Screening of enzyme-producing mushroom species able to grow on beach wracks from Mar Menor lagoon for their valorization

Large amounts of algal beach wracks are accumulating on the shores of the Mar Menor lagoon due to its ecological imbalance. This biomass is collected and discarded in landfills without any added value. In an attempt to valorize this material, semi-solid media including dried algal wracks with or without prior dialysis, wheat straw and mycological malt extract agar (as control) were prepared to cultivate edible mushroom mycelia. The fungal enzymatic activities were analyzed to assess their potential to produce valuable enzymes for biotechnological applications, such as the food industry. The results indicated that Agaricus bisporus , Pleurotus ostreatus , Pleurotus ferulae , Flammulina velutipes , Hypsizygus tessulatus , Pholiota nameko , and Lentinula edodes could grow on both dialyzed and non-dialyzed algal wracks, while Ganoderma lucidum showed poor growth. Notably, most species produced more biomass on the algal wracks than on wheat straw, a standard substrate for mushroom cultivation. Non-dialyzed algal wracks stimulated the production (intramycelial) and secretion (extramycelial) of xylanases, particularly in L. edodes , F. velutipes , and H. tessulatus . When grown on dialyzed wracks, cellulase activity was mainly enhanced in P. ferulae , F. velutipes , and A. bisporus , and proteolytic activity was highest in F. velutipes and H. tessulatus . In contrast, the wracks were not suitable for inducing α-amylase activity. The production of laccases and peroxidases was more species-dependent than influenced by the tested substrate.