Seven new Neocallimastigomycota genera from fecal samples of wild, zoo-housed, and domesticated herbivores: Description of Ghazallomyces constrictus gen. nov., sp. nov., Aklioshbomyces papillarum

ABSTRACT We isolated and characterized sixty-five anaerobic gut fungi (AGF, Neocallimastigomycota) strains from fecal samples of five wild (W), one zoo-housed (Z), and three domesticated (D) herbivores in the US states of Texas (TX) and Oklahoma (OK), Wales (WA), and the Indian states of Kerala (KE) and Haryana (HA). Phylogenetic assessment based on D1-D2 region of the large rRNA subunit (LSU) identified seven distinct lineages, with strains recovered from Axis Deer (W-TX) clustering within the Orpinomyces-Neocallimastix-Pecoramyces-Feramyces clade; Boer Goat-domesticated Goat strains (W-TX, D-KE) clustering within the Oontomyces-Anaeromyces-Liebetanzomyces clade; and domesticated Goat and Sheep strains (D-HA) as well as Nilgiri Tahr strains (W-KE) forming two distinct clades associated with genus Buwchfawromyces . The remaining three lineages, represented by strains recovered from Mouflon-Boer Goat (W-TX), White Tailed Deer (W-OK), and Zebra-Horse (Z-OK, and D-WA), displayed no specific suprageneric affiliation. All strains displayed monocentric thalli and produced mono/uniflagellate zoospores with the exception of Axis Deer strains, which produced polyflagellate zoospores. Isolates displayed multiple interesting microscopic features including sporangia with tightly constricted necks and fine septa at the base (Axis Deer), papillated and pseudo-intercalary sporangia (White-Tailed Deer), swollen sporangiophores and zoospores with long flagella (Mouflon-Boer Goat), zoospore release through an apical pore followed by either sporangial wall collapse (Axis Deer and Boer Goat-domesticated Goat) or sporangial wall remaining intact after discharge (Zebra-Horse), multi-sporangiated thalli with branched sporangiophores (Zebra-Horse), and short sporangiophores with subsporangial swellings (Nilgiri Tahr). Internal transcribed spacer-1 region (ITS-1) sequence analysis indicated that Zebra-Horse strains are representatives of the AL1 lineage, frequently encountered in culture-independent surveys of the alimentary tract and fecal samples from hindgut fermenters. The other six lineages, five of which were isolated from wild herbivores, have not been previously encountered in such surveys. Our results significantly expand the genus level diversity within the Neocallimastigomycota, and strongly suggest that wild herbivores represent a yet-untapped reservoir of AGF diversity. We propose the creation of seven novel genera and eight novel Neocallimastigomycota species to accommodate these strains, for which we propose the names Agriosomyces longus (Mouflon and wild Boer Goat), Aklioshbomyces papillarum (White tailed Deer), Capellomyces foraminis (wild Boar Goat) and C. elongatus (domesticated Goat), Ghazallomyces constrictus (Axis Deer), Joblinomyces apicalis (domesticated Goat and Sheep), Khoyollomyces ramosus (Zebra-Horse), and Tahromyces munnarensis (Nilgiri Tahr). The type species are strains Axs-31, WT-2, MS-4, BGB-11, GFKJa1916, GFH683, ZS-33, and TDFKJa193, respectively.