Species diversity in Penicillium and Acaulium from herbivore dung in China, and description of Acaulium stercorarius sp. nov

Penicillium and Acaulium species are common in fresh herbivore dung and can produce many diverse secondary metabolites, and these fungi play important roles as decomposers of organic materials, food industry, or enzyme factories. Besides, the well-characterized diversity of coprophilous fungi offers accessible systems for dissecting the function of fungi and for exploring the potential to produce high amounts of cellulases in herbivore guts. During a survey of coprophilous fungi from herbivorous animals in China, more than 400 strains were isolated. Thirty-eight strains belonging to Penicillium and 4 belonging to Acaulium were obtained from 12 healthy animals including marmot and chinchilla and selected for detailed study. The strains were characterized by a multi-gene sequencing analysis of partial β-tubulin ( TUB ), the internal transcribed spacer rDNA (ITS), calmodulin ( CAM ), and RNA polymerase II second largest subunit ( RPB2 ) genes, and a detailed phenotypic study. Penicillium strains were identified as belonging to six sections and 12 known species. In addition, four Acaulium isolates were identified as Acaulium album and A. stercorarius sp. nov. based on morphology and multi-gene sequence phylogeny. This study shows that the species diversity of Penicillium on herbivore dung has not been widely studied and that this substrate seems to be a good reservoir of interesting penicillium-like fungi.