![\"An](\"https:\/\/res.cloudinary.com\/cognitives-s3\/image\/upload\/c_limit,dpr_auto,f_auto,fl_lossy,q_75\/v1\/cog-live\/n\/1271\/2023\/Mar\/08\/dwpWR4W3Y3De38GXRvom.jpg\")
Professor Greening\u2019s lab specialises in how bacteria obtain energy.<\/a> Dr Grinter\u2019s lab<\/a> focuses on the molecular machines that make up bacteria, and how they work.<\/p> \u201cWe’ve known for some time that bacteria can use the trace hydrogen in the air as a source of energy,\u201d Professor Greening said. \u201cBut we didn’t know how they did this, until now.\u201d<\/p> Huc works as a hydrogen gas scavenger, and unlike all other known enzymes and chemical catalysts, it can consume the gas below atmospheric levels.<\/p> In this way it\u2019s like a natural battery, making a small electrical current from air or added hydrogen. Science has been stumped as to how it worked. This finding opens the way to create devices that literally make energy, in the form of electricity, from thin air.<\/p> \u201cWhat we really wanted to do was isolate Huc from a bacterium able to scavenge atmospheric hydrogen,\u201d says Dr Grinter.<\/p> \u201cThat is a challenging thing to do, because often these environmental bacteria are hard to cultivate. So, we developed a series of new methods for, first, growing the bacteria, then breaking them open and then using chemistry to try and isolate this single component.\u201d<\/p> The chosen bacterium was Mycobacterium smegmatis<\/em>, discovered in 1884 in Austria by a doctor, Sigmund Lustgarten<\/a>, who was looking into skin diseases. Despite being isolated in this context, M. smegmatis<\/em> generally lives in the soil, doesn\u2019t cause disease, and is relatively well-studied because of its use as a model for organism for its cousin tuberculosis.<\/p> \u201cAlso,\u201d he says, \u201cone of the things that’s important for studying bacteria or purifying the components is to be able to change their genomes. Add genes, take them away and put in a little bit of extra DNA that allows you to purify the complexes. These tools exist for M. smegmatis<\/em>.\u201d<\/p> Team member Ashleigh Kropp did much of the lab work, including extracting Huc from the bacteria cells.<\/p> \u201cWe found that Huc has an extra component that we didn\u2019t know existed,\u201d he says.<\/p> \u201cUsing this, Huc forms a large complex, and when we remove it, Huc doesn\u2019t form that large complex anymore. It turns out that this component and the complex is really important for how Huc functions in the cells.\u201d<\/p> The lab work showed that purified Huc can be stored for long periods.<\/p> \u201cIt\u2019s very stable. It\u2019s possible to freeze the enzyme or heat it to 80\u00b0 Celsius, and it retains its power to generate energy,\u201d Kropp says. \u201cThis reflects that this enzyme helps bacteria to survive in the most extreme environments.\u201d<\/p> \u201cWhile there\u2019s a lot of work to do to make this happen, there\u2019s a number of potential applications,\u201d says Dr Grinter. \u201cThe synthesis of fine chemicals requires very specific modifications to a molecule, which can be difficult to perform chemically. Huc could use the electrons from small amounts of hydrogen in air to perform these chemical modifications, in industrial chemical synthesis.\u201d<\/p> Huc could also be used as a sensor for hydrogen. Huc produces electrical current when hydrogen is present. When Huc is placed in an electrical circuit, this current can be measured to determine the hydrogen concentration.<\/p> Because Huc can oxidise hydrogen to extremely low concentrations, a sensor that incorporates it would be very sensitive.<\/p> Possibly the most interesting application of Huc is to power small electronic devices using air or low concentrations of hydrogen.<\/p> This would mean these devices are powered by a super-clean and sustainable energy source. Because the amount of hydrogen present in air is so small, only a small amount of electricity could be extracted from it.<\/p> However, if these devices were provided with more hydrogen, produced in the burgeoning hydrogen economy, Huc could produce significantly more power.<\/p> \u201cOnce we produce Huc in sufficient quantities,\u201d Dr Grinter says, \u201cthe sky is quite literally the limit for using it to produce clean energy.<\/p> \u201cIn addition to the potential applications of the research, this work is really important, because it can help us understand how our planet works.<\/p> \u201cBetween 60% to 80% of bacteria in soils, especially nutrient-deprived soils, have enzymes like Huc, and are constantly absorbing hydrogen.<\/p> \u201cThey absorb 70 million tonnes of hydrogen every year, and this shapes the composition of our atmosphere, which makes this process important for modulating the climate. Understanding the biochemistry of this process may allow us to harness it to stabilise our climate in the future.\u201d<\/p> This article was first published on Monash Lens<\/a>. Read the original article<\/a><\/p>What can Huc power, and how could it be used?<\/h2>
![\"\"](\"https:\/\/res.cloudinary.com\/cognitives-s3\/image\/upload\/c_limit,dpr_auto,f_auto,fl_lossy,q_75\/v1\/cog-live\/n\/1271\/2023\/Mar\/08\/mRKSdJPlZQHbZYuRBULh.jpg\")
![\"A](\"https:\/\/res.cloudinary.com\/cognitives-s3\/image\/upload\/c_limit,dpr_auto,f_auto,fl_lossy,q_75\/v1\/cog-live\/n\/1271\/2023\/Mar\/08\/9lD2K9MM4N7crbRGKOQ2.jpg\")