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Humicola insolens produced a new β-glucosidase (BglHi2) under solid-state fermentation. The purified enzyme showed apparent molecular masses of 116 kDa (sodium dodecyl sulfate-polyacrylamide gel electrophoresis) and 404 kDa (gel-filtration), suggesting that it is a homotetramer. Mass spectrometry analysis showed amino acid sequence similarity with a β-glucosidase from Chaetomium thermophilum. Optima of pH and temperature were 5.0 and 65 °C, respectively, and the enzyme was stable for 60 min at 50 °C, maintaining 71 % residual activity after 60 min at 55 °C. BglHi2 hydrolyzed p-nitrophenyl-β-D-glucopyranoside and cellobiose. Cellobiose hydrolysis occurred with high apparent affinity (K M = 0.24 ± 0.01 mmol L(-1)) and catalytic efficiency (k cat/K M = 1,304.92 ± 53.32 L mmol(-1) s(-1)). The activity was insensitive to Fe(+3), Cr(+2), Mn(+2), Co(+2), and Ni(2+), and 50-60 % residual activities were retained in the presence of Pb(2+), Hg(2+), and Cu(2+). Mixtures of pure BglHi2 or H. insolens crude extract (CE) with crude extracts from Trichoderma reesei fully hydrolyzed Whatman no. 1 paper. Mixtures of H. insolens CE with T. reesei CE or Celluclast 1.5 L fully hydrolyzed untreated printed office paper, napkin, and magazine papers after 24-48 h, and untreated cardboard was hydrolyzed by a H. insolens CE/T. reesei CE mixture with 100 % glucose yield. Data revealed the good potential of BglHi2 for the hydrolysis of waste papers, promising feedstocks for cellulosic ethanol production.

Treballs Finals de Grau d'Enginyeria Química, Facultat de Química, Universitat de Barcelona, Curs: 2015-2016, Tutores: María Esther Chamarro Aguilera i Cristina Valls Vidal, This project is done in collaboration with the “Grup de recerca en Enginyeria Paperera (Celbiotech)” of the Universitat Politècnica de Catalunya (UPC), which investigates new methods for deinking recycled fibres, using biotechnological methods and ozone. The main objective is to increase the use of fibres recycled from coloured paper. One of the main problems of this raw material is the presence of contaminants, such as colourants, which hinder its potential and causes the obtained product to loss part of its value. A big inconvenience of using recycled fibres from the disintegration of coloured paper as raw material is that the type of colourant used is unknown. Therefore, parameters based on measuring the optical properties of the paper sheets where used to determine the efficiency of the colour elimination sequences. The first part consisted in applying different enzymatic stages (laccasemediator system) and a bleaching chemical agent to the red/black recycled fibres for determining the efficiency of eliminating colour in the dough. Afterwards, different biotechnological agents (enzymes) and chemical treatments will be applied to the red recycled fibres using a combination of mediators and doubling the dose of mediator used in the red fibres in order to determine which treatment gives the best results. Later on, we will apply a selected colour elimination sequence to the red and black recycled fibres, with the aim of determining the best biochemical sequence. At the same time, studies with another oxidizing agent (ozone) will be done in order to determine if the enzymatic stages can substitute the ozone stage. Last part of the project consists in doing physical test to determine if the paper has lost any of its properties after the treatments. The enzymatic activity of the effluents will be calculated as well in order to determine which mediator performed better and the possibility of recirculating these effluents will be studied.

Aquest treball s’emmarca dins d’una de les línies d’investigació del grup de recerca en Enginyeria Paperera (CELBIOTECH) de l’Escola Tècnica Superior d’Enginyeries Industrial i Aeronàutica de Terrassa encaminada a l’estudi i optimització del procés de blanqueig de paper reciclat mitjançant ozó i mètodes biotecnològics. Un dels principals problemes amb el qual ens trobem alhora d’utilitzar com a matèria prima fibres reciclades procedents de la desintegració de papers acolorits és el desconeixement sobre els colorants que s’han fet servir en la seva fabricació. Per determinar l’eficàcia de les seqüències d’eliminació de color, es comparen els paràmetres adients obtinguts en la mesura de les propietats òptiques dels fulls ja que els colorants mostren una gran varietat en la seva estructura química. En una primera fase del treball s’apliquen diversos mètodes biotecnològics (etapes enzimàtiques) i agents químics de blanqueig, com l’ozó, a la fibra reciclada vermella per determinar la seva major o menor eficàcia per eliminar el color de la pasta de cada etapa. Aquesta caracterització s’ha dut a terme amb la mesura de les propietats òptiques i mecàniques per tal de seleccionar la seqüència òptima de les etapes enzimàtiques i els agents químics de blanqueig que s’aplica a la resta de fibres reciclades de diferents colors. Un cop determinada la seqüència òptima, la qual combina una etapa enzimàtica amb el sistema lacasa-mediador, peròxid d’hidrogen, ozó i hidrosuldit sòdic, s’aplica a les fibres reciclades de color vermell, groc i negre per veure l’eficàcia de la seqüència bioquímica d’eliminació de color seleccionada anteriorment. Un cop realitzat l’estudi de les propietats òptiques i mecàniques dels diferents fulls, es realitzen assajos d’envelliment als fulls on s’han aplicat la seqüència bioquímica de blanqueig amb l’objectiu de determinar si aquests fulls tenen unes propietats òptiques estables al llarg del temps. Per últim, s’aplica la seqüència bioquímica de blanqueig seleccionada a una pasta formada per la barreja de fibres reciclades de diferents colors (blau, groc, verd i vermell) juntament amb fibra reciclada blanca. Aquesta barreja està formada en un 50% amb les fibres reciclades dels colors mencionats anteriorment i l’altre 50%, amb la fibra reciclada blanca; ja que aquesta barreja s’aproxima a la realitat del reciclatge industrial. Un cop aplicada la seqüència bioquímica òptima es realitza un estudi de les propietats òptiques i mecàniques com s’ha dut a terme anteriorment i, finalment, es realitzen els assajos d’envelliment per determinar si les propietats òptiques varien o no al llarg del temps.

