Can mushroom spores survive the vacuum and radiation of space?

Question

From this source, it states that:

Living spores have been found and collected in every level of earth’s atmosphere. Mushroom spores are electron-dense and can survive in the vacuum of space. Additionally, their outer layer is actually metallic and of a purple hue, which naturally allows the spore to deflect ultraviolet light. And as if all this wasn’t unique enough, the outer shell of the spore is the hardest organic compound to exist in nature.

Has the survival ability of mushroom spores been backed up with any actual experimental results done in space?

i.e.: how long can they survive while being in vacuum and exposed to space radiation, what is the survival rate in terms of the spore being recovered and being able to grow into mushrooms again? etc.

Answer 1

Apparently STS-56 had a student experiment with spores of Agaricus bisporus. This fungus is known as the "common mushroom" or "button mushroom" when immature, and "portobello mushroom" when fully grown. (I don't think you can get more mushroom-y than that.) According to the mission press kit:

Mushroom Spore Generation (MDA-student): Using a selected strain of Agaricus bisporus (the cultivated mushroom), this experiment will attempt to determine the effect(s) of microgravity on the development of mushroom spores. The spores then will be used as a comparison and later, lead to the eventual growth of new and improved mushrooms.

It sounds like it wasn't exposed to vacuum, but it would have been exposed to radiation. I can't find any information on the results. Perhaps @OrganicMarble can help us.

Fun fact: This species of mushroom produces small amounts of hydrazine, an important rocket fuel.

Answer 2

I found an answer based on this study (2010, G. Horneck et al., "Space Microbiology") linked by a NY times article (2017, C. Ray, "Q&A: What Happens to Spores in Space?").

Outer space as a test bed for assessing limits for survival of microorganisms. The question of whether certain microorganisms can survive in the harsh environment of outer space has intrigued scientists since the beginning of spaceflight, and opportunities were provided to expose samples to space. The first tests were made in 1966, during the Gemini IX and XII missions, when samples of bacteriophage T1 and spores of Penicillium roqueforti were exposed to outer space for 16.8 h and 6.5 h, respectively. Analyses after retrieval gave surviving fractions of 3 × 10−5 (Gemini IX) and <2 × 10−6 (Gemini XII) for P. roqueforti and 2 × 10−6 (Gemini IX) and 3 × 10−5 (Gemini XII) for bacteriophage T1, demonstrating the strong killing power of the full space environment (117). However, covering the samples by a thin (0.4 mm) layer of aluminum caused a 3,000-fold higher survival of T1 and full survival of the fungal spores. This was the first indication that nonpenetrating radiation of space, probably solar UV radiation or soft X-rays, was mainly responsible for the inactivation of the test samples.

So basically, with sufficient shielding against non-penetrating radiation, fungal spores (and some bacteria for that matter) can survive the vacuum of space.