scholarly journals Construction of a tunable promoter library to optimize gene expression in Methylomonas sp. DH-1, a methanotroph, and its application to cadaverine production

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Hyang-Mi Lee ◽  
Jun Ren ◽  
Myeong-Sang Yu ◽  
Hyunjoo Kim ◽  
Woo Young Kim ◽  
...  
Keyword(s):  
Gene Expression ◽  
Carbon Dioxide ◽  
Metabolic Engineering ◽  
Value Added ◽  
Cell Factory ◽  
Methanotrophic Bacteria ◽  
Practical Application ◽  
Expression Optimization ◽  
Promoter Library ◽  
Precursor Supply

Abstract Background As methane is 84 times more potent than carbon dioxide in exacerbating the greenhouse effect, there is an increasing interest in the utilization of methanotrophic bacteria that can convert harmful methane into various value-added compounds. A recently isolated methanotroph, Methylomonas sp. DH-1, is a promising biofactory platform because of its relatively fast growth. However, the lack of genetic engineering tools hampers its wide use in the bioindustry. Results Through three different approaches, we constructed a tunable promoter library comprising 33 promoters that can be used for the metabolic engineering of Methylomonas sp. DH-1. The library had an expression level of 0.24–410% when compared with the strength of the lac promoter. For practical application of the promoter library, we fine-tuned the expressions of cadA and cadB genes, required for cadaverine synthesis and export, respectively. The strain with PrpmB-cadA and PDnaA-cadB produced the highest cadaverine titre (18.12 ± 1.06 mg/L) in Methylomonas sp. DH-1, which was up to 2.8-fold higher than that obtained from a non-optimized strain. In addition, cell growth and lysine (a precursor of cadaverine) production assays suggested that gene expression optimization through transcription tuning can afford a balance between the growth and precursor supply. Conclusions The tunable promoter library provides standard and tunable components for gene expression, thereby facilitating the use of methanotrophs, specifically Methylomonas sp. DH-1, as a sustainable cell factory. Graphical Abstract

scholarly journals Bioproduction of Isoprenoids and Other Secondary Metabolites Using Methanotrophic Bacteria as an Alternative Microbial Cell Factory Option: Current Stage and Future Aspects

Catalysts ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 883 ◽  
Author(s):  
Young Chan Jeon ◽  
Anh Duc Nguyen ◽  
Eun Yeol Lee
Keyword(s):  
Metabolic Engineering ◽  
Secondary Metabolites ◽  
Value Added ◽  
Industrial Applications ◽  
Cell Factory ◽  
Methanotrophic Bacteria ◽  
Microbial Cell Factory ◽  
Future Outlook ◽  
Metabolites Production ◽  
Current Stage

Methane is a promising carbon feedstock for industrial biomanufacturing because of its low price and high abundance. Recent advances in metabolic engineering and systems biology in methanotrophs have made it possible to produce a variety of value-added compounds from methane, including secondary metabolites. Isoprenoids are one of the largest family of secondary metabolites and have many useful industrial applications. In this review, we highlight the current efforts invested to methanotrophs for the production of isoprenoids and other secondary metabolites, including riboflavin and ectoine. The future outlook for improving secondary metabolites production (especially of isoprenoids) using metabolic engineering of methanotrophs is also discussed.

Gas Diffusion Electrodes (GDEs) for Electrochemical Reduction of Carbon Dioxide, Carbon Monoxide, and Dinitrogen to Value-added Products: A Review

2021 ◽  
Author(s):  
Hesamoddin Rabiee ◽  
Lei Ge ◽  
Xueqin Zhang ◽  
Shihu Hu ◽  
Mengran Li ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Mass Transport ◽  
Electrochemical Reduction ◽  
Value Added ◽  
Gas Diffusion ◽  
Practical Application ◽  
Gas Diffusion Electrodes ◽  
Chemical Production ◽  
Value Added Products

Electrochemical reduction of gaseous feeds such as CO2, CO, and N2 holds promise for sustainable energy and chemical production. Practical application of this technology is impeded by slow mass transport...

