Biomedical Engineering Reference
In-Depth Information
β
- 1/
β
- O - 4 break
Lip
MnP,Lac
MnP
MnPC
break
Alkylaryl break
α
- C
β
C
α
- C
β
break
Alkylaryl break
Phenolic
α oxhydryl
Phenolic
α
oxhydryl
Loss of
alkoxy
Lip
Lip
Non-phenolic
α
oxhydryl
C
α
- C
β
break
Alkylaryl break
Laccase and
mediator
Non-phenolic
α
oxhydryl
Lip
β
- 1/
- O - 4
break
β
Fig. 8.6
Route of the lignin biodegradation process [
35
]
obtaining xylanase tolerant to heat and alkali with strong activity has become the
current research focus. Under the joint efforts of microbiologists, biochemists, and
related technologists, it is expected that a series of mature applications of economic
and effective xylanase technology will be developed.
8.3.7
Biobleaching of Lignin-Degrading Enzymes
LiP, MnP, and Lac are the major enzymes in the lignin biodegradation process. The
LiP and MnP can degrade phenolic and nonphenolic lignin, and Lac, because of
its low redox potential, can only oxidize phenolic lignin. However, if used with a
suitable redox mediator, Lac can oxidize the nonphenolic structural unit of lignin.
The possible route is shown in Fig.
8.6
[
35
].
8.3.7.1
Lignin Peroxidase Biobleaching
LiP is a series of isozymes containing an Fe(III)-porphyrin ring (IX) heme, of which
the most important feature is the ability to oxidize the electron-rich nonphenolic
aromatic compound.
