Thesis supervisor: Mani Subramanian. Includes bibliographic references (p. 121-125).

Thèse (M.Sc.)--Université Laval, 2004. / Bibliogr.: f. 78-88. Publié aussi en version électronique.

Techn. Hochsch., Diss., 2005--Aachen.

Made available in DSpace on 2014-06-12T15:54:21Z (GMT). No. of bitstreams: 2 arquivo6477_1.pdf: 1747465 bytes, checksum: 133a5b019bfb201fdaaf6595bdecbb40 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2011 / Faculdade de Amparo à Ciência e Tecnologia do Estado de Pernambuco / Nos últimos 15 anos, um grande esforço tem sido feito para uma maior utilização de resíduos agroindustriais renováveis, podendo a biomassa lignocélulosica ser matéria prima para os bicombustíveis. A composição dessas biomassas varia bastante, mas em geral os substratos lignocelulósicos são constituídos de celulose (homopolímero de glicose), hemicelulose (heteropolímero de hexoses e pentoses) e pela lignina (compostos aromáticos). Considerando que a fermentação de glicose pode ser realizado de forma eficiente, a bioconversão da fração das pentoses (xilose, principal açúcar pentose obtido na hidrólise da hemicelulose), apresenta um desafio. A levedura Pichia stipitis pode converter xilose a etanol com rendimentos industrialmente relevantes. Porém necessita de condições limitantes de oxigênio, além do consumo da glicose inibir de modo não competitivo a xilose e sob condições de crescimento similares o consumo de glicose é maior que o de xilose. Com base na análise da via metabolica desta levedura, o presente trabalho teve como objetivo redirecionar o fluxo metabólico da via glicolitica para via das pentose fosfato dentro do que se chama modernamente de Engeharia Metabólica. O gene PGI1 codificador da fosfoglicose isomerase foi completamente removido do genoma da linhagem nativa NRRL 7124 com o uso de fragmentos de PCR que continham seqüências com mais de 350 bp de homologia com as regiões 5 e 3´ do gene alvo. Quando este gene foi deletado, a glicose-6-fosfato foi inteiramente rotada para via da pentose fosfato. Este fluxo direciona a produção de NADPH fundamental para a produção de precursores de nucleotídeos, aminoácidos, em reações biossinteticas redutivas e também na conversão de xilose a xilitol. Para seleção do transformante, foi necessária uma concentração de 1200μg/ml de Geneticina. Além disso, a eficiência de transformação foi baixa, em parte devido à utilização do sistema não convencional de códons por esta levedura. O cassete de deleção construído apresenta a marca de seleção resistente a geneticina ladeado por duas regiões denominadas loxp, que permitem a recombinação por sistemas de contra-seleção. Possibilitando a remoção da marca de resistência

Submitted in fulfillment for the requirement of a Degree of Master in Biotechnology, Durban University of Technology, 2017. / Microbial xylanases have attracted considerable research interest because of their various applications in biotechnology including the biobleaching of kraft pulp, to increase the nutritional value of foods and animal feed as well as for their potential use in the production of ethanol and methane. In the paper and pulp industry, the bleaching process involves the use of toxic chemicals and in the interim produces harmful gases that have a negative impact on the environment. The application of enzymes for this process will potentially reduce the environmental pollution by this industry. In addition, using an enzyme that is thermostable and alkali tolerant means that they will remain active under the required processing conditions. The xylanase gene, xynA derived from Thermomyces lanuginosus DSM 5826, was previously evolved to produce a number of xylanase variants, which were further enhanced for increased thermostability and alkalinity. In this study, these variants were cloned in Pichia pastoris using the pBGP1 vector to achieve extracellular production of the recombinant proteins. The xylanase genes were isolated using PCR. Both vector and DNA inserts were linearized with restriction enzymes EcoRI and XbaI and ligated. Electroporation was employed to transform the yeast with the recombinant plasmids. This was followed by the expression of the enzymes in P. pastoris grown in yeast peptone glucose (YPD) medium. Enzyme activity was thereafter assessed and the yeast was found to produce 164, 78, 96 and 142 IU/ml of S325, S340, G41 and G53 xylanase respectively, higher levels than bacterial hosts. The enzymes were then characterized and it was established that