ORCID Profile
0000-0001-8036-8937
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Research Topics
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Environmental Technologies | Environmental Engineering | Biomedical Instrumentation | Materials Engineering | Organic Semiconductors | Bioprocessing, Bioproduction and Bioproducts | Industrial Microbiology (incl. Biofeedstocks) | Systems Biology | Nanofabrication, Growth and Self Assembly
ANZSRC Socio-Economic Objective (SEO)
Expanding Knowledge in the Biological Sciences | Climate Change Mitigation Strategies | Management of Greenhouse Gas Emissions from Plant Production | Expanding Knowledge in Engineering | Human Diagnostics | Environmentally Sustainable Manufacturing not elsewhere classified | Manufacturing not elsewhere classified |
Related Links
Publications
Use of SWATH mass spectrometry for quantitative proteomic investigation of Shewanella oneidensis MR-1 biofilms grown on graphite cloth electrodes
Publisher: Elsevier BV
Date: 03-2015
DOI: 10.1016/J.SYAPM.2014.11.007
Abstract: Quantitative proteomics from low biomass, biofilm s les is not well documented. In this study we show successful use of SWATH-MS for quantitative proteomic analysis of a microbial electrochemically active biofilm. Shewanella oneidensis MR-1 was grown on carbon cloth electrodes under continuous anodic electrochemical polarizations in a bioelectrochemical system (BES). Using lactate as the electron donor, anodes serving as terminal microbial electron acceptors were operated at three different electrode potentials (+0.71 V, +0.21 V & -0.19 V vs. SHE) and the development of catalytic activity was monitored by measuring the current traces over time. Once maximum current was reached (usually within 21-29 h) the electrochemical systems were shut off and biofilm proteins were extracted from the electrodes for proteomic assessment. SWATH-MS analysis identified 704 proteins, and quantitative comparison was made of those associated with tricarboxcylic acid (TCA) cycle. Metabolic differences detected between the biofilms suggested a branching of the S. oneidensis TCA cycle when grown at the different electrode potentials. In addition, the higher abundance of enzymes involved in the TCA cycle at higher potential indicates an increase in metabolic activity, which is expected given the assumed higher energy gains. This study demonstrates high numbers of identifications on BES biofilm s les can be achieved in comparison to what is currently reported. This is most likely due to the minimal preparation steps required for SWATH-MS.
Polyhydroxyalkanoate-driven current generation via acetate by an anaerobic methanotrophic consortium
Publisher: Elsevier BV
Date: 08-2022
The nanostructure of microbially-reduced graphene oxide fosters thick and highly-performing electrochemically-active biofilms
Publisher: Elsevier BV
Date: 07-2017
Anode potential influences the structure and function of anodic electrode and electrolyte-associated microbiomes
Publisher: Springer Science and Business Media LLC
Date: 19-12-2016
DOI: 10.1038/SREP39114
Abstract: Three bioelectrochemical systems were operated with set anode potentials of +300 mV, +550 mV and +800 mV vs. Standard Hydrogen Electrode (SHE) to test the hypothesis that anode potential influences microbial ersity and is positively associated with microbial biomass and activity. Bacterial and archaeal ersity was characterized using 16 S rRNA gene licon sequencing, and biofilm thickness was measured as a proxy for biomass. Current production and substrate utilization patterns were used as measures of microbial activity and the mid-point potentials of putative terminal oxidases were assessed using cyclic voltammetry. All measurements were performed after 4, 16, 23, 30 and 38 days. Microbial biomass and activity differed significantly between anode potentials and were lower at the highest potential. Anodic electrode and electrolyte associated community composition was also significantly influenced by anode potential. While biofilms at +800 mV were thinner, transferred less charge and oxidized less substrate than those at lower potentials, they were also associated with putative terminal oxidases with higher mid-point potentials and generated more biomass per unit charge. This indicates that microbes at +800 mV were unable to capitalize on the potential for additional energy gain due to a lack of adaptive traits to high potential solid electron acceptors and/or sensitivity to oxidative stress.
Molecular understanding of Eubacterium limosum chemostat methanol metabolism
Publisher: Royal Society of Chemistry (RSC)
Date: 2023
DOI: 10.1039/D2SE01551J
Abstract: Methanol is a promising renewable energy carrier that can be used as a favourable substrate for biotechnology, due to its high energy efficiency conversion and ease of integration within existing infrastructure.
