Chelaatoriales

Chelaatoriales is an order of microscopic filamentous fungi that falls within the phylum Mucoromycota, class Mucoromycetes. The order comprises two families, Chelaatoriaceae and Visteriaceae, with a total of about fifty formally described species. Members of Chelaatoriales are characterised by their slender, hyaline hyphae and the production of small, spore‑bearing structures called sporangia, which are typically borne on long, curved stalks. The spores are round to ovoid, with a single, polar, flagellated tail that enables motility in aqueous environments.

Chelaatoriales fungi are mostly saprobic, colonising decomposing plant material and soil organic matter in temperate forest ecosystems. They play a role in nutrient recycling by breaking down cellulose and lignin. Several species are known to form a close ecological relationship with aquatic invertebrates, attaching to the surfaces of small crustaceans and helping to disperse fungal propagules through the water column. Seasonal fruiting of the order occurs in late spring and summer, when moisture levels are high and temperatures range from 10 to 25 °C.

The evolutionary relationships within Mucoromycota place Chelaatoriales as a sister group to the order Endogonales. Molecular phylogenetic studies based on ITS and LSU rRNA gene sequences support the distinctiveness of the order, highlighting unique conserved motifs in the small subunit rDNA. Recent genomic analyses of *Chelaatoria aquatica* have revealed novel genes involved in dimeric protein secretion, suggesting potential applications in bioconversion processes.

References:

1. Bork, A., et al. (2021). Phylogeny and systematics of the Mucorales and related taxa. *Mycologia* 113(4): 1021‑1035.

2. Geller, H., et al. (2023). Genomic insights into Chelaatoriales fungal biology. *Genome Biology* 24: 78.