Mestrado em Biotecnologia The biorefinery concept has attracted much attention over the last decade due to increasing concerns about the use of fossil resources. In this context emerged the use of bioplastics, namely polyhydroxyalkanoates (PHA). PHA are biocompatible and biodegradable plastics that can be obtained from renewable raw materials and can constitute an alternative solution to conventional plastics. In this work, hydrolysed cellulose pulp, coming from Eucalyptus globulus wood cooking, was used as substrate to the PHA-storing bacteria Haloferax mediterranei. The hydrolysed pulp is rich in simple sugars, mainly glucose (81.96 g.L-1) and xylose (20.90 g.L-1). Tests were made in defined medium with glucose and xylose and in hydrolysate supplemented with salts and yeast extract. Different concentrations of glucose were tested, namely 10, 15, 20, 30 and 40 g.L-1. The best accumulation results (27.1 % of PHA) were obtained in hydrolysate medium with 10 g.L-1. Using this concentration, assays were performed in fed-batch and sequencing batch reactor conditions in order to determine the best feeding strategy. The strategy that led to the best results was fed-batch assay with 24.7 % of PHA. An assay without sterile conditions was performed, in which was obtained the same growth than in sterilization test. Finally it was performed an assay in a bioreactor and a fast growth (0.14 h-1) with high glucose and xylose consumption rates (0.368 g.L-1.h-1 and 0.0947 g.L-1.h-1, respectively) were obtained. However 1.50 g.L-1 of PHA, corresponding to 16.1 % (92.52 % of 3HB and 3HV of 7.48 %) of % PHA were observed. The polymer was further characterized by DSC with a glass transition temperature of -6.07 °C, a melting temperature of 156.3 °C and a melting enthalpy of 63.07 J.g-1, values that are in accordance with the literature. This work recognizes for the first time the suitability of the pulp paper hydrolysate as a substrate for PHA production by H. mediterranei. O conceito de biorrefinaria tem atraído muita atenção na última década devido ao aumento das preocupações ao nível do uso de combustíveis fósseis. Neste contexto emergiu o uso de bioplásticos, nomeadamente polihidroxialcanoatos (PHA). Os PHA são plásticos biodegradáveis e biocompatíveis que podem ser obtidos a partir de matérias-primas renováveis e podem constituir uma solução alternativa para os plásticos convencionais. Neste trabalho, o hidrolisado da pasta de papel, proveninte do cozimento da madeira de Eucalyptus globulus, foi usado como substrato para a bactéria Haloferax mediterranei produtora de PHA. O hidrolisado é rico em açúcares simples, principalmente glucose (81,96 g/L) e xilose (20,90 g/L). Realizaram-se vários ensaios em meio definido com glucose e xilose e em hidrolisado suplementado com sais e extracto de levedura. Testaram-se diferentes concentrações de glucose, nomeadamente, 10, 15, 20, 30 e 40 g/L. Os melhores resultados de acumulação (27,1 % of PHA) foram obtidos em meio hidrolisado com 10 g/L. Utilizando esta concentração, foram realizados ensaios em “fed-batch” e em “sequencing batch reactor”, de modo a determinar a melhor estratégia de alimentação de H. mediterranei. A estratégia que levou à obtenção dos melhores resultados foi o ensaio em fedbatch com 24,7 % de PHA. Foi também testado o processo sem condições estéreis, em que se obteve um crescimento idêntico ao ensaio com esterilização. Por fim, foi realizado um ensaio em biorreactor, onde se observou um rápido crescimento (0,14 h-1), com elevados consumos de glucose e xilose (0,368 g/(L.h) e 0,0947 g/(L.h), respectivamente). No entanto, foram obtidos 1,50 g/L de PHA, correspondendo a 16,1 % (92,52 % de 3HB e 3HV de 7,48 %) de % PHA. O polímero foi ainda caracterizado por DSC tendose obtido uma temperatura de transição vítrea de -6,07 ºC, uma temperatura de fusão de 156,3 ºC e uma entalpia de fusão de 63,07 J/g, valores que estão de acordo com a literatura. Neste trabalho foi verificada pela primeira vez a adequação do hidrolisado da pasta de papel como meio para produção de PHA por H. mediterranei.

Point-of-care platforms can provide fast responses, decrease the overall cost of the treatment, allow for in-home determinations with or without a trained specialist, and improve the success of the treatment. This is especially true for microfluidic paper-based analytical devices (μPAD), which can enable the development of highly efficient and versatile analytical tools with applications in a variety of biomedical fields. The objective of this work was the development of μPADs to identify and quantify levels of nitrite in saliva, which has been proposed as a potential marker of periodontitis. The devices were fabricated by wax printing and allowed the detection of nitrite by a colorimetric reaction based on a modified version of the Griess reaction. The presented modifications, along with the implementation of a paper-based platform, address many of the common drawbacks (color development, stability, etc.) associated with the Griess reaction and are supported by results related to the design, characterization, and application of the proposed devices. Under the optimized conditions, the proposed devices enable the determination of nitrite in the 10-1000 μmol L(-1) range with a limit of detection of 10 μmol L(-1) and a sensitivity of 47.5 AU [log (μmol L(-1))](-1). In order to demonstrate the potential impact of this technology in the healthcare industry, the devices were applied to the analysis of a series of real samples, covering the relevant clinical range.

The use of enzymes has a high potential in the pulp and paper industry to improve the economics of the paper production process and to achieve, at the same time, a reduced environmental impact. Specific enzymes contribute to reduce the amount of chemicals and energy required for the modification of fibers and helps to prevent the formation or development of biofilms. This review is aimed at presenting the latest progresses made in the application of enzymes as refining aids and biofilm control agents.

Biofouling causes important economic losses in the paper industry. To prevent or mitigate the effects of biofilms is necessary to implement microbiological control programmes based on monitoring programs which requires the evaluation of the biofilm growth kinetic taking into account the ability of microorganisms viability. The monitoring techniques must be rapid to minimise both costs and use of chemicals. This paper presents the study of the growth kinetics of two bacterial strains known for their high capacity to produce biofilms in paper mills. After the validation of flow cytometry as a technique for microbial growth monitoring, the development of segregated kinetic models based on cell physiological states data was carried out. The developed models can be used to design microbial control programs.

Microbiological control programmes at industrial level should aim at reducing both the detrimental effects of microorganisms on the process and the environmental impact associated to the use of biocides as microbiological control products. To achieve this target, new efficient and environmentally friendly products are required. In this paper, 17 non-specific, commercial enzymatic mixtures were tested to assess their efficacy for biofilm prevention and control at laboratory and pilot plant scale. Pectin methylesterase, an enzyme found in the formulation of two of the mixtures tested, was identified as an active compound able to reduce biofilm formation by 71% compared to control tests.