the optimum temperatures and pH for maximum xylanase activity were, 60°C, pH 6 for S325; 40°C, pH 5 for S340; 60°C, pH 6 for G41 and 60°C, pH 7 for G53. i The pH and temperature stabilities of the respective enzymes were investigated, the S325 variant was exceptionally stable at a pH between 5 and 7 and temperature range of 40-80°C and retained a minimum of 40% of activity at higher pH and temperature after an incubation period of 90 min. The S340 variant was the least thermostable and alkali stable from all four variants, it however retained 40% of activity when subjected to conditions of pH 9, 80°C after 90 min. The G41 and G53 were highly stable under the pH and temperature conditions that they were subjected to. Thus being suitable for potential application in the pulp and paper industry. The enzymes were able to retain 80% of activity at pH 9, 80°C after 120 min. P. pastoris has been proven to be a more suitable protein expression vector than E. coli for a number of reasons, including; the ability to perform complex post-translational modifications and grow to high densities in minimal media resulting in the production of a high yield of heterologous proteins. / M

Thesis (PhD)--Stellenbosch University, 2003. / ENGLISH ABSTRACT: Plant biomass, the most abundant renewable resource in nature, consists of matrices of mainly lignin, cellulose, hemicellulose as well as inorganic components. Xylan, the major hemicellulose component in plant cell walls, is the most abundant polysaccharide after cellulose. This makes the main constituent sugar of xylan, D-xylose, the second most abundant renewable monosaccharide in nature. Very few hemicelluloses are either homopolymeric or entirely linear. Therefore, the variety of enzymes involved in their hydrolysis is more complex than the enzyme group responsible for the hydrolysis of cellulose. Although the ability to degrade xylan is common among bacteria and filamentous fungi, this trait is relatively rare among yeasts. However, some strains of the yeast Pichia stipitis are, amongst others, able to degrade xylan. As P. stipitis is also one of the best D-xylose fermenting yeasts thus far described, this yeast has the potential of fermenting polymeric xylan directly to ethanol. However, it was shown that the natural xylanolytic ability of this yeast is very weak. In this study, xylanolytic genes were expressed in P. stipitis to test the ability of the yeast to produce heterologous proteins, and to determine the enhancement of xylan utilisation by the recombinant strain. The native xylose reductase gene (XYLl) and transketolase gene (TKL) and the heterologous Saccharomyces cerevisiae phosphoglycerate kinase (PGKl) gene promoter were cloned into P. stipitis transformation vectors and used to express the Trichoderma reesei ~-xylanase encoding gene (xyn2) as reporter gene. It was shown that the XYLl promoter was induced in the presence of D-xylose and that the TKL promoter was constitutively expressed. The PGKl promoter of S. cerevisiae did not function in P. stipitis . When the T reesei xyn2 gene and the Aspergillus kawachii ~-xylanase encoding gene (xynC) were expressed under control of the XYLl promoter, extracellular ~-xylanase activity of up to 136 nkat/ml and 171 nkatlml was observed, respectively. This activity declined over time due to the presence of extracellular proteases, secreted by P. stipitis. Growing the cultures in a fermentor and controlling the pH level to pH 6 did not alleviate the reduction of heterologous l3-xylanase activity. When the Aspergillus niger l3-xylosidase encoding gene (xlnD) was expressed as a fusion gene (designated XL02) with the S. cerevisiae mating factor secretion signal (MFal) under control of the P. stipitis TKL promoter, extracellular l3-xylosidase activity of 0.132 nkatlml was observed. Co-expression of the xyn2 and XL02 genes led to B-xylanase and l3-xylosidase activities of 128 nkatlml and 0.113 nkat/ml, respectively. Co-expression of the xynC and XL02 genes led to l3-xylanase and l3-xylosidase activities of 165 nkat/ml and 0.124 nkatlml, respectively. The expression of the fungal xylanolytic genes in P. stipitis also led to an increased biomass yield when the recombinant strains were cultured on birchwood xylan as sole carbon source. The strain co-expressing the A. kawachii l3-xylanase and A. niger l3-xylosidase encoding genes was the most successful, yielding a 3.2-fold higher biomass level than the control strain. Biomass levels of the recombinant