Gas fermentation for commodity chemicals and fuels

The manufacturing industry must diverge from a ‘take, make and waste’ linear production paradigm towards more circular economies. Truly sustainable, circular economies are intrinsically tied to renewable resource flows, where vast quantities need to be available at a central point of consumption. Abundant, renewable carbon feedstocks are often structurally complex and recalcitrant, requiring costly pre-treatment to harness their potential fully. As such, the heat integration of supercritical water gasification and aerobic gas fermentation, unlocks the promise of renewable feedstocks such as lignin. This study models the technoeconomics and life cycle assessment for the sustainable production of the commodity chemicals, isopropanol and acetone, from gasified Kraft black liquor. The investment case is underpinned by rigorous process modelling informed by published continuous gas fermentation experimental data. Time series analyses support the price forecasts for the solvent products. Furthermore, a Monte Carlo simulation frames an uncertain boundary for the technoeconomic model. The technoeconomic analysis demonstrates that production of commodity chemicals priced at ~$1000 per ton is within reach of aerobic gas fermentation. In addition, owed to the sequestration of biogenic carbon into the solvent products, negative greenhouse gas emissions are achieved within a cradle-to-gate life cycle assessment framework. As such, the heat integrated aerobic gas fermentation platform has promise as a best-in-class technology for the production of a broad spectrum of renewable commodity chemicals.

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From gas to sugar: Trehalose production in Cupriavidus necator from CO2 and hydrogen gas

10.1101/2020.06.05.136564 ◽

2020 ◽

Author(s):

Hannes Löwe ◽

Marleen Beentjes ◽

Katharina Pflüger-Grau ◽

Andreas Kremling

Keyword(s):

Dry Weight ◽

Glycogen Metabolism ◽

Hydrogen Gas ◽

Cupriavidus Necator ◽

Renewable Electricity ◽

Gas Fermentation ◽

New Process ◽

Commodity Chemicals ◽

Synthesis Gas Fermentation ◽

Trehalose Synthesis

AbstractThe paradigm of a fossil based, non-renewable economy will have to change in the future due to environmental concerns and the inevitable depletion of resources. Therefore, the way we produce and consume chemicals has to be rethought: The bio-economy offers such a concept for the sustainable production of commodity chemicals using waste streams or renewable electricity and CO2. Residual biomass or organic wastes can be gasified to energy rich mixtures that in turn can be used for synthesis gas fermentation.Within this scope, we present a new process for the production of trehalose from gaseous substrates with the hydrogen-oxidizing bacterium Cupriavidus necator H16. We first show that C. necator is a natural producer of trehalose, accumulating up to 3.6% of its cell dry weight as trehalose when stressed with 150 mM sodium chloride. Bioinformatic investigations revealed a so far unknown mode of trehalose and glycogen metabolism in this organism. Next, we evaluated different concepts for the secretion of trehalose and found that expression of the sugar efflux transporter A (setA) from Escherichia coli was able to lead to a trehalose-leaky phenotype. Finally, we characterized the strain under autotrophic conditions using a H2/CO2/O2-mixture and other substrates. Even without overexpressing trehalose synthesis genes, titers of 0.47 g/L and yields of around 10% were reached, which shows the great potential of this process.Taken together, this process represents a new way to produce sugars with a higher areal efficiency than photosynthesis by crop plants. With further metabolic engineering, we anticipate an application of this technology for the renewable production of trehalose and other sugars, as well as for the synthesis of 13C-labeled sugars.Graphical abstract

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Renewable Diesel Blendstocks and Biopriviliged Chemicals Distilled from Algal Biocrude Oil Converted via Hydrothermal Liquefaction

10.26434/chemrxiv.9630695 ◽

2019 ◽

Author(s):

Wan-Ting (Grace) Chen ◽

Zhenwei Wu ◽

Buchun Si ◽

Yuanhui Zhang

Keyword(s):