Redox dependent metabolic shift in Clostridium autoethanogenum by extracellular electron supply
Publisher: Springer Science and Business Media LLC
Date: 16-11-2016
Bioelectrochemical systems: Microbial versus enzymatic catalysis
Publisher: Elsevier BV
Date: 11-2012
Self-Powered Bioelectrochemical Nutrient Recovery for Fertilizer Generation from Human Urine
Publisher: MDPI AG
Date: 03-10-2019
DOI: 10.3390/SU11195490
Abstract: Nutrient recovery from source-separated human urine has been identified by many as a viable avenue towards the circular economy of nutrients. Moreover, untreated (and partially treated) urine is the main anthropogenic route of environmental discharge of nutrients, most concerning for nitrogen, whose release has exceeded the planet’s own self-healing capacity. Urine contains all key macronutrients (N, P, and K) and micronutrients (S, Ca, Mg, and trace metals) needed for plant growth and is, therefore, an excellent fertilizer. However, direct reuse is not recommended in modern society due to the presence of active organic molecules and heavy metals in urine. Many systems have been proposed and tested for nutrient recovery from urine, but none so far has reached technological maturity due to usually high power or chemical requirements or the need for advanced process controls. This work is the proof of concept for the world’s first nutrient recovery system that powers itself and does not require any chemicals or process controls. This is a variation of the previously proposed microbial electrochemical Ugold process, where a novel air cathode catalyst active in urine conditions (pH 9, high ammonia) enables in situ generation of electricity in a microbial fuel cell setup, and the simultaneous harvesting of such electricity for the electrodialytic concentration of ionic nutrients into a product stream, which is free of heavy metals. The system was able to sustain electrical current densities around 3 A m–2 for over two months while simultaneously upconcentrating N and K by a factor of 1.5–1.7.
Dissimilatory nitrate reduction to ammonium as an electron sink during cathodic denitrification
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C5RA19241B
Abstract: Nitrate reduction to ammonium is shown as a competitive pathway during cathodic denitrification at low potential, and is dependent on biofilm age and electron uptake capacity.
High methanol-to-formate ratios induce butanol production in Eubacterium limosum
Publisher: Wiley
Date: 28-11-2022
Abstract: Unlike gaseous C 1 feedstocks for acetogenic bacteria, there has been less attention on liquid C 1 feedstocks, despite benefits in terms of energy efficiency, mass transfer and integration within existing fermentation infrastructure. Here, we present growth of Eubacterium limosum ATCC8486 using methanol and formate as substrates, finding evidence for the first time of native butanol production. We varied ratios of methanol‐to‐formate in batch serum bottle fermentations, showing butyrate is the major product (maximum specific rate 220 ± 23 mmol‐C gDCW ‐1 day ‐1 ). Increasing this ratio showed methanol is the key feedstock driving the product spectrum towards more reduced products, such as butanol (maximum titre 2.0 ± 1.1 mM‐C). However, both substrates are required for a high growth rate (maximum 0.19 ± 0.011 h ‐1 ) and cell density (maximum 1.2 ± 0.043 gDCW l ‐1 ), with formate being the preferred substrate. In fact, formate and methanol are consumed in two distinct growth phases – growth phase 1, on predominately formate and growth phase 2 on methanol, which must balance. Because the second growth varied according to the first growth on formate, this suggests butanol production is due to overflow metabolism, similar to 2,3‐butanediol production in other acetogens. However, further research is required to confirm the butanol production pathway in E. limosum , particularly given, unlike other substrates, methanol likely results in mostly NADH generation, not reduced ferredoxin.
Enhancing methane oxidation in a bioelectrochemical membrane reactor using a soluble electron mediator
Publisher: Springer Science and Business Media LLC
Date: 16-10-2020
DOI: 10.1186/S13068-020-01808-7
Abstract: Bioelectrochemical methane oxidation catalysed by anaerobic methanotrophic archaea (ANME) is constrained by limited methane bioavailability as well as by slow kinetics of extracellular electron transfer (EET) of ANME. In this study, we tested a combination of two strategies to improve the performance of methane-driven bioelectrochemical systems that includes (1) the use of hollow fibre membranes (HFMs) for efficient methane delivery to the ANME organisms and (2) the amendment of ferricyanide, an effective soluble redox mediator, to the liquid medium to enable electrochemical bridging between the ANME organisms and the anode, as well as to promote EET kinetics of ANME. The combined use of HFMs and the soluble mediator increased the performance of ANME-based bioelectrochemical methane oxidation, enabling the delivery of up to 196 mA m −2 , thereby outperforming the control system by 244 times when HFMs were pressurized at 1.6 bar. Improving methane delivery and EET are critical to enhance the performance of bioelectrochemical methane oxidation. This work demonstrates that by process engineering optimization, energy recovery from methane through its direct oxidation at relevant rates is feasible.
Use of Stone Wool By-Products in the Construction of Sanitary Landfills and Tailing Dams
Publisher: Informa UK Limited
Date: 27-12-2004
Abstract: The delay of the introduction of a used item or residual material in the "waste circuit" is a key factor of an effective and environmentally sound waste management policy. This principle has been fully adopted by the European legislation and consequently, in most of the member countries. In the same time, re-use of low cost materials or, even better, by-products in environment protection works (sanitary landfills, mineral processing residues dams, etc.) could make easier the effective implementation of an environmentally sound waste management policy, especially in developing countries. However, the assessment of the recovery options has to be performed on the basis of proper technical specifications concerning the kind of reuse proposed and of an accurate investigation on the technical and environmental properties of the residue. The present article reports the results of a research programme aiming at evaluating the feasibility of use of stone wool by-products, usually directly disposed in landfills, as construction materials for sanitary landfills and tailing dams.
