Valorisation of deinking sludge as a substrate for lignocellulolytic enzymes production by Pleurotus ostreatus. (1st October 2018)

• Record Type: Journal Article
• Authors: Vodovnik, Maša; Vrabec, Katja; Hellwig, Patrick; Benndorf, Dirk; Sežun, Mija; Gregori, Andrej; Gottumukkala, Lalitha D.; Anderson, Robin C.; Reichl, Udo
• Is Part Of: Journal of cleaner production. Volume 197(2018)Part 1
• Page Start: 253
• Page End: 263
• Publication Date: 2018-10-01
• Subjects: Paper mill waste -- Deinking sludge -- Fungi -- Lignocellulolytic enzymes -- Solid-state fermentation; DIS deinking sludge -- SF submerged fermentation -- SSF solid state fermentation -- TOC total organic carbon -- TON total organic nitrogen -- WRF white rot fungi -- PDA potato dextrose agar -- SEEs secreted enzyme extracts -- CMC carboxymethyl cellulose -- BX birchwood xylan -- EG endoglucanase -- EX endoxylanase -- ABTS 2, 2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) -- PDA potato dextrose agar -- SDS PAGE sodium dodecyl sulphate polyacrylamide gel electrophoresis -- TCA trichloroacetic acid -- LC MS/MS liquid chromatography coupled to tandem mass spectrometry; Factory and trade waste -- Management -- Periodicals; Manufactures -- Environmental aspects -- Periodicals; Déchets industriels -- Gestion -- Périodiques; Usines -- Aspect de l'environnement -- Périodiques; 628.5
• DOI: 10.1016/j.jclepro.2018.06.163
• Languages: English
• ISSNs: 0959-6526

Abstract

Abstract: Disposal of waste sludges produced in large amounts in the pulp and paper industry imposes significant environmental and economical problems. One strategy to address these issues involves revalorization of paper mill sludges by their application as substrates for microbial production of biotechnologically relevant enzymes. The application of lignocellulolytic enzymes in paper, textile and bioenergy industries is encouraged in order to decrease chemicals and energy consumptions. In the following work, deinking sludge was assessed as a substrate for production of lignocellulases. Based on the results of growth and activity screenings, Pleurotus ostreatus PLAB was chosen as the most promising candidate among 30 tested strains and its secretome was further studied by quantitative enzyme assays and mass spectrometry. While endoglucanase and xylanase activities detected in P. ostreatus secretome produced on deinking sludge were similar to activities of cultures grown on other lignocellulosic substrates, average laccase activity was significantly higher (46 000 U/kgDIS ). Mass spectrometry identification of the most prominent proteins in the secretome of the target strain confirmed that significant amounts of different lignin-modifying oxidases were produced on this substrate despite its low lignin content, indicating the presence of other inducible compounds. The findings of this study suggest deinking sludge may represent a good substrate for fungal production of the aforementioned enzymes with broad biotechnological applications, including bioremediation, paper and bioenergy industries. Graphical abstract: Highlights: Deinking sludge was applied for production of lignocellulolytic enzymes. Thirty fungal strains were screened in a two-stage process. P. ostreatus PLAB was selected as the most promising producer of target enzymes. SSF of DIS resulted in exceptional production of lignin-modifying oxidases.