Integrative genome-scale metabolic modeling reveals versatile metabolic strategies for methane utilization in Methylomicrobium album BG8

2021 ◽  
Author(s):  
Juan C. Villada ◽  
Maria F. Duran ◽  
Chee Kent Lim ◽  
Lisa Y. Stein ◽  
Patrick K. H. Lee
Keyword(s):  
Carbon Dioxide ◽  
Value Added ◽  
System Level ◽  
Cell Factory ◽  
Trade Off ◽  
A Genome ◽  
Uptake Rates ◽  
Methylomicrobium Album ◽  
Specific Uptake ◽  
Genome Scale

Methylomicrobium album BG8 is an aerobic methanotrophic bacterium that can mitigate environmental methane emission, and is a promising microbial cell factory for the conversion of methane to value-added chemicals. However, the lack of a genome-scale metabolic model (GEM) of M. album BG8 has hindered the development of systems biology and metabolic engineering of this methanotroph. To fill this gap, a high-quality GEM was constructed to facilitate a system-level understanding on the biochemistry of M. album BG8. Next, experimental time-series growth and exometabolomics data were integrated into the model to generate context-specific GEMs. Flux balance analysis (FBA) constrained with experimental data derived from varying levels of methane, oxygen, and biomass were used to model the metabolism of M. album BG8 and investigate the metabolic states that promote the production of biomass and the excretion of carbon dioxide, formate, and acetate. The experimental and modeling results indicated that the system-level metabolic functions of M. album BG8 require a ratio > 1:1 between the oxygen and methane specific uptake rates for optimal growth. Integrative modeling revealed that at a high ratio of oxygen-to-methane uptake flux, carbon dioxide and formate were the preferred excreted compounds; at lower ratios, however, acetate accounted for a larger fraction of the total excreted flux. The results of this study reveal a trade-off between biomass production and organic compound excretion and provide evidence that this trade-off is linked to the ratio between the oxygen and methane specific uptake rates.

Research on creation and practical application of high-value-added recycling technology for waste plastic

Impact ◽  
2020 ◽  
Vol 2020 (6) ◽  
pp. 15-17
Author(s):  
Shigeru Yao ◽  
Patchiya Phanthong
Keyword(s):  
Collaborative Research ◽  
Chemical Engineering ◽  
Technology Development ◽  
Value Added ◽  
Assistant Professor ◽  
Research Assistant ◽  
Practical Application ◽  
Development Organization ◽  
New Energy ◽  
Environmental Technologies

Professor Shigeru Yao and Dr Patchiya Phanthong are conducting highly collaborative research that is focused on improving mechanical technology for recycling plastics, as well as extending the shelf life of plastics, thus reducing plastic waste. The researchers are based at the Yao Laboratory, in the Department of Chemical Engineering, Fukuoka University, Japan. Phanthong is a Project Research Assistant Professor from the Research Institute for the Creation of Functional and Structural Materials working under the supervision of Yao. In addition to heading up the lab, Yao is also the lead for the NEDO (New Energy and Industrial Technology Development Organization) Advanced Research Program for Energy and Environmental Technologies. In their work, the researchers are collaborating with both industry and academia which is essential to its progression.

Graphdiyne Anchored Ultrafine Ag Nanoparticles for High Efficient and Solvent-Free Catalysis of CO2 Cycloaddition

2021 ◽  
Author(s):  
Chang Liu ◽  
Chao Zhang ◽  
Tongbu Lu
Keyword(s):  
Ag Nanoparticles ◽  
Co2 Reduction ◽  
Value Added ◽  
Solvent Free ◽  
Alternative Route ◽  
Practical Application ◽  
Co2 Utilization ◽  
High Efficient

Apart from photo-/electro-catalytic CO2 reduction, an important alternative route to CO2 utilization is to use this inert molecule as a C1 source to synthesize value-added chemicals, while the practical application...

