scholarly journals Reassessing Escherichia coli as a cell factory for biofuel production

2017 ◽  
Vol 45 ◽  
pp. 92-103 ◽  
Author(s):  
Chonglong Wang ◽  
Brian F Pfleger ◽  
Seon-Won Kim
Keyword(s):  
Escherichia Coli ◽  
Biofuel Production ◽  
Cell Factory ◽  
A Cell

scholarly journals Development of chromosome-based T7 RNA polymerase and orthogonal T7 promoter circuit in Escherichia coli W3110 as a cell factory

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Wan-Wen Ting ◽  
Shih-I Tan ◽  
I-Son Ng
Keyword(s):  
Escherichia Coli ◽  
Protein Expression ◽  
Rna Polymerase ◽  
Green Fluorescence Protein ◽  
T7 Rna Polymerase ◽  
Cell Factory ◽  
T7 Promoter ◽  
Iptg Induction ◽  
E Coli ◽  
A Cell

Abstract Background Orthogonal T7 RNA polymerase (T7RNAP) and T7 promoter is a powerful genetic element to mediate protein expression in different cells. Among all, Escherichia coli possess advantages of fast growth rate, easy for culture and comprehensive elements for genetic engineering. As E. coli W3110 owns the benefits of more heat shock proteins and higher tolerance to toxic chemicals, further execution of T7-based system in W3110 as cell factory is a conceivable strategy. Results Three novel W3110 strains, i.e., W3110:IL5, W3110::L5 and W3110::pI, were accomplished by chromosome-equipped T7RNAP. At first, the LacZ and T7RNAP with isopropyl-β-D-thiogalactopyranoside (IPTG) induction showed higher expression levels in W3110 derivatives than that in BL21(DE3). The plasmids with and without lacI/lacO repression were used to investigate the protein expression of super-fold green fluorescence protein (sfGFP), carbonic anhydrase (CA) for carbon dioxide uptake and lysine decarboxylase (CadA) to produce a toxic chemical cadaverine (DAP). All the proteins showed better expression in W3110::L5 and W3110::pI, respectively. As a result, the highest cadaverine production of 36.9 g/L, lysine consumption of 43.8 g/L and up to 100% yield were obtained in W3110::pI(−) with plasmid pSU-T7-CadA constitutively. Conclusion Effect of IPTG and lacI/lacO regulator has been investigated in three chromosome-based T7RNAP E. coli strains. The newly engineered W3110 strains possessed similar protein expression compared to commercial BL21(DE3). Furthermore, W3110::pI displays higher production of sfGFP, CA and CadA, due to it having the highest sensitivity to IPTG, thus it represents the greatest potential as a cell factory.

scholarly journals Zymomonas mobilis as an emerging biotechnological chassis for the production of industrially relevant compounds

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Adelaide Braga ◽  
Daniela Gomes ◽  
João Rainha ◽  
Cláudia Amorim ◽  
Beatriz B. Cardoso ◽  
...  
Keyword(s):  
Metabolic Engineering ◽  
Zymomonas Mobilis ◽  
Building Blocks ◽  
Biofuel Production ◽  
Cell Factory ◽  
Proof Of Concept ◽  
Biotechnological Applications ◽  
Biotechnological Production ◽  
Lignocellulosic Substrates ◽  
A Cell

AbstractZymomonas mobilis is a well-recognized ethanologenic bacterium with outstanding characteristics which make it a promising platform for the biotechnological production of relevant building blocks and fine chemicals compounds. In the last years, research has been focused on the physiological, genetic, and metabolic engineering strategies aiming at expanding Z. mobilis ability to metabolize lignocellulosic substrates toward biofuel production. With the expansion of the Z. mobilis molecular and computational modeling toolbox, the potential of this bacterium as a cell factory has been thoroughly explored. The number of genomic, transcriptomic, proteomic, and fluxomic data that is becoming available for this bacterium has increased. For this reason, in the forthcoming years, systems biology is expected to continue driving the improvement of Z. mobilis for current and emergent biotechnological applications. While the existing molecular toolbox allowed the creation of stable Z. mobilis strains with improved traits for pinpointed biotechnological applications, the development of new and more flexible tools is crucial to boost the engineering capabilities of this bacterium. Novel genetic toolkits based on the CRISPR-Cas9 system and recombineering have been recently used for the metabolic engineering of Z. mobilis. However, they are mostly at the proof-of-concept stage and need to be further improved. Graphical Abstract

scholarly journals Genome-scale target identification in Escherichia coli for high-titer production of free fatty acids