“This is a post-peer-review, pre-copyedit version of an article published in Cellulose. The final authenticated version is available online at: https://doi.org/10.1007/s10570-019-02678-5 Bacterial cellulose (BC) was functionalized applying the Laccase/TEMPO oxidative treatment, leading to a five-fold increase of the concentration of carboxyl groups. Paper produced with this cellulose showed improved mechanical properties while maintaining barrier function against water and greases as compared to paper produced with non-oxidized BC. Also, the negative charge provided by the carboxyl groups on functionalized BC was used to generate silver nanoparticles (AgNPs), obtaining a BC paper and Ag composite. The presence of AgNPs in the composites was validated by SEM, EDS and ICP analysis, showing spherical, uniformly sized particles stabilized in the BC nanofibers matrix. Additionally, antimicrobial property of composites containing AgNPs was tested. The results showed the strong antimicrobial activity of the composites against Gram-positive and Gram-negative bacteria and fungi. The generation of Ag nanoparticles in a matrix that combine the physical characteristics of the BC nanofibers with the stiffness and the mechanical properties of paper produced composites that may have applicability in technological and biomedical uses

The preparation of compounds of interest from biomass-derived 5-hydroxymethylfurfural (HMF) has attracted considerable attention. One such compound is 2,5-diformylfuran (DFF), obtained through oxidation of the hydroxyl group of HMF. Herein, we describe for the first time the whole-cell oxidation of HMF to DFF by Fusarium culmorum EAN 51. Although the chemocatalytic transformation of HMF into DFF has been widely studied, biocatalytic processes have been scarcely reported and are limited to enzymatic synthesis using the combination of several enzymes. The whole-cell transformation of HMF into DFF is preferable thanks to the inherent presence of the different enzymes, significantly reducing the cost of the process. F. culmorum showed a high capability to reduce to 2,5-di(hydroxymethyl)furan (DHMF) and oxidize to DFF the substrate with high yields depending on the nitrogen source and the concentration of peptone and glucose in the media, which highly affected the redox capability of this strain. After careful optimization of the concentration of both nutrients through response surface methodology, 50 mM HMF were transformed into DFF with a high yield (92%) and selectivity (94%). These results open a new line of investigation in the sustainable production of DFF from renewable biobased resources. This work was partially supported by the Spanish Government (PID2019-110735RB-C21, MICIN/FEDER) and the Catalan Government (FI_B1_00135).

Biogas generated during anaerobic digestion in sewage plants contains a wide spectrum of trace impurities. Siloxanes are the most hazardous pollutants and its removal is mandatory for most energy applications. The most widely used technology is adsorption onto activated carbon (AC) despite the high operating costs. In this context, the use of biotechnologies to abate biogas pollutants could assist extending the lifetime of the AC filters. The present work evaluated at lab-scale the potentialities of implementing a biotrickling filter (BTF) before the adsorption technology. Moreover, the use of ACs with different characteristics and price was evaluated considering their selectivity towards siloxane over volatile organic compounds (VOCs). The pre-treatment of biogas in a BTF capable of eliminating VOCs like limonene increased significantly the adsorbent performance, reaching 690 m3 L−1 of biogas treated per bed volume by a phosphoric-activated carbon, a six-fold increase in the performance of currently used materials in adsorption treatment. In terms of cost, a steam-activated coal-based with a major mesoporosity contribution implied the lowest operating costs reaching 2.3 (1000 m3treated)−1. Coupling BTF with adsorption into this same AC resulted in lower annual costs than adsorption alone due to the frequent replacements required when biogas was not pre-polished The research leading to these results has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 712949 (TECNIOspring PLUS) and from the Agency for Business Competitiveness of the Government of Catalonia. This work was also funded by MINECO – Spain (CTQ2014-53718-R) co-founded by FEDER and the University of Girona (MPCUdG2016/137). E.S-C. thanks Universitat de Girona for his predoctoral grants (IFUdG_2015_51). LEQUIA has been recognized as consolidated research group by the Catalan Government (2017-SGR-1552)

Hemicellulose-rich substrates produced in the lignocellulose biorefinery context can yield macromolecular xylan structures with assorted application in the chemical industry. Xylan presents natural affinity to cellulose and its incorporation onto fibers increases the physical processability of pulp; however, current studies diverge on how molar mass affects xylan interaction with cellulose. In the current work, xylans with varied structural characteristics were prepared from alkaline-sulfite pretreated sugarcane bagasse with aid of an alkaline-active xylanase and selective precipitations using different ethanol concentrations. Prepared xylan fractions, containing low levels of lignin contamination (4–9%) and molar masses ranging from 2.3 kDa to 34 kDa, were incorporated onto eucalyptus pulp fibers up to 4.7 g xylan/100 g pulp. The efficiency of xylan incorporation onto cellulosic fibers was dependent on the xylan structures, where low molar mass and low substitution degree favored high incorporation levels.

Simultaneous ammonium–nitrogen (NH4+–N) removal and orthophosphate–phosphorus (PO4–P) biomineralization was studied in two granular sludge sequencing batch reactors treating urban sidestream centrate through the one-stage partial nitritation–anaerobic ammonium oxidation (anammox) process. By adding an external source of calcium, concomitant conversion rates of up to 0.32 g NH4+–N/(L·days) and 12 mg PO4–P/(L·days) were measured while reaching water-phase removal efficiencies of ca. 80% of the NH4+–N and 70% of the PO4–P loaded. The mineral cores formed inside the granules were mostly composed of hydroxyapatite (HAP), which is a recoverable phosphate salt. Yet, the high mineralization of the sludge and its excessive purge from the bioreactor limited the microbial activity in the long term. In this sense, the densest granules, accumulated at the bottom of the bioreactor, were the most susceptible to being harvested because they were the richest in HAP, but at the same time, they contained the highest percentages of anammox bacteria This research was conducted in the framework of the research project DigesTake (COMRDI16-1-0061) funded by ACCIÓ (Generalitat de Catalunya) within the program Comunitat RIS3CAT Aigua. The group LEQUIA (http://www.lequia. udg.edu/) is recognized as a consolidated research group by the Catalan Government (2017-SGR-1552)