Molecular understanding ofEubacterium limosumchemostat methanol metabolism
Publisher: Cold Spring Harbor Laboratory
Date: 04-11-2022
DOI: 10.1101/2022.11.04.514945
Abstract: Methanol is a promising renewable energy carrier that can be used as a favourable substrate for biotechnology, due to its high energy efficiency conversion and ease of integration within existing infrastructure. Some acetogenic bacteria have the native ability to utilise methanol, along with other C 1 substrates such as CO 2 and formate, to produce valuable chemicals. Continuous cultures favour economically viable bioprocesses, however, the performance of acetogens has not been investigated at the molecular level when grown on methanol. Here we present steady-state chemostat quantification of the metabolism of Eubacterium limosum , finding maximum methanol uptake rates up to 640±22 mmol/gDCW/d, with significant fluxes to butyrate. To better understand metabolism of acetogens under methanol growth conditions, we s led chemostats for proteomics and metabolomics. Changes in protein expression and intracellular metabolomics highlighted key aspects of methanol metabolism, and highlighted bottleneck conditions preventing formation of the more valuable product, butanol. Interestingly, a small amount of formate in methylotrophic metabolism triggered a cellular state known in other acetogens to correlate with solventogenesis. Unfortunately, this was prevented by post-translation effects including an oxidised NAD pool. There remains uncertainty around ferredoxin balance at the methylene-tetrahydrofolate reductase (MTHFR) and at the Rnf level.
Multi-heme cytochrome-mediated extracellular electron transfer by the anaerobic methanotroph ‘Candidatus Methanoperedens nitroreducens’
Publisher: Springer Science and Business Media LLC
Date: 30-09-2023
Simultaneous nitrification, denitrification and carbon removal in microbial fuel cells
Publisher: Elsevier BV
Date: 05-2010
DOI: 10.1016/J.WATRES.2010.02.022
Abstract: Microbial fuel cells (MFCs) can use nitrate as a cathodic electron acceptor, allowing for simultaneous removal of carbon (at the anode) and nitrogen (at the cathode). In this study, we supplemented the cathodic process with in situ nitrification through specific aeration, and thus obtained simultaneous nitrification and denitrification (SND) in the one half-cell. Synthetic wastewater containing acetate and ammonium was supplied to the anode the effluent was subsequently directed to the cathode. The influence of oxygen levels and carbon/nitrogen concentrations and ratios on the system performances was investigated. Denitrification occurred simultaneously with nitrification at the cathode, producing an effluent with levels of nitrate and ammonium as low as 1.0+/-0.5 mg N L(-1) and 2.13+/-0.05 mg N L(-1), respectively, resulting in a nitrogen removal efficiency of 94.1+/-0.9%. The integration of the nitrification process into the cathode solves the drawback of ammonium losses due to diffusion between compartments in the MFC, as previously reported in a system operating with external nitrification stage. This work represents the first successful attempt to combine SND and organics oxidation while producing electricity in an MFC.
Plasma treatment of electrodes significantly enhances the development of anodic electrochemically active biofilms
Publisher: Elsevier BV
Date: 10-2013
Evaluating the potential impact of proton carriers on syntrophic propionate oxidation
Publisher: Springer Science and Business Media LLC
Date: 16-12-2015
DOI: 10.1038/SREP18364
Abstract: Anaerobic propionic acid degradation relies on interspecies electron transfer (IET) between propionate oxidisers and electron acceptor microorganisms, via either molecular hydrogen, formate or direct transfers. We evaluated the possibility of stimulating direct IET, hence enhancing propionate oxidation, by increasing availability of proton carriers to decrease solution resistance and reduce pH gradients. Phosphate was used as a proton carrying anion and chloride as control ion together with potassium as counter ion. Propionic acid consumption in anaerobic granules was assessed in a square factorial design with ratios (1:0, 2:1, 1:1, 1:2 and 0:1) of total phosphate (TP) to Cl − , at 1X, 10X and 30X native conductivity (1.5 mS.cm −1 ). Maximum specific uptake rate, half saturation and time delay were estimated using model-based analysis. Community profiles were analysed by fluorescent in situ hybridisation and 16S rRNA gene pyrosequencing. The strongest performance was at balanced (1:1) ratios at 10X conductivity where presumptive propionate oxidisers namely Syntrophobacter and Candidatus Cloacamonas were more abundant. There was a shift from Methanobacteriales at high phosphate, to Methanosaeta at low TP:Cl ratios and low conductivity. A lack of response to TP and low percentage of presumptive electroactive organisms suggested that DIET was not favoured under the current experimental conditions.
