Figure1. Mycelium of Mortierella humilis PMI1414 growing on malt extract agar (a, c) and potato dextrose agar (c). Images by Alessandro Desirò.

Mortierella humilis (PMI1414)

Within the framework of the 'Comparative genomics of early diverging terrestrial fungi and their bacterial endosymbionts' CSP project, we are exploring interactions and evolutionary histories of early diverging lineages of terrestrial fungi and their endobacteria (Uehling et al. 2017). Towards this goal, we are sequencing metagenomes and metatranscriptomes of a diverse panel of fungi in Mucoromycota that host endohyphal bacteria.

Mortierella is a large genus of fungi within Mucoromycota, formally classified as zygomycetes. These fungi are industrially important given their unique fatty acid and lipid metabolism, which is of interest for biofuel production. Mortierella species are distributed globally and are frequently isolated and detected in soils and plant rhizospheres. Many species grow rapidly, in part owing to their coenocytic mycelium that has occasional septa and frequent anastomosis. Mortierella are considered to be haploid and heterothallic, although some isolates have been reported to be homothallic (Gams et al. 1972).

Mortierella humilis PMI1414 was isolated from soil at the Harvard Forest LTER site in Massachusetts, USA. This species grows rapidly, producing a rosette colony morphology characteristic of many Mortierella species (Figure 1a, 1b). It also produces abundant aerial hyphae (Figure 1c) and sporangia that contain a single spore.

References:

Gams, W., Chiu-Yuan Chien, and K. H. Domsch. 1972. Zygospore formation by the heterothallic Mortierella elongata and a related homothallic species, M. epigama sp.nov.. Transactions of the British Mycological Society 58 (1): 5-IN2.

Uehling J, Gryganskyi A, Hameed K, Tschaplinski T, Misztal PK, Wu S, Desirò A, Vande Pol N, Du Z, Zienkiewicz A, Zienkiewicz K, Morin E, Tisserant E, Splivallo R, Hainaut M, Henrissat B, Ohm R, Kuo A, Yan J, Lipzen A, Nolan M, LaButti K, Barry K, Goldstein A, Labbé J, Schadt C, Tuskan G, Grigoriev I, Martin F, Vilgalys R, Bonito G. 2017. Comparative genomics of Mortierella elongata and its bacterial endosymbiont Mycoavidus cysteinexigens. Environmental Microbiology. DOI: 10.1111/1462-2920.13669