Effect of mycelial morphology on ergothioneine production during liquid fermentation of <i>Lentinula edodes</i>

Abstract

The morphological type of a microorganism generally influences its metabolite production. In the present study, we investigated the effects of the mycelial morphology of shiitake (Lentinula edodes) on the production of 2-mercaptohistidine trimethylbetaine (ergothioneine, ESH) during liquid fermentation. Analyses of the distribution of ESH in mycelial cells of different morphological types revealed that the ESH content of pellets obtained from the liquid fermentation media was much greater than the content in the free mycelia and clumps. The concentration of ESH in pellets on day 15 of liquid fermentation reached 0.79 mg/g dry weight (DW), which is approximately three times the concentration found in mycelia clumps (0.28 mg/g DW) and free mycelia (0.31 mg/g DW). Macroscopic image analysis of the development and morphological changes of the pellets during a liquid fermentation period of up to 25 days indicated that pellet growth showed a highly positive correlation with the increase in ESH concentration (r 2 = 0.9851). A reduced agitation rate of 50 rpm for the culture medium was suitable for pellet formation and size enlargement. The results obtained in this work would be helpful in guiding the intentional manipulation of the distribution and enrichment of ESH in L. edodes through changes in liquid fermentation conditions.

Antioxidant Compounds from Edible Mushrooms as Potential Candidates for Treating Age-Related Neurodegenerative Diseases

“…Liu et al [132] demonstrated that approximately 25% of the total antioxidant capacity present in culinary medicinal mushroom extracts was attributable to ERG. The ergothioneine concentration in different species of mushrooms has been found to be significantly different and to vary with physiological or environmental conditions [133][134][135]. Among the most popular mushrooms, those with the highest amounts of ERG include Pleurotus spp., [130,136,137], Lentinula edodes, Boletus edulis [134], and Agaricus bisporus [133].…”