strains were further improved on average by 85% by growing them in a fermentor under conditions of high oxygenation. The strains were also tested for direct conversion of xylan to ethanol and the strain co-expressing the A. kawachii l3-xylanase and A. niger l3-xylosidase encoding genes produced 1.35 giL ethanol, which represents a 3.6-fold increase in ethanol yield over the reference strain. These strains represent a step towards the efficient degradation and utilisation of hemicellulosic materials by ethanol-producing yeasts. / AFRIKAANSE OPSOMMING: Plant biomassa, die volopste hernubare koolstotbron in die natuur, bestaan uit matrikse van lignien, sellulose en hemisellulose. Xilaan, die hoof hemisellulose komponent in plantselwande, is na sellulose die volopste polisakkaried. Gevolglik is die hoof suikerkomponent van xilaan, naamlik D-xilose, die tweede volopste hernubare monosakkaried in die natuur. Baie min hemisellulose molekules is homopolimere of heeltemal linieêr. Daarom is die ensieme betrokke by die atbraak van hemiselluloses meer kompleks as die ensieme betrokke by die atbraak van sellulose. Bakterieë en filamentagtige fungi wat oor die vermoë om xilaan af te breek beskik, kom wydversprei voor maar relatief min giste kan xilaan benut. Sommige rasse van die gisspesie Pichia stipitis het egter beperkte vermoë om xilaan af te breek. P. stipitis is ook een van die beste D-xilose fermenterende giste wat tot dusver beskryf is en het dus die potensiaalom etanol vanafpolimeriese xilaan te produseer. In hierdie studie is gene wat kodeer vir xilaanatbrekende ensieme in P. stipitis uitgedruk om die vermoë van die gis as heteroloë uitdrukking sisteem te evalueer. Verder is die effek van die heteroloë xilaanatbrekende ensieme tydens groei op xilaan as enigste koolstotbron getoets. Die promoters van die xilosereduktasegeen (XYLl), die transketolasegeen (TKL) van P. stipitis en die fosfogliseraatkinasegeen (PGKl) van Saccharomyces cerevisiae is in P. stipitis transformasie vektore gekloneer en gebruik om die Trichoderma reesei ~-xilanasegeen (xyn2) as verklikkergeen uit te druk. Dit het bewys dat die XYLI promotor induseerbaar is in die teenwoordigheid van D-xilose terwyl die TKL geen konstant uitgedruk was. Die PGKI promotor van S. cerevisiae was nie funksioneel in P. stipitis nie. Ekstrasellulêre ~-xilanase aktiwiteit van onderskeidelik 136 nkatlml en 171 nkatlml kon waargeneem word wanneer die T reesei xyn2 geen of die Aspergillus kawachii ~-xilanasegeen (xynC) onder beheer van die XYLI promotor uitgedruk is. Hierdie aktiwiteit het afgeneem na gelang van tyd a.g.v. die teenwoordigheid van ekstrasellulêre proteases wat deur P. stipitis uitgeskei word. Die afname van ekstrasellulêre ~-xilanase aktiwiteit kon nie voorkom word deur die kulture in 'n fermentor te groei en die pH vlak tot pH 6 te beheer nie. Tydens uitdrukking van die Aspergillus niger ~-xilosidase geen (xlnD) as 'n fusiegeen (genoem XL02) met die paringsfaktor sekresiesein (MFal) van S. cerevisiae onder transkripsionele beheer van die P. stipitis TKL promotor, kon ekstrasellulêre ~-xilosidase aktiwiteit van 0.132 nkatlml waargeneem word. Gesamentlike uitdrukking van die xyn2 en XL02 gene het gelei tot ~-xilanase en ~-xilosidase aktiwiteite van 128 nkatlml and 0.113 nkat/ml, onderskeidelik. Gesamentlike uitdrukking van die xynC en XL02 gene het gelei tot ~-xilanase en ~-xilosidase aktiwiteite van 165 nkatlml and 0.124 nkatlml, onderskeidelik. Die uitdrukking van xilaanatbrekende ensieme III P. stipitis het verhoogbe biomassaproduksie teweeg gebring wanneer die rekombinante gisrasse op birchwood xilaan as enigste koolstotbron gegroei het. Die rekombinante ras wat die A. kawachii ~-xilanasegeen en die A. niger ~-xilosidase geen gesamentlik uitdruk, was die mees suksesvolle ras en het 3.2-voudig hoër biomassa as die kontrole ras opgelewer. Die biomassa van die rekombinante rasse tydens groei op xilaan as enigste koolstotbron kon gemiddeld met 85% verhoog word deur die giste onder hoë suurstotkonsentrase in 'n fermentor te kweek. Die rekombinante rasse is verder ook getoets vir hul vermoë om xilaan direk tot etanol om te skakel. Die rekombinante ras wat die A. kawachii ~-xilanasegeen en die A. niger ~-xilosidase geen gesamentlik uitgedruk het, het 'n 3.6- voudige verhoging in etanolproduksie getoon en 1.35 gIL ethanol gelewer. Hierdie rekombinante gisrasse verteenwoordig 'n stap nader aan die doeltreffende atbraak en benutting van hemisellulose deur etanolproduserende giste.

