Characterization of Achlya americana and A. bisexualis (Saprolegniales, Oomycota) Isolated from Freshwater Environments in Korea

Many members of the Saprolegniales (Oomycete) cause mycoses and disorders of fishes, of which Achlya and Saprolegnia are most ubiquitous genera worldwide. During a survey of the diversity of freshwater oomycetes in Korea, we collected seven isolates of Achlya, for which morphological and molecular phylogenetic analyses enabled them to identify as Achlya americana and Achlya bisexualis. In Korea, only a species of Achlya, A. prolifera, has been previously found to cause seedling rot on rice (Oryza sativa), but none of the two species have been reported yet. Importantly, A. bisexualis was isolated from a live fish, namely rice fish (Oryzias sinensis), as well as freshwater, and this is the first report of Achlya-causing mycoses on freshwater fishes in Korea. The presence of A. americana and A. bisexualis on live fish in Korea should be closely monitored, as considering the well-known broad infectivity of these species it has the potential to cause an important emerging disease on aquaculture industry.

New Records of Four Species Belonging to Eurotiales from Soil and Freshwater in Korea

Four strains of Penicillium and Talaromyces species are described and illustrated in an inventory of fungal species belonging to Eurotiales. The strains, CNUFC-DDS17-1, CNUFC-DDS27-1, CNUFC-PTM72-1, and CNUFC-YJW3-31, were isolated from soil and freshwater samples from South Korea. Based on their morphological characteristics and sequence analyses by the combined β-tubulin and calmodulin gene, the CNUFC-DDS17-1, CNUFC-DDS27-1, CNUFC-PTM72-1, and CNUFC-YJW3-31 isolates were identified as Penicillium pasqualense, Penicillium sanguifluum, Talaromyces apiculatus, and Talaromyces liani, respectively. The designated strains were found to represent a previously undescribed species of Korean fungal biota. In this study, detailed morphological descriptions and phylogenetic relationships of these species are provided.

First Records of Rare Ascomycete Fungi, Acrostalagmus luteoalbus, Bartalinia robillardoides, and Collariella carteri from Freshwater Samples in Korea

The distribution and occurrence of rare ascomycete fungi within freshwater samples in Korea was investigated. Three rare fungal strains, CNUFC-YR537-1, CNUFC-CNUP1-1, and CNUFC-NDR3-1, were isolated using serial dilution method. On the basis of their morphological characteristics and phylogenetic analysis of their internal transcribed spacer regions and 28S rDNA sequences, the three isolates were identified as Acrostalagmus luteoalbus, Bartalinia robillardoides, and Collariella carteri, respectively. To our knowledge, these are the first records of rare genera Acrostalagmus, Bartalinia, and Collariella from Korea, and the first reports of A. luteoalbus, B. robillardoides, and C. carteri from freshwater samples.

Characterization of Three Species of Sordariomycetes Isolated from Freshwater and Soil Samples in Korea

During a survey of fungal diversity in the class Sordariomycetes, 3 fungal strains, CNUFC-KMHY6-1, CNUFC-MSW24-2-11, and CNUFC-GW2S-4 were isolated from soil and freshwater samples, respectively in Korea. The strains were analyzed both morphologically and phylogenetically on the basis of internal transcribed spacer and RNA polymerase II second largest subunit gene sequences. On the basis of their morphology and phylogeny, CNUFC-KMHY6-1, CNUFC-MSW24-2-11, and CNUFC-GW2S-4 isolates were identified as Arcopilus aureus, Memnoniella echinata, and Stachybotrys sansevieriae, respectively. To the best of our knowledge, Ar. aureus and M. echinata have not been previously recorded in Korea, and this is the first report of S. sansevieriae from freshwater niche.

Molecular and Morphological Confirmation of Three Undescribed Species of Mortierella from Korea

Three fungal isolates designated as CNUFC-YR329-1, CNUFC-PTS103-1, and CNUFC-PTS2-1 were discovered during a survey of fungal diversity of the order Mortierellales from freshwater and pine tree rhizosphere soil samples in Korea. The strains were analyzed morphologically and phylogenetically based on the internal transcribed spacer (ITS) and large subunit (LSU) of ribosomal DNA gene sequences. Based on their morphology and phylogeny, the three isolates were identified as Mortierella elongata, M. horticola, and M. humilis, respectively. To the best of our knowledge, M. elongata, M. horticola, and M. humilis, belonging to an undiscovered taxon, have not been previously described in Korea.