Evolutionary optimization of a fed-batch penicillin fermentation process

This paper presents a genetic algorithms approach for the optimization of a fed-batch penicillin fermentation process. A customized float-encoding genetic algorithm is developed and implemented to a benchmark fed-batch penicillin fermentation process. Off-line optimization of the initial conditions and set points are carried out in two stages for a single variable and multiple variables. Further investigations with online optimization have been carried out to demonstrate that the yield can be significantly improved with an optimal feed rate profile. The results have shown that the proposed approaches can be successfully applied to optimization problems of fed-batch fermentation to improve the operation of such processes

ECUT (Energy Conversion and Utilization Technologies Program). Biocatalysis Project

Presented are the FY 1985 accomplishments, activities, and planned research efforts of the Biocatalysis Project of the U.S. Department of Energy, Energy Conversion and Utilization Technologies (ECUT) Program. The Project's technical activities were organized as follows: In the Molecular Modeling and Applied Genetics work element, research focused on (1) modeling and simulation studies to establish the physiological basis of high temperature tolerance in a selected enzyme and the catalytic mechanisms of three species of another enzyme, and (2) determining the degree of plasmid amplification and stability of several DNA bacterial strains. In the Bioprocess Engineering work element, research focused on (1) studies of plasmid propagation and the generation of models, (2) developing methods for preparing immobilized biocatalyst beads, and (3) developing an enzyme encapsulation method. In the Process Design and Analysis work element, research focused on (1) further refinement of a test case simulation of the economics and energy efficiency of alternative biocatalyzed production processes, (2) developing a candidate bioprocess to determine the potential for reduced energy consumption and facility/operating costs, and (3) a techno-economic assessment of potential advancements in microbial ammonia production

Continuous Biochemical Processing: Investigating Novel Strategies to Produce Sustainable Fuels and Pharmaceuticals

Biochemical processing methods have been targeted as one of the potential renewable strategies for producing commodities currently dominated by the petrochemical industry. To design biochemical systems with the ability to compete with petrochemical facilities, inroads are needed to transition from traditional batch methods to continuous methods. Recent advancements in the areas of process systems and biochemical engineering have provided the tools necessary to study and design these continuous biochemical systems to maximize productivity and substrate utilization while reducing capital and operating costs. The first goal of this thesis is to propose a novel strategy for the continuous biochemical production of pharmaceuticals. The structural complexity of most pharmaceutical compounds makes chemical synthesis a difficult option, facilitating the need for their biological production. To this end, a continuous, multi-feed bioreactor system composed of multiple independently controlled feeds for substrate(s) and media is proposed to freely manipulate the bioreactor dilution rate and substrate concentrations. The optimal feed flow rates are determined through the solution to an optimal control problem where the kinetic models describing the time-variant system states are used as constraints. This new bioreactor paradigm is exemplified through the batch and continuous cultivation of β-carotene, a representative product of the mevalonate pathway, using Saccharomyces cerevisiae strain mutant SM14. The second goal of this thesis is to design continuous, biochemical processes capable of economically producing alternative liquid fuels. The large-scale, continuous production of ethanol via consolidated bioprocessing (CBP) is examined. Optimal process topologies for the CBP technology selected from a superstructure considering multiple biomass feeds, chosen from those available across the United States, and multiple prospective pretreatment technologies. Similarly, the production of butanol via acetone-butanol-ethanol (ABE) fermentation is explored using process intensification to improve process productivity and profitability. To overcome the inhibitory nature of the butanol product, the multi-feed bioreactor paradigm developed for pharmaceutical production is utilized with in situ gas stripping to simultaneously provide dilution effects and selectively remove the volatile ABE components. Optimal control and process synthesis techniques are utilized to determine the benefits of gas stripping and design a butanol production process guaranteed to be profitable

Evaluation of Somatic Embryogenesis Ability in Robusta Coffee (Coffea Canephora Pierre)

