Biochemical contributions to the taxonomic status of the Endogonaceae

Abstract

The Endogonaceae are generally considered as zygomycete representatives, although zygospores have only been observed in the type genus Endogone. Consequently, the oomycetous or chytridiomycetous nature of some fungi classified in the Endogonaceae cannot be excluded. The presence or absence of chitin in cell walls can indicate the oomycetous or zygomycetous relationship. The occurrence of glucosamine was investigated by gas–liquid chromatographic analysis of intact cell hydrolyzates, a process requiring small quantities of material. The cells were also characterized by Curie-point pyrolysis mass spectrometry. These two techniques were applied to lyophilized spores or sporocarps of Endogone, Glomus, Glaziella, and Gigaspora. Mucor mucedo, Allomyces arbuscula, Pythium spinosum, and Saprolegnia ferax were included for comparison.In all endogonaceous isolates tested, a strong predominance of chitin was indicated, supporting their classification within the Zygomycetes.The phylogenetic significance of chitin and cellulose distribution in fungal cell walls is discussed.