Estudo do meio de cultivo para estabilidade genética do fungo parasita Cordyceps militaris cultivado em Tenebrio molitor

Abstract

Cordyceps militaris is a fungus of growing commercial and medicinal interest, due to its bioactive compounds, such as cordycepin, cordycerebroside, cordymine, polysaccharides and ergosterols. However, the laboratory and industrial cultivation of this fungus presents difficulties in conservation and propagation of the strain, since it has a rapid genetic degeneration along the peaks. Therefore, this work aims to evaluate whether different forms of cultivation of C. militaris using larvae and pupae of Tenebrio molitor as substrate contribute to the generation of more resistant strains against the genetic degradation of the fungus. Among the different methodologies tested, the culture that obtained the best result was performed by making a small incision in the insect and subsequent immersion (10 seconds) in basal culture of the fungus (composed of dextrose, sodium nitrate, potassium phosphate, phosphate of sodium, magnesium sulfate and yeast extract) and incubated at 21 °C and constant humidity of 75%. After total coverage of the mycelium, the cultivation proceeded to a photoperiod of 12 h/d until the fruiting of the mushrooms. Furthermore, the evaluated strain showed potential for the development of the mushroom in the insect pupae after 59 days of inoculation, however there was no progression and prolongation of the fruiting body, which may be due to some missing essential factor in mimicking the fungus environment. Therefore, it is necessary to use new strains to consolidate this methodology that allows the conservation of the biological and productive characteristics of strains of Cordyceps militaris using Tenebrio molitor as a medium for maintenance.