Embriogenesis somatik diharapkan sebagai metode perbanyakan tanaman yang sangat efektif pada kopi. Evaluasi dua jenis proses embriogenesis somatik, yaitu proses langsung dan tidak langsung akan bermanfaat untuk menggambarkan kemampuan proliferasi sel. Penelitian untuk mengevaluasi embriogenesis somatik kopi Robusta (Coffea canephora) yang mempunyai tingkat keragaman genetik tinggi telah dilakukan di Nestlé R&D Centre Tours, Perancis. Bahan tanam menggunakan kopi Robusta koleksi Nestle Perancis dan tiga klon koleksi Pusat Penelitian Kopi dan Kakao Indonesia (Puslitkoka). Tiga aspek, yaitu proses embriogenesis, keragaman embriogenesis dan kemantapan embriogenesis dievaluasi dalam penelitian ini. Hasil penelitian menunjukkan bahwa baik embriogenesis somatik langsung maupun tidak langsung dapat diamati. Penelitian ini menunjukkan bahwa kedua proses embriogenesis somatik tersebut merupakan dua mekanisme yang berbeda. Dalam penelitian ini ditunjukkan bahwa kemampuan embriognesis somatik tergantung pada genotipe, baik antar maupun di dalam kelompok genetik kopi Robusta, yaitu Congolese,Guinean dan Conillon. Lebih lanjut diketahui bahwa kedua proses embriogenesis somatik tersebut stabil terhadap indukan sebagai sumber eksplan. Kemampuan embriogenesis somatik tidak langsung ketiga klon Puslitkoka (BP409, BP961 dan Q121) sangat beragam, sehingga memberikan harapan adanya pola segregasi yang baik berdasarkan kemampuan embriogenesis somatik tidak langsung pada populasi yang dibuat dari silangan klon tersebut

Evolutionary algorithms for optimal control in fed-batch fermentation processes

In this work, Evolutionary Algorithms (EAs) are used to achieve optimal feedforward control in a recombinant bacterial fed-batch fermentation process, that aims at producing a bio-pharmaceutical product. Three diferent aspects are the target of the optimization procedure: the feeding trajectory (the amount of substrate introduced in a bioreactor per time unit), the duration of the fermentation and the initial conditions of the process. A novel EA with variable size chromosomes and using real-valued representations is proposed that is capable of simultaneously optimizing the aforementioned aspects. Outstanding productivity levels were achieved and the results are validated by practice

Development of a Perfusion Based System for Cardiac Decellularization

Heart failure is one of the leading causes of death worldwide. Currently, heart transplantation is the treatment of choice for end-stage heart failure, but lack of donor hearts and risk of rejection remain a challenge. Research has shown that decellularized hearts, in which cells are removed from the cardiac extracellular matrix (ECM), can provide a scaffold for use in engineering patient-specific heart transplants. This project presents a low-cost, semi-automated, small-organ (ie. rat heart) decellularization bioreactor designed for cardiac research, Testing has shown that this device can successfully decellularize rat hearts, and offers functionality similar to commercial devices

Multi-Scale Host-Aware Modeling for Analysis and Tuning of Synthetic Gene Circuits for Bioproduction

