Publish in OALib Journal
APC: Only $99
Selenium (Se) is an essential element to human. However, this element
can be in low content in soil of some regions. Se deficiency may cause Keshan disease,
thyroid dysfunction and osteoarthritis. The Se-enriched cereals are an interesting
way to prevent these diseases. But, recent studies have shown that Se-enriched
mushrooms are a better Se source. This occurs due to the high capacity of the fungi
to absorb and transform the inorganic Se to organic forms, which are more bioavailable. Pleurotus ostreatus and Pleurotus eryngii are mushrooms species worldwide consumed
and able to Se bioaccumulate. However, depending on the level of this
element, it can be toxic for the fungus. Here we showed that the presence of the
Se in culture medium decreases fungal growth rate, hyphae diameter and septum
distance and causes alteration in color of colony. A garlic strong smell was directly
proportional to Se level. P. eryngii was more tolerant to Se than P. ostreatus.
So, it is important to screen this element level for Se-enriched mushroom production.
The production of mushrooms
enriched with essential elements, e.g. selenium, for human health is an
interesting strategy to improve the functional foods supply. The selenium is an essential mineral and
makes part of structure of enzymes involved in the oxidative metabolism.
However, the selenium effect on the activity of respiratory and lignocellulolytic enzymes has not been considered. The understanding of this effect is important to determine the selenium concentration
that increases the mushroom productivity and the degradation rate of the
substrate. In this study, it was observed reduction of the respiratory activity
of Lentinula edodes (Berk.)
Pegler, the shiitake mushroom, in
function of the increasing of the sodium selenite concentration in the
substrate (p < 0.05). Selenium did not inhibit the activity of the hydrolytic
enzymes (cellulase and xylanase), but it increased the activity of the oxidative enzyme (laccase). Respiratory activity of L.
edodes has a negative correlation with sodium selenite concentration added
in substrate. Thus is important to define the ideal dose of
selenium to be added to the substrate for
increasing lignocellulosic residues degradation and, consequently, guarantee a higher production of