New aspects of the biology of Mortierella alliacea

Abstract

A fungal genotype related to Mortierella alliacea was detected by environmental PCR in samples of the mite species Leptogamasus obesus and Oppiella subpectinata, as well as in the soil body. The association may be epi- or endozoic. A genotypically corresponding strain was newly isolated from mites and examined to gain deeper insight into the biology of the scarcely known fungal species. Morphological and physiological traits, as well as molecular data confirmed an affiliation to Mortierella alliacea Linnemann. However, the strain showed minor morphological differences to the original description of M. alliacea (selected here as lectotype) and to the isolate CBS 894.68 (selected here as epitype) with regard to sporocystospore and chlamydospore morphology. Therefore, an emended species description is provided. The psychrotolerant fungus is able to grow at temperatures between 0 and 25 °C. Chitin degradation was not observed, and it lacked the capability to degrade starch, cellulose, lignin, and lipids. Proteolytic activity was only exhibited at 4 °C. Co-incubated mites were not affected by the fungus, indicating that the mites predominantly serve as vectors. The fungus’ limited degradation capabilities suggest that it predominantly lives on readily accessible carbohydrates in soil.