[ES] Esta Tesis ha sido dedicada al modelado multiescala considerando al anfitrión celular para el análisis y ajuste de circuitos genéticos sintéticos para bioproducción. Los objetivos principales fueron: 1. El desarrollo de un modelo que considere el anfitrión celular de tamaño reducido enfocado para simulación y análisis. 2. El desarrollo de herramientas de programación para el modelado y la simulación, orientada a la biología sintética. 3. La implementación de un modelo multiescala que considere las escalas relevantes para la bioproducción (biorreactor, célula y circuito sintético). 4. El análisis del controlador antitético considerando las interacciones célula-circuito, como ejemplo de aplicación de las herramientas desarrolladas. 5. El desarrollo y la validación experimental de leyes de control robusto para biorreactores continuos. El trabajo presentado en esta Tesis cubre las tres escalas del proceso de bioproducción. La primera escala es el biorreactor: esta escala considera la dinámica macroscópica del sustrato y la biomasa, y como estas dinámica se conecta con el estado interno de las células. La segunda escala es la célula anfitriona: esta escala considera la dinámica interna de la célula y la competencia por los recursos limitados compartidos para la expresión de proteínas. La tercera escala es el circuito genético sintético: esta escala considera la dinámica de expresión de los circuitos sintéticos exógenos y la carga que inducen en la célula anfitriona. Por último, como > escala, parte de la Tesis se ha dedicado a desarrollar herramientas de software para el modelado y la simulación. Este documento se divide en siete capítulos. El Capítulo 1 es una introducción general al trabajo de la Tesis y su justificación; también presenta un mapa visual de la Tesis y enumera las principales contribuciones. El Capítulo 2 muestra el desarrollo del modelo del anfitrión celular (los Capítulos 4 y 5 hacen uso de este modelo para sus simulaciones). El Capítulo 3 presenta OneModel: una herramienta de software desarrollada en la Tesis que facilita el modelado y la simulación en biología sintética, en particular, facilita el uso del modelo del anfitrión celular. El Capítulo 4 utiliza el modelo del anfitrión celular para montar el modelo multiescala que considera el biorreactor y analiza el título, la productividad y el rendimiento en la expresión de una proteína exógena. El Capítulo 5 analiza un circuito más complejo, el recientemente propuesto y muy citado controlador biomolecular antitético, utilizando el modelo del anfitrión celular. El Capítulo 6 muestra el diseño de estrategias de control no lineal que permiten controlar la concentración de biomasa en un biorreactor continuo de forma robusta. El Capítulo 7 resume y presenta las principales conclusiones de la Tesis. En el Apéndice A se muestra el desarrollo teórico del modelo del anfitrión celular. Esta Tesis destaca la importancia de estudiar la carga celular en los sistemas biológicos, ya que estos efectos son muy notables y generan interacciones entre circuitos aparentemente independientes. La Tesis proporciona herramientas para modelar, simular y diseñar circuitos genéticos sintéticos teniendo en cuenta estos efectos de carga y permite el desarrollo de modelos que conecten estos fenómenos en los circuitos genéticos sintéticos, que van desde la dinámica intracelular de la expresión génica hasta la dinámica macroscópica de la población de células dentro del biorreactor.[CA] Aquesta Tesi tracta del modelat multiescala considerant l'amfitrió ce\lgem ular per a l'anàlisi i ajust de circuits genètics sintètics per a bioproducció. Els objectius principals van ser: 1. El desenvolupament d'un model de grandària reduïda que considere l'amfitrió ce\lgem ular, enfocat al seu ús en simulació i anàlisi. 2. El desenvolupament d'eines de programari per al modelatge i la simulació, orientada a la biologia sintètica. 3. La implementació d'un model multiescala que considere les escales rellevants per a la bioproducció (bioreactor, cè\lgem ula i circuit sintètic). 4. L'anàlisi del controlador antitètic considerant les interacciones cè\lgem ula-circuit, com a exemple d'aplicació de les eines desenvolupades. 5. El desenvolupament i la validació experimental de lleis de control robust per a bioreactors continus. El treball presentat en aquesta Tesi cobreix les tres escales del procés de bioproducció. La primera escala és el bioreactor: aquesta escala considera la dinàmica macroscòpica del substrat i la biomassa, i com aquestes dinàmiques es connecten amb l'estat intern de les cè\lgem ules. La segona escala és la cè\lgem ula amfitriona: aquesta escala considera la dinàmica interna de la cè\lgem ula i la competència pels recursos limitats compartits per a l'expressió de proteïnes. La tercera escala és la del circuit genètic sintètic: aquesta escala considera la dinàmica d'expressió de circuits sintètics exógens i la càrrega que indueixen en la cè\lgem ula amfitriona. Finalment, com a > escala, part de la Tesi s'ha dedicat a desenvolupar eines de programari per al modelatge i la simulació. Aquest document es divideix en set capítols. El Capítol 1 és una introducció general al treball de la Tesi i la seua justificació; també presenta un mapa visual de la Tesi i enumera les principals contribucions. El Capítol 2 mostra el desenvolupament del model de l'amfitrió ce\lgem ular (els Capítols 4 i 5 fan ús d'aquest model per a les seues simulacions). El Capítol 3 presenta OneModel: una eina de programari desenvolupada en la Tesi que facilita el modelatge i la simulació en biologia sintètica, en particular, facilita l'ús del model de l'amfitrió ce\lgem ular. El Capítol 4 utilitza el model de l'amfitrió ce\lgem ular per a muntar el model multiescala que considera el bioreactor i analitza el títol, la productivitat i el rendiment en l'expressió d'una proteïna exògena. El Capítol 5 analitza un circuit