154 A MANUAL OF THE PENICILLIA 



coverer, to produce a pectolase which rapidly hydrolyzes pectolic acid into 

 pectolactonic acid and further into molecular d-galacturonic acid. The 

 enzyme was not found in yeasts, but was demonstrated in Taka-diastase, 

 in some green Penicilliwn designated P. glaiicum, and in the snail, Helix. 



Oxford, Raistrick, and Simonart (1935) isolated fulvic acid, a crystalline 

 yellow pigment from Penicillium hrefeldianum Dodge. The same pigment 

 was found in P. griseo-julvum Dierckx (see p. 536) and P. flezuosum Dale 

 (see p. 534). 



No biochemical or physiological studies have yet been made on Raper 

 and Fennell's new species Penicillium parvum and P. levitum (1948). 



Hettinger (1934) published a doctoral dissertation on the morphology 

 and physiology of Penicillium zukalii Biourge. In the same year, and 

 using the same culture, Hornung published a dissertation on the physiology 

 and biochemistry of this species. When received by us a few years later, 

 the culture was found to represent a typical strain of Penicillium hrefeldi- 

 anum. The culture which they used had been received directly from 

 Biourge. 



Penicillium thomii Series 

 Outstanding Characters 



Sclerotia characteristically produced, but in some species not developed 

 upon all substrata (including Czapek's solution agar); typically hard 

 and gritty, but in some species consisting of comparatively soft masses 

 of pseudoparenchymatous cells. 



Colonies typically rather fast growing, developing abundant sclerotia which 

 often characterize the colony appearance, but in some species slow grow- 

 ing and developing sclerotia only on certain substrata. 



Conidiophores abundant in some species, not in others; arising from the 

 substratum, to produce a velvety effect, or from trailing vegetative 

 hyphae; from very short up to 300 to 4bOju long; walls smooth or deli- 

 cately echinulate. 



Penicilli monoverticillate, usually strictly so but sometimes showing an 

 independent branch, sparsely produced in some species and strains; typi- 

 cally showing parallel sterigmata in compact clusters. 



Conidia mostly elliptical to subglobose, smooth-walled, 2.5 to 3.5n in diam- 

 eter, borne in long chains often adherent in loose columns. 



Series Key 



a. Sclerotia produced upon all substrata, hard, brittle, crushing with difficulty, com- 

 posed of thick-walled sclerenchyma-like cells P. thomii series 



1'. Sclerotia uncolored or nearly so, borne in small clusters surrounded by con- 

 spicuous envelopes of bright orange-red mycelium 



P. scleroliorum van Beyma 



