title: A valuable peroxidase activity from the novel speciesNonomuraea gerenzanensisgrowing on alkali lignin.
abstract: Degradation of lignin constitutes a key step in processing biomass to become useful monomers but it remains challenging. Compared to fungi, bacteria are much less characterized with respect to their lignin metabolism, although it is reported that many soil bacteria, especially actinomycetes, attack and solubilize lignin. In this work, we screened 43 filamentous actinomycetes by assaying their activity on chemically different substrates including a soluble and semi-degraded lignin derivative (known as alkali lignin or Kraft lignin), and we discovered a novel and valuable peroxidase activity produced by the recently classified actinomyceteNonomuraea gerenzanensis.Compared to known fungal manganese and versatile peroxidases, the stability ofN. gerenzanensisperoxidase activity at alkaline pHs and its thermostability are significantly higher. From a kinetic point of view,N. gerenzanensisperoxidase activity shows aKmfor H2O2similar to that ofPhanerochaete chrysosporiumandBjerkanderaenzymes and a lower affinity for Mn2+, whereas it differs from the sixPleurotus ostreatusmanganese peroxidase isoenzymes described in the literature. Additionally,N. gerenzanensisperoxidase shows a remarkable dye-decolorizing activity that expands its substrate range and paves the way for an industrial use of this enzyme. These results confirm that by exploring new bacterial diversity, we may be able to discover and exploit alternative biological tools putatively involved in lignin modification and degradation.
authors.affiliation: Department of Biotechnology and Life Sciences, University of Insubria, via J.H. Dunant 3, 21100 Varese, Italy; The Protein Factory Research Center, Politecnico of Milano and University of Insubria, via Mancinelli 7, 20131 Milano, Italy.
authors.forename: Carmine
authors.initials: C
authors.lastname: Casciello
authors.affiliation: Department of Biotechnology and Life Sciences, University of Insubria, via J.H. Dunant 3, 21100 Varese, Italy; The Protein Factory Research Center, Politecnico of Milano and University of Insubria, via Mancinelli 7, 20131 Milano, Italy.
authors.forename: Fabio
authors.initials: F
authors.lastname: Tonin
authors.affiliation: Department of Biotechnology and Life Sciences, University of Insubria, via J.H. Dunant 3, 21100 Varese, Italy; The Protein Factory Research Center, Politecnico of Milano and University of Insubria, via Mancinelli 7, 20131 Milano, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Berini
authors.affiliation: Department of Chemistry, Materials and Chemical Engineering "Giulio Natta", Politecnico of Milano, via Mancinelli 7, 20131, Milano, Italy.
authors.forename: Elisa
authors.initials: E
authors.lastname: Fasoli
authors.affiliation: Department of Biotechnology and Life Sciences, University of Insubria, via J.H. Dunant 3, 21100 Varese, Italy; The Protein Factory Research Center, Politecnico of Milano and University of Insubria, via Mancinelli 7, 20131 Milano, Italy.
authors.forename: Flavia
authors.initials: F
authors.lastname: Marinelli
authors.affiliation: Department of Biotechnology and Life Sciences, University of Insubria, via J.H. Dunant 3, 21100 Varese, Italy; The Protein Factory Research Center, Politecnico of Milano and University of Insubria, via Mancinelli 7, 20131 Milano, Italy.
authors.forename: Loredano
authors.initials: L
authors.lastname: Pollegioni
authors.affiliation: Department of Biotechnology and Life Sciences, University of Insubria, via J.H. Dunant 3, 21100 Varese, Italy; The Protein Factory Research Center, Politecnico of Milano and University of Insubria, via Mancinelli 7, 20131 Milano, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Rosini
keywords: 2,4-DCP, 2,4-dichlorophenol; 2,6-DMP, 2,6-dimethoxyphenol; ABTS, 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid); Alkali lignin; DyP, dye decolorizing peroxidase; Filamentous actinomycetes; Kraft lignin; LiP, lignin peroxidase; MAM, mannitol agar medium; MM-L, minimal salt medium plus lignin; MnP, manganese peroxidase; Nonomuraea gerenzanensis; Peroxidases; RB5, reactive black 5; RBBR, remazol brilliant blue R; VP, versatile peroxidase