skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.


Title: Metabolic Engineering and the Synthetic Biology Toolbox for Clostridium
The Clostridium genus contains a diverse range of Gram-positive, sporulating, obligate anaerobes that have been of historical biotechnological interest due to their acetone–butanol–ethanol (ABE) solvent production. Within the last few decades, interest has grown in the Clostridium spp. capable of consuming a wider variety of feedstocks, which include gaseous and renewable biomass sources. Additionally, attenuated pathogens have been of interest as potential therapeutics. The fruition of the genus's great promise has been limited by the slow progress in genetic engineering and synthetic biology methods and tools, relative to workhorse organisms such as Escherichia coli . Recent advances in these areas, not least of which include CRISPR-based tools, renew the promise of metabolic engineering for a broad range of feedstock consumption and production of chemicals. In this chapter, we describe the current state of engineering in the Clostridium genus by describing efforts and continued challenges in directed evolution, the use of systems biology for greater understanding, methods for performing genomic editing, and the expanding library of genetic parts. These new capabilities and tools have expanded the number of species that are able to be engineered for biotechnological purposes, increased the throughput of genetic studies, and expanded the range of products made from Clostridium.  more » « less
Award ID(s):
1736123
PAR ID:
10379520
Author(s) / Creator(s):
; ; ;
Editor(s):
Nielsen, Jens; Stephanopoulos, Gregory; Lee, Sang Yup
Date Published:
Journal Name:
Metabolic engineering
Volume:
1
ISSN:
1096-7184
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. null (Ed.)
    Abstract Yarrowia lipolytica has emerged as a biomanufacturing platform for a variety of industrial applications. It has been demonstrated to be a robust cell factory for the production of renewable chemicals and enzymes for fuel, feed, oleochemical, nutraceutical and pharmaceutical applications. Metabolic engineering of this non-conventional yeast started through conventional molecular genetic engineering tools; however, recent advances in gene/genome editing systems, such as CRISPR–Cas9, transposons, and TALENs, has greatly expanded the applications of synthetic biology, metabolic engineering and functional genomics of Y. lipolytica . In this review we summarize the work to develop these tools and their demonstrated uses in engineering Y. lipolytica , discuss important subtleties and challenges to using these tools, and give our perspective on important gaps in gene/genome editing tools in Y. lipolytica . 
    more » « less
  2. Industrial biotechnology and biopharmaceutical manufacturing leverage biology to enable cellular systems to serve as factories to produce molecules of value to humankind. These biotechnological processes utilize diverse host organisms and address applications from biofuel, polymer building blocks, antibiotics, and whole cell therapies. Industrial biotechnology can address environmental and sustainability goals in addition to chemical production. In a similar fashion, the field of biopharmaceutical manufacturing has and continues to produce life-saving medicines. Despite these diverse applications, these fields rely on common biological themes and require similar approaches for genetic and metabolic engineering as discussed in this review. Through advances in synthetic biology, targeted genetic engineering, DNA sequencing, adaptation and high-throughput screening, industrial biotechnology and biopharmaceutical manufacturing utilize the same framework for efficient biochemical production which can be leveraged in current and future collaborations to enable rapid innovation. 
    more » « less
  3. As the name of the genusPantoea(“of all sorts and sources”) suggests, this genus includes bacteria with a wide range of provenances, including plants, animals, soils, components of the water cycle, and humans. Some members of the genus are pathogenic to plants, and some are suspected to be opportunistic human pathogens; while others are used as microbial pesticides or show promise in biotechnological applications. During its taxonomic history, the genus and its species have seen many revisions. However, evolutionary and comparative genomics studies have started to provide a solid foundation for a more stable taxonomy. To move further toward this goal, we have built a 2,509-gene core genome tree of 437 public genome sequences representing the currently known diversity of the genusPantoea. Clades were evaluated for being evolutionarily and ecologically significant by determining bootstrap support, gene content differences, and recent recombination events. These results were then integrated with genome metadata, published literature, descriptions of named species with standing in nomenclature, and circumscriptions of yet-unnamed species clusters, 15 of which we assigned names under the nascent SeqCode. Finally, genome-based circumscriptions and descriptions of each species and each significant genetic lineage within species were uploaded to the LINbase Web server so that newly sequenced genomes of isolates belonging to any of these groups could be precisely and accurately identified. 
    more » « less
  4. The piRNA pathway is a specialized small RNA interference that in mosquitoes is mechanistically distant from analogous biology in the Drosophila model. Current genetic engineering methods, such as targeted genome manipulation, have a high potential to tease out the functional complexity of this intricate molecular pathway. However, progress in utilizing these methods in arthropod vectors has been geared mostly toward the development of new vector control strategies rather than to study cellular functions. Herein we propose that genetic engineering methods will be essential to uncover the full functionality of PIWI/piRNA biology in mosquitoes and that extending the applications of genetic engineering on other aspects of mosquito biology will grant access to a much larger pool of knowledge in disease vectors that is just out of reach. We discuss motivations for and impediments to expanding the utility of genetic engineering to study the underlying biology and disease transmission and describe specific areas where efforts can be placed to achieve the full potential for genetic engineering in basic biology in mosquito vectors. Such efforts will generate a refreshed intellectual source of novel approaches to disease control and strong support for the effective use of approaches currently in development. 
    more » « less
  5. ABSTRACT The continuously growing demand for dietary protein raises the urgency of expanding supply chains beyond conventional animal‐based sources. Microalgae are well‐known as biofactories due to their high photosynthetic efficiency, rapid growth, minimal resource requirements, and ability to thrive in diverse environments. To maximize protein production, mixotrophic cultivation is often preferred, as it enables significantly higher biomass yields. Key factors, including light quality (intensity and wavelength), carbon sources (inorganic CO2and organic substrates), and nitrogen availability, play significant roles in directing metabolic fluxes toward protein biosynthesis, the modulation of which refers to biochemical engineering. In the field of genetic engineering, precise gene editing tools, especially CRISPR/Cas9, have demonstrated considerable promise, although the application in enhancing microalgal protein production remains challenging and limited. By contrast, random mutagenesis has been proven effective in improving multiple strains for increased protein accumulation. Beyond upstream strategies, downstream engineering, including drying, extrusion forming, and fermentation, is emphasized for improving the nutritional and functional properties of microalgal proteins for food and feed applications in the form of whole cells. Furthermore, extracted microalgal proteins broaden the range of potential applications, whose quality is significantly affected by the methods used for cell disruption/extraction, purification, and hydrolysis. Novel biorefinery strategies are also discussed to enhance economic viability by integrating value‐added biomass utilization within a protein‐first recovery scheme. Altogether, by combining advances in cultivation technologies, strain modification, processing, and supportive policy frameworks, this review supports the development of sustainable protein production platforms based on microalgae. 
    more » « less