Laboratory-Scale Submerged Liquid Fermentation of Morchella sp. MC1 Isolate: Green Extraction and Environmental Assessment of Mycelial Extract
Vanja Grahovac, Ilija Djekic, Maja Kozarski, Shin-Yee Chong, Wan Abd Al Qadr Imad Wan-Mohtar, Fabiola Bastian, Isabelle Adt, Nadia Oulahal, Anita KlausIn this study, mycelial biomass production from an isolate obtained from a naturally collected fruiting body morphologically assigned to the genus Morchella was investigated using laboratory-scale submerged liquid fermentation, together with the extraction and characterization of its constituent groups using environmentally friendly extraction methods. Molecular identification was performed by sequencing the internal transcribed spacer (ITS) region of DNA extracted from the mycelial hyphae. Growth conditions were optimized using an experimental design to evaluate the effects of temperature, pH, and agitation speed on biomass yield. Temperature and agitation speed significantly influenced mycelial production; the response surface model predicted maximum biomass production at 15 °C and 118.8 rpm, whereas pH did not exert a statistically significant effect within the investigated range, and the highest experimentally observed biomass yield was obtained at 15 °C, pH 7.5, and 100 rpm. Dried mycelium was extracted using ultrasound-assisted extraction with water, 50% ethanol, and 96% ethanol as green solvents. The obtained extracts were characterized in terms of total carbohydrates, proteins, and phenolic compounds, while antioxidant activity was assessed using the ABTS radical cation (ABTS●+) and DPPH radical (DPPH●) scavenging assays. Water extraction resulted in the highest carbohydrate and total phenolic contents, which corresponded to the highest potential of ABTS●+ scavenging (EC50 = 1.84 mg/mL) and the highest potential of DPPH● scavenging (EC50 = 0.39 mg/mL). In contrast, ethanolic extraction produced a lower overall mass yield but showed a distinct extraction profile for the measured compound class. Although the mixed solvent system provided the highest extraction yield, solvent selection influenced both the chemical composition and radical scavenging capacity of the extracts. Considering extraction selectivity and green chemistry principles, ethanol may represent a more suitable solvent option for obtaining extracts with the measured constituent profiles. These findings support further investigation of the Morchella sp. MC1 isolate mycelium produced under controlled submerged conditions as a promising and sustainable source of functional biomolecules with potential applications in food and biotechnology.