Metabolic engineers endeavor to create a bio-based manufacturing industry using microbes to produce fuels, chemicals, and medicines. Plant natural products (PNPs) are historically challenging to ...produce and are ubiquitous in medicines, flavors, and fragrances. Engineering PNP pathways into new hosts requires finding or modifying a suitable host to accommodate the pathway, planning and implementing a biosynthetic route to the compound, and discovering or engineering enzymes for missing steps. In this review, we describe recent developments in metabolic engineering at the level of host, pathway, and enzyme, and discuss how the field is approaching ever more complex biosynthetic opportunities.
Metabolic engineering in the host Yarrowia lipolytica Abdel-Mawgoud, Ahmad M.; Markham, Kelly A.; Palmer, Claire M. ...
Metabolic engineering,
November 2018, 2018-11-00, 20181101, 2018-11-01, Letnik:
50, Številka:
C
Journal Article
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The nonconventional, oleaginous yeast, Yarrowia lipolytica is rapidly emerging as a valuable host for the production of a variety of both lipid and nonlipid chemical products. While the unique ...genetics of this organism pose some challenges, many new metabolic engineering tools have emerged to facilitate improved genetic manipulation in this host. This review establishes a case for Y. lipolytica as a premier metabolic engineering host based on innate metabolic capacity, emerging synthetic tools, and engineering examples. The metabolism underlying the lipid accumulation phenotype of this yeast as well as high flux through acyl-CoA precursors and the TCA cycle provide a favorable metabolic environment for expression of relevant heterologous pathways. These properties allow Y. lipolytica to be successfully engineered for the production of both native and nonnative lipid, organic acid, sugar and acetyl-CoA derived products. Finally, this host has unique metabolic pathways enabling growth on a wide range of carbon sources, including waste products. The expansion of carbon sources, together with the improvement of tools as highlighted here, have allowed this nonconventional organism to act as a cellular factory for valuable chemicals and fuels.
•Yarrowia lipolytica is a host for both lipid and nonlipid chemical products.•Emerging synthetic biology tools enable further engineering in this host.•Successful engineering for lipid production phenotypes.•Engineering for both native and nonnative lipid, organic acid, sugar and acetyl-CoA derived products.
Metabolic engineering can have a pivotal role in increasing the environmental sustainability of the transportation and chemical manufacturing sectors. The field has already developed engineered ...microorganisms that are currently being used in industrial-scale processes. However, it is often challenging to achieve the titres, yields and productivities required for commercial viability. The efficiency of microbial chemical production is usually dependent on the physiological traits of the host organism, which may either impose limitations on engineered biosynthetic pathways or, conversely, boost their performance. In this Review, we discuss different aspects of microbial physiology that often create obstacles for metabolic engineering, and present solutions to overcome them. We also describe various instances in which natural or engineered physiological traits in host organisms have been harnessed to benefit engineered metabolic pathways for chemical production.
Metabolic engineering: past and future Woolston, Benjamin M; Edgar, Steven; Stephanopoulos, Gregory
Annual review of chemical and biomolecular engineering,
01/2013, Letnik:
4
Journal Article
Recenzirano
We present here a broad overview of the field of metabolic engineering, describing in the first section the key fundamental principles that define and distinguish it, as well as the technological and ...intellectual developments over the past approximately 20 years that have led to the current state of the art. Discussion of concepts such as metabolic flux analysis, metabolic control analysis, and rational and combinatorial methods is facilitated by illustrative examples of their application drawn from the extensive metabolic engineering literature. In the second section, we present some of the rapidly emerging technologies that we think will play pivotal roles in the continued growth of the field, from improving production metrics to expanding the range of attainable compounds.
Summary
The last few years have witnessed an unprecedented increase in the number of novel bacterial species that hold potential to be used for metabolic engineering. Historically, however, only a ...handful of bacteria have attained the acceptance and widespread use that are needed to fulfil the needs of industrial bioproduction – and only for the synthesis of very few, structurally simple compounds. One of the reasons for this unfortunate circumstance has been the dearth of tools for targeted genome engineering of bacterial chassis, and, nowadays, synthetic biology is significantly helping to bridge such knowledge gap. Against this background, in this review, we discuss the state of the art in the rational design and construction of robust bacterial chassis for metabolic engineering, presenting key examples of bacterial species that have secured a place in industrial bioproduction. The emergence of novel bacterial chassis is also considered at the light of the unique properties of their physiology and metabolism, and the practical applications in which they are expected to outperform other microbial platforms. Emerging opportunities, essential strategies to enable successful development of industrial phenotypes, and major challenges in the field of bacterial chassis development are also discussed, outlining the solutions that contemporary synthetic biology‐guided metabolic engineering offers to tackle these issues.
