Genomic and morphological characterization of Knufia obscura isolated from the Mars 2020 spacecraft assembly facility

Abstract Members of the family Trichomeriaceae, belonging to the Chaetothyriales order and the Ascomycota phylum, are known for their capability to inhabit hostile environments characterized by extreme temperatures, nutrient scarcity (oligotrophic conditions), presence of toxic compounds, or drought conditions. Within this family, the genus Knufia encompasses the vast majority of polyextremophilic species. In this report, the genomic and morphological features of the strain FJI-L2-BK-P2, identified as Knufia obscura, are presented. The identification is based on multi-locus sequence analysis and whole genome sequence phylogeny. The strain FJI-L2-BK-P2 was isolated from the Mars 2020 mission spacecraft assembly facility located at the Jet Propulsion Laboratory in Pasadena, California. Additionally, the type strain of K. obscura (CBS 148926T), originally isolated from a car's gas tank in Italy, has been sequenced and annotated. The morphological analysis and description of the genomic characteristics of K. obscura FJI-L2-BK-P2 may contribute to refining the taxonomy of Knufia species. Key morphological features are reported in this K. obscura strain, resembling microsclerotia and chlamydospore-like propagules. These features, known to be significant in black fungi, could potentially facilitate their adaptation to harsh environments.