MICRO-ORGANISMS 19 



organisms, which will produce in their metabolism new reactions and 

 new products. Taxonomy and nomenclature are, therefore, basic to 

 both fundamental and applied microbiology. 



In 1928 when A. Fleming, a British bacteriology professor, first iso- 

 lated the Penicillium strain that produced the antibiotic penicillin, 

 the name P. rubrum Biourge was applied to it. Later, after study of 

 this strain, C. Thorn, a U.S. Department of Agriculture mycologist, 

 found that it was actually P. notatum Westl. When this correction 

 was made, it became apparent that one should look for better penicil- 

 lin-producing strains among the isolates of P. notatum. With this 

 knowledge of the correct classification, it was possible to find a second 

 strain that produced penicillin in submerged culture and thus opened 

 up the practical industrial-scale production of penicillin in time for 

 use during the last years of World ^Yar II. 



Certainly if penicillin were formed in this species and if the classi- 

 fication of the genus Penicillium were anywhere near a natural one, the 

 next place to look would be in the near relatives of P. notatum. This 

 assumption proved correct, for the same antibiotic was found to occur 

 in the species P. chrysogenum Thorn, which belongs in the same series 

 of species as P. notatum. From an isolate of P. chrysogenum came the 

 strain that is the ancestor of the highly developed strains used today 

 to manufacture penicillin. 



A similar case, but one in which identification did not turn out so 

 well, was the report in 1918 that Aspergillus fumaricus Wehmer was 

 able to convert sugar to f umaric acid with yields of 70-percent conver- 

 sion of the sugar. C. Wehmer, who reported this discovery and named 

 the species, did not distribute it. His strain was not fully described, 

 and no one knows what kind of Aspergillus he worked with. To date 

 no one has obtained yields of f umaric acid as high as he did from an 

 Aspergillus. Had a more careful description been prepared and had 

 the culture been carefully preserved, it might be available today. 



Another example of how elucidation of the taxonomy of a new 

 organism has aided microbiological studies is the work of J. PL 

 Grosklags and M. E. Swift on the fungus that produces the anti- 

 biotic synnematin. This fungus was originally isolated and classified 

 as a species of Cephalosporium. Later these same investigators ex- 

 amined the particular strain on a variety of media and discovered 

 that it formed ascocarps. Since the genus Cephalosporium is based on 

 the imperfect state, it was necessary, according to the International 

 Code of Botanical Nomenclature (16), to transfer this species to the 

 perfect-state genus, namely Emericellopsis. They then examined liv- 

 ing cultures of the six other taxa in the genus Emericellopsis and 

 found that all can produce an antibiotic inhibiting the growth of 

 Micrococcus and Salmonella. Consequently, a considerable number 

 of strains became available for study. 



The correct identification of a micro-organism may have far-reach- 

 ing consequences and greatly affect subsequent work. A striking ex- 

 ample resulted from the first antibiotic discoveries in the genus 

 Streptomyces, which had received little attention before 1940, except 

 by a few soil microbiologists and pathologists. Yet, after it became 

 apparent that this genus of actinomycetes was a source of new anti- 

 biotics, probably no other group of micro-organisms has been so 