CHAPTER 16. Denitrification Processes for Wastewater Treatment
Publisher: Royal Society of Chemistry
Date: 2016
Microbial nanowires – Electron transport and the role of synthetic analogues
Publisher: Elsevier BV
Date: 03-2018
DOI: 10.1016/J.ACTBIO.2018.01.007
Abstract: Electron transfer is central to cellular life, from photosynthesis to respiration. In the case of anaerobic respiration, some microbes have extracellular appendages that can be utilised to transport electrons over great distances. Two model organisms heavily studied in this arena are Shewanella oneidensis and Geobacter sulfurreducens. There is some debate over how, in particular, the Geobacter sulfurreducens nanowires (formed from pilin nanofilaments) are capable of achieving the impressive feats of natural conductivity that they display. In this article, we outline the mechanisms of electron transfer through delocalised electron transport, quantum tunnelling, and hopping as they pertain to biomaterials. These are described along with existing ex les of the different types of conductivity observed in natural systems such as DNA and proteins in order to provide context for understanding the complexities involved in studying the electron transport properties of these unique nanowires. We then introduce some synthetic analogues, made using peptides, which may assist in resolving this debate. Microbial nanowires and the synthetic analogues thereof are of particular interest, not just for biogeochemistry, but also for the exciting potential bioelectronic and clinical applications as covered in the final section of the review. Some microbes have extracellular appendages that transport electrons over vast distances in order to respire, such as the dissimilatory metal-reducing bacteria Geobacter sulfurreducens. There is significant debate over how G. sulfurreducens nanowires are capable of achieving the impressive feats of natural conductivity that they display: This mechanism is a fundamental scientific challenge, with important environmental and technological implications. Through outlining the techniques and outcomes of investigations into the mechanisms of such protein-based nanofibrils, we provide a platform for the general study of the electronic properties of biomaterials. The implications are broad-reaching, with fundamental investigations into electron transfer processes in natural and biomimetic materials underway. From these studies, applications in the medical, energy, and IT industries can be developed utilising bioelectronics.
Biofuels
Publisher: Springer Berlin Heidelberg
Date: 2013
Characterisation of acetogen formatotrophic potential using E. limosum
Publisher: Cold Spring Harbor Laboratory
Date: 03-11-2022
DOI: 10.1101/2022.11.02.514939
Abstract: Formate is a promising energy carrier that could be used to transport renewable electricity. Some acetogenic bacteria, such as Eubacterium limosum , have the native ability to utilise formate as a sole substrate for growth, which has sparked interest in the biotechnology industry. However, formatotrophic metabolism in acetogens is poorly understood, and a systems-level characterization in continuous cultures is yet to be reported. Here we present the first steady-state dataset for E. limosum formatotrophic growth. At a defined dilution rate of 0.4 d -1 , there was a high specific uptake rate of formate (280±56 mmol/gDCW/d), however, most carbon went to CO 2 (150±11 mmol/gDCW/d). Compared to methylotrophic growth, protein differential expression data and intracellular metabolomics revealed several key features of formate metabolism. Upregulation of pta appears to be a futile attempt of cells to produce acetate as the major product. Instead, a cellular energy limitation resulted in the accumulation of intracellular pyruvate and upregulation of Pfl to convert formate to pyruvate. Therefore, metabolism is controlled, at least partially, at the protein expression level, an unusual feature for an acetogen. We anticipate that formate could be an important one-carbon substrate for acetogens to produce chemicals rich in pyruvate, a metabolite generally in low abundance during syngas growth.
Real-Time Measurements of the Redox States of c-Type Cytochromes in Electroactive Biofilms: A Confocal Resonance Raman Microscopy Study
Publisher: Public Library of Science (PLoS)
Date: 25-02-2014
A slurry electrode based on reduced graphene oxide and poly(sodium 4-styrenesulfonate) for applications in microbial electrochemical technologies
Publisher: Elsevier BV
Date: 09-2022
Anodic electro‐fermentation: Anaerobic production of L‐Lysine by recombinant Corynebacterium glutamicum
Publisher: Wiley
Date: 24-03-2020
DOI: 10.1002/BIT.26562
Abstract: Microbial electrochemical technologies (MET) are promising to drive metabolic processes for the production of chemicals of interest. They provide microorganisms with an electrode as an electron sink or an electron source to stabilize their redox and/or energy state. Here, we applied an anode as additional electron sink to enhance the anoxic metabolism of the industrial bacterium Corynebacterium glutamicum through an anodic electro-fermentation. In using ferricyanide as extracellular electron carrier, anaerobic growth was enabled and the feedback-deregulated mutant Corynebacterium glutamicum lysC further accumulated L-lysine. Under such oxidizing conditions we achieved L-lysine titers of 2.9 mM at rates of 0.2 mmol/L/hr. That titer is comparable to recently reported L-lysine concentrations achieved by anaerobic production under reductive conditions (cathodic electro-fermentation). However unlike other studies, our oxidative conditions allowed anaerobic cell growth, indicating an improved cellular energy supply during anodic electro-fermentation. In that light, we propose anodic electro-fermentation as the right choice to support C. glutamicum stabilizing its redox and energy state and empower a stable anaerobic production of L-lysine.
