Light-induced inhibition of laccase in Pycnoporus sanguineus Christian A. Hernández 1 & Yareni Perroni 1 & José Antonio García Pérez 2 & Beatriz Gutiérrez Rivera 3 & Enrique Alarcón 1 Received: 22 April 2015 /Accepted: 15 July 2015 # Institute of Microbiology, Academy of Sciences of the Czech Republic, v.v.i. 2015 Abstract The aim was to determine which specific regions of the visible light spectrum were responsible for the induction or inhibition of laccase in Pycnoporus sanguineus. Cultures were exposed to various bandwidth lights: blue (460 nm), green (525 nm), white (a combination of 460 and 560 nm), red (660 nm), and darkness. The results indicate that short wave- lengths strongly inhibit the production of laccase: green (3.76 ±1.12 U/L), blue (1.94±0.36 U/L), and white (1.05±0.21 U/ L) in proportions of 85.8, 92.6, and 96.0 %, respectively; whereas long wavelengths inhibit laccase production only par- tially i.e., red light (14.05±4.79 U/L) in a proportion of 46.8 %. Maximum activity was induced in absence of visible light (30 °C, darkness), i.e., 30.76±4.0 U/L. It is concluded that the production of laccase in P. sanguineus responds to light stimuli [measured as wavelengths and lx] and that it does so inversely. This can be explained as an ecological mecha- nism of environmental recognition, given that P. sanguineus develops inside lignocellulose structures in conditions of dark- ness. The presence of short wavelength light (460–510 nm) would indicate that the organism finds itself in an external environment, unprovided of lignin, and that it is therefore unnecessary to secrete laccase. This possible new regulation in the laccase production in P. sanguineus has important bio- technological implications, for it would be possible to control the production of laccase using light stimuli. Introduction It is known that the production of some extracellular enzymes involved in the degradation of lignocellulose by certain fungi is differentially affected by the various wavelengths of the visible light spectrum (Schmoll et al. 2005; 2012). However, in spite of the fact that light has been associated to the regu- latory processes in the production of exoenzymes, little is known about the mechanisms of the perception of light and the transduction of signals ( Rodríguez-Romero et al. 2010). From the adaptive viewpoint, changes in the detection of light furnishes fungi with information on orientation as well as exposition to external environments (Herrera-Estrella and Horwitz 2007; Corrochano 2011), allowing them to adjust their metabolism to the prevailing conditions for optimal use of the resources at hand. Pycnoporus sanguineus (Polyporaceae) is a basidiomycete fungus that, as a saprobe, produces extracellular enzymes that allow it to decompose organic polymers and consume its monomers. These fungi are of special interest because they produce enzymes of the laccase group that decompose mainly lignin. Laccases are enzymes with a wide specificity of substratum involved in * Enrique Alarcón enalarcon@uv.mx Christian A. Hernández criss_hdez@live.com Yareni Perroni yperroni@uv.mx José Antonio García Pérez antoniogarcia01@uv.mx Beatriz Gutiérrez Rivera beatriz.gutierrez@itstb.edu.mx 1 Institute of Biotechnology and Applied Ecology (INBIOTECA), Universidad Veracruzana, Av. Culturas Veracruzanas 101, Col. Emiliano Zapata, Xalapa, Veracruz 91090, Mexico 2 Faculty of Biology, Universidad Veracruzana, Cto. Gonzalo Aguirre Beltrán s/n, Col. Emiliano Zapata, Xalapa, Veracruz 91090, Mexico 3 Instituto Tecnológico Superior de Tierra Blanca, Av. Veracruz S/N Esq. Héroes de Puebla, Colonia Pemex, Tierra Blanca, Veracruz 95180, Mexico Folia Microbiol DOI 10.1007/s12223-015-0418-7