Salt Tolerance of Fungi and Prospects for Mycodiagnostics of Contamination in Saline Soils: A Review

The specific features of halotolerant fungi are analyzed to assess their potential for indicating chemical contamination of saline soils and to search for the promising test species for laboratory mycotesting. The listed halophile and halotolerant micromycete genera comprise the representatives suitable as indicators of pollution by heavy metals, oil products, and other toxicants on the background of increased salinity of soil substrates. The moderately halotolerant species of micromycetes are proposed as promising for biotesting of the soils with moderate salinity. Morphological, physiological, and molecular mechanisms underlying the adaptation of halophilic and halotolerant fungi to an increased salinity of habitats are analyzed. The responses of fungal communities to the combined impact of salinization and toxic substances of different natures are discussed. The methodological aspects of the application of halotolerant fungi for biotesting the degree of disturbance of saline soils are considered, including the composition of media, cultivation conditions, and test responses of fungal cultures optimal for an adequate assessment of the degree of fungal halotolerance and the ecotoxicity of soil samples.