title: Comparative analysis of lignin peroxidase and manganese peroxidase activity on coniferous and deciduous wood using ToF-SIMS.
abstract: White-rot fungi are distinguished by their ability to efficiently degrade lignin via lignin-modifying type II peroxidases, including manganese peroxidase (MnP) and lignin peroxidase (LiP). In the present study, time-of flight secondary ion mass spectrometry (ToF-SIMS) was used to evaluate lignin modification in three coniferous and three deciduous wood preparations following treatment with commercial preparations of LiP and MnP from two different white-rot fungi. Percent modification of lignin was calculated as a loss of intact methoxylated lignin over nonfunctionalized aromatic rings, which is consistent with oxidative cleavage of methoxy moieties within the lignin structure. Exposure to MnP resulted in greater modification of lignin in coniferous compared to deciduous wood (28 vs. 18 % modification of lignin); and greater modification of G-lignin compared to S-lignin within the deciduous wood samples (21 vs. 12 %). In contrast, exposure to LiP resulted in similar percent modification of lignin in all wood samples (21 vs 22 %), and of G- and S-lignin within the deciduous wood (22 vs. 23 %). These findings suggest that the selected MnP and LiP may particularly benefit delignification of coniferous and deciduous wood, respectively. Moreover, the current analysis further demonstrates the utility of ToF-SIMS for characterizing enzymatic modification of lignin in wood fibre along with potential advantages over UV and HPCL-MS detection of solubilized delignification products.
authors.affiliation: Department of Chemical Engineering & Applied Chemistry, University of Toronto, 200 College Street, Toronto, ON, M5S 3E5, Canada.|London Research and Development Centre, Agriculture and Agri-Food Canada, 1391 Sandford Street, London, ON, N5V 4T3, Canada.
authors.forename: Jacqueline
authors.initials: J
authors.lastname: MacDonald
authors.affiliation: Department of Chemical Engineering & Applied Chemistry, University of Toronto, 200 College Street, Toronto, ON, M5S 3E5, Canada.|Department of Biochemistry, Chemistry and Physics, Niagara University, Niagara, NY, USA.
authors.forename: Robyn E
authors.initials: RE
authors.lastname: Goacher
authors.affiliation: Great Lakes Forestry Centre, 1219 Queen Street East, Sault Ste. Marie, ON, P6A 2E5, Canada.|Department of Chemical and Biochemical Engineering, Western University, Claudette Mackay-Lassonde Pavilion Room CMLP 2329, London, ON, N6A 5B9, Canada.
authors.forename: Mamdouh
authors.initials: M
authors.lastname: Abou-Zaid
authors.affiliation: Department of Chemical Engineering & Applied Chemistry, University of Toronto, 200 College Street, Toronto, ON, M5S 3E5, Canada. emma.master@utoronto.ca.
authors.forename: Emma R
authors.initials: ER
authors.lastname: Master
mesh_terms: D005658:Fungi / Q000201:enzymology; D008031:Lignin / Q000378:metabolism*; D010544:Peroxidases / Q000378:metabolism*; D018629:Spectrometry, Mass, Secondary Ion; D014934:Wood / Q000378:metabolism*
chemical_list: D008031:Lignin; D010544:Peroxidases; C042858:lignin peroxidase; C051129:manganese peroxidase
keywords: Lignin peroxidase; Manganese peroxidase; Time-of-flight secondary ion mass spectrometry; Wood fibre