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

The levels of ergothioneine (ERG), which have been shown to act as an excellent antioxidant, were determined in both fruiting bodies and mycelia of various mushroom species. We found that ERG accumulated at different levels in fruiting bodies of mushrooms and showed up to a 92.3-fold difference between mushrooms. We also found that ERG accumulated at higher levels in mycelia than in fruiting bodies of economically important mushroom species such as Ganoderma neo-japonicum, G. applanatum and Paecilomyces tenuipes. The addition of 2 mM methionine (Met) to mycelial culture medium increased the ERG contents in most mushroom species tested, indicating that Met is a good additive to enhance the ERG levels in a variety of mushroom species. Taking these results into consideration, we suggest that the addition of Met to the mycelial culture medium is an efficient way to enhance the antioxidant properties in economically important mushroom species.

Improvement of Ergone Production from Mycelial Culture of Polyporus umbellatus

Ergone,a fungal metabolite derived from ergosterol,was previously isolated and identified from Polyporus umbellatus. Ergone is a major component of P. umbellatus known to have anti-aldosteronic diuretic effect and also displays cytotoxic activities. Most of mushroom's fruit bodies used for test contained less than 10 microg/g of ergone. But P. umbellatus have larger amount of ergone than any other mushrooms. In order to improve the ergone production from the submerged culture of P. umbellatus, several factors including medium composition,culture conditions (temperature and pH) and different combinations of co-cultivation with various mycelia were studied. Among various carbon sources examined,starch proved to be most effective for the production of mycelia. The optimum pH and temperature for a flask culture of P. umbellatus mycelia were found to be 4.5 and 25degrees C,respectively. Under the optimized culture conditions,both the ergone production (86.9 microg/g) and mycelial growth (3.5 g/l) increased when P. umbellatus was cultured with Armillariella mellea. When the optimized conditions were applied,both mycelium and ergone production were significantly enhanced.

Anti-complementary Activities of Exo- and Endo-biopolymer Produced by Submerged Mycelial Culture of Eight Different Mushrooms

The Elfvingia applanata (EA), Hericium erinaceum (HE),Grifola frondosa (GF), Pholiota nameko (PN), Pleurotus eryngii (PE), Trametes suaveolens (TS), Fomes fomentarius (FF), and Inonotus obliquus (IO) could produce the endo- (EN) and exo-biopolymer (EX) in submerged culture. The highest anti-complementary activity of the EN was exhibited by PN (49.1%), followed by HE (38.6%), TS (37.0%),and FF (33.0%),whereas the high activity of the EX was found with GF (59.8%),followed by HE (36.3%),TS (30.8%),and IO (28.8%). The EN of P. nameko (EN-PN) and EX of G. frondosa (EX-GF) were found to contain 78.6% and 41.2% carbohydrates, while 21.4% and 58.8% protein, respectively. The sugar and amino acid compositions of EN-PN and EX-GF were also analyzed in detail.

Production of Polysaccharide by the Edible Mushroom, Grifola frondosa

The production of polysaccharide according to various developmental stages (mycelium growth, primordium appearance, and fruiting-body formation) in the edible mushroom Grifola frondosa was studied. The cap of the mature mushroom showed the highest amount of polysacchride. Mycelial growth and polysaccharide synthesis were optimal at pH 5 and 20degrees C. Polysaccharide synthesis was maximal after 12 days of cultivation, whereas maximum mycelial growth was shown after 18 days. Mannose, cellobiose and starch increased the level of polysaccharide as well as growth in submerged culture. Glucose and sucrose appeared to be good substrates for fruiting of Grifola frondosa.