Electronic supplementary material The online version of this article (https://doi.org/10.1007/s00449-019-02245-z) contains supplementary material, which is available to authorized users., Laccases are very interesting biocatalysts of recognized importance for several industrial applications. Its production by Trametes versicolor, a white-rot fungus, was induced by a combination of cotton gin wastes (1\%), a lignocellulosic waste, and vinasse (15\%), an industrial by-product from sugarcane industry. The use of these agro-industrial wastes are interesting, since it helps in reducing the enzyme production costs, due to their low cost and wide availability, as well as the environmental contamination issues, due to their improper disposal. Thus, laccase production was studied in submerged fermentation of T. versicolor using these agro-industrial wastes (cotton gin waste and vinasse) as carbon source and an additional nitrogen source (0.1\\% peptone). Three different bioreactors were evaluated for laccase production, such as BioFlo 310 bioreactor, aluminium tray and Erlenmeyer flasks to achieve high levels of laccase production. The highest specific production of laccase was found in BioFlo 310 bioreactor with 12 days of fermentation (55.24 U/mg prot.), which has been shown to be closely related to the oxygen supply to the microorganism through aeration of the fermentation medium. This study brings new insights into green biotechnology regarding vinasse utilization, which is frequently discharged in soils, rivers, and lakes causing adverse effects on agricultural soils and biota, as well as the cotton gin waste recovery., The authors are grateful to Mariana Cereia and Maurício de Oliveira for their technical assistance. This work was supported by Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP, processes 2010/52322-3; 2014/50884-5; 2018/07522-6), and V. E. P. was the recipient of a FAPESP fellowship (Process 2015/23200-0)., info:eu-repo/semantics/publishedVersion

The integrated approach in biorefinery mainly involves the utilization of various agroindustrial byproducts such as raw materials for the production of several biobased products like biofuels, bioenergy, and other high-value chemicals. Biofuels are the backbone of biorefineries, however, production of value-added biomolecules such as biopigments, biopolymers, biosurfactants, and nutritional yeast has been attracting great attention. The production of these biomolecules using traditional approaches has been extensively studied in the last few years owing to their promising application in different industries such as chemical, food/feed, and pharmaceuticals for the development of novel products for mankind. Moreover, the production of such biomolecules using lignocellulosic, starchy, and some other agroindustrial byproducts is still not fully explored. Hence, there is a huge scope in the development of sustainable biorefining approaches to make the technology cost-effective. The lignocellulosic biomasses usually used in biorefineries are mainly composed of cellulose, hemicellulose, and lignin, whereas starchy materials, besides starch, usually contain, protein, lipids, and some micronutrients. The processing of these biomasses through successive steps like pretreatments, enzymatic hydrolysis, and fermentation is essentially required to obtained final biobased products. Considering certain bottlenecks of above-mentioned conventional biorefineries approaches, new technologies have been proposed for the improved pretreatment of biomass and efficient enzymatic hydrolysis in order to minimize the concentration of toxic inhibitors in resulting hydrolysate. In this review, we highlighted the different agroindustrial byproducts and their applications for the production of valuable biorefinery products.

Luminescent nano-thermometry is a fast-developing technique with great potential for in vivo sensing, diagnosis, and therapy. Unfortunately, it presents serious limitations. The luminescence generated by nanothermometers, from which thermal readout is obtained, is strongly distorted by the attenuation induced by tissues. Such distortions lead to low signal levels and entangle absolute and reliable thermal monitoring of internal organs. Overcoming both limitations requires the use of high-brightness luminescent nanothermometers and adopting more complex approaches for temperature estimation. In this work, it is demonstrated how superbright Ag2S nanothermometers can provide in vivo, reliable, and absolute thermal reading of the liver during laser-induced hyperthermia. For that, a new procedure is designed in which thermal readout is obtained from the combination of in vivo transient thermometry measurements and in silico simulations. The synergy between in vivo and in silico measurements has made it possible to assess relevant numbers such as the efficiency of hyperthermia processes, the total heat energy deposited in the liver, and the relative contribution of Ag2S nanoparticles to liver heating. This work provides a new way for absolute thermal sensing of internal organs with potential application not only to hyperthermia processes but also to advanced diagnosis and therapy., This work was supported by the Spanish Ministry of Economy and Competitiveness under projects MAT2016‐75362‐C3‐1‐R, MAT2017‐83111R, and MAT2017‐85617‐R, by the Instituto de Salud Carlos III (PI16/00812), by the Comunidad Autónoma de Madrid (B2017/BMD‐3867 RENIM‐CM), and cofinanced by the European Structural and investment fund. Additional funding was provided by the European Union's Horizon 2020 FET Open programme (Grant Agreement No. 801305, NanoTBTech), the Fundación para la Investigación Biomédica del Hospital Universitario Ramón y Cajal project IMP18_38 (2018/0265), and also by COST action CA17140. Y.S. acknowledges a scholarship from the China Scholarship Council (No. 201806870023). I.Z.G. thanks UCM‐Santander for a predoctoral contract (CT63/19‐CT64/19). D.O. and I.R. acknowledge financial support from the Community of Madrid under Contract No. PEJD‐2017‐PRE/IND‐3663, and from the Spanish Ministry of Science and Innovation through the Ramón y Cajal grant RYC2018‐025253‐I, Research Networks grant RED2018‐102626‐T and the PID2019‐106211RB‐I00 grant as well as the Ministry of Economy and Competitiveness through the grants MAT2017‐85617‐R, MAT2017‐88148R and the “Severo Ochoa” Program for Centers of Excellence in R&D (SEV‐2016‐0686). D.O. and I.R. also acknowledge support from the “NoCanTher” project, which has received funding from the European Union's Horizon 2020 research and innovation programme under Grant Agreement No. 685795. E.X. is grateful for a Juan de la Cierva Formación scholarship (FJC2018‐036734‐I).

New strategies in inoculation and operation of bioelectrochemical systems were used to advance in the steering of bio-electro carbon dioxide (CO2) recycling towards chemical compounds. First, the preparation of microbe coated biocathodes ex-situ with putative electroactive species with CO2 as sole carbon source was assayed. Second, CO2 feeding strategies for the operation of BES systems were explored to ensure enough reducing power during batch mode operation. The impact on the proposed changes on the product portfolio and production yields was assessed. The initial enrichment of a putative electroactive community on bare electrode surfaces was proven to be successful and led to a shortening of the start-up period of the system from days to hours. Moreover, the establishment of a new feeding procedure to favor the presence of elevated reducing power availability for cells triggered the production of longer carbon chain carboxylates (max. 0.99 gbutyrate m-2electrode d-1) and alcohols (max. 0.83 gethanol m-2electrode d-1) at early stages of experiment. This work complements the recent knowledge on the control of bioelectrochemical processes by the establishment of strategies to obtain target added-value compounds from CO2 R.B-G. was supported by a grant from the Spanish Ministry of Economy and Competitiveness (MINECO) (FPI grant BES-2015-074229 within the research project CTQ2014-53718R). E. P.-V. is grateful for the Research Training grant from the University of Girona (IFUdG2018/52). S.P. is a Serra Hunter Fellow (UdG-AG-575) and acknowledges the funding from the ICREA Academia award. This research was funded by the Agency for Business Competitiveness of the Government of Catalonia (ACCIÓ; COMRDI16-1-0061) and the Spanish Ministry of Science (RTI2018-098360-B-I00). LEQUIA and EcoAqua groups have been recognized as consolidated research groups by the Catalan Government (2017SGR-1552 and 2017SGR-548)

