1) Apophysate sporangia of Absidia glauca. 2) Zygospores and suspensors of Absidia glauca, adorned with appendages from both opposite mates. Image by Kerry O'Donnell.

Absidia species, including A. repens Tiegh (1878), are members of the family Cunninghamellaceae of the order Mucorales and a member of the “zygomycete” fungi. Absidia species are characterized by the formation of relatively small, apophysate sporangia (Fig 1) with deliquescent walls, a single septum is formed in the subtending sporangiophore, and the production of stolons and rhizoids; the sporangiophore is never formed opposite the rhizoids (as in Rhizopus). Zygospores are formed on opposed, more or less equal suspensors adorned with several appendages (Fig 2). One species, Absidia coerulea Bainier has been used in industry for biotransformation and chitosan production, and (Nwe 2008). Some former members of this genus are pathogenic (e.g. A. corymbifera) causing mucoromycoses in humans and cows but these taxa are now in the genus Lichtheimia Vuill.

Sequencing of A. repens will advance the 1000 Fungal Genome Project by providing a representative genome for Cunninghamellaceae, an important family of “zygomycetes” and additional insight into this early branching group of fungi.

References:

Hesseltine, C.W., and J. J. Ellis. 1961. Notes on Mucorales, especially Absidia. Mycologia 53: 406-426.
Hesseltine, C.W., and J. J. Ellis. 1964. The genus Absidia: Gongronella and cylindrical-spored species of Absidia. Mycologia 56: 568-601.
Hesseltine, C.W., and J. J. Ellis. 1966. Species of Absidia with ovoid sporangiospores. I. Mycologia 58:761-785.
Nwe N, Stevens WF, Montet D, Tokura S, Tamura H. Decomposition of myceliar matrix and extraction of chitosan from Gongronella butleri USDB 0201 and Absidia coerulea ATCC 14076. Int J Biol Macromol. 2008;43(1):2-7.

Also see http://zygomycetes.org/index.php?id=108