However, in this work, the addition of LiCl to the coffee husk did not affect the mycelial growth nor the BE of P. ostreatus mushrooms (P > 0.05, Table 1). The fact that BE was not reduced by the addition of different concentrations of LiCl may indicate (a) a resistance or tolerance of the fungus to the metal or (b) that the amount selleck screening library of LiCl added to the substrate was not sufficient to cause inhibition or any toxic effect to the fungus. Some fungal mechanisms may have contributed to this tolerance, for example, a reduction of absorption or an increase in the efflux of metals through cell wall adsorption, the precipitation
of minerals and polysaccharides or extracellular binding by intracellular sequestration of metallothionein ( Gadd, 2007). The levels of minerals and the percentage of crude protein found in the mushrooms enriched with Li were consistent with data from the literature (Gençcelep et al., 2009, Kalac, 2009, Petrovska, 2001 and Sturion and Ranzani, 2000) and, therefore, the enrichment of the substrate with LiCl did not affect the nutritional quality of the mushrooms according to the parameters observed in this work (Table 2). The high concentration of Li in mushroom without enrichment (Fig. 1) can be due to the presence of Li in substrate without addition CP-673451 of the lithium chloride (Table 2). In different vegetables concentrations of Li greater
than 200 ppm have been found (Schrauzer, 2002). Vetter (2005) observed concentrations less than those found in this work, when investigating wild mushroom growing in Hungary. This may be due to the low concentration of lithium in the soil. As shown in Fig. 1, the increase in the accumulation of Li in P. ostreatus mushrooms was directly dependent on the concentration of LiCl that was added to the coffee husk. This result shows the potential to use mushrooms enriched with
the desired concentration of Li to obtain a positive effect when administered to patients for psychiatric treatment. Although accessibility of a mineral cannot be considered acetylcholine synonymous with bioavailability, it is an important factor that affects bioavailability. In addition, for an element to be absorbed and possibly used by an organism, it must be in an accessible form in the intestinal fluid: (a) as a free ion or (b) as a complex with other nutrients (Elless et al., 2000). The chemical forms of highly accessible minerals are also considered more bioavailable. It can be seen, therefore, that minerals present in non-residual fractions (water-soluble, exchangeable, acid-soluble or reduced bound) are potentially more bioavailable than those present in the residual fraction (Rabinovich et al., 2007). The residual fraction is only solubilised chemically using a very aggressive extraction, which suggests that the mineral is not bioavailable.