A dynamic periplasmic electron transfer network enables respiratory flexibility beyond a thermodynamic regulatory regime

Sturm, Gunnar; Richter, Katrin; Doetsch, Andreas; Heide, Heinrich; Louro, Ricardo O.; Gescher, Johannes

doi:10.1038/ismej.2014.264

Cited by 118 publications

(98 citation statements)

References 49 publications

(55 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This result may suggest that with the aeration conditions used, the metabolism of the bacteria was probably mixed, i.e. split between aerobic and anaerobic as also suggested by . The utilization of the anaerobic metabolic pathways by the bacteria was promoted mainly due to the more often discharge of electrons from the cytochrome “capacitor” pool onto the reactor electrodes.…”

Section: Resultsmentioning

confidence: 77%

Paving the way for bioelectrotechnology: Integrating electrochemistry into bioreactors

Rosa

Hunger

Gimkiewicz

et al. 2016

Engineering in Life Sciences

View full text Add to dashboard Cite

The reactor systems used for microbial electrosynthesis, i.e. bioelectrochemical systems for achieving bioproduction so far reported in literature are relatively small in scale and highly diverse in their architecture and modes of operation. The often diverging requirements of the electrochemical and the biological processes and the interdisciplinarity of the field make the engineering of these systems a special challenge. This has led to multiple, differently optimized approaches of reactor vessels, designs and operating conditions making standardization and normalization or even a systematic engineering almost impossible. Overcoming this lack of standardization, scalability and knowledge‐driven engineering is the driving force for this work introducing an upgrade kit for bioreactors transforming these reversibly to bioelectroreactors. The prototypes of the bioreactor upgrade kit were integrated with commercial bioreactor (fermentor) systems and performances compared to a classic, small‐scale bioelectrochemical glass cell system. The use of the upgrade kit allowed interfacing with the existing infrastructure of the conventional bioreactors for growing electroactive microorganisms in pure culture conditions, with the added electrochemical control and further process monitoring. The results of growing Shewanella oneidensis MR‐1 clearly show that these systems can be used to control, monitor, and scale microbial bioelectrochemical processes, providing better resolution of the data for the tested experimental conditions.

show abstract

Section: Resultsmentioning

confidence: 77%

Paving the way for bioelectrotechnology: Integrating electrochemistry into bioreactors

Rosa

Hunger

Gimkiewicz

et al. 2016

Engineering in Life Sciences

View full text Add to dashboard Cite

show abstract

“…Consistent with this hypothesis, Fonseca et al (2012) reported that soluble periplasmic cytochromes, STC (SO_2727) and FccA (SO_0970), interact with both CymA and MtrA with relatively large dissociation constants and thereby promote transient electron-transfer reactions between CymA and MtrA. Furthermore, Sturm et al (2015) recently reported that the periplasmic space of MR-1 contains abundant soluble c-type cytochromes (approximately 350,000 hemes per cell), and that a double-deletion mutant of fccA and stc ( cctA ) exhibits substantial growth deficiencies on ferric iron and other soluble electron acceptors. These observations suggest that the periplasmic cytochrome pool, which mainly consists of STC and FccA, plays important roles in mediating electron transfer from CymA to OM-cyts in the Mtr pathway.…”

Section: Eet Pathwaymentioning

confidence: 78%

“…Genetic and biochemical studies have identified five primary protein components, CymA, MtrA, MtrB, MtrC, and OmcA, comprising the EET pathway in S. oneidensis MR-1 (the Mtr pathway; Figure 1; Shi et al, 2007). In addition, recent studies have demonstrated that the periplasmic cytochrome pool, which mainly consists of small tetraheme cytochromes (STCs; also referred to as CctA) and flavocytochrome c (FccA) proteins, is also involved in the EET process (Fonseca et al, 2012; Sturm et al, 2015). These findings indicate that the Mtr pathway serves as the major electron conduit that links the IM quinone pool to extracellular solid electron acceptors via a series of electron-transfer reactions between these component proteins.…”

