The physical description from the 1977 publication “A key to the species of Mortierella” states that M. antarctica has sporangiosphores with distinctly widening bases, contain many spores per sporangia, has spores ranging from 3-10um in diameter, and has fairly numerous globose chlamydospores raining from 6-15um in diameter (Gams, 1977).
Mortierella antarctica Linnem. was discovered in Antarctic soils in the late 1960s and first described by G. Linnemann(Zycha et al., 1969). There is no common name for this fungus, as the only incidences of observance are from the soils of Antarctica , but generally, Mortierella fungi are known as molds (Furbino et al., 2014; Maggi et al., 2013; Tosi et al., 2002).
Mortierella antarctica has been isolated from the soil directly under two endemic Antarctic macroalgae: Monostroma hariotii and Pyropia endiviifolia (Furbino et al., 2014). Additionally, multiple mosses (Bryum pseudotriquetrum. Schistidium antarctici, Sarconeurum glaciale, and Syntrichia princeps) have also been associated with M. antarctica (Tosi et al., 2002). Since M. antarctica is often isolated from soil with or without the presence of macroalgae and mosses, it could be a symbiont on bryophytes as well as a saprobe in the soil. However, current knowledge of its full associations and carbon sources are limited due to the difficult working conditions of Antarctic surveys.
Fatty acids are a key component to preserve membrane stability at low temperatures. M. antarctica was found to produce large amounts of highly unsaturated fatty acids. One of these fatty acids is eicosapentaenoic acid (EPA), which is mainly found in human’s diets through consuming fish oil (Jacobs et al., 2009). EPA, besides being an essential oil, is also used in the production of industrial applications such as food enzymes and oils (Jacobs et al., 2009). A study conducted by Jacobs et al. grew various Mortierella species screening for high producers of EPA while testing brewer’s spent grain as a substrate. They were able to utilize brewer’s spent grain, which is a by-product of distilling beer, which is apparently significantly less expensive than the traditional means of extracting EPA from fish oil. One of the two strains that made the most EPA was a M. antarctica strain, implicating that if this project was commercially viable M. antarctica could be utilized commercially to be an alternative to fish oil (Jacobs et al., 2009). In 2014 Dr. Wenstrom wrote an editorial on the FDA’s guidelines involving pregnant women, fish, EPA, and mercury levels (Wenstrom, 2014). Due to these observations Mortierella’s biochemistry could be used as an EPA replacement to reduce mercury exposure found through fish oil and also reduce ecological damage caused by fishery associated activities.
Mortierella antarcticais known to create a significant amount of linoleic acid, which increases in cultivation when exposed low temperature (Onofri et al., 2003). M. antarctica was also found to produce high levels of arachidonic acid, which increased in strains cultivated at 8°C (Ding et al., 2016). Linoleic and arachidonic acid are essential acids found in a wide variety of plants, including olive oil (Beltan et al., 2004). There was a study in 1994 from The Lancet that indicated Linoleic acid was a main contributor to the cardiovascular health advantages that the Mediterranean diet provides (De Longeril et al., 1994). Thus, if M. antarctica could be cultured in a manner conducive to produce large scale Linoleic acid, then perhaps it could be made into a supplement. These observations support psychotropic fungi produce fatty acids as part of a cold response; as fatty acids help with fluidity of membrane structures (Robinson, 2001).
M. antarctica has only been isolated from Antarctic soil. This fungus can survive in soils that reach -7.6°C at a depth of 3cm (Robinson, 2015). The vast majority of the strains collected have originated from the coastline of Antarctica, including several islands (Del Frate and Caretta, 1994; Ding et al., 2016; Laichmanová et al., 2009; Tosi et al., 2002).
Unlike Mortierella aplina, Mortierella antarctica is not able to inhibit the bacterial growth of organisms Candida albicans, Escherichia coli, Mycobacterium phlei, Proteus mirabilis, or Staphylococcus aureus (Ding et al., 2016). In the same study, M. antarctica was found to have a cytotoxicity percentage of 44.3/18.6; this rating was measured by the inhibition rate of a lymphocytic leukemic cell line, P388. Ding et al. rated this particular fungus as a ‘medium’ cytotoxin producer in their study (Ding et al., 2016) due to partial inhibition. They conclude that M. antarctica does produce inhibitory compounds, but not at a commercially viable level.
Psychotropic fungi have the ability to grow at temperatures as low as 0°C and have a maximum temperature above 20°C (Robinson, 2001). M. antarctica shows no growth response when subjected to temperatures over 24°C, but has been shown to grow between 5-24°C (Tosi et al., 2002). Though not observed in the Tosi et al. study, M. antarctica is also known to grow and sporulate at temperatures as low as 0°C (Onofri et al., 2003; Zycha et al., 1969)
In 2013, Wagner et al. published a large phylogenetic study on over 400 specimens of Mortierella sp. which included three strains of M. antarctica. This study determined that M. antarctica is part of a heterogeneous cluster with two other species in the genus Mortierella: M. alpina and M. amoeboidea (Wagner et al., 2013).
