Role of laccases and peroxidases in saprotrophic activities in the lichen Usnea undulata Richard P. BECKETT a, *, Nomcebo NTOMBELA a , Erin SCOTT a , Oleg P. GURJANOV b , Farida V. MINIBAYEVA b , Christiane LIERS c a School of Biological and Conservation Sciences, University of KwaZulu-Natal, Private Bag X01, Pietermaritzburg, Scottsville 3209, South Africa b Kazan Institute of Biochemistry and Biophysics, Russian Academy of Sciences, PO Box 30, Kazan 420111, Russia c T U Dresden, International Institute Zittau, Unit of Environmental Biotechnology, Markt 23, Zittau 02763, Germany article info Article history: Received 22 August 2014 Revision received 1 December 2014 Accepted 1 December 2014 Available online Corresponding editor: Darwyn Coxson Keywords: Laccase Lichens Peroxidase Saprophyte Usnic acid abstract Lichens produce various oxidoreductases including heme-containing peroxidases and the copper-containing phenol oxidases tyrosinase and laccase. Our earlier findings suggested that significant oxidoreductase activity occurs mainly in lichens from the order Peltiger- ales. Here we show that the non-Peltigeralean lichen Usnea can display significant activities of peroxidases and laccases. Strong evidence for the involvement of peroxidases and lac- cases in saprotrophic activities comes from the observation that their activities are induced by “starvation” due to prolonged dark storage, and also by treatment with soluble cellulose and lignin breakdown products. We also show that, given a quinone and chelated Fe, Usnea can produce hydroxyl radicals; these radicals contribute to the break down of carbohy- drates or lignin. However, hydroxyl radical production is independent of laccase and peroxidase activity. Laccases and peroxidases are involved in other aspects of lichen biology; here we show that peroxidases, but not laccases, can break down lichen sub- stances. Reduction in the amounts of lichen substances will reduce photoprotection, which will increase the photosynthetic capacity of thalli during winter when light intensities are low. ª 2014 Elsevier Ltd and The British Mycological Society. All rights reserved. Introduction Lichens produce various metal-containing oxidoreductases such as the copper-containing phenol oxidases tyrosinase and laccase, and heme peroxidases (Beckett et al., 2013b). Our earlier work showed that significant oxidoreductase activity only occurs in lichens from the order Peltigerales (Beckett et al., 2012, 2103a); here we used freshly collected material that was slowly dried and stored for no more than 4 weeks. In Peltigeralean lichens the average laccase, tyrosinase and peroxidase activities were 19.7, 17.0 and 12.7 units g 1 dry mass, while the corresponding activities from non- Peltigeralean species were 0.2, 0.7 and 0.1 respectively. How- ever, our later work showed that significant laccase and per- oxidase activities can be induced in some non-Peltigeralean lichens by hydrating them for several days in the dark (Beckett et al., 2014), suggesting that the occurrence of these enzymes may be more widespread. The first aim of the present study * Corresponding author. E-mail address: rpbeckett@gmail.com (R.P. Beckett). available at www.sciencedirect.com ScienceDirect journal homepage: www.elsevier.com/locate/funeco http://dx.doi.org/10.1016/j.funeco.2014.12.004 1754-5048/ª 2014 Elsevier Ltd and The British Mycological Society. All rights reserved. fungal ecology 14 (2015) 71 e78