Antarctic fungi: a bio-source alternative to produce polyunsaturated fatty acids (PUFAs)

The Antarctic ecosystems are a combination of conditions, including extremely low values of temperature and humidity. Nonetheless, some organisms, such as fungi, can adapt to these extreme conditions. The environmental temperature is one of the parameters thoroughly affecting the structure and composition of fungal membrane lipids. The psychrophilic fungi generally increase the disorder within macromolecules to maintain membrane fluidity at low temperatures. To do so, Antarctic fungi increase the proportion of unsaturated fatty acids that allow maintaining a semi-fluid state of the membranes and survive at extremely low temperatures. This ecological feature may be of interest for the characterization of phenotypical traits of the ecological adaptation of these fungi to the extreme environmental conditions of Antarctica. Moreover, this can be of inspiration to find solutions inspired by nature for alternative sources of polyunsaturated fatty acids (PUFAs) for diets of humans and animals. We characterized three fungal strains isolated from Antarctica and set up a laboratory/small-scale production of fungal biomass with a high content of beneficial PUFAs. In detail, three fungal species previously isolated from Antarctic environmental matrices were tested and identified at the genome level. We also conducted growth experiments to determine the effects of temperature and substrate on biomass and PUFA production. The results showed that these fungi have a high percentage of PUFAs compared to saturated ones; the growth at low temperatures (10°C) increases the production of linolenic acid (C18:3) while the biomass amount (yield) depends on the composition of the growth substrate; a satisfying qualitative-quantitative production is achieved using agri-food chain waste products, such as brewing and whey waste, as a growth substrate.