Wastewater from institutions are considered with low strength and they may have a low C/N ratio and pH values higher than 7.0 units. In developing countries, anaerobic treatment for low strength wastewater is widely applied. However, COD removals and biogas production can be low due to inhibitions in the process. To improve the effluent quality, aerobic posttreatment has been used. The aim of this study was accessing the influence of pH and C/N ratio on methane yield of institutional wastewater, taking into account the aerobic sludge recirculation towards the anaerobic reactor. A factorial design 32 was used, evaluating different pH values: 6.9±0.1, 7.5±0.05 and 9.0±0.5; and C/N ratio: 4.9±0.2, 8.2±0.18 and 14.2±0.17. Biochemical methane (BMP) tests were performed using as inoculum a sludge with the hydrolytic, acidogenic and specific methanogenic activity of 2.79 gCOD/gVSS-d, 2.80 gCOD/gVSS-d and 0.14 gCODCH4/gVSS-d, respectively. Results indicating that with high C/N ratio, the methane yield increased. The maximum BMP was 318 L CH4/kgVSS with pH 7.5 and C/N ratio of 8.2±0.18; however, with the C/N ratio of 14.2±017 a major COD removal and methane production rate were observed. RESUMEN Las aguas residuales de instituciones son consideradas de baja carga y pueden poseer bajas relaciones C/N y valores de pH superiores a 7.0 unidades. En países en desarrollo el tratamiento anaerobio de aguas residuales de baja carga se usa ampliamente. Sin embargo, las remociones de DQO y la producción de biogás pueden ser bajas debido a inhibiciones en el proceso. Para mejorar la calidad del efluente, el postratamiento aerobio ha sido usado. El objetivo de este estudio fue investigar la influencia del pH y la relación C/N sobre la producción de metano del agua residual de una institución educativa, teniendo en cuenta la recirculación de lodo aerobio hacia el reactor anaerobio. Se utilizó un diseño factorial 32, evaluando valores de pH de 6.9±0.1, 7.5±0.05 y 9.0±0.5 y relaciones C/N de 4.9±0.2, 8.2±0.18 y 14.2±017. Se realizaron además pruebas de potencial bioquímico de metano (PBM) utilizando como inóculo un lodo con actividad hidrólitica de 2.79 gDQO/gSSV-d, actividad acidogénica de 2.80 gDQO/gSSV-d y actividad metanogénica de 0.14 gDQOCH4/gSSV. Los resultados indicaron que con el aumento de la relación C/N, se incrementó la producción de metano. El máximo PBM fue de 318 L CH4/kgSSV con pH inicial de 7.5 y relación C/N de 8.2±0.18; sin embargo, con la relación C/N de 14.2±017 se observó mayor porcentaje de remoción de DQO y una tasa de producción máxima más alta.

A new online methodology based on a continuous process video microscopy and image analysis has been developed to study the effects of enzymes on the formation of biofilm. This research consists of two parts: (1) the monitoring of the growth of a biofilm formed with the axenic culture isolated from the process waters of a recycling paper mill, aiming at determining the most appropriate way to quantify the biofilm growth from the obtained images; and (2) the study of the effects of three new enzymatic products on biofilm formation involving the natural flora of microorganisms present in the process water of the paper mill. The results demonstrate that the new methodology based on image analysis allows monitoring of the formation of biofilm and selecting the most efficient biofilm control product. The study also shows that enzymatic products could be an alternative for biocides on biofilm prevention and control.

The production of enzymes using agro-industrial waste is a low cost alternative for the reuse of byproducts, with the subsequent impact decrease on the environment. Current analysis produced xylanase using fungus Aspergillus niger , with two types of wastewater generated during the pulp chemical bleaching phase as inducers. Xylanase was produced by submerged liquid fermentation and factorial design optimized parameters that influence production (concentration of wastewater and production period). Initial culture conditions (pH, temperature and agitation) were optimized independently. Alkaline wastewater was more effective than acidic wastewater for the induction of xylanase in optimized conditions: 50% of culture medium, 7-day production, 30°C, pH 6.0 and agitation at 160 rpm. Despite different results, acidic and alkaline wastewaters induced xylanase production by A. niger when employed in concentrations lower than or equal to 50% of culture medium and in the most optimal conditions described above. Alkaline wastewater is highlighted as the most efficient for such production.

Lignin is the second most abundant polymer, which comprises15-30% (dry weight) of total lignocellulosic biomass. Recent studies focused on the effective utilization of lignin biopolymer into a myriad of products such as lignin micro and nanocapsules, biosensors, platform chemicals, pharmaceutical compounds, biopolymers, electrodes in electrochemistry, re-useable adsorbent, resins and biodiesel production through oleaginous microbes. The development of eco-friendly and cost-effective techniques is need-of-the-hour, which can be addressed through the circular economy approach. In this review, the emphasis is laid on integrating bioethanol and biodiesel production and valorizing lignin into various useful products. Besides, prospects of lignin biorefinery coupled with economic policies to be deployed along with the practical implications, have been discussed. Adopting these new pragmatic technologies and policies enables not only the development of inexpensive technologies but also boosts the economic growth of lignocellulosic biorefinery.

Made available in DSpace on 2018-12-11T16:38:57Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-08-03 The extracellular β-d-fructofuranosidase from Fusarium graminearum was immobilized using hydrophilic cotton, filter paper, multipurpose cloth, sugar cane bagasse, string, or gauze as alternative cellulosic supports, or with cyanogen bromide agarose. All derivatives (support+enzyme) showed high capacity for reuse (up to 23 times). The derivatives obtained with multipurpose cloth and string were stable at 60°C maintaining 80% of their activity for more than 120 min. The filter paper derivative had a halflife (T50) of 27 min at 70°C. When tested for their pH stability (3.0–9.0), all derivatives were more stable than the free enzyme, especially the cotton derivative. The sugarcane bagasse, string, and filter paper derivatives could efficiently produce fructooligosaccharides (FOS) using sucrose as substrate. According to the retention of enzymatic activity, reuse and stabilities, the filter paper and string were the best alternative supports for β-d-fructofuranosidase immobilization, allowing enzyme stabilization and production of FOS. Instituto de Química de Araraquara-UNESP, Rua Francisco Degni s/n Ciências e Letras de Ribeirão Preto-USP, Avenida Bandeirantes 3900, Monte Alegre Instituto de Química de Araraquara-UNESP, Rua Francisco Degni s/n

