English
Ten New Species of Penicillium sect. Exilicaulis in Volcanic Soils of a Dokdo Islet in Korea
Yein Kim, Ki Sung Lee, Mijung Kim and Seong Hwan Kim*
Department of Microbiology, Dankook University, Cheonan, 31116, Korea
*Email: piceae@dankook.ac.kr
Designated as a Natural Monument, Dokdo is a protected natural reserve located in the Southern area of the subantarctic zone in Korea. The Dokdo terrestrial ecosystem has an environment with strong winds and salinity. Fungi have not been much explored in this place. Thus, this study was carried out to explore fungi in this islet. Soil samples of volcanic rock powder were collected, suspended in sterile water and plated on DG18 media. Interestingly, many distinct fungal colonies emerged and subsequently, isolated and purified on PDA. Colony morphology and microscopic observation of microstructures revealed that they are Penicillium. Strikingly, sequence similarity analysis of the ITS rDNA region, β-tubulin gene, calmodulin gene and RPB2 gene shows that there are ten unique sequences from ten individual isolates which show low similarity with the known Penicillium sequences. Phylogenetic analysis based on these four sequences using maximum-likely hood and Bayesian algorithms supported that all the ten isolates are novel Penicillium species. The growth of these new species slow on several different media. Together with the observation of mono- to biverticillate conidiophores with non-vesiculate stipes and phylogenetic analysis results, all ten Penicillium were classified into the species belonging to section Exilicaulis. Our work surely explored new cases of Penicillium species that are originated from marine-derived sediments. This study enhances the taxonomic research of Penicillium and extends our knowledge on the fungal diversity of Dokdo in Korea.
