process for the synthesis of any 

 fermentation product which has proved to be a commercial success. 

 As a rule the microbiologist will be unable to compete with synthetic 

 chemistry which starts from the 'cheap carbon' in fossil raw materials 

 like coal, mineral oil or natural gas. In this respect the continuously 

 declining part which fermentation products have in the total produc- 

 tion of ethyl alcohol, butyl alcohol and acetone may be deemed symp- 

 tomatic. 



At first sight there seems to be only one consolation. The earth's 

 reservoir of fossil fuel is apt to be exhausted in a not too far-away 

 future. At that moment mankind will again have to depend on the 

 products of the recent green vegetable kingdom also for its organic 

 syntheses. In the conversion of the carbohydrates of the world-crops 

 into useful chemicals the industrial microbiologist of the future may 

 again achieve new triumphs. This consideration leads to the more or 

 less paradoxical conclusion that industrial microbiology may be a useful 

 science, but that it may as well be 'mothballed' for one or two centuries ! 



Fortunately the situation is quite different. Until now I have only 

 dealt with those manifestations of microbial metabolism which may 

 lead to a wholesale production of comparatively simple organic com- 

 pounds. Yet the true force of the microbe world is to be found in the 

 production of characteristic vital compounds often of complicated 

 structure, or in the production of inextricable and refined mixtures of 

 compounds with a definite physiological activity. 



The latter part of this statement will not need much documentation. 

 It seems quite possible that, in time, the chemist may succeed in prod- 

 ucing a tolerable gin by using ethyl alcohol from coke gas and adding 

 some cleverly mixed synthetic essence. But I do not think that we shall 



459 



