Plant natural products include a diverse array of compounds that play important roles in plant metabolism and physiology. After elucidation of biosynthetic pathways and regulatory factors, it has become possible to metabolically engineer new capabilities in planta as well as successfully engineer whole pathways into microbial systems. Microbial expression systems for producing valuable plant compounds have evolved to incorporate polyculture and co-culture consortiums for carrying out robust biosynthesis strategies. This review focuses on four classes of plant secondary metabolites and the recent advances in generating useful compounds in microbial expression platforms and in plant metabolic engineering. They are the flavonoids, alkaloids, betalains, and glucosinolates.

Synthetic biology is an emerging field which has led to development of many useful applications of engineered biological networks and systems. One of the exciting advancements of the field are living cells which can serve as molecular factories, diagnostics or therapeutics. A widely used chassis in synthetic biology is yeast due to simple and inexpensive culturing conditions and the ability to heterologously express eukaryotic proteins. In this thesis, we present work exploring and expanding biosensing and responding capabilities of engineered lab strain yeast. Chapter 1 gives background information related to synthetic biology, living engineered biosensors, theranostics and more specifically on Saccharomyces cerevisiae general overview and applications in synthetic biology. Chapter 2 describes progress on establishing redox active peptides as a modular electrochemical interfacing language between electronics and engineered yeast. Chapter 3 covers yeast engineering as a heavy metal and metalloid biosensor, as well as the exploration of peptide-containing hydrobeads in conjunction with peptide-responsive yeast as a physical damage biosensor. In Chapter 4, we establish living yeast biosensor for detection of pathogenic fungus Aspergillus fumigatus and expanded biosensing of other Aspergillus species, as well as additional optimization of the biosensing yeast’s signal-to-noise ratio, sensitivity and readout time. Chapter 5 demonstrates the utility of specific peptide proteases in combination with promiscuous GPCRs in living yeast biosensor for detection and differentiation of peptide variants differing in single amino acid. Lastly, in Chapter 6 we implement yeast sense-and-respond community which is activated by pheromone-secreting fungi and as a response secretes a toxin which kills sensed fungi.

京都大学 / 0048 / 新制・課程博士 / 博士(医科学) / 甲第21689号 / 医科博第93号 / 新制||医||1036(附属図書館) / 京都大学大学院医学研究科医科学専攻 / (主査)教授 斎藤 通紀, 教授 中川 一路, 教授 竹内 理 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

京都大学 / 0048 / 新制・課程博士 / 博士(医科学) / 甲第21694号 / 医科博第98号 / 新制||医科||7(附属図書館) / 京都大学大学院医学研究科医科学専攻 / (主査)教授 竹内 理, 教授 Shohab YOUSSEFIAN, 教授 藤渕 航 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

No description available.

Eukaryotic genes are often regulated by multivalent transcription factor (TF) complexes. Through the process of cooperative self-assembly, these complexes carry out non-linear regulatory operations involved in cellular decision-making and signal processing. In this thesis, we apply this natural design principle to artificial networks, testing whether engineered cooperative TF assemblies can be used to program non-linear synthetic circuit behavior in yeast. Using a model-guided approach, we show that specifying strength and number of interactions in an assembly enables predictive tuning between regimes of linear and non-linear regulatory response for single- and multi-input circuits. We demonstrate that synthetic assemblies can be adjusted to control circuit dynamics, shaping the timing of activation. We harness this capability to engineer circuits that perform dynamic filtering, enabling frequency-dependent decoding in cell populations. Thru this work, we find that cooperative assembly provides a versatile way to tune nonlinearity of network connections, dramatically expanding the range engineerable behaviors available to synthetic circuits. We then extend our modeling-framework to predict genome-wide binding of our TF assemblies and find that cooperative complexes made of weakly-interacting proteins can reduce unintended activation of endogenous genes. Thus, we are able to introduce synthetic regulatory components with low fitness costs on the cell, ensuring long-term stability of our integrated circuits over time. Taken together, this dissertation outlines a synthetic framework for building cooperative transcriptional complexes in vivo in order to engineer complex regulatory behaviors that are functionally orthogonal to the host cell. / 2019-10-22T00:00:00Z

Yes / Membrane computing is a new natural computing paradigm inspired by the functioning and structure of biological cells, and has been successfully applied to many different areas, from biology to engineering. In this paper, we present kPWorkbench, a software framework developed to support membrane computing and its applications. kPWorkbench offers unique features, including modelling, simulation, agent-based high performance simulation and verification, which allow modelling and computational analysis of membrane systems. The kPWorkbench formal verification component provides the opportunity to analyse the behaviour of a model and validate that important system requirements are met and certain behaviours are observed. The platform also features a property language based on natural language statements to facilitate property specification. / EPSRC

Natural cellular networks are very good at processing diverse inputs, generating complicated responses, and confounding researchers with their complexities. As an alternative to traditional cellular engineering approaches, the field of synthetic biology attempts to avoid the complexities of natural systems by focusing on the bottom-up construction of artificial cellular circuits. By rationally building up circuit complexity, synthetic biologists hope to both create novel systems capable of programming unique cellular responses, and gain insights into the design principles of natural systems. Circuits that allow for the programming of intercellular responses are of particular interest, and researchers have focused on the use of bacterial communication mechanisms (quorum sensing) to construct such circuits. At their most basic, quorum-sensing systems are composed of three main components, making them amenable to genetic manipulation. These components, however, have properties that have been finely tuned through evolution to function in very specific ways, and repurposing them for our own uses requires methods to overcome their naturally evolved properties. This thesis details our work in the construction and engineering of synthetic circuits based on components of the LuxI-LuxR quorum-sensing system. Using these components, we demonstrate methods for altering both the sensitivity and the form of the quorum-sensing response through the creation of three unique systems: an ultrasensitive positive feedback loop, a logical AND gate, and a coupled feedback loop oscillator. Construction and tuning of each circuit's properties were achieved through a mixture of rational and evolutionary approaches, with particular emphasis on the directed evolution of the LuxR transcriptional activator. Mathematical modeling was also used during the construction of the more complex circuits to predict the properties that were essential to their functionalities. With the construction and characterization of these circuits, we have provided both well-defined modules that can be used in the construction of more complex systems, and developed methods that will allow for the creation and engineering of additional synthetic circuits.

Yes

No description available.