Agro-wastes bioconvertion by an Amazonian isolate of Ganoderma sp. and a commercial strain of Ganoderma lingzhi

Abstract

Agro-industrial wastes discarded in nature may cause environmental damage; however, they have potential for application in mushroom cultivation, making it possible to bioconvert these wastes into materials of higher added value with the possibility of application in different industrial segments. The aim of this work was to compare the biotransformation potential of Amazon lignocellulosic wastes by Ganoderma sp. (isolated in the Amazon) and G. lingzhi (a commercial strain). The mushrooms were grown in açaí (Euterpe sp.), guaruba-cedro (Vochysia maxima), and three different batches of marupá (Simarouba amara) wastes. Initial substrates (IS) and spent mushroom substrates (SMS) were subjected to physico-chemical analysis, scanning electron microscopy (SEM), X-ray diffraction (XRD), and crystallinity index (CrI). A trend to decrease moisture, ash, lipids, carbon, and cellulose levels was observed in SMS. It is highlighted that after the growth of G. lingzhi and Ganoderma sp., there was a reduction in lignin by 29% and 48%, respectively, while there was an average increase in nitrogen content of 44% and 142% in SMS, respectively. SEM analysis showed visible loosening of lignocellulose fibers; XRD showed a characteristic peak of amorphous cellulose; and the CrI highlighted the coexistence of ordered and disordered regions. Thus, the mushrooms have shown potential in the bioconversion of Amazon wastes, notably for Ganoderma sp., which has demonstrated high potential for delignification and fortification of waste playing potential for application in the cellulose and animal feed industries.