Termitispirillum cryptocerci gen. nov. sp. nov.

Members of this family are uncultured and inhabit the guts of insects, including termites and Cryptocercus cockroaches. This family is a sister clade of the family Mucispirillaceae in the phylum Deferribacterota. The type genus of this family is Termitispirillum.

Members of this genus are uncultured and spiral or curved long rods that specifically attach to parabasalid protists in the guts of termites and Cryptocercus cockroaches. Cells measure 3–13 µm in length and 0.4 µm in width. Genomic analyses indicated that these bacteria possess a Gram-negative-type cell wall and chemoheterotrophic metabolism with fermentation and respiratory pathways. Motility was inferred from the presence of genes involved in flagellar assembly and chemotaxis. Taxonomic assignment is based on the 16S rRNA gene sequence and specific detection by FISH using the oligonucleotide probe RsTz2-092-190 or Deferri-term-661 (Table S2). The nomenclatural type is Termitispirillum cryptocerci with its genome sequence as the type material.

The bacterium specifically attaches to the cell surfaces of Trichonympha acuta and Trichonympha lata in the gut of Cryptocercus punctulatus. The cell dimensions are 3–13 µm by 0.4 µm. This assignment is based on the 16S rRNA gene sequence (LC866555, LC866555) and detection by FISH using the oligonucleotide probe Deferri-term-661 (Table S2). A complete genome sequence (AP043677) was obtained. This species includes phylotypes CpT06-9, CpT15-2, and CpT32-4.