Features of development of microscopic fungi in conditions of ultra-weak magnetic fields

Abstract. The paper presents the results of a study of the effect of ultra-weak magnetic fields (MF) on the viability, growth characteristics, respiratory activity, and antagonistic properties of microscopic fungi. The experiments were conducted on strains isolated from the interior of the International Space Station. To create hypomagnetic conditions (HMC), the hypomagnetic chambers GMK-1 and GMK-2, shielding the Earth’s MF, were used in the experiments. The chamber walls are a two-section magnetic screen made of amorphous permalloy tape. In the experiments, the GMK chambers made it possible to reduce the geomagnetic field by 1000–2000 times. The maximum value of the MF after demagnetization did not exceed 45 nT. It was found that the hypomagnetic field (HMC) did not have a predominantly inhibitory and/or stimulating effect on the viability of spores and the growth of fungal colonies, as indicated by the absence of reliable changes in the quantitative level, percentage of spore germination and radial growth rate of the tested strains in the HMC compared to geomagnetic conditions. At the same time, the growth and respiration rate of micromycetes in some cases was significantly stimulated in the GMF during their development on the surface of samples of structural materials under conditions of limited availability of nutrients. It was also found that the GMF affects the antagonistic properties of some microscopic fungi. The Penicillium rugulosum 633.12 strain grown in the GMF completely lost its antagonistic activity towards bacteria, which was found to be high when cultivated under standard geomagnetic conditions. The results obtained are discussed in the context of the features of microbial colonization of the habitat of future lunar complexes.