The field of engineering bacterial chassis for bioproduction is experiencing an unprecedented attention due to the adoption of alternative bacterial hosts that can perform under a wide variety of industrially‐relevant conditions.
Butanol as an advanced biofuel has gained great attention due to its environmental benefits and superior properties compared to ethanol. However, the cost of biobutanol production via conventional ...acetone-butanol-ethanol (ABE) fermentation by Clostridium acetobutylicum is not economically competitive, which has hampered its industrial application. The strain performance and downstream process greatly impact the economics of biobutanol production. Although various engineered strains with carefully orchestrated metabolic and sporulation-specific pathways have been developed, none of them is ideal for industrial biobutanol production. For further strain improvement, it is necessary to develop advanced genome editing tools and a deep understanding of cellular functioning of genes in metabolic and regulatory pathways. Processes with integrated product recovery can increase fermentation productivity by continuously removing inhibitory products while generating butanol (ABE) in a concentrated solution. In this review, we provide an overview of recent advances in C. acetobutylicum strain engineering and process development focusing on in situ product recovery. With deep understanding of systematic cellular bioinformatics, the exploration of state-of-the-art genome editing tools such as CRISPR-Cas for targeted gene knock-out and knock-in would play a vital role in Clostridium cell engineering for biobutanol production. Developing advanced hybrid separation processes for in situ butanol recovery, which will be discussed with a detailed comparison of advantages and disadvantages of various recovery techniques, is also imperative to the economical development of biobutanol.
The itinerary followed by Pseudomonas putida from being a soil-dweller and plant colonizer bacterium to become a flexible and engineer-able platform for metabolic engineering stems from its natural ...lifestyle, which is adapted to harsh environmental conditions and all sorts of physicochemical stresses. Over the years, these properties have been capitalized biotechnologically owing to the expanding wealth of genetic tools designed for deep-editing the P. putida genome. A suite of dedicated vectors inspired in the core tenets of synthetic biology have enabled to suppress many of the naturally-occurring undesirable traits native to this species while enhancing its many appealing properties, and also to import catalytic activities and attributes from other biological systems. Much of the biotechnological interest on P. putida stems from the distinct architecture of its central carbon metabolism. The native biochemistry is naturally geared to generate reductive currency i.e., NAD(P)H that makes this bacterium a phenomenal host for redox-intensive reactions. In some cases, genetic editing of the indigenous biochemical network of P. putida (cis-metabolism) has sufficed to obtain target compounds of industrial interest. Yet, the main value and promise of this species (in particular, strain KT2440) resides not only in its capacity to host heterologous pathways from other microorganisms, but also altogether artificial routes (trans-metabolism) for making complex, new-to-Nature molecules. A number of examples are presented for substantiating the worth of P. putida as one of the favorite workhorses for sustainable manufacturing of fine and bulk chemicals in the current times of the 4th Industrial Revolution. The potential of P. putida to extend its rich native biochemistry beyond existing boundaries is discussed and research bottlenecks to this end are also identified. These aspects include not just the innovative genetic design of new strains but also the incorporation of novel chemical elements into the extant biochemistry, as well as genomic stability and scaling-up issues.
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•Efficient cell factories require the adoption of specific bacterial chasses.•Pseudomonas putida is a robust microbial platform for metabolic engineering.•Tools of contemporary synthetic biology facilitate deep engineering of P. putida.•De novo design of complex, autonomous biochemistries is the frontier in the field.•Trans-metabolisms, composed by orthogonal blocks, will facilitate these endeavors.
Carotenoids are indispensable to plants and critical in human diets. Plastids are the organelles for carotenoid biosynthesis and storage in plant cells. They exist in various types, which include ...proplastids, etioplasts, chloroplasts, amyloplasts, and chromoplasts. These plastids have dramatic differences in their capacity to synthesize and sequester carotenoids. Clearly, plastids play a central role in governing carotenogenic activity, carotenoid stability, and pigment diversity. Understanding of carotenoid metabolism and accumulation in various plastids expands our view on the multifaceted regulation of carotenogenesis and facilitates our efforts toward developing nutrient-enriched food crops. In this review, we provide a comprehensive overview of the impact of various types of plastids on carotenoid biosynthesis and accumulation, and discuss recent advances in our understanding of the regulatory control of carotenogenesis and metabolic engineering of carotenoids in light of plastid types in plants.
Plastids, the sites for carotenoid biosynthesis and storage, play a central role in governing carotenogenic activity, carotenoid stability, and pigment diversity in plants. This review provides a comprehensive overview of the impact of various plastids on carotenoid biosynthesis and accumulation, as well as the effect of plastid types on the multifaceted regulation of carotenoid metabolism and metabolic engineering of carotenoids.
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