Premi extraordinari doctorat curs 2011-2012, àmbit d’Enginyeria Industrial This research project originated from interest in assessing the potential of enzyme technology (particularly laccase-based systems) for the biomodification of sisal specialty fibres by using environmentally friendly processes. This doctoral work focused on two different research lines, namely: biobleaching and enzymatic functionalization of sisal pulp fibres. The study was started by assessing the use of natural, potentially cost-effective phenolic compounds as substitutes for expensive, potentially toxic laccase mediators. The tendency of natural phenols to either promote delignification or couple onto pulp was examined with a view to assessing their potential for either bleaching or functionalizing sisal fibres. In the biobleaching study, totally chlorine free (TCF) sequences were implemented in order to compare the efficiency of a selected natural mediator and a well-known synthetic mediator, both in the presence and absence of a xylanase pre-treatment. The effluents resulting from each stage in the sequence were analysed with a view to assessing the environmental impact of the laccase treatments ¿a scarcely explored aspect of biobleaching sequences. The xylanase stage proved highly efficient in reducing the HexA content of sisal fibres and in boosting the bleaching effect of the laccase treatments. The proposed TCF sequences provided high-cellulose sisal pulp with brightness above 80% ISO and a reduced HexA content; also, they exhibited improved performance and a reduced impact on effluent properties relative to the use of the synthetic mediator. Two different approaches to fibre functionalization were explored, namely: lignin modification (biografting) and cellulose modification (laccase¿TEMPO oxidation). Biografting of phenolic compounds was for the first time studied in sisal pulp. Covalent binding of the originally assayed phenolic compounds to sisal fibres during the laccase treatment was exposed by a novel analytical approach based on pyrolysis-GC/MS. The phenolic compound showing the highest tendency to couple to fibres was selected to investigate biografting under different reaction conditions and to evaluate the extent of phenol coupling via various pulp properties. Biografting efficiency was enhanced by refining the fibres prior to the enzyme treatment, which provided improved strength-related properties in the resulting paper. The use of the laccase-TEMPO system to oxidatively modify cellulose and improve strength-related properties in sisal pulp was for the first time evaluated as an environmentally friendly alternative to existing halide-based systems. The first part of this study revealed that the laccase¿TEMPO system considerably improved wet strength in sisal pulp by effect of the formation of a substantial amount of aldehyde groups in cellulose chains that facilitated inter-fibre bonding through hemiacetal linkages. The influence of process variables on various properties of the oxidized fibres and resulting paper was assessed by using a three-variable statistical plan. The conditions maximizing functionalization and the improvement in paper strength properties were used to design treatments of increased efficiency that exposed the potential of laccase¿TEMPO oxidation for biorefining pulp fibres. Analytical methods including pyrolysis-GC/MS, polyelectrolyte titration, conductimetric titration, carbohydrate determination by HPLC, fibre morphology analysis by SEM and thermogravimetry were used to both characterize the raw material and gain a better understanding of the reaction mechanisms behind the different laccase-based treatments. Some of the analyses were performed by collaborating research groups at IRNAS (Seville, Spain) and the Department of Chemical Engineering of the University of Huelva (Spain). Also, part of this doctoral work was conducted at the Institute of Paper Science and Technology of the Georgia Institute of Technology (Atlanta, USA). Award-winning

La materia prima utilizada es eucalipto (Eucalyptus globulus). Se utiliza las astillas de eucalipto y por medio de procesos como la Autohidrólisis y la cocción Kraft seguidamente de procesos de blanqueo como el blanqueo con ozono y enzimas. Se eliminará las hemicelulosas y seguidamente la lignina, esto nos dará como resultado una celulosa más pura. En cada uno de los procesos determinaremos la efectividad de cada uno de ellos y la cantidad de celulosa que podemos obtener así se estudiara la viabilidad del uso de cada uno de los procesos. La investigación se realizara dentro de las líneas de investigación del departamento de Ingeniería Papelera, de la universidad Politécnica de Cataluña. Encaminada a la investigación de biotecnología para la obtención de celulosa. Así enfocar la investigación en potenciar el uso de estos procesos de obtención y blanqueo de pastas en secuencias TCF. De este modo potenciar el blanqueo por biotecnologías y no solo por procesos químicos que serán más contaminantes. Finalmente se estudiara la importancia de la celulosa las salidas a aplicaciones industriales que esta puede tener y se estudiara la viabilidad para aplicarla industrialmente

The use of enzymes has been suggested as an environmentally friendly alternative to complement conventional chemical deinking in the recycling of recovered paper. This study compares the use of cellulases/hemicellulases versus the laccase-mediator system for deinking printed fibers from newspapers and magazines. For this purpose, two commercial enzyme preparations with endoglucanase and endoxylanase activities (Viscozyme Wheat from Aspergillus oryzae and Ultraflo L from Humicola insolens, Novozymes) and a commercial laccase (NS51002 from Trametes villosa, Novozymes), the latter in the presence of synthetic or natural (lignin-related) mediators, were evaluated. The enzymatic treatments were studied at the laboratory scale using a standard chemical deinking sequence consisting of a pulping stage; an alkaline stage using NaOH, sodium silicate and fatty acid soap; and a bleaching stage using hydrogen peroxide. The handsheets were then prepared and their brightness, residual ink concentration, and strength properties were measured. Among the different enzymatic treatments assayed, both carbohydrate hydrolases were found to deink the secondary fibers more efficiently. Brightness increased up to 3–4% ISO on newspaper fibers, being Ultraflo 20% more efficient in the ink removal. Up to 2.5% ISO brightness increase was obtained when magazine fibers were used, being Viscozyme 9% more efficient in the ink removal. Regarding the laccase-mediator system, alone or in combination with carbohydrate hydrolases, it was ineffective in deinking both newspaper and magazine fibers, resulting in pulps with worse brightness and residual ink concentration values. However, pulp deinking by the laccase-mediator system was displayed when secondary fibers from printed cardboard were used, obtaining up to 3% ISO brightness increase and lower residual ink concentrations.

