Lithium chloride affects mycelial growth of white rot fungi: Fungal screening for Li-enrichment

The enrichment of edible mushrooms with lithium (Li) may be a strategy to provide forms of lithium that are more soluble and bioavailable for humans. Therefore, it is important to determine which species of fungi are able to grow in the presence of Li, and which concentrations of Li allow fungal growth. Twelve white rot fungi strains were grown in potato dextrose agar media, supplemented with 0 to 1.65 g L-1 lithium chloride (LiCl). The fungal growth rate, morphological alterations of the colonies, changes in the length of the lag phase, fungal dry mass, changes in hyphae diameter and cell length were evaluated. Most fungi had decrease in their growth rates and dry mass, and had macroscopic/microscopic morphological alterations at increasing LiCl concentration. Generally, the fungi were sensitive to LiCl. However, Pholiota nameko was moderately tolerant to LiCl and Pleurotus ostreatusroseus tolerate the highest LiCl level tested, suggesting that it is the most appropriate fungus for Li-enrichment.   Key words: Fungal enrichment, mycelial morphology, screening.