Penicillium tunisiense sp. nov., a novel species of Penicillium section Ramosa discovered from Tunisian orchard apples.

Two similar Penicillium isolates could not be identified as previously described species in a survey of orchard apples from Tunisia for patulin-producing fungi. These isolates are described as novel species using multilocus DNA sequence analysis of partial β-tubulin, calmodulin and nuclear ribosomal internal transcribed spacer regions; and morphological, physiological and biochemical characteristics. The isolates were considered negative for patulin production since the IDH gene fragment was not detected and the compound detected at the same retention time of patulin (14.9 min) showed a different UV spectrum using U-HPLC/UV-DAD. In terms of phylogeny, the two isolates clustered with Penicillium section Ramosa and are closely related to Penicillium chroogomphum, Penicillium lenticrescens and Penicillium soppii. Furthermore, their macro- and micromorphological traits differed from these species. Hence, the isolates represent a novel species in Penicillium section Ramosa and the name Penicillium tunisiense sp. nov. is proposed, with the type strain MUM 17.62 (=ITEM 17445).