Chapter XII _ 191 — Summary 



Utilization of Actinomycetes for the Prockiction of Enzymes and 



Vitamins:— Comparatively little use has been made so far of aetinomy- 

 cetes for production of chemical compounds that hnd application in in- 

 dustry or in nutrition. Only one attempt has been made to utilize the 

 diastatic enzyme of an actinomyces; this has been produced under the 

 name "superbiolase," because of its ability to withstand higher tempera- 

 tures than the corresponding enzymes of barley and of certain micro- 

 organisms. Of much greater importance is the recent finding (359a) 

 that certain strains of S. grisens (grisein-producing) are capable of pro- 

 ducing vitamin Bi2- The red crystalline material isolated from these 

 cultures had all the properties of the compound isolated from liver. 

 These crystals possessed optimal "animal protein factor" activity for the 

 chick at a level of 30 [^-g/kg of diet, similar to that found for vitamin 

 Bio. 



Production of Antibiotics:— Among the various groups of micro- 

 organisms that have the capacity to produce antibiotic substances, or 

 agents vi'hich have the capacity to inhibit the growth of and even to 

 destroy bacteria and other microorganisms, the actinomycetes occupy a 

 prominent place. Within the last 7 or 8 years, nearly 30 antibiotics 

 have been isolated. They vary greatly in their antibacterial properties 

 or in their antibiotic spectrum, in their chemical nature, in their toxicity 

 to animals, and in their chemotherapeutic potentialities. Some, like 

 actinomycin, are highly toxic; others, like streptomycin, possess only a 

 very limited toxicity. Some are produced by more than one organism; 

 and some organisms produce more than one antibiotic. 



Of the various antibiotics produced by actinomycetes, streptomycin 

 occupies a leading place. First announced in January 1944, it was used 

 clinically within less than 2 years. Among its most striking properties 

 are its action against gram-negative bacteria and the bacteria causing tu- 

 berculosis. Thus, a chemotherapeutic agent that has marked effects 

 against the "white plague" of man has been discovered. What ap- 

 peared only a few years ago to be one of the greatest scourges affecting 

 millions of human beings has been subjected to control by the product 

 of an actinomyces. Within 5 years after its announcement, the produc- 

 tion of this antibiotic has risen to nearly 8 million grams per month. 



Some of the newer antibiotics, notably aureomycin and Chloromy- 

 cetin, have also attained remarkable production records. 



The possibility of discovering other antibiotics that would supple- 

 ment streptomycin or take a place by its side as an important therapeutic 

 agent appear very promising. Although some agents, like streptothricin, 

 appear to be too toxic to offer great immediate promise, others, like 

 grisein, are highly active and possess only very limited toxicity. These, 

 therefore, appear promising. 



J Thus, the actinomycetes have contributed important tools for com- 

 bating human and animal infections. The end of these possibiUties is 



