Integrated bioprocess system for ethanol production and separation from lignocellulosic raw materials by using different bioreactors

doctoral thesis

• Title (croatian): Integrirani bioprocesni sustav za prozvodnju i izdvajanje etanola iz lignoceluloznih sirovina primjenom različitih bioreaktora
• Author: Martina Andlar
• Mentor: Tonči Rezić (mentor)
• Committee member: Božidar Šantek (predsjednik povjerenstva)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; Zagreb
• Defense date and country: 2018-07-17, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology
• Universal decimal classification (UDC): 60 - Biotechnology. Genetic engineering. Products of cloning

Abstract

The objective of this work was to develop an integrated bioprocess system for ethanol production and separation from selected lignocellulosic raw material (sugar beet pulp) by using different bioreactors. For that purpose, a column and horizontal rotating tubular bioreactor (HRTB) were used. The second objective was to develop an efficient enzyme system for cellulose fraction degradation of lignocellulosic biomass based on the application of fungal lytic polysaccharide monooxygenase (LPMO), with the aim to support hydrolytic enzymes, and different electron donors present in the lignocellulose hydrolysates. LPMOs oxidatively degrade insoluble lignocellulose polysaccharides and soluble oligosaccharides. Upon reductive activation, they cleave the substrate and promote biomass degradation by hydrolytic enzymes. Binding studies showed that the reduction of the LPMO’s active site increased the affinity and the maximum binding capacity for cellulose. The next step was related to an optimization of enzymatic sugar beet pulp hydrolysis using various commercial enzyme mixtures (Ultrazym AFP-L, Viscozyme L, Pectinase and Cellulase). Ultrazym AFP-L showed the highest efficiency and together with produced extracellular degradation system from fungus Neurospora crassa, was used for sugar beet pulp hydrolysis at a large scale. A three step process comprising the hydrolysation, fermentation and in-situ gas stripping with a vacuum assisted recovery system, was integrated and optimized to increase the ethanol production. Environmental sustainability of the integrated processes has been evaluated and used for calculation of environmental impacts based on mass and energy balances of the processes.

Abstract (croatian)

Cilj ovo rada bio je razvoj integriranog bioprocesnog sustava za proizvodnju i izdvajanje etanola iz odabrane lignocelulozne sirovine (pulpa šećerne repe) primjenom različitih bioreaktora. Za tu svrhu korišteni su cijevni i horizontalni rotirajući cijevni bioreaktor (HRCB). Drugi cilj je bio razviti učinkovit enzimski sustav za razgradnju celulozne frakcije lignocelulozne sirovine primjenom fungalnog enzima, litičke polisaharidne monooksigenaze (LPMO) sa svrhom poticanja rada hidrolitičkih enzima, i različitih donora elektrona prisutnih u hidrolizatima lignoceluloze. LPMO enzimi reakcijama oksidacije razgrađuju netopljive polisaharide i topljive oligosaharide lignocelulozne biomase. Nakon aktivacije redukcijom LPMO je sposoban razgraditi supstrat i time potaknuti djelovanje hidrolitičkih enzima čime se uvelike pospješuje degradacija biomase. Rezultati dobiveni istraživanjem vezanja enzima za supstrat su pokazali da se redukcijom aktivnog mjesta LPMO-a povećava afinitet i ostvaruje maksimalna sposobnost vezanja enzima za celulozu. Slijedeći korak bio je optimizacija enzimske hidrolize pulpe šećerne repe upotrebom komercijalnih enzimskih pripravaka (Ultrazym AFP-L, Viscozyme L, Pectinase i Cellulase). Ultrazym AFP-L pokazao se najučinkovitijim te je zajedno sa proizvedenim ekstracelularnim enzimima plijesni Neurospora crassa, korišten za hidrolizu pulpe šećerne repe u velikom mjerilu. Sa ciljem povećanja proizvodnje etanola iz pulpe šećerne repe provedena je integracija i optimizacija procesa sastavljenog od tri stupnja: hidrolize, fermentacije i direktnog izdvajanja etanola stripiranja plinom potpomognuto vakuumom. Na temelju bilanca mase i energije provedenih procesa, izračunat je njihov utjecaj na okoliš i procijenjena je ekološka održivost procesa.

• Keywords: ethanol; lignocellulosic biomass; lytic polysaccharide monooxygenase; enzymatic hydrolysis; column bioreactor; horizontal rotating tubular bioreactor; integrated bioprocess system; environmental sustainability
• Keywords (croatian): etanol; lignocelulozna sirovina; litički polisaharid monooksigenaza; enzimska hidroliza; cijevni bioreaktor; horizontalni rotirajući cijevni bioreaktor; integrirani bioprocesni sustav; ekološka održivost procesa
• Language: english
• URN:NBN: urn:nbn:hr:159:340755
• Study programme: Title: Biotechnology & Bioprocess Engineering; Study programme type: university; Study level: postgraduate; Academic / professional title: doktor znanosti/doktorica znanosti (doktor znanosti/doktorica znanosti)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2018-09-10 07:46:27