No description available.

Xing, Lei. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 111-120). / Abstracts in English and Chinese. / ABSTRACT OF THESIS ENTITLED: --- p.I / 論文摘要 --- p.Ill / ACKNOWLEDGEMENTS --- p.IV / ABBREVIATIONS --- p.V / CONTENTS --- p.VI / LIST OF FIGURES --- p.X / LIST OF TABLES --- p.XII / Chapter CHAPTER 1: --- LITERATURE REVIEW --- p.1 / Chapter 1.1 --- Introduction --- p.1 / Chapter 1.1.1 --- Pectic substances --- p.1 / Chapter 1.1.2 --- Structure and classification of pectins --- p.2 / Chapter 1.1.3 --- Classification of pectinases --- p.4 / Chapter 1.1.4 --- Application of pectinases --- p.5 / Chapter 1.1.5 --- Production of pectinases --- p.5 / Chapter 1.2 --- Lentinula edodes as a source of pectinolytic enzymes --- p.12 / Chapter 1.2.1 --- Taxonomy and Life cycle of L. edodes --- p.12 / Chapter 1.2.2 --- Pectin-degrading enzymes in L edodes --- p.13 / Chapter 1.3 --- Expression systems for fungal pectinolytic enzymes --- p.16 / Chapter 1.4 --- Gene expression analysis --- p.19 / Chapter 1.5 --- Objectives and Long-term significance --- p.20 / Chapter CHAPTER 2: P --- EGTINASES IN L. EDODES --- p.23 / Chapter 2.1 --- Introduction --- p.23 / Chapter 2.2 --- Materials and Methods --- p.25 / Chapter 2.2.1 --- Fungal strains and growth conditions --- p.25 / Chapter 2.3.2 --- Gene models --- p.25 / Chapter 2.2.4 --- Enzyme activity assays --- p.26 / Chapter 2.3 --- Results --- p.30 / Chapter 2.3.1 --- Alignment of 24 candidate pectin-degradation gene models --- p.30 / Chapter 2.3.2 --- Conserved domains in protein sequences of 24 gene models --- p.30 / Chapter 2.3.3 --- Signal Peptide prediction of pectin-degradation gene models --- p.30 / Chapter 2.3.4 --- Pectinases activities in L. edodes --- p.31 / Chapter 2.3.5 --- Growth of mycelia of L. edodes on pectin and non-pectin media --- p.31 / Chapter 2.4 --- Discussion --- p.48 / Chapter 2.4.1 --- Elimination of non-pectinolytic genes --- p.48 / Chapter 2.4.2 --- Conserved domains and active sites of 6 polygalacturonases --- p.49 / Chapter 2.4.3 --- Pectinases activities in L. edodes --- p.49 / Chapter 2.4.4 --- Effect of pectin on the growth of mycelia in L. edodes --- p.50 / Chapter 2.5 --- Conclusion --- p.51 / Chapter CHAPTER 3: --- TRANSCRIPTIONAL PROFILING OF PECTINASES GENES IN L. EDODES --- p.52 / Chapter 3.1 --- Introduction --- p.52 / Chapter 3.2 --- Materials and Methods --- p.57 / Chapter 3.2.2 --- Strain cultivation --- p.57 / Chapter 3.2.3 --- RNA extraction and first strand cDNA synthesis --- p.58 / Chapter 3.2.4 --- Quantitative RT-PCR --- p.58 / Chapter 3.2.5 --- Data analysis --- p.59 / Chapter 3.3 --- Results --- p.62 / Chapter 3.3.2 --- RNA quality of various samples in L. edodes --- p.62 / Chapter 3.3.3 --- Transcription of 14 putative pectinases genes --- p.62 / Chapter 3.3.4 --- Transcription profiling of pectinases genes during the development of L. edodes --- p.62 / Chapter 3.3.5 --- Transcriptional levels of pectinases genes in mycelia of L. edodes grown in different media --- p.63 / Chapter 3.4 --- Discussions --- p.73 / Chapter 3.4.2 --- Transcription profiling of pectinases genes in L. edodes during four developmental stages --- p.73 / Chapter 3.4.3 --- Differential transcriptional levels of pectinases genes in L. edodes mycelia grown in two media --- p.73 / Chapter 3.4.4 --- Effect of pectic substrates on the pectinases genes transcription in mycelia of L. edodes --- p.74 / Chapter 3.5 --- Conclusion --- p.76 / Chapter CHAPTER 4: --- CLONING OF PECTINASES GENES AND THEIR HETEROLOGOUS