Electron fluxes in a microbial fuel cell performing carbon and nitrogen removal
Publisher: American Chemical Society (ACS)
Date: 29-05-2009
DOI: 10.1021/ES8036302
Abstract: The electron recovery in microbial fuel cells (MFCs) is decreased by processes like methanogenesis, bacterial growth, and the accumulation of intermediates. Using a suite of analytical techniques, including electrochemical monitoring, chemical analysis, microsensor analysis, and Titration and Off-Gas Analysis (TOGA), this study aimed to (a) identify and quantify the electron losses occurring at the anode and the cathode of a MFC removing acetate and nitrate (NO3-), respectively, and (b) to investigate the impact of the operational characteristics of the cathode on the denitrification process. Our results show that methane (CH4) production and estimated biomass formation at the anode and nitrous oxide (N2O) accumulation at the cathode were responsible for the reduction of Coulombic efficiency (epsilon) during continuous feeding conditions. At the anode, up to 40.1% of the acetate consumed was released as methane at closed circuit. At the cathode, N2O accumulation represented instead the main loss accounting for up to 10.0 +/- 2.1% of the oxidation capacity of the electron acceptor provided as NO3-. Batch experiments at controlled potentials and currents revealed that for a given current the fraction of electron transferred and released as N2O is significantly reduced by low cathodic potentials.
Biomimetic Peptide Nanowires Designed for Conductivity
Publisher: American Chemical Society (ACS)
Date: 22-01-2019
Selective Extraction of Medium-Chain Carboxylic Acids by Electrodialysis and Phase Separation
Publisher: American Chemical Society (ACS)
Date: 12-03-2021
Analysis of electron transfer dynamics in mixed community electroactive microbial biofilms
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C5RA15676A
Abstract: Electrochemically active microbial biofilms are capable to produce electric current when grown onto electrodes. This work investigates the dynamics of electron transfer inside the biofilm as well as at the biofilm/electrode interface.
The role of anaerobic digestion in the emerging energy economy
Publisher: Elsevier BV
Date: 06-2014
DOI: 10.1016/J.COPBIO.2014.01.013
Abstract: Anaerobic digestion is the default process for biological conversion of residue organics to renewable energy and biofuel in the form of methane. However, its scope of application is expanding, due to availability of new technologies, and the emerging drivers of energy and nutrient conservation and recovery. Here, we outline two of these new application areas, namely wastewater nutrient and energy recovery, and generation of value added chemicals through mixed culture biotechnology. There exist two options for nutrient and energy recovery from domestic wastewater: low energy mainline and partition-release-recovery. Both are heavily dependent on anaerobic digestion as an energy generating and nutrient release step, and have been enabled by new technologies such as low emission anaerobic membrane processes. The area of mixed culture biotechnology has been previously identified as a key industrial opportunity, but is now moving closer to application due application of existing and new technologies. As well as acting as a core technology option in bioproduction, anaerobic digestion has a key role in residual waste valorization and generation of energy for downstream processing. These new application areas and technologies are emerging simultaneously with substantial advances in knowledge of underlying mechanisms such as electron transfer, understanding of which is critical to development of the new application areas.
Bioelectrochemical Denitrification for the Treatment of Saltwater Recirculating Aquaculture Streams
Publisher: American Chemical Society (ACS)
Date: 16-04-2018
Effect of geomorphological setting and rainfall on nutrient exchange in mangroves during tidal inundation
Publisher: CSIRO Publishing
Date: 2010
DOI: 10.1071/MF10013
Abstract: One of the key ecosystem services provided by mangroves is their role in mediating nutrient exchange, thereby protecting coastal ecosystems from negative impacts of nutrient enrichment. In this study, we tested whether geomorphological setting and level of rainfall affect the intensity and direction of nutrient exchange. Our hypotheses were that tidal mangroves retain more nutrients than riverine mangroves and that nutrient retention is stronger during periods of high rainfall. Concentrations of soluble reactive phosphorus (SRP), nitrogen oxides (NOx–-N) and ammonium (NH4+) were measured from water entering and leaving the mangroves during tidal cycles. Our results show that nutrient concentrations were higher in the flood tide compared with the ebb tide by up to 28% for NOx–-N, 51% for SRP and 83% for NH4+, suggesting retention by the mangroves. Geomorphological setting determined nutrient exchange to some extent, with some riverine sites receiving more nutrients than tidal sites and thus, being more important in nutrient retention. Rainfall was important in determining nutrient exchange as it enhanced SRP and NH4+ retention. These results show that mangroves can improve water quality of creeks and rivers, and underscore the need for conservation of mangroves over a range of geomorphological settings.
