Screening of selective lignin-degrading basidiomycetes and biological pretreatment for enzymatic hydrolysis of bamboo culms

Fifty-one fungal isolates were screened for their biological pretreatment of bamboo culms (Phyllostachys pubescence) by enzymatic saccharification. These fungi were isolated from the interior of decayed bamboo culms or from basidiomata on bamboo culms. The white rot basidiomycete Punctularia sp. TUFC20056 and an unidentified basidiomycete TUFC20057 showed high lignin degradation (>50%) and high lignin/holocellulose loss ratios (>6) after 12 weeks of treatment. Other Punctularia sp. strains also showed high lignin/holocellulose ratios (>4). In residual component of Punctularia sp. TUFC20056-treated bamboo, glucose and total sugar were increased (42.9 ± 10.9 and 60.3 ± 16.1%, respectively). Pretreatment of bamboo culms with Punctularia sp. TUFC20056 improved the effect of enzymatic hydrolysis. Total reducing sugar yields reached 10.1 ± 1.2% with 1 month of treatment, and higher than that of two famous white rot fungi. Punctularia sp. TUFC20056 may be suitable for the biological pretreatment of bamboo for bioethanol production.

► Punctularia sp. TUFC20056 that preferentially remove lignin from bamboo was obtained.
► 53.3% of lignin was removed from bamboo by Punctularia sp. TUFC20056.
► Pretreatment of bamboo with the fungus improved total sugar yield to 10.1%.
► We propose Punctularia sp. TUFC20056 is suitable for fermentation of bamboo.