140 FUNGI AS ANTAGONISTS 



Various cocci are 6 to 8 times more sensitive to X than to commercial 

 penicillin, which is largely G (695). 



Penicillin or penicillin-like substances are also produced by A. flavus, 

 A. farasiticus (149), A. giganteus (722), and a variety of other fungi, 

 largely species of Aspergillus and Penicillium, including A. niger, A. 

 nidulans, A. oryzae, P. citreo-roseum (281), P. cms to sum (1039), and 

 others, such as A. jlavifes ( 1005). 



Certain species of PenicilUum are also capable of producing other 

 antibacterial substances, namely, citrinin, penicillic acid, and clavacin, 

 the first of which is also produced by species of Aspergillus belonging to 

 the candidus group (906). 



Atkinson (29) tested 68 cultures of PenicilUum and found that 18 

 possessed antibacterial properties. These cultures were divided into 

 two groups : first, those largely active against gram-positive bacteria and 

 producing substances like penicillin and citrinin 5 second, those active 

 also against gram-negative bacteria and producing substances of the 

 penicillic acid and penicidin types. 



Aspergillus -fiavus-oryzae Group 



The. A. oryzae members of this group possess only limited antagonis- 

 tic properties. Many of the A. flavus strains, however, apparently have 

 the property of producing at least two antibacterial substances when 

 grown on suitable media and under suitable conditions. 



White and Hill (1006) isolated from cultures of a strain oi A. flavus 

 grown on tryptone media a crystalline substance, aspergillic acid, that 

 showed antibacterial activity against certain gram-negative as well as 

 gram-positive bacteria. The substance was produced when the organism 

 was grown on organic media, but not on synthetic. It was soluble in 

 ether, alcohol, acetone, or acetic acid, but not in petroleum ether j it was 

 soluble in dilute acid or alkaline aqueous solutions, and was precipitated 

 by phosphotungstic acid. Aspergillic acid proved to have relatively high 

 toxicity, and showed no protective action against hemolytic streptococci 

 or pneumococci infections in mice. 



Glister isolated a culture (338) that also produced an antibacterial 

 agent with a wide range of activity, both gram-positive and gram-nega- 

 tive bacteria being inhibited by the culture filtrate. An extract was ob- 



