Taxonomic delimitation of a termite gut-associated lineage in Penicillium section Aspergilloides: introduction of a new series and new species from India

We describe Penicillium termitintestinicola sp. nov., isolated from the gut of an Odontotermes termite species collected from the Satara district of Maharashtra, India. Its taxonomic placement was assessed using an integrative approach combining morphology with multilocus phylogenetic analyses of the ribosomal internal transcribed spacer (ITS) region, partial beta-tubulin (BenA), calmodulin (CaM), and RNA polymerase II second-largest subunit (RPB2) genes. The new species formed a well-supported lineage sister to the series Thiersiorum within the section Aspergilloides, distinct from all currently recognised series. Consequently, we propose the series Termitintestinicolarum ser. nov. to accommodate this lineage. Penicillium termitintestinicola is characterised by non-vesiculate, monoverticillate conidiophores with short stipes, predominantly ellipsoidal, smooth conidia, greyish brown sclerotia on Malt Extract Agar (MEA) and Oatmeal Agar (OA), and colonies that produce a strong acid on Creatine Sucrose Agar (CREA). These findings highlight termite gut microhabitats as an underexplored niche for fungal discovery in India.