Characterization of Bioactive Compounds in Spent Mushroom Substrate: A Metabolomic Perspective on Its Untapped...

Area of Science:

• Mycology
• Biochemistry
• Natural Products Chemistry

Background:

• Ergothioneine is a natural compound with significant anti-aging properties, making it highly desirable.
• Mushroom cultivation substrates are potential sources for valuable natural products.
• Oyster mushrooms (pink and pearl) are widely cultivated, generating substantial spent substrate.

Purpose of the Study:

• To quantify ergothioneine levels in spent pink and pearl oyster mushroom substrates.
• To investigate the changes in low-molecular-weight compounds after mushroom cultivation.
• To identify other potentially valuable compounds in spent mushroom substrates.

Main Methods:

• Analysis of ergothioneine content in unused and spent mushroom substrates.
• Untargeted metabolomic profiling of spent substrates.
• Comparison of compound profiles between unused and spent substrates.

Main Results:

• Ergothioneine levels in spent substrates were low, ranging from 1.66 to 10.38 μg·g^-1, with no significant increase compared to unused substrate.
• Metabolomic analysis showed a reduction in polyphenols and other low-molecular-weight compounds in spent substrates.
• Spent substrates were found to be enriched in cerebroside B and ganoderenic acid D.

Conclusions:

• Spent oyster mushroom substrates are not a rich source of ergothioneine.
• Mushroom cultivation significantly alters the metabolomic profile of the substrate.
• Spent mushroom substrates may be a valuable source of compounds like cerebroside B and ganoderenic acid D, requiring further validation.