The invention discloses a method for modifying and
cracking lignin by a bacterial
laccase /
mediator system, which comprises the following steps: carrying out
enzyme modification treatment on ground wood
lignin macromolecules by using various laccases and a
mediator HBT (
Heterojunction Bipolar
Transistor), reacting the modified
lignin with a NiMoS / P-Al2O3 catalyst and a
methanol solution, centrifuging, adding a
tetrahydrofuran extraction catalyst, and carrying out
solid-liquid separation, thereby obtaining the bacterial
laccase /
mediator system. And adding the extract into the supernatant, and carrying out reduced pressure
distillation and
vacuum drying to obtain the lignin oil. And finally, dissolving with
dichloromethane, adding an
internal standard, and carrying out quantitative analysis through GC-MS (
Gas Chromatography-
Mass Spectrometer). The contact property of the ground wood lignin and the
enzyme catalyst is improved, so that the
enzyme catalytic reaction efficiency is improved; and carrying out catalytic
cracking on lignin with a NiMoS / P-Al2O3 catalyst to obtain lignin oil. The bacterial type multifunctional alkali-resistant
laccase and hydrodepolymerization combined technology is used for catalyzing lignin
depolymerization to prepare monophenol substances, and the yield of lignin
depolymerization is greatly improved.