Abstract
The species Trametes versicolor refers to medicinal mushroom well known in traditional Asian medicine for over 2000 years. Due to the long time required for basidiocarp formation, attention has recently been given to the submerged cultivation method for the production of mycelial biomass and various bioactive components. Exopolysaccharides (EPS) produced by Trametes versicolor are essential components possessing numerous functionalities and exhibiting potential medicinal applications. The subject of this investigation is higher fungus Trametes versicolor isolated from Bulgaria. Four well-defined culture media were studied to select the medium that maximizes production of EPS in submerged cultivation. The M3 was shown to provide the highest yields of EPS and was further investigated to optimize EPS production conditions.
The initial glucose concentration was found to be the most important factor in both EPS production and cell growth. The maximum biopolymer quantity of 1.067 g/L was obtained at 40 g/L glucose. For examination and evaluation of the correlation between the carbon source and the complex influence of the nitrogen sources over the mycelial growth and the EPS synthesis and the optimization of the media orthogonal central composition design 23 with star arm ±α=1.454671 was applied. The experimental design was based on 21 combinations. Dynamic cultivation was carried out after the optimization of the media for determination of the effect of the duration of the cultivation process over the Trametes versicolor growth and EPS gain. Maximum EPS yield was observed after 216 hours.
Keywords: exopolysaccharide, optimization, medicinal fungus, Trametes versicolor.