Supplementation of Methionine Enhanced the Ergothioneine Accumulation in the Ganoderma neo-japonicum Mycelia

Abstract

The methods for increasing the production of ergothioneine (ERG) were investigated by using the mycelial culture of several mushroom species, primarily Ganoderma neo-japonicum. We first found that ERG was accumulated at the different levels in mycelia and fruiting bodies, respectively, depending on the mushroom species. As a result of adding various amino acids to the mycelial culture medium, methionine (Met) was shown to be the most effective additive. The most preferable condition of the additive was the combination of 4 mM Met and 1 g/l of yeast extract, and the maximum ERG production reached approximately 1.7 mg/l, which corresponds to 2.4 times (0.7 mg/l) that in the basal medium without Met. Although the supplementation of Met enhanced the ERG production, the mycelial growth was significantly inhibited. Furthermore, the analysis of amino acids in the culture medium revealed that the Met additive reduced the consumption rates of most amino acids tested, probably due to the decrease in mycelial growth. Taking these results into consideration, we suggest that the addition of Met to the mycelial culture medium is an efficient way to enhance the ERG production in economically important mushroom species.

Ergothioneine Contents in Fruiting Bodies and Their Enhancement in Mycelial Cultures by the Addition of Methionine

“…Previously, we have shown that the supplementation of Met in culture media increased the ERG production in the Ganoderma neo-japonicum mycelia (Lee et al, In press). It has long been known that ERG is synthesized from the amino acids, such as histidine (His), Met, and Cysteine (Cys) (Askari and Melville, 1962).…”

“…It has long been known that ERG is synthesized from the amino acids, such as histidine (His), Met, and Cysteine (Cys) (Askari and Melville, 1962). Cys and Met increased the ERG levels up to 1.7- and 3.1-fold, respectively, although His did not (Lee et al, In press). In order to know if the Met supplementation also increases the ERG levels in other mushroom species, two mmol of Met was added to the mycelial culture medium.…”

Enhanced seed production and metabolic alterations in Larix leptolepis by girdling

“…All needle samples were prepared in a 5% PCA solution for further analysis. The amino acid content was analyzed as previously described (Lee et al, 2009) using a HPLC system (Thermo Electron Co, Finnigan Surveyor System, MA, USA) equipped with a Waters Pico-Tag column (3.9 mm × 150 mm, 5 m; Waters, MA, USA) and UV detector. The same HPLC was used for all other measurements described below.…”

Effect of mycelial morphology on ergothioneine production during liquid fermentation of Lentinula edodes

“…Several studies involving the manipulation of culture media constituents have been conducted to improve the accumulation of ESH in fruiting bodies and mycelia (Dubost et al 2007;Estrada et al 2009;Lee et al 2009). However, the relationship between the morphology of mycelia and ESH production, which might assist in designing the physicochemical parameters of a liquid fermentation system to facilitate the enriched production of ESH, has not yet been elucidated.…”