EXPRESSION IN PICHIA PASTORIS --- p.77 / Chapter 4.1 --- Introduction --- p.77 / Chapter 4.2 --- Materials and methods --- p.79 / Chapter 4.2.2 --- Strain cultivation --- p.79 / Chapter 4.2.3 --- RNA extraction and first strand cDNA synthesis --- p.79 / Chapter 4.2.4 --- Cloning and sequencing of pectinases genes --- p.80 / Chapter 4.2.5 --- Subcloning and expression vector construction --- p.80 / Chapter 4.2.6 --- Growth of Pichia pastoris strains --- p.81 / Chapter 4.2.7 --- Transformation into P. pastoris and vivo screening of multiple inserts --- p.81 / Chapter 4.2.8 --- Expression of recombinant P. pastoris strains --- p.82 / Chapter 4.2.9 --- RNA extraction and transcription analysis of pectinases genes in recombinant Pichia strains --- p.83 / Chapter 4.2.10 --- Enzyme activity assays --- p.83 / Chapter 4.2.11 --- SDS-PAGE --- p.84 / Chapter 4.3 --- Results --- p.88 / Chapter 4.3.2 --- RT-PCR for full-length cDNA of 13 pectinases genes --- p.88 / Chapter 4.3.3 --- Cloning and sequences analysis of 4 putative pectinases genes --- p.88 / Chapter 4.3.4 --- Construction of expression vectors of pectinases genes and transformation to P. pastoris --- p.88 / Chapter 4.3.5 --- Screening of multiple inserts clones --- p.88 / Chapter 4.3.6 --- Recombination and integration of pectinases genes in P. pastoris --- p.89 / Chapter 4.3.7 --- Transcription and expression of pectinases genes in recombinant Pichia strains. --- p.89 / Chapter 4.4 --- Discussion --- p.104 / Chapter 4.4.2 --- cDNA sequences of 4 pectinases genes --- p.104 / Chapter 4.4.3 --- Heterologous expression of 2 pectinases genes in P. pastoris --- p.104 / Chapter 4.4.4 --- Characterization of the pectinases expressed by recombinant Pichia strains --- p.106 / Chapter 4.5 --- Conclusion --- p.108 / Chapter CHAPTER 5: --- CONCLUDING REMARKS --- p.109 / REFERENCES --- p.121

Aquest treball es centra en la investigació sobre la producció de proteïnes heteròlogues en el llevat metilotròfic Pichia Pastoris. El principal avantatge de la utilització d'aquest sistema d'expressió és l'existència del promotor d'alcohol oxidasa, un dels més eficaços i fortament regulats per la presència de metanol com a única font de carboni. El gen hoste emprat és la lipasa del fong Rhizopus oryzae, proteïna d'elevat interès industrial i biotecnològic per les seves nombroses i variades aplicacions.De quatre tipus de soques diferents, dos parelles de diferent fenotip (Mut+ i Muts) i dins el mateix fenotip amb una o vàries còpies del gen hoste, s'ha seleccionat la soca més adient, en aquest cas Muts singlecopy, per una posterior explotació en cultiu semicontinu segons criteris de productivitat i dinàmica de creixement.S'ha observat que un dels problemes que presenta aquest tipus de cultiu és la reproductibilitat i el control de la concentració de metanol que s'aconsella no superar els nivells considerats com a tòxics de 10 g·l-1. Diferents mesures com l'anàlisi de la composició dels gasos de sortida del fermentador, l'extracció automàtica de mostres i la gestió de tota la informació del cultiu des de un programari dissenyat específicament, milloren significativament el seguiment i el control del cultiu. La disponibilitat de noves mesures del cultiu permeten estimar variables d'estat com la biomassa i la velocitat específica de creixement que són molt útils per conèixer el estat fisiològic del microorganisme.Per aconseguir mantenir estable la concentració de substrat inductor s'ha proposat utilitzar un llaç de control en retroalimentació començant pels sistemes de