Effects of phytohormones on mycelial growth and exopolysaccharide biosynthesis of medicinal mushroom Phellinus [corrected] linteus.

Effects of phytohormones including indole-3-acetic acid (IAA), indole-3-butyric acid (IBA) and 1-naphthaleneacetic [corrected] acid (NAA) on mycelial growth of medicinal mushroom Phellinus linteus were investigated. Under the optimal IAA, IBA and NAA concentration of 1.0, 1.5 and 5.0 mg/l, the maximal mycelial diameter reached 8.6 +/- 0.4, 7.3 +/- 2.6 and 9.0 +/- 1.0 mm, respectively. The mycelial biomass and exopolysaccharide (EPS) production with addition of 5.0 mg/l NAA in a shake flask were 6.24 +/- 0.18 g/l at 168 h and 0.86 +/-0.01 g/l at 192 h, which were enhanced by 15.98 and 56.36% compared to the control, respectively. However, the molecular weight and infrared spectrum of EPS were coincident with the control. Results indicated that NAA at the proper concentration was beneficial in stimulating mycelial growth and EPS biosynthesis, whereas it could not alter the molecular structure of EPS.