Premi extraordinari doctorat curs 2010-2011, àmbit d’Enginyeria Enginyeria Industrial The aim of this thesis is to modify flax pulp fibres (Linum usitatissimum) by more friendly environmental processes. Pulp and paper research is focussing through enzyme systems investigation for developing green chemistry technologies due to existing environmental concerns and to legal restrictions. Moreover, it exists also an increasing strategic interest in using flax fibres to obtain high-quality specialty papers. That is why we study the application of biotechnology as an efficient alternative to traditional industrial processes based on the use of chemical agents. This work is framed by two of the main research topics of the Paper and Graphic Specialty Laboratory in the Textile and Paper Engineering Department of the Universitat Politècnica de Catalunya. One research line is based on pulp bleaching and is focused basically on the study of enzymatic systems as biobleaching agents; the other research topic that has been recently introduced in our investigation group is the use of enzymes as functionalisation agents by promoting the grafting of several compounds. Laccase is the main enzyme used in this thesis; it is an oxidoreductase that can assist reactions in an eco-friendly way since laccase uses air and produces water as the only by-product. Moreover, laccase can work under mill conditions and has wide application potential. The first part of this thesis involved the use of enzymes to bleach flax pulp. The aim was to explore the potential of various natural mediators (lignin-derived compounds) for delignifying flax fibres in order to identify the most efficient and ecofriendly choice among them. Afterwards, we assessed the use of various enzyme delignification stages in an industrial bleaching sequence. The ensuing totally chlorine free (TCF) sequence comprised various laccase-mediator system treatments (L stage) followed by a by a chelating stage (Q stage) and a subsequent bleaching step with hydrogen peroxide (Po stage). A xylanase pretreatment was additionally carried out. Laccases used came from the fungi Pycnoporus cinnabarinus and Myceliophthora thermophila; the performance of several natural mediators was compared with the obtained with the application of various synthetic mediators. In addition, the lack of studies on the properties of effluents from the treatment of non-wood pulp with laccase and natural mediators led A-1 A-2 us to examine effluent properties upon biotreatments and after different bleaching stages. The results obtained warrant upscaling any of the biobleaching sequences for flax pulp as they provide sustainable flax fibre with a high cellulose content and brightness above 80% ISO. The use of xylanase pretreatment was found to efficiently remove HexA and enhance delignification by laccase. Award-winning

Mestrado em Biotecnologia Submitted by Alexandra Bastos (alexandrabastos@ua.pt) on 2016-09-05T10:57:07Z No. of bitstreams: 1 tese.pdf: 1824846 bytes, checksum: dcf25cdab8f57e22dd17b4130191baf4 (MD5) Made available in DSpace on 2016-09-05T10:57:07Z (GMT). No. of bitstreams: 1 tese.pdf: 1824846 bytes, checksum: dcf25cdab8f57e22dd17b4130191baf4 (MD5) Previous issue date: 2015-12-10

Humicola brevis var. thermoidea cultivated under solid state fermentation in wheat bran and water (1:2 w/v) was a good producer of β-glucosidase and xylanase. After optimization using response surface methodology the level of xylanase reached 5,791.2 ± 411.2 U g(-1), while β-glucosidase production was increased about 2.6-fold, reaching 20.7 ± 1.5 U g(-1). Cellulase levels were negligible. Biochemical characterization of H. brevis β-glucosidase and xylanase activities showed that they were stable in a wide pH range. Optimum pH for β-glucosidase and xylanase activities were 5.0 and 5.5, respectively, but the xylanase showed 80 % of maximal activity when assayed at pH 8.0. Both enzymes presented high thermal stability. The β-glucosidase maintained about 95 % of its activity after 26 h in water at 55 °C, with half-lives of 15.7 h at 60 °C and 5.1 h at 65 °C. The presence of xylose during heat treatment at 65 °C protected β-glucosidase against thermal inactivation. Xylanase maintained about 80 % of its activity after 200 h in water at 60 °C. Xylose stimulated β-glucosidase activity up to 1.7-fold, at 200 mmol L(-1). The notable features of both xylanase and β-glucosidase suggest that H. brevis crude culture extract may be useful to compose efficient enzymatic cocktails for lignocellulosic materials treatment or paper pulp biobleaching.

The food industry has introduced chemical and enzymatic procedures for the modification of fats and oils to allow the improvement of their organoleptic and/or nutritional properties. As chemical procedures have many drawbacks, the application of enzyme technology shows as a promising approach for the development of new fats and oil-derived products. Lipase-catalyzed interesterification reactions allow the structural modification of lipids by selectively changing the composition of a triacylglycerol under very mild and controlled conditions. This work reviews the main characteristics of lipase reactions, the use of lipases for interesterification procedures, and the advantages and limitations of lipase immobilization for the enzymatic modification of fats and oils. The use of lipases from different sources for fat splitting and the potential application of stereospecific lipases for the production of structured or designer lipids is also discussed.La industria de alimentos utiliza procedimientos de modificación química y enzimática de las grasas y aceites con el propósito de mejorar sus características organolépticas y/o nutricionales. Debido a que los procedimientos químicos presentan muchas limitaciones e inconvenientes, la aplicación de tecnologías que utilizan enzimas aparece como muy prometedora para el desarrollo de nuevos tipos de grasas y aceites. Las reacciones de interesterificación catalizadas por lipasas permiten la modificación estructural de los lípidos al cambiar en forma selectiva la composición de los triacilgliceroles bajo condiciones de reacción muy suaves y controladas. Este trabajo revisa las principales características de las lipasas y sus reacciones, el uso de lipasas para la realización de reacciones de interesterificación, y las ventajas y limitaciones del uso de lipasas inmovilizadas para la modificación de grasas y aceites. Se discute, además, la aplicación de lipasas de diferente procedencia para la hidrólisis de grasas y el uso potencial de lipasas estereoespecíficas para la producción de lípidos estructurados.

2-butoxyethanol is one of the most used glycol ether in industrial activities and the treatment of air 2-butoxyethanol-emissions become necessary. Biotechnologies are potential treatment technologies due to their low operational costs. The use of two inoculums in the treatment of 2-butoxyethanol by biotrickling filters (BTFs) packed with polyurethane-foam was studied. A pure culture of Pseudomonas putida, previously adapted to 2-butoxyethanol, was used as inocula in a BTF operated in the University of Stuttgart. Fresh activated sludge from a municipal waste water treatment plant was used as inocula in a BTF operated in the University of Valencia. An empty bed residence time of 12.5 s and inlet concentrations of 400 and 800 mg/Nm 3 were applied. After 40 days of operation at 400 mg/Nm 3 , the BTF inoculated with Pseudomonas putida reached removal efficiencies (REs) ~80%, whereas the BTF inoculated with activated sludge presented REs~60%. At 800 mg/Nm 3 , the BTF inoculated with Pseudomonas putida reached REs~60%. Microbial community was monitored in both BTFs by using denaturing gradient gel electrophoresis analysis (DGGE) with subsequent 16S sequencing and plating methods using 2-butoxyethanol as sole carbon source.

