Reclassification of a pneumocandin-producing anamorph, Glarea lozoyensis gen. et sp. nov., previously identified as Zalerion arboricola

The importance of pneumocandin B-0 as the fermentation-derived starting mat erial for the antifungal drug candidate, MK-991, along with the identificat ion of our production strain as Z. arboricola (ATCC 20868) as CBS prompted a search for other strains of Z. arboricola or Zalerion species with improv ed titres or that might produce natural pneumocandin analogues. Analysis of morphology, secondary metabolites profiles, and DNA fingerprinting demonst rated that ATCC 20868 was not congeneric with Z. arbaricola. Ribosomal DNA sequences were compared among Zalerion species and pneumocandin-producing f ungi and with rDNA sequences in GenBank. No good matches with sequences in GenBank were obtained for Z. arboricola or Z. maritimum, but for Z. varium, P. carpinea and ATCC 20868, relevant similarities were observed with ITS1 sequences from fungi of Leotiales. ATCC 20868 was phylogenetically more aki n to P. carpinea, another pneumocandin producer, than initially suspected. The closest relative of ATCC 20868 seemed to be Hymenoscyphus monotropae. W e conclude that the genus Zalerion is artificial; its species bear no phylo genetic relation among themselves. ATCC 20868 and Z. varium were related to fungi of the Leotiales. We propose a new anamorph genus and species, Glare a lozoyensis, to accommodate ATCC 20868.