1,529 research outputs found
Co-culture engineering for microbial biosynthesis of 3-amino-benzoic acid in Escherichia coli
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Engineering the shikimate pathway for biosynthesis of molecules with pharmaceutical activities in E. coli
No full textEngineering the shikimate pathway is a primary approach for biosynthesis of various aromatic compounds, many of which are involved in formation of important compounds with pharmaceutical values. The development of metabolic engineering allows for high-efficiency production of desired molecules derived from the shikimate pathway using engineered microbes as biosynthetic factories. This review summarizes successful and generally applicable strategies for engineering this important pathway in the context of the model bacterium E. coli for biosynthesis of molecules with pharmaceutical activities. Similar approaches can also be employed for shikimate pathway engineering in other microorganisms.Peer reviewe
Balancing the non-linear rosmarinic acid biosynthetic pathway by modular co-culture engineering
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Modular co-culture engineering, a new approach for metabolic engineering
No full textWith the development of metabolic engineering, employment of a selected microbial host for accommodation of a designed biosynthetic pathway to produce a target compound has achieved tremendous success in the past several decades. Yet, increasing requirements for sophisticated microbial biosynthesis call for establishment and application of more advanced metabolic engineering methodologies. Recently, important progress has been made towards employing more than one engineered microbial strains to constitute synthetic co-cultures and modularizing the biosynthetic labor between the co-culture members in order to improve bioproduction performance. This emerging approach, referred to as modular co-culture engineering in this review, presents a valuable opportunity for expanding the scope of the broad field of metabolic engineering. We highlight representative research accomplishments using this approach, especially those utilizing metabolic engineering tools for microbial co-culture manipulation. Key benefits and major challenges associated with modular co-culture engineering are also presented and discussed
Developing E. coli-E. coli co-cultures to overcome barriers of heterologous tryptamine biosynthesis
No full textTryptamine is an alkaloid compound with demonstrated bioactivities and is also a precursor molecule to many important hormones and neurotransmitters. The high efficiency biosynthesis of tryptamine from inexpensive and renewable carbon substrates is of great research and application significance. In the present study, a tryptamine biosynthesis pathway was established in a metabolically engineered E. coli-E. coli co-culture. The upstream and downstream strains of the co-culture were dedicated to tryptophan provision and conversion totryptamine, respectively. The constructed co-culture was cultivated using either glucose or glycerol as carbon source for de novo production of tryptamine.The manipulation of the co-culture strains’ inoculation ratio was adapted to balance the biosynthetic strengths of the pathway modules for bioproduction optimization. Moreover, a biosensor-assisted cell selection strategy was adapted to improve the pathway intermediate tryptophan provision by the upstream strain, which further enhanced the tryptamine biosynthesis. The resulting biosensor-assisted modular co-culture produced 194mg/L tryptamine with a yield of 0.02 g/g glucose using shake flask cultivation.The findings of this work demonstrate that the biosensor-assisted modular co-culture engineering offers a new perspective for conducting microbial biosynthesis.Peer reviewe
Constructing E. coli co-cultures for de novo biosynthesis of natural product acacetin
No full textModular co-culture engineering is an emerging approach for biosynthesis of complex natural products. In this study, we constructed microbial co-cultures composed of two and three E. coli strains, respectively, for de novo biosynthesis of flavonoid acacetin, a value-added natural compound possessing numerous demonstrated biological activities, from simple carbon substrate glucose. To this end, the heterologous biosynthetic pathway was divided into different modules, each of which was accommodated in a dedicated E. coli strain for functional expression. After the optimization of the inoculation ratio between the constituent strains, the engineered cocultures showed a 4.83-fold improvement in production comparing to the mono-culture controls. Importantly, cultivation of the three-strain co-culture in shake flasks resulted in the production of 20.3 mg/L acacetin after 48 h. To our knowledge, this is the first report on acacetin de novo biosynthesis in a heterologous microbial host. The results of this work confirm the effectiveness of modular co-culture engineering for complex flavonoid biosynthesis.Peer reviewe
Comparing E. coli mono-cultures and co-cultures for biosynthesis of protocatechuic acid and hydroquinone
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Establishing microbial co-cultures for 3-hydroxybenzoic acid biosynthesis on glycerol
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Biosensor-assisted high performing cell selection using an E. coli toxin/antitoxin system
No full textSelection for high-producing cells in a mixed population is of great significance for synthetic biology and metabolic engineering applications. Here, we developed a cell selection mechanism that utilized a product-responsive biosensor to control the expression of E. coli endogenous toxin hipA or antitoxin hipB genes for selective removal of low-performing cells. This approach eliminates the use of exogenous antibiotics as the selection marker and offers a solution to flexibly meet the need of using either downregulating (off-switch) or upregulating (on-switch) biosensors. As a proof-of-concept, we showed that the developed cell selection systems encompassing a tryptophan biosensor (off-switch) and the toxin hipA gene dramatically enhanced the tryptophan production in E. coli, which was mechanistically characterized by monitoring the dynamic expression of the GFP-labelled hipA gene. The cell selection system was also extended for phenylalanine over-production using a phenylalanine biosensor (on-switch) and the antitoxin gene hipB. Our findings show that this approach has strong potential for wide applications in synthetic biology and metabolic engineering.Peer reviewe
Enhancing anthranilic acid biosynthesis using biosensor-assisted cell selection and in situ product removal
No full textAnthranilic acid is an important chemical with recognized industrial values. As a precursor of amino acid tryptophan, anthranilic acid can be over-produced by engineering the tryptophan biosynthesis pathway. In this study, we utilized metabolic engineering approaches to enable anthranilic acid production in bacterium E. coli. Furthermore, an anthranilic acid biosensor20 assisted cell selection technique was adopted to improve the microbial cell population composition and the overall production performance. An anthranilic acid in situ extraction method was also recruited to reduce the product accumulation and facilitate the cell selection. Based on these efforts, the engineered E. coli produced 688 mg/L anthranilic acid from glucose within 48 h. The results of this work hereby demonstrate the effectiveness of coupling biosensor-assisted cell selection and in situ product removal for microbial biosynthesis enhancement.Peer reviewe
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