MICROBIAL METABOLISM AND ITS INDUSTRIAL IMPLICATIONS 



features which are quite unusual for a metabolic product. Although 

 the merit of the first discovery of a mould product containing non- 

 ionic chlorine falls to Raistrick and his group working at the London 

 School of Hygiene, further examples of such compounds have remain- 

 ed rare, and organic chemists, taking into account their own achieve- 

 ments, will not be able to suppress their admiration for Streptomyces 

 venezuelae which succeeds in chlorinating some organic compound in 

 an aqueous medium at room temperature. Moreover, scarcely recov- 

 ered from this surprise, one discovers the nitro-group in the molecule, 

 a new feature for a naturally-occurring compound, and especially 

 striking because of the marked activity of other nitro-compounds in 

 physiology. 



However, the most surprising point of all is that three molecules 

 which are so utterly different should be equally effective in inhibiting 

 the growth of a great number of bacterial species, whilst at the same 

 time showing striking differences in their behaviour towards other 

 bacteria. 



Thus, one decade of antibiotic research has led to the discovery of 

 a series of economically important microbial metabolic products never 

 dreamed of in our philosophy until that time. New terms will probably 

 be added to this series, and aureomycin, neomycin and terramycin are 

 already there to corroborate this. 



May we not hope that in a not too far distant future a further pen- 

 etration into the secrets of microbial metabolism will lead to the dis- 

 covery of a penicillin substitute fit for oral administration, a strepto- 

 mycin substitute without side-effects and which does not induce resist- 

 ance in Mycobacterium tuberculosis and a chloramphenicol substitute with 

 an anti-viridal next to its anti-rickettsial spectrum? The microbes 

 which then will be engaged in the production process may well have 

 quite different requirements from those cultivated at present, and 

 new industrial implications will emerge. 



To all this, one point should be added. The time has passed when 

 biologists could content themselves with living organisms as they are 

 found in nature. In his scientific fantasia 'Last and First Men; A Story 

 of the Near and Far Future' Stapledon describes how in the age of the 

 'Third Men' mankind as a whole will satisfy its creative urge in the 

 cultivation of surprisingly new forms of life : on the one hand, crea- 

 tures of unimaginably perfect harmony; on the other hand, the most 



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