Laccase induction by synthetic dyes in Pycnoporus sanguineus and their possible use for sugar cane bagasse delignification

Christian Hernández (1) , Anne Marie Farnet da Silva (2) , Fabio Ziarelli (3) , Isabelle Perraud-Gaime (2) , Beatriz Gutierrez-Rivera (4) , José Antonio García-Pérez (1) , Enrique Alarcón (1)

1 Universidad Veracruzana
2 IMBE - Institut méditerranéen de biodiversité et d'écologie marine et continentale
3 FSCM - Fédération des Sciences Chimiques de Marseille
4 ITSTB - Instituto Tecnológico Superior de Tierra Blanca

The use of synthetic dyes for laccase induction in vivo has been scarcely explored. We characterized the effect of adding different synthetic dyes to liquid cultures of Pycnoporus sanguineus on laccase production. We found that carminic acid (CA) can induce 722 % and alizarin yellow 317 % more laccase than control does, and they promoted better fungal biomass development in liquid cultures. Aniline blue and crystal violet did not show such positive effect. CA and alizarin yellow were degraded up to 95 % during P. sanguineus culturing (12 days). With this basis, CA was selected as the best inducer and used to evaluate the induction of laccase on solid-state fermentation (SSF), using sugarcane bagasse (SCB) as substrate, in an attempt to reach selective delignification. We found that laccase induction occurred in SSF, and a slight inhibition of cellulase production was observed when CA was added to the substrate; also, a transformation of SCB under SSF was followed by the 13 C cross polarization magic angle spinning (CPMAS) solid-state nuclear magnetic resonance (NMR). Results showed that P. sanguineus can selectively delignify SCB, decreasing aromatic C compounds by 32.67 % in 16 days; O-alkyl C region (polysaccharides) was degraded less than 2 %; delignification values were not correlated with laccase activities. Cellulose-crystallinity index was increased by 27.24 % in absence of CA and 15.94 % when 0.01 mM of CA was added to SCB; this dye also inhibits the production of fungal biomass in SSF (measured as alkyl C gain). We conclude that CA is a good inducer of laccase in liquid media, and that P. sanguineus is a fungus with high potential for biomass delignification.

Mots clés: Alizarin yellow; Carminic acid; Endoglucanase; 13C CPMAS; solid-state NMR; Cellulose crystallinity

Domaines: Biotechnologies; Ingénierie de l'environnement; Polymères

Christian Hernández, Anne Marie Farnet da Silva, Fabio Ziarelli, Isabelle Perraud-Gaime, Beatriz Gutierrez-Rivera, et al.. Laccase induction by synthetic dyes in Pycnoporus sanguineus and their possible use for sugar cane bagasse delignification. Applied Microbiology and Biotechnology, 2017, 101 (3), pp.1189-1201. ⟨10.1007/s00253-016-7890-0⟩. ⟨hal-02069482⟩