més complex, el recentment proposat i molt citat controlador biomolecular antitètic, utilitzant el model de l'amfitrió ce\lgem ular. El Capítol 6 mostra el disseny d'estratègies de control no lineal que permeten controlar la concentració de biomassa en un bioreactor continu de manera robusta. El Capítol 7 resumeix i presenta les principals conclusions de la Tesi. En l'Apèndix A es mostra el desenvolupament teòric del model de l'amfitrió ce\lgem ular. Aquesta Tesi destaca la importància d'estudiar la càrrega ce\lgem ular en els sistemes biològics, ja que aquests efectes són molt notables i generen interaccions entre circuits aparentment independents. La Tesi proporciona eines per a modelar, simular i dissenyar circuits genètics sintètics tenint en compte aquests efectes de càrrega i permet el desenvolupament de models que connecten aquests fenòmens en els circuits genètics sintètics, que van des de la dinàmica intrace\lgem ular de l'expressió gènica fins a la dinàmica macroscòpica de la població de cè\lgem ules dins del bioreactor.[EN] This Thesis was devoted to the multi-scale host-aware analysis and tuning of synthetic gene circuits for bioproduction. The main objectives were: 1. The development of a reduced-size host-aware model for simulation and analysis purposes. 2. The development of a software toolbox for modeling and simulation, oriented to synthetic biology. 3. The implementation of a multi-scale model that considers the scales relevant to bioproduction (bioreactor, cell, and synthetic circuit). 4. The host-aware analysis of the antithetic controller, as an example of the application of the developed tools. 5. The development and experimental validation of robust control laws for continuous bioreactors. The work presented in this Thesis covers the three scales of the bioproduction process. The first scale is the bioreactor: this scale considers the macroscopic substrate and biomass dynamics and how these dynamics connect to the internal state of the cells. The second scale is the host cell: this scale considers the internal dynamics of the cell and the competition for limited shared resources for protein expression. The third scale is the synthetic genetic circuit: this scale considers the dynamics of expressing exogenous synthetic circuits and the burden they induce on the host cell. Finally, as a > scale, part of the Thesis was devoted to developing software tools for modeling and simulation. This document is divided into seven chapters. Chapter 1 is an overall introduction to the Thesis work and its justification; it also presents a visual map of the Thesis and lists the main contributions. Chapter 2 shows the development of the host-aware model (Chapters 4 and 5 make use of this model for their simulations). Chapter 3 presents OneModel: a software tool developed in the Thesis that facilitates modeling and simulation for synthetic biology---in particular, it facilitates the use of the host-aware model---. Chapter 4 uses the host-aware model to assemble the multi-scale model considering the bioreactor and analyzes the titer, productivity (rate), and yield in expressing an exogenous protein. Chapter 5 analyzes a more complex circuit, the recently proposed and highly cited antithetic biomolecular controller, using the host-aware model. Chapter 6 shows the design of nonlinear control strategies that allow controlling the concentration of biomass in a continuous bioreactor in a robust way. Chapter 7 summarizes and presents the main conclusions of the Thesis. Appendix A shows the theoretical development of the host-aware model. This Thesis emphasizes the importance of studying cell burden in biological systems since these effects are very noticeable and generate interactions between seemingly unconnected circuits. The Thesis provides tools to model, simulate and design synthetic genetic circuits taking into account these burden effects and allowing the development of models that connect phenomena in synthetic genetic circuits, ranging from the intracelullar dynamics of gene expression to the macroscopic dynamics of the population of cells inside the bioreactor.This research was funded by MCIN/AEI/10.13039/501100011033 grant number PID2020-117271RB-C21, and MINECO/AEI, EU grant number DPI2017-82896- C2-1-R. The author was recipient of the grant “Programa para la Formación de Personal Investigador (FPI) de la Universitat Politècnica de València — Subprograma 1 (PAID-01-2017)”. The author was also a grantee of the predoctoral stay “Ayudas para Movilidad de Estudiantes de Doctorado de la Universitat Politècnica de València 2019”. The Control Theory and Systems Biology Lab of the ETH Zürich is acknowledged for accepting the author in their facilities as predoctoral stay and their valuable collaboration sharing knowledge.Santos Navarro, FN. (2022). Multi-Scale Host-Aware Modeling for Analysis and Tuning of Synthetic Gene Circuits for Bioproduction [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/183473Premios Extraordinarios de tesis doctorale

A Genetic Algorithm for Feeding Trajectory Optimisation of Fed-batch Fermentation Processes

In this work a genetic algorithm is proposed with the purpose of the feeding trajectory optimization during a fed-batch fermentation of E. coli. The feed rate profiles are evaluated based on a number of objective functions. Optimization results obtained for different feeding trajectories demonstrate that the genetic algorithm works well and shows good computational performance. Developed optimal feed profiles meet the defined criteria. The ration of the substrate concentration and the difference between actual cell concentration and theoretical maximum cell concentration is defined as the most appropriate objective function. In this case the final cell concentration of 43 g·l-1 and final product concentration of 125 g·l-1 are achieved and there is not significant excess of substrate