238 A MANUAL OF THE PENICILLIA 



hyphae. Colonies are also more restricted and produce little or no exu- 

 date. 



Occurrence and Significance 



Members of the present series appear to be abundant in all soils, 

 particularly forms approximating Penicillium adametzi. Representative 

 strains have been received from Professor G. R. Bisby from Manitoba soils, 

 from Professor M. B. Morrow from Texas soils, and numerous other in- 

 vestigators making soil population studies. These species were commonly 

 isolated in our work in the Division of Soil Microbiology, U. S. Depart- 

 ment of Agriculture, Washington, D. C, and have been frequently en- 

 countered at this Laboratory in our search for penicillin-producing and 

 other industrially useful molds. Not unexpectedly, members of the series 

 have occasionally occurred among the isolates from deteriorating military 

 equipment submitted for identification. The significance of these forms 

 in decomposition processes has not been adequately investigated. 



Penicillium ierlikowskii Zal. has been shown to be an active producer 

 of the antibiotic gliotoxin (Brian, 1946), and because of this characteristic, 

 the species is believed to exert a marked effect upon the microbiological 

 population of certain soils in which it is unusually prevalent. Brian, 

 Hemming, and McGowan (1945) reported that the toxicity to mycorrhiza 

 in Wareham Health soil was due to antibiotics, particularly gliotoxin 

 produced by Trichoderma viride and certain strains of Penicillium, reported 

 as P. jenseni. These latter strains, when examined by us, were diagnosed 

 as more nearly representing P. ierlikowskii Zal. Our identification was 

 accepted and used in a subsequent report by Brian (1946). In this report, 

 the 'influence of various substrate constituents and strain variation on 

 gliotoxin production was discussed. 



Sasaki (1939) reported Penicillium jantho-citrinum as the active patho- 

 gen in eleven cases of otomycosis, although the identification of the fungus 

 is not verifiable. 



Penicillium phoeniceum v. Beyma has been studied particularly with 

 reference to the striking pigment which it produces. Friedheim (1933) 

 reported a red pigment, phenicin, to be produced in the mycelium of this 

 mold. The pigment in its red form was soluble in water but insoluble in 

 ether or chloroform. When acidified the pigment turned yellow and could 

 then be extracted with the above solvents and from them wuth NaHCOs. 

 The pigment was found to increase respiration 200-300 percent when 

 added to a suspension of washed, non-pigmented Bacillus pyocyaceus 

 (= Pseudomonas aeruginosus) cells. In a subsequent paper (1938), yields 

 of 44 mg. pigment were reported from 3.5 gms. mycelimn produced in 



