title: Fungal demethylation of Kraft lignin.
abstract: Demethylation of industrial lignin has been for long coveted as a pathway to the production of an abundant natural substitute for fossil-oil derived phenol. In an attempt to possibly identify a novel Kraft lignin-demethylating enzyme, we surveyed a collection of fungi by using selected ion flow tube-mass spectrometry (SIFT-MS). This method readily identifies methanol resulting from lignin demethylation activity. Absidia cylindrospora, and unidentified Cylindrocladium sp. and Aspergillus sp. were shown to metabolize lignin via different pathways, based on the HPLC analysis of lignin fragments. Of these three, Cylindrocladium and Aspergillus were shown to retain most of the lignin intact after 3 weeks in culture, while removing about 40% of the available methoxy groups. Our results demonstrate that after optimization of culture and lignin recovery methods, biological modification of Kraft lignin may be a feasible pathway to obtaining demethylated lignin for further industrial use.
authors.affiliation: Qinghai Academy of Agriculture and Forestry Sciences, 253 Ningda Rd, Xining, Qinghai 810016, PR China. Electronic address: zly198300@163.com.
authors.forename: Linyou
authors.initials: L
authors.lastname: Zou
authors.affiliation: Northern Ontario School of Medicine, Lakehead University, Thunder Bay, Ontario, Canada P7B 5E1. Electronic address: bross@nosm.ca.
authors.forename: Brian M
authors.initials: BM
authors.lastname: Ross
authors.affiliation: Faculty of Natural Resources Management, Lakehead University, 955 Oliver Rd, Thunder Bay, Ontario, Canada P7B 5E1. Electronic address: ljhutchi@lakeheadu.ca.
authors.forename: Leonard J
authors.initials: LJ
authors.lastname: Hutchison
authors.affiliation: Biorefining Research Institute, Lakehead University, 955 Oliver Rd, Thunder Bay, Ontario, Canada P7B 5E1. Electronic address: lchristo@lakeheadu.ca.
authors.forename: Lew P
authors.initials: LP
authors.lastname: Christopher
authors.affiliation: Biorefining Research Institute, Lakehead University, 955 Oliver Rd, Thunder Bay, Ontario, Canada P7B 5E1.
authors.forename: Robert F H
authors.initials: RF
authors.lastname: Dekker
authors.affiliation: Biorefining Research Institute, Lakehead University, 955 Oliver Rd, Thunder Bay, Ontario, Canada P7B 5E1; Department of Biology, Lakehead University, 955 Oliver Rd, Thunder Bay, Ontario, Canada P7B 5E1. Electronic address: lmalek@lakeheadu.ca.
authors.forename: Lada
authors.initials: L
authors.lastname: Malek
mesh_terms: D002851:Chromatography, High Pressure Liquid; D005656:Fungal Proteins / Q000378:metabolism*; D005658:Fungi / Q000378:metabolism*; D008031:Lignin / Q000378:metabolism*; D013058:Mass Spectrometry / Q000379:methods*; D000432:Methanol / Q000032:analysis; D008745:Methylation; D009172:Mycology / Q000379:methods; D013045:Species Specificity; D014462:Ultrafiltration
chemical_list: D005656:Fungal Proteins; C076151:Kraft lignin; D008031:Lignin; D000432:Methanol
keywords: Fungal culture; HPLC; Lignin demethylation; Methanol mass spectrometry; Vicinal hydroxyl assay