Molecular assessment of fungi in “black spots” that deface murals in the Takamatsuzuka and Kitora Tumuli in Japan: Acremonium sect. Gliomastix including Acremonium tumulicola sp. nov. and Acremonium felinum comb. nov

Unidentified black spots (or stains) appeared on the plaster walls of the Takamatsuzuka and Kitora Tumuli in the village of Asuka, Nara Prefecture, Japan. Public attention was drawn to the biodeterioration of the colorful 1,300-year-old murals. A total of 46 isolates of Acremonium sect. Gliomastix were obtained from various samples (mainly black spots) of the Takamatsuzuka Tumulus (TT) (sampling period, May 2004–December 2006) and the Kitora Tumulus (KT) (June 2004–May 2007). These isolates were assignable to four known taxa and a new species in the ‘series Murorum’ sensu W. Gams as inferred from the integrated analysis of phenotypic and genotypic (i.e., ITS and 28S rDNA-D1/D2 sequences) characters: these were Acremonium masseei, A. murorum, A. felinum comb. nov. with the neotype designation, A. polychromum, and A. tumulicola sp. nov., which have been accommodated in the validated series Murorum in the section Gliomastix. The black spots on the murals of the TT and KT were caused mainly by A. masseei and A. murorum, respectively.