Growth and Survival of Colored Fungi in Space (CFS-A) - 07.29.14
ISS Science for Everyone
Science Objectives for Everyone
Growth and Survival of Coloured Fungi in Space-A (CFS-A) determines the effect of microgravity and cosmic radiation on the growth and survival of coloured fungi species.
Science Results for Everyone
This experiment showed that fungi can grow inside the space station and could decompose food and other organic materials in humid conditions. After exposure to air growth stopped, fungal hairs (filaments) developed within the food source and decomposed it by producing digesting enzymes. Submerged filaments don’t make spores, but fungi could still spread through direct contact. Dry spores remained living after 5 months in microgravity, with some fungi living longer than others. The data show that spores would grow well on salted food in space, and some species grow on iron surfaces covered with small quantities of carbohydrates.
Sponsoring Space Agency
European Space Agency (ESA)
ISS Expedition Duration
September 2010 - September 2011
Previous ISS Missions
- Objective is to determine the effect of microgravity and cosmic radiation on the growth and survival of coloured fungi species. The proposal "Growth and survival of coloured fungi in space" is based on experiments both on the Earth and in Space inside of microcapsules made by experts from Romanian Institute of Space Science. The fungal species choose for experiments belong to 6 genera selected as organic material decomposers, possible contaminants of materials destinated for interplanetary travel, aggressive biodeteriogens of artworks and wooden buildings . Those, containing melanin are protected against UV rays.
Growth of Ulocladium chartarum colonies takes place in real microgravity conditions with different rates that are correlated with the age of the colonies. Different growth rates were observed for the aerial and for the submerged mycelium. Growth of aerial mycelium has a high rate in flight and ground controls up to Flight Day 5, then becomes lower and stops between Flight Day 8-9. Sporulation takes place in flight and ground but it is less abundant compared to ground and laboratory control.Integration of the microcapsules in the biocontainers shows a negative effect on the growth and on the sporulation in comparison with the laboratory control; new ground experiments will be made to acquire more information.Microgravity reduces the rate of growth of aerial mycelium and stimulates the growth of submerged mycelium. The CFS-A experiment demonstrates that fungi as biodeteriogens and biodegraders are able to grow in microgravity, such as inside the ISS where substrates are humid. In gravity the growth of fungi can be identified from the size of the macroscopical colonies. However, in microgravity the development of exclusively submerged mycelium, after aerial growth is stopped, needs microscopic methods to be identified. Submerged mycelium is able to synthesise extra cellular enzymes which decompose the substrate where it is grown. So different astronaut food and materials (mostly those composed of organics) can be decomposed in humid conditions. Spreading of fungus in microgravity is very low because submerged mycelium is not able to make spores. This process can take place in the environment, following the growth pattern of the hyphae and branch tips (it is a way of colonization of the substrate), in cases such as when it comes to direct contact to the astronauts, by transporting contaminated item to other items which are not contaminated. Real colonies can be developed on ISS only if the submerged mycelium sense mechanical pressure. In such cases colonies can be visible by the astronauts, and therefore they will require urgent decontamination. For the dry spore samples the spores chosen for the CFS-A experiment were still viable after 5 months in microgravity. Ulocladium chartarum spores are more resistant from a viability point of view then Basipetospora halophila and Cladosporium herbarum spores but less then Aspergillus niger spores. Aspergillus niger spores were more than 91% viable on all types of wafers. Ulocladium chartarum CM-1 spores have a good viability (87-92%) after 5 months as dried samples in weightlessness. Basipetospora halophila spores have a lower viability on ISS then on ground, which could suggest that white spores are more sensitive to ISS environment than black spores. Basipetospora halophila spores also showed a lower viability on the silica wafers then on plastic wafers and no viability on iron wafers probably due to a strong oxidation of iron wafer in contact with salts removed from the nutrient. If by chance food preserved in salt that is contaminated with this species, is brought to space, a degradation process could start. Salted food is good nutrient for fungal spores in space. Viability of Cladosporium herbarum spores is lower on the silica wafers then on plastic wafers. Again iron wafers did not sustain viability of the spores. The main reason is most probably the toxic effect of iron ions. High viability of Aspergillus niger and Ulocladium chartarum spores on iron wafers showed that these species could grow on iron surfaces covered with small quantities of carbohydrates on ISS. These results will feed into the wafers chosen for a follow-up experiments.
Gomoiu I, Chatzitheodoridis E, Vadrucci S, Walther I. The effect of spaceflight on growth of Ulocladium chartarum colonies on the International Space Station. PLOS ONE. 2013 April 24; 8(4): e62130.
Ground Based Results Publications
Colored fungi. Image provided courtesy of ESA.
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NASA Image: ISS010E11563 - An example of contamination that has developed on one of the interior panels aboard ISS. Crews have weekly sessions to clean ISS surfaces.
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