Submitted to: Mycological Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 19, 2004
Publication Date: April 1, 2004
Citation: Peterson, S.W. 2004. Multilocus DNA sequence analysis shows that Penicillium biourgeianum Zaleski is a distinct species closely related to P. brevicompactum and P. olsonii. Mycological Research. 108(4):434-440. Interpretive Summary: Cultures of the molds species Penicillium brevicompactum can be subdivided into three groups on the basis of the color of the growing mold and the color of compounds that are released into the agar it is being grown on. It is unclear whether these differences indicate that there are three species of molds lumped into one category, or whether the differences are the normal variation of appearance that one might expect. It is important to know whether these are distinct species because some of the groups make chemicals that may be useful in industrial applications. Molecular genetic testing was conducted to determine whether these are distinct species, and it was found that the three different colored groups of molds are different species.
Technical Abstract: Penicillium brevicompactum and other isolates with the compact, complex conidiogenous apparatus typical of the species were sequenced in one ribosomal and two protein coding regions. The aligned DNA sequences were analyzed by maximum parsimony and the data from different loci were tested for compatibility using the partition homogeneity test. Analysis of each of the three loci revealed three clades corresponding to Penicillium brevicompactum, P. olsonii and Penicillium biourgeianum. Using the phylogenetic species concept and the genetic isolation of the clades, we can list P. hagemi Zaleski, P. patrismei Zaleski, P. stoloniferum Thom, and P. griseobrunneum Dierckx as synonyms of P. brevicompactum. Penicillium volgaense Beljakova & Milko is a synonym of Penicillium olsonii. Penicillium biourgeianum Zaleski is a distinct species closely related to P. brevicompactum and P. olsonii. Phenotypic distinctions between the species are mostly based on colony characteristics such as color.