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Home • Mortierella minutissima AD051 v1.0
Figure 1 Mycelium of Mortierella minutissima AD051 growing on malt extract agar (MEA). Image by Abigail Bryson and Alessandro DesirĂ².
Figure 1 Mycelium of Mortierella minutissima AD051 growing on malt extract agar (MEA). Image by Abigail Bryson and Alessandro Desirò.

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 (Desirò et al. 2018; 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). Of particular interest, Mortierella species can harbor endobacteria within their cells, which affect the fungal host's growth and physiology.

Mortierella minutissima AD051 was isolated from a spruce rhizosphere soil sample collected in Laingsburg, Michigan, USA. This species grows rapidly, producing a rosette colony morphology characteristic of many Mortierella species (Figure 1). It also produces abundant aerial hyphae and sporangiola that contain a few spores. A novel endobacterium closely related to Mycoavidus cysteinexigens (Ohshima et al. 2016) was identified within the mycelium of M. minutissima AD051.

References:

Desirò A, Hao Z, Liber JA, Benucci GM, Lowry D, Roberson R, Bonito G. 2018. Mycoplasma-related endobacteria within Mortierellomycotina fungi: diversity, distribution and functional insights into their lifestyle. The ISME journal. DOI: 10.1038/s41396-018-0053-9
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.

Ohshima S, Sato Y, Fujimura R, Takashima Y, Hamada M, Nishizawa T, Narisawa K, Ohta H. 2016. Mycoavidus cysteinexigens gen. nov., sp. nov., an endohyphal bacterium isolated from a soil isolate of the fungus Mortierella elongata. International journal of systematic and evolutionary microbiology 66:2052-2057.

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.