Khoyollomyces was isolated from the feces of a zoo-housed zebra and a domesticated horse (Hanafy et al, 2020a). Like several anaerobic fungal genera, Khoyollomyces is a monocentric fungus with a filamentous rhizoidal system and monoflagellated zoospores.
The genus name, Khoyollomyces, is derived from the Arabic word for horses: “khoyollo”. The type species is called K. ramosus. The species name means branched in Latin, and refers to the branched sporangiophores produced by K. ramosus. The type strain for the genus is ZS-33. To date, no other Khoyollomyces species have been described.
Khoyollomyces represents the first cultured representative of clade AL1 (Kittelmann et al. 2012), which was first discovered and reported (as NG1) in a previous ITS1-based culture independent survey (Liggenstoffer et al. 2010). Interestingly, Khoyollomyces is highly abundant in hindgut herbivores especially those associated with the family Equidae e.g. horses and zebras (Hanafy et al, 2020b; Mura et al, 2019; Edwards et al, 2020).
Within the family Neocallimastigaceae, Khoyollomyces is phylogenetically most closely related to Agriosomyces (when using LSU as a taxonomic marker).
Images are shown above of Khoyollomyces ramosus strain ZS-33.
In liquid medium, Khoyollomyces produces a loose, sand-like fungal biofilm (Image 1). On solid roll agar medium, it forms small yellowish-brown irregularly shaped colonies (Image 2).
Microscopically, Khoyollomyces produces monoflagellated zoospores (Image 3). Khoyollomyces has monocentric thalli with filamentous anucleate rhizoidal systems, as shown by the DAPI overlay of a light microscopy image (Image 4).
Both endogenous (Image 5) and exogenous (Image 6) sporangia are produced. Khoyollomyces is characterized by the multisporangiate thalli, with the majority of sporangiophores being branched and bearing two to four sporangia (Images 7 & 8). Zoospores are released from the sporangia through a wide apical pore (Image 9).
No sequenced genome or transcriptomes are currently available for Khoyollomyces.
For the Khoyollomyces ramosus strain ZS-33 that is pictured above, the LSU sequence is available in the NCBI database (accession number MK881981).