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Mineralization of Synthetic Lignins in the Presence of a Phenol Oxidase Activity and Hydroxyl Radicals Produced by Petriellidium fusoideum. Petriellidium fusoideum MUCL 40751 Isolation from Soil Samples Collected in Peruvian Amazonia 14 C-MWL-Wheat Straw 37% 14 CO 2 Optimal ligninolytic conditions: C/N=12, T=28ºC, pH=4,5 Dehydropolymerised Coniferyl Alcohol (DHP)
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0 2000 4000 6000 8000 10000 dpm Days 0 20 40 60 12345678910 mU / mL Laccase Activity Mineralization of a Synthetic Lignin with thioglycolate control
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Detection of HO. radicals in fungal cultures 1)Enoki et al., (1989) Target substrate: 2-keto thiomethyl butyric acid (KTBA) Substrate produced: Ethylene 2)Babbs and Gale (1987) Target substrate: Dimethyl sulphoxide (DMSO) Substrate produced: Methyl sulphinic acid
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Ethylene Generation and Mineralization of a Synthetic Lignin in P. fusoideum Cultures 0 5 10 15 20 25 012345678910 Days ppm 0 2000 4000 6000 8000 10000 dpm
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Mineralization of a Synthetic Lignin in P. fusoideum Cultures Control After addition benzoate (1 mM) 0 1000 2000 3000 4000 5000 012345678910 Days dpm
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Low molecular weight substance containing cation metals. Single electron oxidation activity. Hirano (1995); Tanaka et al., (1996; 1999) ; Enoki et al., (1997) O 2 O 2. - H 2 O 2. OH LMW LMW substance containing reduced cation LMW substance containing oxidized cation Electron source
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0 50 100 150 Day 2Day 3Day 4 Abs max x 10 -3 0 50 100 150 4045505560 Kav x 10 -2 Abs x 10 -3 Area of LMW-S Detected by Gel Filtration (Sephadex G-50) in P. fusoideum Cultures
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ppm 0 2000 4000 6000 8000 10000 dpm Laccase Activity, MWL-substance and Ethylene Production Compared with the Mineralization in P. fusoideum Cultures 0 10 20 30 40 50 01234567 Days mU / mL Abs max x 10
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Summary of the results The fungus studied produced: 1)A laccase activity as only enzyme related to lignin degradation 2). OH radical detected by ethylene and methyl sulphinic acid production MW = 1000 Da 3)LMW-SNo protein content Fe 2+ 0.1%
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1 st System: KTBA (3 mM) Acetate buffer pH 4.5 Oxygen purging Ascorbic acid (1 mM) LMW-S (1 mg / mL) P. fusoideum laccase (1.62 mU / mL)
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1 st System: KTBA (3 mM) Acetate buffer pH 4.5 Oxygen purging Ascorbic acid (1 mM) LMW-S (1 mg / mL) P. fusoideum laccase (1.62 mU / mL) 0 50 100 150 200 250 ppm Scavengers: Sodium benzoate (10 mM) Thiourea (10 mM) Catalase (6 U) Nitrogen 1 st assay 2 nd assay 3 rd assay 4 th assay 5 th assay 6 th assay Scavengers: Sodium benzoate (10 mM) Thiourea (10 mM) Catalase (6 U) Nitrogen Scavengers: Sodium benzoate (10 mM) Thiourea (10 mM) Catalase (6 U) Nitrogen Scavengers: Sodium benzoate (10 mM) Thiourea (10 mM) Catalase (6 U) Nitrogen Scavengers: Sodium benzoate (10 mM) Thiourea (10 mM) Catalase (6 U) Nitrogen 1 st System: KTBA (3 mM) Acetate buffer pH 4.5 Oxygen purging Ascorbic acid (1 mM) LMW-S (1 mg / mL) P. fusoideum laccase (1.62 mU / mL) 1 st System: KTBA (3 mM) Acetate buffer pH 4.5 Oxygen purging Ascorbic acid (1 mM) LMW-S (1 mg / mL) P. fusoideum laccase (1.62 mU / mL) 1 st System: KTBA (3 mM) Acetate buffer pH 4.5 Oxygen purging Ascorbic acid (1 mM) LMW-S (1 mg / mL) P. fusoideum laccase (1.62 mU / mL) 1 st System: KTBA (3 mM) Acetate buffer pH 4.5 Oxygen purging Ascorbic acid (1 mM) LMW-S (1 mg / mL) P. fusoideum laccase (1.62 mU / mL)
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2 nd System: KTBA (3 mM) Acetate buffer pH 4.5 Oxygen purging Hydroquinone (500 LMW-S (1 mg / mL) P. fusoideum laccase (1.62 mU / mL)
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2 nd System: KTBA (3 mM) Acetate buffer pH 4.5 Oxygen purging Hydroquinone (500 LMW-S (1 mg / mL) P. fusoideum laccase (1.62 mU / mL) Super oxide dismutase Scavengers: Sodium benzoate (10 mM) Thiourea (10 mM) Catalase (6 U) Nitrogen 0 1 2 3 4 ppm 1 st assay 2 nd assay 3 rd assay4 th assay5 th assay6 th assay Super oxide dismutase Scavengers: Sodium benzoate (10 mM) Thiourea (10 mM) Catalase (6 U) Nitrogen Super oxide dismutase Scavengers: Sodium benzoate (10 mM) Thiourea (10 mM) Catalase (6 U) Nitrogen Super oxide dismutase Scavengers: Sodium benzoate (10 mM) Thiourea (10 mM) Catalase (6 U) Nitrogen Super oxide dismutase Scavengers: Sodium benzoate (10 mM) Thiourea (10 mM) Catalase (6 U) Nitrogen Super oxide dismutase Scavengers: Sodium benzoate (10 mM) Thiourea (10 mM) Catalase (6 U) Nitrogen 2 nd System: KTBA (3 mM) Acetate buffer pH 4.5 Oxygen purging Hydroquinone (500 LMW-S (1 mg / mL) P. fusoideum laccase (1.62 mU / mL) 2 nd System: KTBA (3 mM) Acetate buffer pH 4.5 Oxygen purging Hydroquinone (500 LMW-S (1 mg / mL) P. fusoideum laccase (1.62 mU / mL)
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H 2 O. OH H 2 O 2 O 2 O 2. - KTBA Ethylene H2OH2O O2O2 LMW-S Fe 3+ LMW-S Fe 2+ MYCELIUM Q.-Q.- Q 2- Laccase R Laccase Q Fe 3+ + O 2.- Fe 2+ + O 2 H 2 O 2 + Fe 2+ Fe 3+ + OH. + OH - H 2 O 2 + O 2.- O 2 + OH. + OH -
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