BIVERTICILLATA-SYMMETRICA 657 



found the same species and other related forms on leather but reported 

 little evidence of serious damage. Rennerfelt (1938), studying the inter- 

 relation between P. rugulosum and other micro-organisms, in laboratory 

 culture, reported that the color of the PeniciUiuni mycelium ranged from 

 grayish green to brick red depending upon the carbohydrate supplied. 



Penicillium rugulosum occasionally parasitizes other molds, particularly 

 members of the Aspergillus niger group (Thom, 1930 and Romankova, 

 1936). In the commercial production of citric acid from sugar solutions, 

 colonies of this species are reported to produce circular areas of infection 

 in the floating blanket of Aspergillus mycelium which appear to rot and 

 drop away when the mycelium is disturbed. Yields of acid are substan- 

 tially reduced. In plate or tube cultures the Aspergillus colony may be- 

 come penetrated by dense mats of Penicillium hyphae which envelop the 

 stalks and fruits as densely radiating conidial structures, with the green 

 penicilli of the parasite often masking the black heads of the Aspergillus 

 (fig. 23). The development is not unlike that of P. purpurogenum Stoll 

 under similar conditions. 



Molds on military instruments represented the subject of an investi- 

 gation by Takeda, Suematsu, and Nakazawa in 1934. Two new molds 

 were described including a species of Penicillium, P. scorteiim, that closely 

 approximated P. tardum Thom. The use of wax containing 1 percent p- 

 nitrophcnol was recommended as a preservative for instruments. Growth 

 of the mold was prevented by addition of 0.5 cc. chloropicrin or 20 gms. of 

 p-dichlorobenzene per cubic meter of air. 



Oxford and Raistrick (1934) investigated the biochemistry of Penicillium 

 craterijorme Oilman and Abbott, a form which we now believe to have ap- 

 proximated P. rugulosum Thom (see p. 650). When grown upon a Czapek- 

 Dox solution containing glucose as the sole source of C, spiculisporic acid 

 (C17H28O6), succinic acid, and a complex polysaccharide were produced. 

 The first of these products was initially isolated from P. spiculisporum, 

 hence the name (Clutterbuck, Raistrick, and Rintoul, 1931). Chopra 

 and Ray (1939) studied the production of a red pigment by a Penicillium 

 isolated in the Punjab and reported as P. craterijorme Oilman and Al)bott. 

 The pigment was readily produced when methyl, ethyl, or amyl alcohol, 

 glycerol, or tartaric or citric acids were used as a source of C, although 

 growth was most prolific when various carbohydrates were used. Amino 

 acids, peptides, and peptone afforded more suitable sources of N than in- 

 organic salts. Yields of 0.1 gm./l. of crude pigment were obtained. It 

 melted at 180-200°C. and was oxidized to a colorless compound upon 

 boiling with H2O2. 



Johns, Philpot, and Pollock (1946) reported the production of "penicillin- 

 like" antibiotics by different Penicillia including one from the Centraal- 