control més clàssics basats en l'error. La dinàmica canviant del sistema i el temps mort també variable fa que controls de tipus "on-off" i Proporciona Integral no siguin adients per mantenir prou estable la concentració de substrat. Com alternativa, s'ha implementat amb èxit un controlador predictiu basat en model que s'adapta contínuament al consum canviant de substrat inductor.Utilitzant de forma conjunta totes les millores instrumentals i de control del procés s'ha observat la influència que té la concentració de metanol sobre la producció de proteïna. D'aquest estudi se'n dedueix que mantenir la concentració a 1 g·l-1 durant el cultiu pot augmentar de forma significativa la productivitat. Paral·lelament es defineix que per maximitzar la productivitat la durada del cultiu ha de ser al voltant de les 80- 90h.Es pot afirmar que la instal·lació d'instrumentació juntament amb l'estimació, modelització i control d'algunes de les variables principals del cultiu, són mesures que permeten millorar la producció extracel·lular de proteïnes heteròlogues en Pichia Pastoris. / In this work the production of heterologous proteins by the methilotrophic yeast Pichia Pastoris has been studied. The main advantage of this expression system is the existence of a strong and tightly regulated (methanol-inducible) promoter from the alcohol oxidase gene (PAOX1).Using a battery of four strains, which secrete a Rhizophus oryzae lipase (ROL), the combined effects of gene dosage and Mut phenotype on recombinant protein production by P. pastoris were observed in fed-batch cultures. This study concludes that the use of Muts ROL single copy strain is advantageous because it allows easier process control strategies with high productivity.One of the main problems of these cultures is the low reproducibility and the need of accurate control of the methanol concentration in the fermentation to maintain it below toxic limits, 10 g·l-1. The implementation of exhaust gas analyzer, an autosampler system and specific software to on-line administrate the culture information improved significantly the control of the bioprocess.With several of these on-line measures it has been implemented an estimation algorithm that allows to determine both the specific growth rate of the microorganism and biomass concentration, used as physiologic indicators.To control the methanol concentration at an optimal set-point level during the cultivation, a feedback control using different error based controllers has been implemented. The use of on-off and PI (Proportional Integral) controllers is not recommended due to the dynamics of the biological system and the large death time of the system. As alternative, a predictive control algorithm based on the on-line estimation of the methanol rate has been successfully implemented.The improvement of the instrumentation and control of the bioprocess has provided the tools for the study of the influence of the methanol concentration on protein production. It has been observed that if the methanol concentration is maintained at 1 g·l-1 productivity increase about 140% is produced. Moreover, it suggested that to maximize the productivity of the system, the duration of the fed-batch fermentation should be around 80-90 h.The implementation of new instrumentation jointly with the use of software sensors, the modeling of the bioprocess, and the control of some of the fermentation variables significantly improved the production of the extracellular heterologous Rhizopus oryzae lipase by the yeast Pichia pastoris.