Oxidation Stability ◽

Ash Content ◽

Hydrothermal Liquefaction ◽

Fractional Distillation ◽

Chemical Compositions ◽

Steam Temperature ◽

Renewable Diesel ◽

Commodity Chemicals ◽

Biocrude Oil ◽

Specification Analysis

This study aims to produce renewable diesel and biopriviliged chemicals from microalgae that can thrive in wastewater environment. <i>Spirulina</i> (SP) was converted into biocrude oil at 300ºC for a 30-minute reaction time via hydrothermal liquefaction (HTL). Next, fractional distillation was used to separate SP-derived biocrude oil into different distillates. It was found that 62% of the viscous SP-derived biocrude oil can be separated into liquids at about 270ºC (steam temperature of the distillation). Physicochemical characterizations, including density, viscosity, acidity, elemental compositions, higher heating values and chemical compositions, were carried out with the distillates separated from SP-derived biocrude oil. These analyses showed that 15% distillates could be used as renewable diesel because they have similar heating values (43-46 MJ/kg) and carbon numbers (ranging from C8 to C18) to petroleum diesel. The Van Krevelan diagram of the distillates suggests that deoxygenation was effectively achieved by fractional distillation. In addition, GC-MS analysis indicates that some distillates contain biopriviliged chemicals like aromatics, phenols and fatty nitriles that can be used as commodity chemicals. An algal biorefinery roadmap was proposed based on the analyses of different distillates from the SP-derived biocrude oil. Finally, the fuel specification analysis was conducted with the drop-in renewable diesel, which was prepared with 10 vol.% (HTL10) distillates and 90 vol.% petroleum diesel. According to the fuel specification analysis, HTL10 exhibited a qualified lubricity (<520 µm), acidity (<0.3 mg KOH/g) and oxidation stability (>6 hr), as well as a comparable net heat of combustion (1% lower), ash content (29% lower) and viscosity (17% lower) to those of petroleum diesel. Ultimately, it is expected that this study can provide insights for potential application of algal biocrude oil converted via HTL.

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Synthesis, antibiotic structure–activity relationships, and cellulose dissolution studies of new room-temperature ionic liquids derived from lignin

Biotechnology for Biofuels ◽

10.1186/s13068-021-01898-x ◽

2021 ◽

Vol 14 (1) ◽

Cited By ~ 1

Author(s):

Shihong Liu ◽

Michael Gonzalez ◽

Celine Kong ◽

Scott Weir ◽

Aaron M. Socha

Keyword(s):

Antibacterial Activity ◽

Ionic Liquids ◽

Room Temperature ◽

Oxidation Products ◽

Cellulose Dissolution ◽

Melting Points ◽

E Coli ◽

Alkyl Chains ◽

Renewable Feedstocks ◽

Commodity Chemicals

Abstract Background Ionic liquids (ILs) are promising pretreatment solvents for lignocellulosic biomass, but are largely prepared from petroleum precursors. Benzaldehydes from depolymerized lignin, such as vanillin, syringaldehyde, and 4-methoxy benzaldehyde, represent renewable feedstocks for the synthesis of ionic liquids. We herein report syntheses of novel lignin-derived ionic liquids, with extended N-alkyl chains, and examine their melting points, cellulose dissolution capacities, and toxicity profiles against Daphnia magna and E. coli strain 1A1. The latter organism has been engineered to produce isoprenol, a drop-in biofuel and precursor for commodity chemicals. Results The new N,N-diethyl and N,N-dipropyl methyl benzylammonium ILs were liquids at room temperature, showing 75–100 °C decreased melting points as compared to their N,N,N-trimethyl benzylammonium analog. Extension of N-alkyl chains also increased antibacterial activity threefold, while ionic liquids prepared from vanillin showed 2- to 4-fold lower toxicity as compared to those prepared from syringaldehyde and 4-methoxybenzaldehyde. The trend of antibacterial activity for anions of lignin-derived ILs was found to be methanesulfonate < acetate < hydroxide. Microcrystalline cellulose dissolution, from 2 to 4 wt% after 20 min at 100 °C, was observed in all new ILs using light microscopy and IR spectroscopy. Conclusions Ionic liquids prepared from H-, S- and G-lignin oxidation products provided differential cytotoxic activity against E. coli and D. magna, suggesting these compounds could be tailored for application specificity within a biorefinery.

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Aquatic weed Spirodela polyrhiza, a potential source for energy generation and other commodity chemicals production

Renewable Energy ◽

10.1016/j.renene.2021.03.054 ◽

2021 ◽

Author(s):

Vipul R. Patel ◽

Nikhil Bhatt

Keyword(s):

Energy Generation ◽

Aquatic Weed ◽

Spirodela Polyrhiza ◽

Potential Source ◽

Commodity Chemicals

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Metabolic engineering of Moorella thermoacetica for thermophilic bioconversion of gaseous substrates to a volatile chemical

AMB Express ◽

10.1186/s13568-021-01220-w ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Junya Kato ◽

Kaisei Takemura ◽

Setsu Kato ◽

Tatsuya Fujii ◽

Keisuke Wada ◽

...

Keyword(s):

Carbon Flux ◽

Cost Effective ◽

Gas Composition ◽

Autotrophic Growth ◽

Acetyl Coenzyme A ◽

Volatile Chemicals ◽

Moorella Thermoacetica ◽

Gas Fermentation ◽

Dry Cell ◽

Co Gas

AbstractGas fermentation is one of the promising bioprocesses to convert CO2 or syngas to important chemicals. Thermophilic gas fermentation of volatile chemicals has the potential for the development of consolidated bioprocesses that can simultaneously separate products during fermentation. This study reports the production of acetone from CO2 and H2, CO, or syngas by introducing the acetone production pathway using acetyl–coenzyme A (Ac-CoA) and acetate produced via the Wood–Ljungdahl pathway in Moorella thermoacetica. Reducing the carbon flux from Ac-CoA to acetate through genetic engineering successfully enhanced acetone productivity, which varied on the basis of the gas composition. The highest acetone productivity was obtained with CO–H2, while autotrophic growth collapsed with CO2–H2. By adding H2 to CO, the acetone productivity from the same amount of carbon source increased compared to CO gas only, and the maximum specific acetone production rate also increased from 0.04 to 0.09 g-acetone/g-dry cell/h. Our development of the engineered thermophilic acetogen M. thermoacetica, which grows at a temperature higher than the boiling point of acetone (58 °C), would pave the way for developing a consolidated process with simplified and cost-effective recovery via condensation following gas fermentation.