Obtaining highly enriched cultures of Candidatus Accumulibacter phosphates through alternating carbon sources
Publisher: Elsevier BV
Date: 12-2006
DOI: 10.1016/J.WATRES.2006.09.004
Abstract: Candidatus Accumulibacter Phosphatis is widely considered to be a polyphosphate accumulating organism (PAO) of prime importance in enhanced biological phosphorus removal (EBPR) systems. This organism has yet to be isolated, despite many attempts. Previous studies on the biochemical and physiological aspects of this organism, as well as its response to different EBPR operational conditions, have generally relied on the use of mixed culture enrichments. One frequent problem in obtaining highly enriched cultures of this organism is the proliferation of glycogen accumulating organisms (GAO) that can compete with PAOs for limited carbon sources under similar operational conditions. In this study, Candidatus Accumulibacter Phosphatis has been enriched in a lab-scale bioreactor to a level greater than 90% as quantified by fluorescence in situ hyrbridisation (FISH). This is the highest enrichment of this organism that has been reported thus far, and was obtained by alternating the sole carbon source in the feed between acetate and propionate every one to two sludge ages, and operating the bioreactor within a pH range of 7.0-8.0. Simultaneously, the presence of two known groups of GAOs was eliminated under these operational conditions. Excellent phosphorus removal performance and stability were maintained in this system, where the phosphorous concentration in the effluent was below 0.2 mg/L for more than 7 months. When a disturbance was introduced to this system by adding sludge from an enriched GAO culture, Candidatus Accumulibacter Phosphatis once again became highly enriched, while the GAOs were out-competed. This feeding strategy is recommended for future studies focused on describing the physiology and biochemistry of Accumulibacter, where a highly-enriched culture of this organism is of high importance.
Microbial electrosynthesis system with dual biocathode arrangement for simultaneous acetogenesis, solventogenesis and carbon chain elongation
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9CC00208A
Abstract: A microbial electrosynthesis cell comprising two biological cathode chambers sharing the same anode compartment is used to promote the production of C2–C4 carboxylic acids and alcohols from carbon dioxide.
Effect of the anode potential on the physiology and proteome of Shewanella oneidensis MR-1
Publisher: Elsevier BV
Date: 02-2018
DOI: 10.1016/J.BIOELECHEM.2017.10.001
Abstract: Shewanella species respire using iron and manganese oxides as well as electrodes as solid terminal electron acceptors. Shewanella oneidenis MR-1 exploits mediated as well as direct extracellular electron transfer (EET) modes to transfer electrons at different formal potentials. These different EET modes at different potentials may utilise alternate electron transfer pathways. Therefore, we investigated how different anode potentials, providing different maximum microbial energy gains impacted S. oneidensis microbial physiology. Using quantitative proteomics, comparative analysis of the cellular variations to different anode potentials was performed. A label-free proteomic mass spectrometric analysis method, SWATH-MS, was used to gather quantitative information to determine physiological changes of Shewanella oneidensis MR-1 grown at different anodic potentials. S. oneidensis was cultured and grown in electrochemical cells at the set anode potentials of +0.71V, +0.21V & -0.19V versus SHE reference electrode, while the current production was monitored. At maximum current, electrodes were removed and whole-cell proteins extracted. Subsequent SWATH-MS analysis revealed information on 740 identified proteins across the three electrode potentials. For the first time, we show the abundance of S. oneidensis electron transfer proteins differs with electrode potential.
Erratum to: Anoxic metabolism and biochemical production in Pseudomonas putida F1 driven by a bioelectrochemical system
Publisher: Springer Science and Business Media LLC
Date: 19-06-2017
Regulation mechanisms in mixed and pure culture microbial fermentation
Publisher: Wiley
Date: 15-09-2014
DOI: 10.1002/BIT.25321
Abstract: Mixed-culture fermentation is a key central process to enable next generation biofuels and biocommodity production due to economic and process advantages over application of pure cultures. However, a key limitation to the application of mixed-culture fermentation is predicting culture product response, related to metabolic regulation mechanisms. This is also a limitation in pure culture bacterial fermentation. This review evaluates recent literature in both pure and mixed culture studies with a focus on understanding how regulation and signaling mechanisms interact with metabolic routes and activity. In particular, we focus on how microorganisms balance electron sinking while maximizing catabolic energy generation. Analysis of these mechanisms and their effect on metabolism dynamics is absent in current models of mixed-culture fermentation. This limits process prediction and control, which in turn limits industrial application of mixed-culture fermentation. A key mechanism appears to be the role of internal electron mediating cofactors, and related regulatory signaling. This may determine direction of electrons towards either hydrogen or reduced organics as end-products and may form the basis for future mechanistic models.