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Lixia Fang ◽  
Jie Fan ◽  
Shulei Luo ◽  
Yaru Chen ◽  
Congya Wang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Fatty Acids ◽  
Free Fatty Acids ◽  
Stress Responses ◽  
Metabolic Networks ◽  
Target Identification ◽  
High Titer ◽  
Cell Factory ◽  
Microbial Cell Factory ◽  
Ffa Metabolism

AbstractTo construct a superior microbial cell factory for chemical synthesis, a major challenge is to fully exploit cellular potential by identifying and engineering beneficial gene targets in sophisticated metabolic networks. Here, we take advantage of CRISPR interference (CRISPRi) and omics analyses to systematically identify beneficial genes that can be engineered to promote free fatty acids (FFAs) production in Escherichia coli. CRISPRi-mediated genetic perturbation enables the identification of 30 beneficial genes from 108 targets related to FFA metabolism. Then, omics analyses of the FFAs-overproducing strains and a control strain enable the identification of another 26 beneficial genes that are seemingly irrelevant to FFA metabolism. Combinatorial perturbation of four beneficial genes involving cellular stress responses results in a recombinant strain ihfAL−-aidB+-ryfAM−-gadAH−, producing 30.0 g L−1 FFAs in fed-batch fermentation, the maximum titer in E. coli reported to date. Our findings are of help in rewiring cellular metabolism and interwoven intracellular processes to facilitate high-titer production of biochemicals.

scholarly journals Pilot-Scale Production of Fatty Acid Ethyl Esters by an Engineered Escherichia coli Strain Harboring the p(Microdiesel) Plasmid

2010 ◽  
Vol 76 (13) ◽  
pp. 4560-4565 ◽  
Author(s):  
Yasser Elbahloul ◽  
Alexander Steinbüchel
Keyword(s):  
Escherichia Coli ◽  
Fatty Acid ◽  
Carbon Sources ◽  
Dry Mass ◽  
Pilot Scale ◽  
Coli Strain ◽  
Fatty Acid Ethyl Esters ◽  
Ethyl Esters ◽  
Scale Production ◽  
A Cell

ABSTRACT Fatty acid ethyl esters (FAEEs) were produced in this study by the use of an engineered Escherichia coli p(Microdiesel) strain. Four fed-batch pilot scale cultivations were carried out by first using glycerol as sole carbon source for biomass production before glucose and oleic acid were added as carbon sources. Cultivations yielded a cell density of up to 61 ± 3.1 g of cell dry mass (CDM) per liter and a maximal FAEE content of 25.4% ± 1.1% (wt/wt) of CDM.

scholarly journals Metabolic engineering of Escherichia coli for de novo production of 3-phenylpropanol via retrobiosynthesis approach

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Zhenning Liu ◽  
Xue Zhang ◽  
Dengwei Lei ◽  
Bin Qiao ◽  
Guang-Rong Zhao
Keyword(s):  
Escherichia Coli ◽  
Metabolic Engineering ◽  
De Novo ◽  
Microbial Cell ◽  
Cell Factory ◽  
Phosphopantetheinyl Transferase ◽  
Chromosome Engineering ◽  
Microbial Cell Factory ◽  
E Coli ◽  
Artificial Pathway

