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Thanks to all the authors in Chris Howe's, @biophotoelectro.bsky.social and other labs who contributed over the years. Also to the fantastic (and super quick) editors and reviewers whose comments greatly improved the manuscript, as well as the BBSRC and others for funding. (10/10)

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This technique (native membrane electrochemistry) combines the interpretability of protein electrochemistry with the complexity of microbial electrochemistry. We envision applications in investigating #bioenergetics, as well as #bioelectricity and #biocatalysis. (9/10)

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We also identified how wiring membranes to electrodes has inherent advantages in #biohybrid devices for energy conversion. Here we obtain photocurrents at -600 mV vs SHE; ~1V more negative (much higher energy electrons) than is achievable with isolated proteins. (8/10)

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We also showed how these electrochemical measurements can be coupled to spectroscopy, with parameters from each showing agreement with one another. (7/10)

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This alone demonstrates that electrochemistry can interrogate complex biological systems, but what can we actually use it for? Here we use the Spike Charge to measure respiratory reduction and oxidation of the #quinone pool (↑Spike Charge = ↑quinone reduction). (6/10)

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Through many experiments (different inhibitors, mutants, experimental conditions) we could disentangle the different electron transfer pathways within the membranes. This enabled us to create a detailed model of electron transfer between the membranes and the electrode. (5/10)

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These parameters were dependent on different interfacial electron transfer pathways, shown here by the different effects of photosynthetic inhibitors. This suggested analysis of photocurrents could provide information on different membrane electron transfer pathways! (4/10)

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These specialised electrodes enabled sensitive measurements of photocurrents, revealing a distinct profile (not observed in previous studies) which was quantified as two parameters: the Spike Charge and the Steady State Photocurrent. (3/10)

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Josh Lawrence @jmlawrence.bsky.social · 25/03/2025

To analyse bioelectrical pathways, we interfaced thylakoid membranes isolated from #cyanobacteria with structured #electrodes. These #membranes contain a highly complex network of electron transfer, including electron transport chains for #photosynthesis and #respiration. (2/10)

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Was great to be part of this study headed up by @scaralbi.bsky.social. We are very excited by the finding that chromosomal polyploidy could be an important driver in the #evolution of #cyanobacteria and other prokaryotes. 🧬🦠

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This work wouldn't have been possible without my fantastic colleagues in the Zhang lab (@biophotoelectro.bsky.social), Howe lab, and further afield. Also my funders @ukri.org, Leathersellers' foundation and Trinity Hall, who have supported this work which has bridged my PhD and fellowship. 15/15

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Because cyanobacterial thylakoid membranes have some of the most complex electron transport pathways known to nature, the technique should be readily transferrable to any biological membrane. We foresee its use in characterising bioenergetic pathways and biohybrid systems. 14/15

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We think natural membrane electrochemistry sits nicely between protein electrochemistry and microbial electrochemistry in terms of data complexity and interpretibility, making it a perfect system for studying biological electron transport at a systems-level. 13/15

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This thread is a very high-level look at the manuscript which, like biolectrochemistry data, is very information-dense. All comments and questions are welcome! 12/15

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We also developed a spectroelectrochemistry set-up, which we used to prove that these changes in the Spike Charge matched biophysical measurements of plastoquinone pool reduction. 11/15

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In this graph we can see that the magnitude of the feature depends on the dark time (during which quinone reduction occurs), the addition of substrates for dehydrogenase enzymes which reduce the quinone pool, or the deletion of oxidase enzymes which oxidise the quinone pool. 10/15

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But how is this useful? To demonstrate the power of this technique, we used the Spike Charge feature to provide a direct electrochemical readout of plastoquinone pool reduction. 9/15

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To cut a (very long) story short, from these experiments we were able to build a model of the electron transfer processes happening within the isolated thylakoid membranes, and between them and the electrode. 8/15

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In addition to testing experimental conditions and mutants, the beauty of electrochemistry is that just by changing our electrode potential we could control which cofactors could transfer electrons to the electrode; as demonstrated in stepped chronoamperometry experiments like this one. 7/15

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We were were able to show how these two electrochemical parameters related to different thylakoid membrane electron transport pathways, including components of the photosynthetic and respiratory electron transport chains. Disentangling signals from these overlapping pathways is very difficult! 6/15

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When recording photocurrents (change in current over a photoperiod) using these electrodes, we observed a unique profile which could be analysed using two electrochemical parameters: the Steady State Photocurrent and the Spike Charge. 5/15

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Here, we use highly structured electrodes to perform sensitive electrochemical measurements of the thylakoid membranes of our favourite organisms, #cyanobacteria. These contain very complex electron transport pathways, with #photosynthesis and #respiration occuring in the same membranes. 4/15

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There has been some spectacular research in recent years on interfacing membranes and cell biofilms with electrodes (check the references for some of these). But the low sensitivity and high complexity of these analytes have hindered analysis of electron transport in these complex systems. 3/15

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Josh Lawrence @jmlawrence.bsky.social · 12/03/2025

Electrochemistry enables information-rich analysis of redox proteins and enzymes, both soluble and membrane-bound. However, its reliance on protein purification limits it to just one or a few proteins/complexes, which differs from the complexity of electron transport in living cells. 2/15

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Thanks to @cenmag.bsky.social for this great article about our efforts to create music with algae 🎶🦠

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Explore the article collection: Algae at the interface. Published in Applied Phycology.

For more papers of this ilk, check out the special issue on 'algae at the interface', which this publication is part of. 12/12 www.tandfonline.com/journals/tap...

tandfonline.com

Algae at the interface

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A big thank you to Juliet Brodie, as well as the rest of the Applied Phycology editorial team and our peer reviewers for helping us with this (rather unorthodox) paper. 11/12

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We look forward to showing more of this work as it progresses. It's all been made possible through the collaboration of a highly interdisciplinary team of scientists, artists and designers: Alberto Scarampi, Emma Albertini, Paolo Bombelli, Chris Howe, Lucia Giron and Lena Kuzmich. 10/12

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We are now collaborating with artist Lena Kuzmich, who is building our first proper algal musical instrument. A prototype of this device has already been used as a part of a musical ensemble in 'Choir of Kin'- an art installation shown at Brut Vienna last march. 9/12

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We also discuss the different musical applications for this technology, with a particular focus on music which reflects the environment, or 'space' it is generated in. 8/12

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In this perspective we outline the essential design considerations when building these algal musical instruemnts. This includes a detailed description of the different ways bioelectrical signals can be converted into musical ones. 7/12

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From this we surmised that algal bioelectricity could be used to make truly environmental biomusic, which not only reflected but was generated from the environment it was composed or recorded in. 6/12

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By comparison, the electrical signals generated from algae are directly related to the photosynthetic and metabolic activity of the cells. When environmental conditions cause alterations of this activity, this is reflected in the electricity production. 5/12

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Biomusic is music created with no, or minimal, human-input. Previously, researchers have made biomusic using signals recorded from living non-human organisms, including plants and slime molds. However, the signals used to make this music are often not biological in nature. 4/12

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We found this system was a brilliant tool for outreach, enabling us to explain complex scientific topics such as photosynthesis and bacterial metabolism through music. This led us to wonder how else we could use this musical technology. 3/12

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We first began this work back in 2022 for the Cambridge Science Festival. We built a circuit which converted the voltages from a cyanobacterial biofilm into MIDI signals, which we played on electric synthesisers. 2/12

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