Section: Eet Pathwaymentioning

confidence: 99%

Catabolic and regulatory systems in Shewanella oneidensis MR-1 involved in electricity generation in microbial fuel cells

et al. 2015

View full text Add to dashboard Cite

Shewanella oneidensis MR-1 is a facultative anaerobe that respires using a variety of inorganic and organic compounds. MR-1 is also capable of utilizing extracellular solid materials, including anodes in microbial fuel cells (MFCs), as electron acceptors, thereby enabling electricity generation. As MFCs have the potential to generate electricity from biomass waste and wastewater, MR-1 has been extensively studied to identify the molecular systems that are involved in electricity generation in MFCs. These studies have demonstrated the importance of extracellular electron-transfer (EET) pathways that electrically connect the quinone pool in the cytoplasmic membrane to extracellular electron acceptors. Electricity generation is also dependent on intracellular catabolic pathways that oxidize electron donors, such as lactate, and regulatory systems that control the expression of genes encoding the components of catabolic and electron-transfer pathways. In addition, recent findings suggest that cell-surface polymers, e.g., exopolysaccharides, and secreted chemicals, which function as electron shuttles, are also involved in electricity generation. Despite these advances in our knowledge on the EET processes in MR-1, further efforts are necessary to fully understand the underlying intra- and extracellular molecular systems for electricity generation in MFCs. We suggest that investigating how MR-1 coordinates these systems to efficiently transfer electrons to electrodes and conserve electrochemical energy for cell proliferation is important for establishing the biological basis for MFCs.

show abstract

“…The best characterized conduit is the MtrCAB pathway in S. oneidensis MR-1 (Figure 1). A thorough discussion of extracellular electron transfer mechanisms in the MtrCAB pathway in S. oneidensis is provided in the literature 34,37–39 . To briefly summarize, the oxidation of nutrients during anaerobic respiration generates reducing equivalents stored in the membrane-confined quinone pool.…”

Section: Efficient Charge Transfer In Exoelectrogensmentioning

confidence: 99%

A synthetic biology approach to engineering living photovoltaics

Schuergers

Werlang

Ajo‐Franklin

et al. 2017

Energy Environ. Sci.

View full text Add to dashboard Cite

The ability to electronically interface living cells with electron accepting scaffolds is crucial for the development of next-generation biophotovoltaic technologies. Although recent studies have focused on engineering synthetic interfaces that can maximize electronic communication between the cell and scaffold, the efficiency of such devices is limited by the low conductivity of the cell membrane. This review provides a materials science perspective on applying a complementary, synthetic biology approach to engineering membrane-electrode interfaces. It focuses on the technical challenges behind the introduction of foreign extracellular electron transfer pathways in bacterial host cells and the past and future efforts to engineer photosynthetic organisms with artificial electron-export capabilities for biophotovoltaic applications. The article highlights advances in engineering protein-based, electron-exporting conduits in a model host organism, E. coli, before reviewing state-of-the-art biophotovoltaic technologies that use both unmodified and bioengineered photosynthetic bacteria with improved electron transport capabilities. A thermodynamic analysis is used to propose an energetically feasible pathway for extracellular electron transport in engineered cyanobacteria and identify metabolic bottlenecks amenable to protein engineering techniques. Based on this analysis, an engineered photosynthetic organism expressing a foreign, protein-based electron conduit yields a maximum theoretical solar conversion efficiency of 6–10% without accounting for additional bioengineering optimizations for light-harvesting.

show abstract

A dynamic periplasmic electron transfer network enables respiratory flexibility beyond a thermodynamic regulatory regime

Cited by 118 publications

References 49 publications

Paving the way for bioelectrotechnology: Integrating electrochemistry into bioreactors

Paving the way for bioelectrotechnology: Integrating electrochemistry into bioreactors

Catabolic and regulatory systems in Shewanella oneidensis MR-1 involved in electricity generation in microbial fuel cells

A synthetic biology approach to engineering living photovoltaics

Contact Info

Product

Resources

About