LICHTHEIMIA Vuillemin, 1903 (Bull. Soc. Mycol. France 19: 126); 4 spp. (Vuillemin, 1903; Hoffmann et al., 2009).
Colonies rapidly growing between 37 C and 42 C, temperature range 20 C to 53 C; thermotolerant. Lichtheimia (as are Absidia and Lentamyces) is characterized by the formation of relatively small, apophysate sporangia 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). The zygospore has an ornamented zygosporangial wall; the suspensors are opposed and non-appendaged. One species [Absidia (Mycocladus) corymbifera] is a human pathogen (Voigt et al. 1999).
Type species: L. corymbifera
Species of Lichtheimia:
L. blakesleeana (Lendn.) Kerst. Hoffm., G. Walther & K. Voigt, 2009 (Mycol. Res. 113:277).
L. corymbifera (Cohn) Vuill., 1903 (Bull. Soc. Mycol. France 19: 126).
L. hyalospora (Saito) Kerst. Hoffm., G. Walther & K. Voigt, 2009 (Mycol. Res. 113:278).
L. ramosa (Zopf) Vuill., 1903 (Bull. Soc. Mycol. France 19: 126).
Lichtheimia has usually been treated as a synonym of Absidia (Hesseltine and Ellis, 1964). These species, and several other taxa, were described in a several-part monograph of Absidia by Ellis and Hesseltine (1965, 1966) and Hesseltine and Ellis (1961, 1964, 1966). Hoffmann et al. (2007) considered the first three species of Lichtheimia as members of the genus Mycocladus; L. ramosa was considered a synonym of L. corymbifera.
After careful review of the original description of Mycocladus verticellatus (Beauverie, 1900) it was discovered that M. verticellatus did not grow above 40 C and that its optimum was 30 C. Mesophilic growth of the latter species places it in Absidia s.s., as do several other features: subsporangial septa, no terminal sporangia, and a smooth columella. The suspensors of M. vertilcellatus lack appendages and the zygosporangial wall is ornamented with scales (or tubercules) and these are characteristics of Lentamyces parricida, a mycotrophic species (Hoffmann and Voigt, 2009). These characteristics indicate that the above four species cannot be retained in Mycocladus but must be accommodated in Lichtheimia.
Absidia idahoensis var. thermophila (Chen and Zhang, 1998) may belong in Lichtheimia because of its high optimal growth temperature.
Beauverie, J. 1900. Mycocladus verticillatus (gen. nov. sp. nov.). Ann. univ. Lyon, Sér. 2, Sci., Méd. 3:162-180.
Chen, G.-q., and R.-y. Zheng. 1998. A new thermophilic variety of Absidia idahoensis from China. Mycotaxon 69:173-179.
Ellis, J.J., and C.W. Hesseltine. 1965. The genus Absidia: globose-spored species. Mycologia 57: 222-235.
Ellis, J.J., and C.W. Hesseltine. 1966. Species of Absidia with ovoid sporangiospores. II. Sabouraudia 5: 59-77.
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.
Hoffmann K, Discher S, Voigt K. 2007. Revision of the genus Absidia (Mucorales, Zygomycetes) based on physiological, phylogenetic, and morphological characters; thermotolerant Absidia spp. form a coherent group, the Mycocladiaceae fam. nov., Mycological Research 111: 1169-1183.
Hoffmann, K., G. Walther, and K. Voigt. 2009. Mycocladus vs. Lichtheimia: a correction (Lichtheimiaceae fam. nov., Mucorales, Mucoromycotina). Mycol. Res. 113: 277-278.
Hoffman, K. and K. Voigt. 2009. Absidia parricida plays a dominant role in biotrophic fusion parasitism among mucoralean fungi (Zygomycetes): Lentamyces, a new genus for A. parricida and A. zychae. Plant Biology 10: 537-554.
Voigt, K., E. Cigelnik, and K. O’Donnell. 1999. Phylogeny and PCR identification of clinically important Zygomycetes based on nuclear ribosomal-DNA sequence data. J. Clin. Microbiol. 37:3957-3964.
Vuillemin, P. 1903. Le genre Tieghemella et la série de Absidées. Bull. Soc. Mycol. France 19:119-127.
Updated May 31, 2010