Fungal Systematics and Evolution

The study of fungi associated with bats and their habitats has become important after the spread of White-nose Syndrome (WNS) caused by Pseudogymnoascus destructans (Pd), resulted in an ongoing rapid decline of bat populations in North America. Much effort has focused on populations of Pd from positive caves. White-nose Syndrome is named for characteristic white growth caused by P. destructans, which was previously known as Geomyces destructans (Gargas et al. 2009, Minnis & Lindner 2013). Characterization of fungal populations and identification of other fungal species may reveal possible antagonists to Pd (Micalizzi et al. 2017). White-nose Syndrome was first reported in New York in 2006 (Blehert et al. 2009), while the first report from Canada was from Ontario in 2010. In both cases, it led to mass mortality of the hibernating bat populations (McAlpine et al. 2012). The disease only occurs while bats hibernate. Pseudogymnoascus destructans cannot grow at temperatures above ± 20 °C (Gargas et al. 2009), and it is thought that the cool caves and mines inhabited by bats during hibernation serve as environmental reservoirs of Pd (Lorch et al. 2013, Reynolds et al. 2015). The presence of Pd in bat populations was confirmed in many countries in Europe and Asia but no significant mortality was observed, despite the fact that some European bats have been found with clinical WNS (Wibbelt et al. 2010, Puechmaille et al. 2011). Why bats remain healthy in these areas is unclear. The study of fungal diversity is important to determine the true impact of a potential invasive species such as Pd on fungal community structure among bats and hibernacula (Johnson et al. 2013). Understudied environments such as caves are rich sources of undescribed microbial species. Many new fungi have recently been described from underground environments as more studies are conducted, although it is still unknown whether obligate troglobiotic fungi exist (Zhang et al. 2017). Previous studies commonly reported the isolation of Cladosporium, Fusarium, Mortierella, and Penicillium species from bat wings, caves and mines (Johnson et al. 2013, Vanderwolf et al. 2013a, b). Penicillium is one of the most common genera isolated from caves on multiple substrates, particularly sediment and air, although no new Penicillium species have been described from caves apart from P. cavernicola, which has also been found outside of caves on dairy products (Frisvad & Samson 2004, Vanderwolf et al. 2013a, b), and P. gravinicasei recently described from a cave in Italy from ripening Apulian cave cheeses (Anelli et al. 2018). Vanderwolf et al. (2016) studied the fungi associated with over-wintering arthropods in Pd positive hibernacula in Canada. They isolated 87 fungal taxa from four arthropod genera. In the current study, we report Penicillium isolated from these arthropods, but also include strains isolated from various other substrates associated with caves and/or bats. The aims of this study were (1) to determine the Penicillium species diversity in bat caves and hibernacula in New Brunswick and Quebec, and (2) formally describe the new species that was isolated during the survey. Penicillium diversity in Canadian bat caves, including a new species, P. speluncae