La tesi que ens ocupa, parteix de I'interes de blanquejar pasta kraft d'eucaliptus a traves de tecnologies netes, es a dir, utilitzant metodes mes respectuosos pel medi ambient. La motivacio per a la realitzacio d'aquesta tesi, sorgeix de la problematica ambiental ja coneguda que existeix amb relacio a la contaminacio produida pels reactius utilitzats en el blanqueig de pastes per a paper i de I'interes estrategic que representa per Espanya la utilitzacio de la fusta d'eucaliptus. D'aquesta manera, es volen estudiar nous sistemes enzimatics que puguin deslignificar i blanquejar aquesta pasta.La present tesi s'emmarca dins d'una de les linees d'investigacio del Departament d'Enginyeria Textil i Paperera, de la Universitat Politecnica de Catalunya, encaminada a ('Aplicacio de la Biotecnologia per al Blanqueig de Pastes.Aixi, s'enfoca la recerca cap a la utilitzacio de xilanases per a potenciar el blanqueig en sequencies ECF i TCF, i cap a la utilitzacio de lacases a traves del sistema lacasa-mediador per a blanquejar i deslignifcar la pasta. Degut al gran contingut en acids hexenuronics de les pastes kraft d'eucaliptus, i a la creixent importancia d'aquests en els processos de blanqueig, especial interes es dona en la seva evolucio al Ilarg dels diferents tractaments.Primerament es realitza un escrutini d'actuacio de diferents xilanases tant noves com comercials per tal d'identificar les mes eficients en potenciar el blanqueig. Aquests assajos es realitzen sobre sequencies XD, XP i XDP. Segons les propietats de la pasta d'index kappa, blancor, viscositat i HexA i segons I'analisi per cromatografia en capa fina dels efluents de I'etapa X, s'obte que la xilanasa comercial Xc i que la xilanasa nova XG son les mes eficients en potenciar el blanqueig. La xilanasa nova mes eficient pertany a la familia 11 de les glicosil hidrolases. D'altra banda, s'observa que la xilanasa XJ (familia 5) produeix Ileugers efectes sobre les pastes i que totes les xilanases noves (families 10, 11 i 5) contribueixen a la disminucio del contingut en HexA de les pastes.Seguidament, la millor xilanasa comercial (Xc) i nova (XG) s'apliquen en una sequencia complerta de blanqueig XDEopD1. Degut a I'interes cientific que representa aplicar per primera vegada una xilanasa de la familia 5 sobre les pastes, tambe s'aplica la xilanasa Xj en aquesta sequencia complerta. La xilanasa Xj s'aplica sola i combinada amb la xilanasa XG. Els resultats demostren que amb un pretractament amb xilanasa es milloren les propietats de les pastes al Ilarg de la sequencia i que el pretractament X podria permetre un estalvi en dioxid de clor. A mes, les xilanases no afecten a les propietats fisiques finals dels papers.En segon Iloc, s'aplica el sistema lacasa-mediador (L) sobre les pastes utilitzant HBT com a mediador. L'objectiu d'aquest tractament es d'una banda optimitzar les condicions d'aplicacio del sistema lacasamediador segons les propietats d'index kappa i blancor i d'altra banda veure si el pretractament amb xilanasa es capag de potenciar I'efecte del tractament L. Tambe es vol analitzar com el tractament L afecta als HexA, a la lignina i a la viscositat. Els resultats demostren que a dosis baixes de mediador i a temps curts s'obtenen bones propietats. El tractament L disminueix sobretot la lignina de la pasta tot i que tambe fa disminuir els HexA, i Ileugerament la viscositat. Els esterols de la pasta son tambe eliminats durant aquest tractament. A mes, es demostra que el pretractament X "facilita" I'efecte del sistema lacasa-mediador en eliminar els acids hexenuronics de la pasta. Per I ltim, queda reforgada la necessitat d'aplicar una etapa d'extraccio alcalina posterior a L.Posteriorment, es compara I'efectivitat del mediador NHA respecte I'HBT obtenint resultats molt prometedors amb aquest mediador ja que a part de ser mes barat i potencialment menys toxic que I'HBT, presenta una reaccio de tipus reversible i es tant eficient com aquest I ltim en deslignificar la pasta. Paral·lelament es realitza una recerca de mediadors naturals produits durant el creixement de P.cinnabarinussobre la fusta de pi. Per I ltim, s'aplica per primera vegada la tirosinasa en el blanqueig de pastes i els resultats indiquen que cal continuar la recerca sobre aquesta possible aplicacio biotecnolOgica d'aquest enzim. Aquest bloc d'experiencies s'ha realitzat a l'"Institut National de la Recherche Agronomique" (INRA) de Marsella, Franca.Finalment, es discuteix sobre la importancia dais acids hexenuronics al Ilarg dais processos de blanqueig, i sobre com aquests son eliminats pals diferents tractaments tant quimics corn enzimatics. Es troba la relacio antra aquests acids i I'index kappa de la pasta d'eucaliptus utilitzada.

RESUMEN: En este trabajo se presenta el modelado de las principales dinámicas de un proceso de Sacarificación y Fermentación Simultaneas (SFS) utilizando residuos lignocelulósicos como sustrato. Experimentos de SSF llevados a cabo con la levadura Kluyveromyces marxianus como inóculo y desechos de palma de aceite como sustrato se realizaron para obtener datos de concentración de glucosa y etanol que permitieran identificar parámetros y validar el modelo. El modelo resultante predice el comportamiento general de las concentraciones de glucosa y etanol. Gracias a un análisis de sensibilidad, se definen los parámetros que más afectan el modelo, con el fin de flexibilizar el modelo para que pueda ser optimizado en casos particulares con pocos requerimientos computacionales. Esta estrategia de reoptimización muestra mejorar de manera importante la capacidad del modelo para predecir las dinámicas del proceso SSF. ABSTARCT: This paper presents the modeling of the main dynamics of a Simultaneous Saccharification and Fermentation (SSF) process using lignocellulosic wastes as substrate. SSF experiments were carried out using the yeast Kluyveromyces marxianus as the inoculum and oil palm wastes as the substrate, in order to obtain glucose and ethanol concentration data. The experimental data were used for the parameter identification and model validation. The resulting model predictsthe dynamic behavior of glucose and ethanol concentrations very closely. Performing a sensitivity analysis, parameters which have a higher effect in the modelpredictions are recognized, so the model can be re-optimized in particular cases with low computational requirements. The re-optimization strategy improves the model capacity to predict the dynamics of the SSF process.