Optimization of cellobiohydrolase production and secretome analysis of Trametes villosa LBM 033 suitable for lignocellulosic bioconversion

Abstract

The production of bioethanol from lignocellulosic biomass comprises the enzymatic hydrolysis of lignocellulosic structures by three major cellulases. Among them, cellobiohydrolases are considered to be key enzymes playing a significant role on cellulose degradation. The ability to produce lignocellulolytic enzymes by fungi such as Trametes villosa makes them appropriate degraders for large-scale applications. In this context, the aim of this study was to obtain and characterize a cellobiohydrolase-enriched extracellular extract of T. villosa LBM 033 (Misiones, Argentina), which is suitable for the enzymatic hydrolysis of lignocellulosic residues. The effect of carbon and nitrogen sources on cellobiohydrolase activity was evaluated using experimental designs and a culture medium was optimized to obtain a cellobiohydrolase-enriched extract suitable for the hydrolysis of lignocellulosic biomass. Moreover, by secretome analysis, nine enzymes involved in lignocellulosic biomass degradation were identified under the optimized conditions; among them is a cellobiohydrolase II from the glycosil-hydrolase 6 family. ARTICLE HISTORY

Exoproteomic Study and Transcriptional Responses of Laccase and Ligninolytic Peroxidase Genes of White-Rot Fungus Trametes hirsuta LE-BIN 072 Grown in the Presence of Monolignol-Related Phenolic Compounds

“…Possibly, the ability to simultaneously secrete many peroxidase isozymes is a distinctive feature of T. hirsuta species. Similarly with T. hirsuta 072, the T. hirsuta strain X-13 cultivated on lignin-containing media was reported to secrete up to six peroxidase isozymes [57], while the related fungi from Trametes and Pycnoporus genera were reported to secret only from one to four peroxidase isozymes even in wood-containing media [34,54,55,58,59]. The only one reported exception from the above is T. versicolor strain A1-ATF, which secreted from five to nine peroxidase isozymes when cultivated on aspen wafers [56,60].…”

“…As for the orthologues of VP2 and MnP7 isozymes of T. hirsuta 072, these isozymes were previously reported in exoproteomes of Trametes and Pycnoporus spp. in various conditions including media supplemented with cellulose, lignin, lignocellulose, and copper [34,[55][56][57][58][59][60].…”

Review of Recent Advances in the Physiology of the Regulation of Cellulase and Xylanase Production by Basidiomycetes

“…It is possible that this circumstance affected both the secretion of enzymes and the stability of the already synthesized enzyme during long-term cultivation. Nevertheless, Coniglio et al [36] found that both peptone and ammonium sulfate as nitrogen sources favored the secretion of cellobiohydrolase activity by Trametes villosa LBM 033. Unfortunately, in most studies of the effect of nitrogen and its concentration on the cellulase activity of fungi, there are no data on the accumulated biomass.…”

Bioconversion of cassava bagasse and sugarcane bagasse using cheap home-made enzymatic cocktails

“…In addition to this effective pretreatment, we used the crude (home-made) enzymatic cocktails of A. niger LBM 134 instead of purified enzymes because there are clear indications that proteins with still unknown functions (present in the crude cocktails) may contribute to the hydrolysis of cellulose and hemicelluloses [19,23].…”