Pre-treatment of a sugarcane bagasse-based substrate prior to saccharification: Effect of coffee pulp and urea on laccase and cellulase activities of Pycnoporus sanguineus

JOURNAL OF ENVIRONMENTAL MANAGEMENT

卷:239

Article

Gonzalez Bautista, Enrique^1,2  Gutierrez, Enrique²  Dupuy, Nathalie¹  Gaime-Perraud, Isabelle¹  Ziarelli, Fabio³  da Silva, Anne-Marie Farnet¹ 

[1] Aix Marseille Univ, Avignon Univ, CNRS, IRD,IMBE, Marseille, France

[2] Univ Veracruzana, Inst Biotecnol & Ecol Aplicada INBIOTECA, Campus Cultura Artes & Deporte, Xalapa 91090, Veracruz, Mexico

[3] Aix Marseille Univ, CNRS, Federat Sci Chim Marseille, FR 1739, Spectropole Campus St Jerome, F-13397 Marseille, France

关键词: Dephenolisation;    laccase induction;    Second-generation bioethanol;    Solid-state fermentation;    White-rot fungi;   

DOI  :  10.1016/j.jenvman.2019.03.033

来源: Elsevier

【 摘 要 】

Production of second-generation bioethanol uses lignocellulose from agricultural by-products such as sugarcane bagasse (SCB). A lignocellulose pre-treatment is required to degrade lignin, ensuring further efficient saccharification. Two experimental designs were set up to define culture conditions of Pycnoporus sanguineus in mesocosms to increase laccase activities and thus delignification. The first experimental design tested the effect of phenolic complementation (via coffee pulp) and the use of urea as a simple nitrogen source and the second defined more precisely the percentages of coffee pulp and urea to enhance delignification. The responses measured were: lignocellulolytic activities, laccase isoform profiles by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and the chemical transformation of the substrate using solid-state NMR of 13C. Adding 10% of coffee pulp increased laccase activities and fungal biomass (32.5% and 16% respectively), enhanced two constitutive isoforms (R-f 0.23 and 0.27), induced a new isoform (R-f 0.19) and led to a decrease in total aromatics. However, higher concentrations of coffee pulp (25%) decreased laccase and cellulase activities but no decrease in aromaticity was observed, potentially due to the toxic effect of phenols from coffee pulp. Moreover, laccase production was still inhibited even for lower concentrations of urea (0-5%). Our findings revealed that an agricultural by-product like coffee pulp can enhance laccase activity-though to a threshold- and that urea limited this process, indicating that other N-sources should be tested for the biological delignification of SCB.

【 授权许可】

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