Abstract Background 3-Phenylpropanol with a pleasant odor is widely used in foods, beverages and cosmetics as a fragrance ingredient. It also acts as the precursor and reactant in pharmaceutical and chemical industries. Currently, petroleum-based manufacturing processes of 3-phenypropanol is environmentally unfriendly and unsustainable. In this study, we aim to engineer Escherichia coli as microbial cell factory for de novo production of 3-phenypropanol via retrobiosynthesis approach. Results Aided by in silico retrobiosynthesis analysis, we designed a novel 3-phenylpropanol biosynthetic pathway extending from l-phenylalanine and comprising the phenylalanine ammonia lyase (PAL), enoate reductase (ER), aryl carboxylic acid reductase (CAR) and phosphopantetheinyl transferase (PPTase). We screened the enzymes from plants and microorganisms and reconstructed the artificial pathway for conversion of 3-phenylpropanol from l-phenylalanine. Then we conducted chromosome engineering to increase the supply of precursor l-phenylalanine and combined the upstream l-phenylalanine pathway and downstream 3-phenylpropanol pathway. Finally, we regulated the metabolic pathway strength and optimized fermentation conditions. As a consequence, metabolically engineered E. coli strain produced 847.97 mg/L of 3-phenypropanol at 24 h using glucose-glycerol mixture as co-carbon source. Conclusions We successfully developed an artificial 3-phenylpropanol pathway based on retrobiosynthesis approach, and highest titer of 3-phenylpropanol was achieved in E. coli via systems metabolic engineering strategies including enzyme sources variety, chromosome engineering, metabolic strength balancing and fermentation optimization. This work provides an engineered strain with industrial potential for production of 3-phenylpropanol, and the strategies applied here could be practical for bioengineers to design and reconstruct the microbial cell factory for high valuable chemicals.

Evaluation of Gaseous Chlorine Dioxide as a Sanitizer for Killing Salmonella, Escherichia coli O157:H7, Listeria monocytogenes, and Yeasts and Molds on Fresh and Fresh-Cut Produce

2005 ◽  
Vol 68 (6) ◽  
pp. 1176-1187 ◽  
Author(s):  
KAYE V. SY ◽  
MELINDA B. MURRAY ◽  
M. DAVID HARRISON ◽  
LARRY R. BEUCHAT
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Chlorine Dioxide ◽  
Foodborne Pathogens ◽  
Escherichia Coli O157 ◽  
Gaseous Chlorine Dioxide ◽  
Sensory Qualities ◽  
A Cell ◽  
Fresh Cut ◽  
Yeasts And Molds

Gaseous chlorine dioxide (ClO2) was evaluated for effectiveness in killing Salmonella, Escherichia coli O157:H7, and Listeria monocytogenes on fresh-cut lettuce, cabbage, and carrot and Salmonella, yeasts, and molds on apples, peaches, tomatoes, and onions. Inoculum (100 μl, ca. 6.8 log CFU) containing five serotypes of Salmonella enterica, five strains of E. coli O157:H7, or five strains of L. monocytogenes was deposited on the skin and cut surfaces of fresh-cut vegetables, dried for 30 min at 22°C, held for 20 h at 4°C, and then incubated for 30 min at 22°C before treatment. The skin surfaces of apples, peaches, tomatoes, and onions were inoculated with 100 μl of a cell suspension (ca. 8.0 log CFU) containing five serotypes of Salmonella, and inoculated produce was allowed to dry for 20 to 22 h at 22°C before treatment. Treatment with ClO2 at 4.1 mg/liter significantly (α = 0.05) reduced the population of foodborne pathogens on all produce. Reductions resulting from this treatment were 3.13 to 4.42 log CFU/g for fresh-cut cabbage, 5.15 to 5.88 log CFU/g for fresh-cut carrots, 1.53 to 1.58 log CFU/g for fresh-cut lettuce, 4.21 log CFU per apple, 4.33 log CFU per tomato, 1.94 log CFU per onion, and 3.23 log CFU per peach. The highest reductions in yeast and mold populations resulting from the same treatment were 1.68 log CFU per apple and 2.65 log CFU per peach. Populations of yeasts and molds on tomatoes and onions were not significantly reduced by treatment with 4.1 mg/liter ClO2. Substantial reductions in populations of pathogens on apples, tomatoes, and onions but not peaches or fresh-cut cabbage, carrot, and lettuce were achieved by treatment with gaseous ClO2 without markedly adverse effects on sensory qualities.

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