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Start Over Author "Christina Lyra" Journal microbial biotechnology
2 results on '"Christina Lyra"'

1. Depolymerization of biorefinery lignin by improved laccases of the white‐rot fungus Obba rivulosa

Author

Janne Wallenius, Jussi Kontro, Christina Lyra, Jaana Kuuskeri, Xing Wan, Mika A. Kähkönen, Irshad Baig, Paul C. J. Kamer, Jussi Sipilä, Miia R. Mäkelä, Paula Nousiainen, and Kristiina Hildén

Subjects
Biotechnology, TP248.13-248.65
Abstract

Summary Fungal laccases are attracting enzymes for sustainable valorization of biorefinery lignins. To improve the lignin oxidation capacity of two previously characterized laccase isoenzymes from the white‐rot fungus Obba rivulosa, we mutated their substrate‐binding site at T1. As a result, the pH optimum of the recombinantly produced laccase variant rOrLcc2‐D206N shifted by three units towards neutral pH. O. rivulosa laccase variants with redox mediators oxidized both the dimeric lignin model compound and biorefinery poplar lignin. Significant structural changes, such as selective benzylic α‐oxidation, were detected by nuclear magnetic resonance analysis, although no polymerization of lignin was observed by gel permeation chromatography. This suggests that especially rOrLcc2‐D206N is a promising candidate for lignin‐related applications.

Published
2021
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2. Depolymerization of biorefinery lignin by improved laccases of the white-rot fungus Obba rivulosa

Author

Jaana Kuuskeri, Paula Nousiainen, Jussi Sipilä, Jussi Kontro, Irshad Baig, Xing Wan, Kristiina Hildén, Christina Lyra, Janne Wallenius, Paul C. J. Kamer, Miia R. Mäkelä, Mika A. Kähkönen, Department of Microbiology, Department of Chemistry, Fungal Genetics and Biotechnology, Department of Food and Nutrition, Jussi Sipilä / Principal Investigator, and Helsinki Institute of Sustainability Science (HELSUS)

Subjects
116 Chemical sciences, Bioengineering, macromolecular substances, OXIDATION, complex mixtures, 01 natural sciences, Applied Microbiology and Biotechnology, Biochemistry, Redox, Lignin, Gel permeation chromatography, 03 medical and health sciences, chemistry.chemical_compound, Organic chemistry, LIGNOCELLULOSE, 030304 developmental biology, Laccase, 0303 health sciences, biology, 010405 organic chemistry, Chemistry, Depolymerization, fungi, PEROXIDASE, technology, industry, and agriculture, Fungi, food and beverages, Biorefinery, 0104 chemical sciences, Polymerization, biology.protein, MEDIATORS, BOND-CLEAVAGE, Polyporales, Oxidation-Reduction, TP248.13-248.65, Biotechnology, Peroxidase
Abstract

Fungal laccases are attracting enzymes for sustainable valorization of biorefinery lignins. To improve the lignin oxidation capacity of two previously characterized laccase isoenzymes from the white-rot fungus Obba rivulosa, we mutated their substrate-binding site at T1. As a result, the pH optimum of the recombinantly produced laccase variant rOrLcc2-D206N shifted by three units towards neutral pH. O. rivulosa laccase variants with redox mediators oxidized both the dimeric lignin model compound and biorefinery poplar lignin. Significant structural changes, such as selective benzylic alpha-oxidation, were detected by nuclear magnetic resonance analysis, although no polymerization of lignin was observed by gel permeation chromatography. This suggests that especially rOrLcc2-D206N is a promising candidate for lignin-related applications.

Published
2021

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