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Transcriptional Control of Clostridium autoethanogenum using CRISPRi

Synthetic Biology ◽

10.1093/synbio/ysab008 ◽

2021 ◽

Author(s):

Nick Fackler ◽

James Heffernan ◽

Alex Juminaga ◽

Damien Doser ◽

Shilpa Nagaraju ◽

...

Keyword(s):

Transcriptional Repression ◽

Transcriptional Control ◽

Genome Engineering ◽

Low Cost ◽

Pathway Engineering ◽

Industrial Emissions ◽

Gas Fermentation ◽

Control Gene Expression ◽

Clostridium Autoethanogenum ◽

Commercial Process

Abstract Gas fermentation by Clostridium autoethanogenum is a commercial process for the sustainable biomanufacturing of fuels and valuable chemicals using abundant, low cost C1 feedstocks (CO and CO2) from sources such as inedible biomass, unsorted and non-recyclable municipal solid waste, and industrial emissions. Efforts towards pathway engineering and elucidation of gene function in this microbe have been limited by a lack of genetic tools to control gene expression and arduous genome engineering methods. To increase the pace of progress, here we developed an inducible CRISPR interference (CRISPRi) system for C. autoethanogenum and applied that system towards transcriptional repression of genes with ostensibly crucial functions in metabolism.

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Arabinose-Induced Catabolite Repression as a Mechanism for Pentose Hierarchy Control inClostridium acetobutylicumATCC 824

mSystems ◽

10.1128/msystems.00064-18 ◽

2018 ◽

Vol 3 (5) ◽

Cited By ~ 2

Author(s):

Matthew D. Servinsky ◽

Rebecca L. Renberg ◽

Matthew A. Perisin ◽

Elliot S. Gerlach ◽

Sanchao Liu ◽

...

Keyword(s):

Transcriptional Regulation ◽

Genetic Engineering ◽

Catabolite Repression ◽

Clostridium Acetobutylicum ◽

Regulation Mechanism ◽

Mrna Levels ◽

Chemical Production ◽

Content Type ◽

Commodity Chemicals ◽

Pentose Utilization

ABSTRACTBacterial fermentation of carbohydrates from sustainable lignocellulosic biomass into commodity chemicals by the anaerobic bacteriumClostridium acetobutylicumis a promising alternative source to fossil fuel-derived chemicals. Recently, it was demonstrated that xylose is not appreciably fermented in the presence of arabinose, revealing a hierarchy of pentose utilization in this organism (L. Aristilde, I. A. Lewis, J. O. Park, and J. D. Rabinowitz, Appl Environ Microbiol 81:1452–1462, 2015,https://doi.org/10.1128/AEM.03199-14). The goal of the current study is to characterize the transcriptional regulation that occurs and perhaps drives this pentose hierarchy. Carbohydrate consumption rates showed that arabinose, like glucose, actively represses xylose utilization in cultures fermenting xylose. Further, arabinose addition to xylose cultures led to increased acetate-to-butyrate ratios, which indicated a transition of pentose catabolism from the pentose phosphate pathway to the phosphoketolase pathway. Transcriptome sequencing (RNA-Seq) confirmed that arabinose addition to cells actively growing on xylose resulted in increased phosphoketolase (CA_C1343) mRNA levels, providing additional evidence that arabinose induces this metabolic switch. A significant overlap in differentially regulated genes after addition of arabinose or glucose suggested a common regulation mechanism. A putative open reading frame (ORF) encoding a potential catabolite repression phosphocarrier histidine protein (Crh) was identified that likely participates in the observed transcriptional regulation. These results substantiate the claim that arabinose is utilized preferentially over xylose inC. acetobutylicumand suggest that arabinose can activate carbon catabolite repression via Crh. Furthermore, they provide valuable insights into potential mechanisms for altering pentose utilization to modulate fermentation products for chemical production.IMPORTANCEClostridium acetobutylicumcan ferment a wide variety of carbohydrates to the commodity chemicals acetone, butanol, and ethanol. Recent advances in genetic engineering have expanded the chemical production repertoire ofC. acetobutylicumusing synthetic biology. Due to its natural properties and genetic engineering potential, this organism is a promising candidate for converting biomass-derived feedstocks containing carbohydrate mixtures to commodity chemicals via natural or engineered pathways. Understanding how this organism regulates its metabolism during growth on carbohydrate mixtures is imperative to enable control of synthetic gene circuits in order to optimize chemical production. The work presented here unveils a novel mechanism via transcriptional regulation by a predicted Crh that controls the hierarchy of carbohydrate utilization and is essential for guiding robust genetic engineering strategies for chemical production.

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