The present study was designed to evaluate the scaling process used to obtain fungi and enzymes from Trichoderma koningiopsis to produce bioherbicides with low levels of genotoxicity using a stirred-tank bioreactor. We measured fungal biomass and activities of enzymes (amylase, cellulase, lipase and peroxidase). Fermentative products were applied to weeds ( Bidens pilosa and Euphorbia heterophylla ), and the bioherbicide effect was evaluated. We found greater elevations of peroxidase and lipase activity in the scaled-up models than in those at small scale (0.15 L), even with less biomass, suggesting that the scaling was cost-beneficial in terms of enzymatic yield. Bioherbicide activity tests showed up to 100–80% phytotoxic effects on weeds that were resistant to synthetic herbicide. A genotoxicity study of the fermented extract performed in Allium cepa meristem cells showed low genotoxicity and no DNA damage. Our findings point to new perspectives regarding bioherbicides derived from fungal fermentation and enzyme yield technology, aimed at sustainable and ecofriendly agriculture.

Biorefineries require residual biomass as a raw material for their processes.Among all the possible products, 2G ethanol is undoubtedly the most studied and isprobably the most desired in environmental terms. Carbohydrate-rich feedstocks usedin biorefineries are mainly composed of polysaccharides, cellulose and hemicellulose(xylan), which initially require the action of hydrolytic enzymes to release theirconstituent monosaccharides, mostly glucose (from cellulose) and xylose (fromhemicellulose). The conversion of glucose into ethanol is carried out by the yeastSaccharomyces cerevisiae with an efficiency close to the theoretical maximum yield (>90%). Although it is the most widely used yeast in alcoholic fermentation processes, S.cerevisiae cannot metabolize xylose unless it undergoes genetic or evolutionaryengineering. However, in recent decades, wild yeasts with an innate capacity to fermentthis pentose and even hydrolyze the polysaccharides from lignocellulosic biomasseshave been isolated and characterized from natural environments. Facing this duality,we conducted a major literature review and presented the data both in favor ofengineering S. cerevisiae and the prospective use of wild yeasts in this chapter. Toanalyze the strengths of each strategy, this chapter also highlights the applications ofintegrated hydrolysis and fermentation processes and the possibility of simultaneouslygenerating xylitol as the second product in biorefineries.