Light-driven reduction of carbon dioxide: Altering the reaction pathways and designing photocatalysts toward value-added and renewable fuels

2021 ◽  
Vol 237 ◽  
pp. 116547
Author(s):  
Quyet Van Le ◽  
Van-Huy Nguyen ◽  
Trinh Duy Nguyen ◽  
Ajit Sharma ◽  
Gul Rahman ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Value Added ◽  
Reaction Pathways ◽  
Renewable Fuels

scholarly journals Refactoring of a synthetic raspberry ketone pathway with EcoFlex

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Simon J. Moore ◽  
Yonek B. Hleba ◽  
Sarah Bischoff ◽  
David Bell ◽  
Karen M. Polizzi ◽  
...  
Keyword(s):  
Gene Expression ◽  
Synthetic Biology ◽  
Combinatorial Libraries ◽  
Value Added ◽  
Microtiter Plate ◽  
Fine Tuning ◽  
Golden Gate ◽  
E Coli ◽  
Fine Chemical ◽  
Raspberry Ketone

Abstract Background  A key focus of synthetic biology is to develop microbial or cell-free based biobased routes to value-added chemicals such as fragrances. Originally, we developed the EcoFlex system, a Golden Gate toolkit, to study genes/pathways flexibly using Escherichia coli heterologous expression. In this current work, we sought to use EcoFlex to optimise a synthetic raspberry ketone biosynthetic pathway. Raspberry ketone is a high-value (~ £20,000 kg−1) fine chemical farmed from raspberry (Rubeus rubrum) fruit. Results  By applying a synthetic biology led design-build-test-learn cycle approach, we refactor the raspberry ketone pathway from a low level of productivity (0.2 mg/L), to achieve a 65-fold (12.9 mg/L) improvement in production. We perform this optimisation at the prototype level (using microtiter plate cultures) with E. coli DH10β, as a routine cloning host. The use of E. coli DH10β facilitates the Golden Gate cloning process for the screening of combinatorial libraries. In addition, we also newly establish a novel colour-based phenotypic screen to identify productive clones quickly from solid/liquid culture. Conclusions  Our findings provide a stable raspberry ketone pathway that relies upon a natural feedstock (L-tyrosine) and uses only constitutive promoters to control gene expression. In conclusion we demonstrate the capability of EcoFlex for fine-tuning a model fine chemical pathway and provide a range of newly characterised promoter tools gene expression in E. coli.

Atomic-level engineering of two-dimensional electrocatalysts for CO2 Reduction

Nanoscale ◽  
2021 ◽  
Author(s):  
Wei Shao ◽  
Xiaodong Zhang
Keyword(s):  
Carbon Dioxide ◽  
Fossil Fuels ◽  
Co2 Reduction ◽  
Value Added ◽  
Atomic Level ◽  
Two Dimensional ◽  
Excessive Consumption

Carbon dioxide (CO2) from the excessive consumption of fossil fuels has exhibited a huge threat to the planet’s ecosystem. Electrocatalytic CO2 reduction into value-added chemicals have been regarded as a...

Electrografting Amines onto Modified Silver Nanoparticle Electrodes for Electroreduction of CO2 at Low Overpotential

2021 ◽  
Author(s):  
Heinz-Bernhard Kraatz ◽  
Maryam Abdinejad ◽  
Iranaldo Santos da Silva
Keyword(s):  
Carbon Dioxide ◽  
Silver Nanoparticle ◽  
Value Added ◽  
Efficient Manner ◽  
Low Overpotential

Reducing carbon dioxide (CO2) to value-added synthons in a selective and efficient manner remains a sizable challenge to CO2 conversion research. Although many electrocatalysts have been reported to date, those...

An overview of flow cell architectures design and optimization for electrochemical CO2 reduction

2021 ◽  
Author(s):  
Dui Ma ◽  
Ting Jin ◽  
Keyu Xie ◽  
Haitao Huang
Keyword(s):  
Carbon Dioxide ◽  
Global Warming ◽  
Electrochemical Reduction ◽  
Atmospheric Carbon Dioxide ◽  
Co2 Reduction ◽  
Value Added ◽  
Flow Cell ◽  
Design And Optimization ◽  
Electrochemical Co2 Reduction ◽  
Carbon Dioxide Levels

Converting CO2 into value-added fuels or chemical feedstocks through electrochemical reduction is one of the several promising avenues to reduce atmospheric carbon dioxide levels and alleviate global warming. This approach...

Sign in / Sign up

Export Citation Format

Share Document