Downloaded from www.microbiologyresearch.org by IP: 54.70.40.11 On: Thu, 06 Dec 2018 09:42:08 Jaminaea angkorensis gen. nov., sp. nov., a novel anamorphic fungus containing an S943 nuclear small-subunit rRNA group IB intron represents a basal branch of Microstromatales Matthias Sipiczki and Erika Kajdacsi Correspondence M. Sipiczki lipovy@tigris.unideb.hu Department of Genetics and Applied Microbiology, University of Debrecen, PO Box 56, 4010 Debrecen, Hungary In the course of molecular characterization of yeasts isolated from decaying leaves collected in Cambodia, anamorphic yeast strains were detected that clustered with the Microstromatales in molecular phylogenetic analyses of the chromosomal regions coding for the D1/D2 domain of the large-subunit 26S rRNA gene, the small-subunit 18S rRNA gene and the internal transcribed spacer ITS1-5.8S rRNA gene-ITS2. In the trees obtained, the isolates formed a distinct, basal branch of Microstromatales supported with high bootstrap values. As the isolates could not be identified with any known genus, we have described them as Jaminaea angkorensis gen. et sp. nov. (type strain C5b T 5CBS 10918 T 5CCY 88-1-1 T ). In the chromosomal region coding for the 18S rRNA gene, the type strain of the novel species contained a group IB intron that was similar in location and sequence to introns found in certain species of Exobasidiales and Entylomatales. As no similar introns have been detected in Microstromatales, the new genus might represent a phylogenetic link connecting these three orders. Microstromatales, Exobasidiales and Entylomatales are related orders of the class Exobasidiomycetes that comprise species lacking teliospores and mostly occur on woody bushes and trees (Bauer et al., 1997; Begerow et al., 2006). The class Exobasidiomycetes belong to the basidiomyce- tous subphylum Ustilaginomycotina, containing species that are usually dimorphic, having both yeast and hyphal phases (Begerow et al., 2006). Ustilaginomycota also contains anamorphic species such as members of Acaromyces, Malassezia, Meira, Rhodotorula, Tilletiopsis or Sympodiomycopsis (Boekhout et al., 2003, 2006; Xu et al., 2007; Weijman et al., 1988). The latter genus is classified within the Microstromatales and accommodates a species, Sympodiomycopsis paphiopedili (Sugiyama et al., 1991; Suh & Sugiyama, 1994), which secretes an antifungal glycolipid into the culture medium (Kulakovskaya et al., 2004). Antifungal antagonism is a property of numerous yeast genera and can be exploited in bioprotection of crops and horticultural produce (for a review see Spadaro & Gullino, 2004). Certain antagonistic yeasts are pigmented and their antimicrobial activity can be a consequence of the pigment synthesis (Sipiczki, 2006). In a yeast isolation project intended to identify novel pigmented antagonistic yeasts, we isolated two strains from fallen leaves that produced pink colonies. Although they failed to show antimicrobial activities under laboratory conditions, their preliminary examination indicated that they might be interesting from a taxonomic point of view. In this paper we describe their morphology, taxonomy and phylogenesis and propose a species name for them. Isolation and phenotypic characterization of yeast strains Fallen leaves were collected from two different localities of the world heritage site Angkor, Cambodia in 2006. The collected plant material was macerated in sterile water and samples were streaked on YPGA (1 % yeast extract, 1 % peptone, 2% glucose, 2% agar, w/v) plates. After incubation for 14 days at 25 u C, individual yeast colonies were isolated. Two isolates (C5b T and C6b) were selected for further examination. Both strains produced smooth, slightly pink colonies on YPGA medium, which upon prolonged incubation gradually became darker with venose and occasionally warty surfaces, and slightly eroded margins with occasional farinose sectors (Fig. 1a). The Abbreviation: ITS, internal transcribed spacer. The GenBank/EMBL/DDBJ accession numbers for the sequences of isolate C5b T (CBS 10918 T ) are EU587489 (D1/D1 domain of the large-subunit rRNA gene), EU604148 (18S rRNA gene), EU604147 (ITS1-5.8S rRNA gene-ITS2) and EU604149 (group IB intron). Figures showing a CLUSTAL alignment of the rRNA group I introns of Ustilago maydis and strain C5b T and a maximum-likelihood analysis of the S943 nuclear small-subunit rRNA group IB intron sequences are available as supplementary material with the online version of this paper. International Journal of Systematic and Evolutionary Microbiology (2009), 59, 914–920 DOI 10.1099/ijs.0.003939-0 914 003939 G 2009 IUMS Printed in Great Britain