A new Paecilomyces from wooden utility poles in South Africa

Abstract

During a survey of fungi on electricity utility poles in South Africa, a diverse range of fungi were discovered. Paecilomyces was frequently isolated, with five species identified using ITS and β-tubulin (BenA) sequences. These were P. brunneolus, P. dactylethromorphus, P. lecythidis, P. paravariotii and a potential new species. The genomes of 30 of these strains were subsequently sequenced and used in a phylogenomic analysis with 45 previously published genomes of the genus. Phylogenetic analyses were also conducted using ITS, BenA, calmodulin (CaM), RNA polymerase II second largest subunit (RPB2), RNA polymerase II largest subunit (RPB1), the genes coding for the theta subunit of the TCP-1 chaperonin complex (Cct8), and for a putative ribosome biogenesis protein (Tsr1). Both phylogenomic and phylogenetic analyses supported the 15 Paecilomyces species currently accepted and confirmed the novelty of the new species, which we describe as P. lignorum. The latter is the sister species of P. brunneolus and belongs to a clade also containing P. variotii and P. paravariotii. Morphologically, the new species produces longer ellipsoidal conidia and grows more restricted on malt extract agar at 30 °C compared to its closest relatives.