The effect of the polarised cathode, formate and ethanol on chain elongation of acetate in microbial electrosynthesis
Publisher: Elsevier BV
Date: 02-2021
Simultaneous nitrification and denitrification (SND) at a microbial fuel cell (MFC) Biocathode
Publisher: Elsevier BV
Date: 11-2010
Towards carbon neutral chemicals production: Opportunities for combining fermentation with electrochemical processes
Publisher: Elsevier BV
Date: 02-2023
Microbial Electrosynthesis of Isobutyric, Butyric, Caproic Acids, and Corresponding Alcohols from Carbon Dioxide
Publisher: American Chemical Society (ACS)
Date: 04-06-2018
Nutrient Recovery by Bio-Electroconcentration is Limited by Wastewater Conductivity
Publisher: American Chemical Society (ACS)
Date: 28-01-2019
Bio-reduced graphene oxide on hollow fibers as gas-diffusible anodes for enhancing bioelectrochemical methane oxidation
Publisher: Elsevier BV
Date: 07-2022
Strategies to improve viability of a circular carbon bioeconomy-A techno-economic review of microbial electrosynthesis and gas fermentation
Publisher: Elsevier BV
Date: 08-2021
Microbial electrochemical sensors for volatile fatty acid measurement in high strength wastewaters: A review
Publisher: Elsevier BV
Date: 10-2020
Microbial fuel cells for simultaneous carbon and nitrogen removal
Publisher: Elsevier BV
Date: 06-2008
DOI: 10.1016/J.WATRES.2008.03.017
Abstract: The recent demonstration of cathodic nitrate reduction in a microbial fuel cell (MFC) creates opportunities for a new technology for nitrogen removal from wastewater. A novel process configuration that achieves both carbon and nitrogen removal using MFC is designed and demonstrated. The process involves feeding the ammonium-containing effluent from the carbon-utilising anode to an external biofilm-based aerobic reactor for nitrification, and then feeding the nitrified liquor to the MFC cathode for nitrate reduction. Removal rates up to 2 kg COD m(-3)NCC d(-1) (chemical oxygen demand: COD, net cathodic compartment: NCC) and 0.41 kg NO(3)(-)-Nm(-3)NCC d(-1) were continuously achieved in the anodic and cathodic compartment, respectively, while the MFC was producing a maximum power output of 34.6+/-1.1 Wm(-3)NCC and a maximum current of 133.3+/-1.0 Am(-3)NCC. In comparison to conventional activated sludge systems, this MFC-based process achieves nitrogen removal with a decreased carbon requirement. A COD/N ratio of approximately 4.5 g COD g(-1) N was achieved, compared to the conventionally required ratio of above 7. We have demonstrated that also nitrite can be used as cathodic electron acceptor. Hence, upon creating a loop concept based on nitrite, a further reduction of the COD/N ratio would be possible. The process is also more energy effective not only due to the energy production coupled with denitrification, but also because of the reduced aeration costs due to minimised aerobic consumption of organic carbon.
Substrate availability drives mixed culture fermentation of glucose to lactate at steady state.
Publisher: Wiley
Date: 21-01-2021
DOI: 10.1002/BIT.27678
Abstract: Mixed-culture fermentation (MCF) enables carbon recycling from complex organic waste streams into valuable feedstock chemicals. Using complex microbial consortia, MCF systems can be tuned to produce a range of biochemicals to meet market demand. However, the metabolic mechanisms and community interactions which drive biochemical production changes under differing conditions are currently poorly understood. These mechanisms are critical to useful MCF production models. Furthermore, predictable product transitions are currently limited to pH-driven changes between butyrate and ethanol, and chain-elongation (fed by lactate, acetate, and ethanol) to butyrate, valerate, and hexanoate. Lactate, a high-value biopolymer feedstock chemical, has been observed in transition states, but sustained production has not been described. In this study, steady state lactate production was achieved by increasing the organic loading rate of a butyrate-producing system from limiting to nonlimiting conditions at pH 5.5. Crucially, butyrate production resumed upon return to substrate-limited conditions. 16S ribosomal DNA community profiling combined with metaproteomics demonstrated that the butyrate-producing lineage Megasphaera redirected carbon flow through the methylglyoxal bypass when substrate was nonlimiting, which altered the community structure and metabolic expression toward lactate production. This metabolic mechanism can be included in future MCF models to describe the changes in product generation in substrate nonlimiting conditions.
Electrifying White Biotechnology: Engineering and Economic Potential of Electricity‐Driven Bio‐Production
Publisher: Wiley
Date: 10-12-2014
Abstract: The production of fuels and chemicals by electricity-driven bio-production (i.e., using electric energy to drive biosynthesis) holds great promises. However, this electrification of white biotechnology is particularly challenging to achieve because of the different optimal operating conditions of electrochemical and biochemical reactions. In this article, we address the technical parameters and obstacles to be taken into account when engineering microbial bioelectrochemical systems (BES) for bio-production. In addition, BES-based bio-production processes reported in the literature are compared against industrial needs showing that a still large gap has to be closed. Finally, the feasibility of BES bio-production is analysed based on bulk electricity prices. Using the ex le of lysine production from sucrose, we demonstrate that there is a realistic market potential as cost savings of 8.4 % (in EU) and 18.0 % (in US) could be anticipated, if the necessary yields can be obtained.
