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Home • Mortierella sp. AD185 v1.0
Figure 1. The isolate AD185 produces pure white mycelium, which is primarily aerial and rarely embedded in agar media. The fungus may actively dehydrate the media. In later growth stages the culture may form concentric rings. Image courtesy of Julian Liber.
Figure 1. The isolate AD185 produces pure white mycelium, which is primarily aerial and rarely embedded in agar media. The fungus may actively dehydrate the media. In later growth stages the culture may form concentric rings. Image courtesy of Julian Liber.
Figure 2. AD185 and related lineages of Mortierellaceae produce terminal dendritic structures on axillary branches of hyphae. The structures mature into branched, spherical chlamydospores. Image courtesy of Julian Liber.
Figure 2. AD185 and related lineages of Mortierellaceae produce terminal dendritic structures on axillary branches of hyphae. The structures mature into branched, spherical chlamydospores. Image courtesy of Julian Liber.

Within the framework of the ‘Comparative genomics of early diverging terrestrial fungi and their bacterial endosymbionts’ CSP1450 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 anastomoses. Mortierella are generally considered to be haploid and heterothallic, although some species are known 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 (Uehling et al. 2017).

Mortierella sp. AD185 was isolated in 2017 from soil collected in Kenya. It displays fast growth, without rosettes or sectoring, and mycelium appears pure white. As the colony grows, the center clears and the margin remains as primarily aerial hyphae (Fig 1). Young mycelium is coenocytic (Fig 2). Spores are uncommon in this taxon. The most common form of reproduction in AD185 is by production of terminal, branched chlamydospores, which become darkened as they mature. Mortierella sp. AD185 belongs to a novel lineage in the Mortierellaceae. This isolate contains an endosymbiotic bacterium that are classified as Mollicutes-related endobacteria (MRE) (Desirò et al. 2017). 

References:

Desirò, Alessandro, Zhen Hao, Julian A. Liber, Gian Maria Niccolò Benucci, David Lowry, Robert Roberson, and Gregory Bonito. 2018. “Mycoplasma-Related Endobacteria within Mortierellomycotina Fungi: Diversity, Distribution and Functional Insights into Their Lifestyle.” The ISME Journal 12 (7): 1743–57.

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.

Kuhlman, E. G. 1972. “Variation in Zygospore Formation among Species of Mortierella.” Mycologia 64 (2): 325 – &.

Uehling, J., A. Gryganskyi, K. Hameed, T. Tschaplinski, P. K. Misztal, S. Wu, Desirò A, et al. 2017. “Comparative Genomics of Mortierella elongata and Its Bacterial Endosymbiont Mycoavidus cysteinexigens.” Environmental Microbiology.