Improved green manufacturing of thermo-chemical mechanical pulp by crude enzymes secreted from white-rot fungi

Improved green manufacturing of pulp and paper product by biological treatment has attracted great research interest in recent years. We investigated the properties of poplar thermo-chemical mechanical pulp (CTMP) and effluent properties after pretreatment with crude enzymes secreted from several white-rot fungi (Trametes sp. lg-9, Coriolus versicolor sdu-4 and Phanerochaete chrysosporium 25). Pretreatment with all these crude enzymes improved CTMP proterpties, and Trametes sp. lg-9 crude enzymes specifically improved CTMP beating properties, reduced energy input for the beating process. The pretreatment also facilitated bleaching of the CTMP and the charge of bleaching chemicals could be greatly reduced. On the other hand, C. versicolor sdu-4 crude enzymes pretreatment increased the pulp brightness when carried out before CTMP bleaching, while enzyme pretreatment after CTMP bleaching improved other physical indices of pulp. Pretreatment with crude enzymes from P. chrysosporium 25 improved pulp physical properties at a less extent, and pretreatment before bleaching decreased the CTMP brightness. Our findings demonstrated the feasibility of green manufacturing of CTMP and provided additional experimental evidence of using crude enzyme preparation from fungi to improve pulp properties and decrease effluent discharge. Therefore, they will contribute to the advance of green manufacturing pulping in the pulp and paper industry.