Anoxic metabolism and biochemical production in Pseudomonas putida F1 driven by a bioelectrochemical system
Publisher: Springer Science and Business Media LLC
Date: 18-02-2016
Bioelectrochemical nitrogen removal as a polishing mechanism for domestic wastewater treated effluents
Publisher: IWA Publishing
Date: 05-09-2017
DOI: 10.2166/WST.2017.462
Abstract: Addition of an external carbon source is usually necessary to guarantee a sufficiently high C/N ratio and enable denitrification in wastewater treatment plants (WWTPs). Alternatively, denitrification processes using autotrophic microorganisms have been proposed i.e., with the use of H2 as electron donor or with the use of cathodic denitrification in bioelectrochemical systems (BES), in which electrons are transferred directly to a denitrifying biofilm. The aim of this work was to investigate and demonstrate the feasibility of applying an easy-to-operate BES as a polishing mechanism for treated secondary clarified effluent from a municipal WWTP, containing low levels of organic matter, buffer capacity and low concentrations of remaining nitrate. In the proposed system, nitrogen removal rates (0.018–0.121 Kg N m−3 d−1) increased with the nitrogen loading rates, suggesting that biofilm kinetics were not rate limiting. The lowest energy consumption for denitrification was 12.7 kWh Kg N−1, equivalent to 0.021 kWh m−3 and could be further reduced by 14% by adding recirculation circuits within both the anode and cathode.
Spectroelectrochemistry of Microbial Biofilms
Publisher: WORLD SCIENTIFIC (EUROPE)
Date: 25-10-2017
Microbial Fuel Cells
Publisher: Elsevier
Date: 2011
Modelling extracellular limitations for mediated versus direct interspecies electron transfer
Publisher: Springer Science and Business Media LLC
Date: 06-11-2015
Non-invasive characterization of electrochemically active microbial biofilms using confocal Raman microscopy
Publisher: Royal Society of Chemistry (RSC)
Date: 2012
DOI: 10.1039/C2EE03374G
Variable Cell Morphology Approach for Individual-Based Modeling of Microbial Communities
Publisher: Elsevier BV
Date: 05-2014
Electro-fermentation: Sustainable bioproductions steered by electricity
Publisher: Elsevier BV
Date: 10-2022
DOI: 10.1016/J.BIOTECHADV.2022.107950
Abstract: The market of biobased products obtainable via fermentation processes has steadily increased over the past few years, driven by the need to create a decarbonized economy. To date, industrial fermentation (IF) employs either pure or mixed microbial cultures (MMC), whereby the type of the microbial catalysts and the used feedstock affect metabolic pathways and, in turn, the type of product(s) generated. In many cases, especially when dealing with MMC, the economic viability of IF is still hindered by factors such as the low attained product titer and selectivity, which ultimately challenge the downstream recovery and purification steps. In this context, electro-fermentation (EF) represents an innovative approach, based on the use of a polarized electrode interface to trigger changes in the rate, yield, titer or product distribution deriving from traditional fermentation processes. In principle, the electrode in EF can act as an electron acceptor (i.e., anodic electro-fermentation, AEF) or donor (i.e., cathodic electro-fermentation, CEF), or simply as a means to control the oxidation-reduction potential of the fermentation broth. However, the molecular and biochemical basis underlying EF are still largely unknown. This review provides a comprehensive overview of recent literature studies including both AEF and CEF ex les using pure or mixed microbial cultures. A critical analysis of biochemical, microbiological, and engineering aspects which presently h er the transition of the EF technology from the laboratory to the market is also presented.
A facile method to enhance the performance of soil bioelectrochemical systems using in situ reduced graphene oxide
Publisher: Elsevier BV
Date: 11-2019
Biofilm stratification during simultaneous nitrification and denitrification (SND) at a biocathode
Publisher: Elsevier BV
Date: 2011
DOI: 10.1016/J.BIORTECH.2010.06.155
Abstract: The aeration of the cathode compartment of bioelectrochemical systems (BESs) was recently shown to promote simultaneous nitrification and denitrification (SND). This study investigates the cathodic metabolism under different operating conditions as well as the structural organization of the cathodic biofilm during SND. Results show that a maximal nitrogen removal efficiency of 86.9 ± 0.5%, and a removal rate of 3.39 ± 0.08 mg NL(-1)h(-1) could be achieved at a dissolved oxygen (DO) level of 5.73 ± 0.03 mg L(-1) in the catholyte. The DO levels used in this study are higher than the thresholds previously reported as detrimental for denitrification. Analysis of the cathodic half-cell potential during batch tests suggested the existence of an oxygen gradient within the biofilm while performing SND. FISH analysis corroborated this finding revealing that the structure of the biofilm included an outer layer occupied by putative nitrifying organisms, and an inner layer where putative denitrifying organisms were most dominant. To our best knowledge this is the first time that nitrifying and denitrifying microorganisms are simultaneously observed in a cathodic biofilm.
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