Factors affecting accumulation of hydrolysable tannins in cultured mycelia of Inonotus obliquus / 中草药

ABSTRACT

Objective To study the factors affecting the accumulation of hydrolysable tannins in cultured mycelia of Inonotus obliquus. Methods Taking dry weight of mycelia and hydrolysable tannin content as index, different carbon and nitrogen sources, pH levels, and metal ions were evaluated for the accumulation of hydrolysable tannins in the submerged culture of I. obliquus. Results The optimal carbon and nitrogen sources were glucose and peptone. Optimal initial pH value was 5.5. The accumulation of hydrolysable tannins was greatly enhanced in the medium with the presence of Cu2+ at 0.8 mmol/L, Co2+ and Zn2+ at 1.6 mmol/L, Mn2+ at 1 mmol/L, and NH4+ at 4 mmol/L when compared to the control. Conclusion The accumulation of hydrolysable tannins is maximized in the medium containing glucose and peptone with pH value at 5.5. Supplementation of Cu2+, Co2+, Zn2+, and Mn2+ into the medium is an effective method for further increasing the accumulation of hydrolysable tannins in cultured mycelia of I. obliquus.