Influence of Selenium Biofortification on the Growth and Bioactive Metabolites of Ganoderma lucidum

Selenium biofortification of edible and medicinal mushrooms is an effective way to produce selenium-enriched food supplements. Ganoderma lucidum is the typical one with excellent biological activity. This study investigated G. lucidum growth and bioactive metabolites alterations during liquid culture with different concentrations of selenite. Low selenium levels did not affect growth and mycelia morphology, whereas high selenium levels negatively influenced growth, dramatically decreased biomass, caused nucleic acid and protein leakage, damaged cell walls and membranes, and resulted in indicators such as degraded cells, a red color, and an unpleasant odor. Through headspace-solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) analysis, ten volatile Se compounds were identified in G. lucidum with 200 ppm selenite, which led to an odor change, whereas only three with 50 ppm selenite. SeMet was the major selenoamino acid in the 50 ppm selenite group by high-performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP-MS), but more MeSeCys was produced with 200 ppm selenite. Polysaccharide yields were promoted and inhibited with 50 and 200 ppm selenite, respectively. These results provide comprehensive insights into the effects of selenite on G. lucidum in liquid culture and are beneficial for functional selenium-enriched mushroom production and improving nutritive values.