Boosting triterpene production in cell suspension culrures of Betula pendula Roth: the role of endophytic and basidiomycete fungi isolated from birch trees.

This research aims to improve the synthesis of triterpenoids in cell suspension cultures of Betula pendula Roth stem cells using biological elicitors, including basidiomycete fungi (Arthrinium arundinis, Hyphodontia paradoxa, and Stereum hirsutum) and endophytes (Fusarium fuckelii, Alternaria alternata, and Penicillium citrinum). Five of the mentioned fungi were isolated from the bark, while A. arundinis was isolated from lichen of birch trees. Their extracellular extracts were used as elicitors. In most cases, these factors were significantly higher than the control. The growth index of Birch stem cells under the influence of different elicitors mostly yielded positive results. The highest percentage of cell viability was observed after a 24-hour treatment with 300 mg/L of F. fuckelii extract. Elicitation for 24 h with P. citrinum at concentrations of 150 and 450 mg/L, respectively, caused the greatest increase in betulin (8.8 times) and its terpenoid derivatives (2 times) compared to the control. A 36-hour elicitation with H. paradoxa at 450 mg/L resulted in a fourfold increase in betulinic acid compared to the control. The highest function of betulin and betulinic acid was achieved with A. alternata at concentrations of 300 mg/L and 150 mg/L respectively, within 36 h of exposure time. The highest function of terpenoid derivatives was achieved after 12 h of elicitation with 450 mg/L P. citrinum (5 times). This report presents, the positive effect of fungal elicitors extracted from birch trees on induced betulin, betulinic acid, and their triterpenoid derivatives production in cell suspension cultures of Betula pendula, for the first time.