El desenvolupament de bioprocessos productius reproduïbles i escalables s'ha convertit en un dels colls d'ampolla a mesura que es consolida l'obtenció de proteïnes recombinants. Per poder superar-ho, la FDA i la EMEA han posat en marxa la iniciativa Process Analytical Technologies (PAT) que cerca el desenvolupament de processos productius eficients i controlats i que serveix de marc pel desenvolupament del present treball.El treball desenvolupat te com a objectiu el desenvolupament i implementació d'eines que permetin monitoritzar i controlar els processos de producció amb el llevat metilotròfic P. pastoris. Aquest objectiu es materialitza en forma de un desenvolupament d'eines per la correcta monitorització de paràmetres i variables associats al procés productiu, com són el desenvolupament d'un sistema automàtic de presa de mostra, el desenvolupament d'eines per a l'eliminació d'interferències per un sensor en línea de metanol, el desenvolupament d'un sistema en línea de compostos amínics i el desenvolupar un software sensor que permeti determinar en línea la velocitat específica de creixement de P. pastoris en base a un algoritme d'identificació RLS. A més a més, s'ha implementat un sistema de control per a poder analitzar l'efecte de la concentració de metanol en una soca de fenotip Mut+ de P. pastoris sobre la productivitat del procés productiu i posteriorment s'ha avaluat l'efecte de la utilització de substrats mixtes per a la producció de proteïnes recombinants pels fenotips Muts i Mut+ de P. pastoris.Paraules clauDiscontinu alimentat, Pichia pastoris, substrats mixtes, bioprocés, control, optimització, RLS / El desarrollo de bioprocesos productivos reproducibles y escalables se ha convertido en uno de los cuellos de botella a medida que se consolida la obtención de proteínas recombinantes. Para poder superarlo, la FDA y la EMEA han puesto en marcha la iniciativa Process Analytical Technologies (PAT) que busca el desarrollo de procesos productivos eficientes y controlados y que sirve de marco para el desarrollo del presente trabajo.El trabajo desarrollado tiene como objetivo el desarrollo e implementación de herramientas que permitan monitorizar y controlar los procesos de producción de la levadura metilotrófica P. pastoris. Este objetivo se materializa en forma de un desarrollo de herramientas para la correcta monitorización de parámetros y variables asociadas al proceso productivo, como son el desarrollo de un sistema automático de toma de muestra, el desarrollo de herramientas para la eliminación de interferencias para un sensor en línea de metanol, el desarrollo de un sistema en línea de medida de la concentración de compuestos amínicos y el desarrollo de un software sensor que permita determinar en línea la velocidad específica de crecimiento de P. pastoris en base a un algoritmo de identificación RLS. Además, se ha implementado un sistema de control para poder analizar el efecto de la concentración de metanol en una cepa de fenotipo Mut+ de P. pastoris sobre la productividad del proceso productivo y posteriormente se ha evaluado el efecto de la utilización de sustratos mixtos en la producción de proteínas recombinantes para los fenotipos Muts y Mut+ de P. pastoris.Palabras ClaveDiscontinuo alimentado, Pichia pastoris, substratos mixtos, bioproceso, control, optimización, RLS / The development of reproducible and scalable productive bioprocesses has become one of the bottlenecks for the production of recombinants proteins. In order to overcome it, the FDA and the EMEA have started off the Process Analytical Technologies (PAT). That initiative looks for the development of efficient and controlled productive processes and is in this concept where the present work is framed.The goal of this experimental work is the development and implementation of tools that allow monitorization and control of P. pastoris production processes.This goal is materialized with the creation and implementation of tools for the correct monitorization of parameters and state variables of the productive process, such as the development of an automatic sampling system, the development of tools for the elimination of interferences of an on-line methanol sensor, the development of an amine compounds analyzer and the development of a sensor software that allows to gauge the specific growth rate of P. pastoris using a RLS identification algorithm. Moreover, a methanol control system has been implemented for analyzing the effect of the substrate concentration in the productivity on a P. pastoris (phenotype Mut+) culture. And finally it has been analyzed the effect of mixed substrate strategy in Muts and Mut+ phenotypes of P. pastoris for the production of recombinant proteins. Key wordsFed-batch, Pichia pastoris, mixed substrates, bioprocess, control, optimization, RLS.