Gavin Thomas

Gavin Thomas

I am a microbiologist at the University of York who studies how bacteria interact with the world around them, whether this be inside our bodies, inside insects or in our armpits!

Location York, UK

Activity

  • Yes, we use Archaea often to source interesting enzymes with useful properties like heat tolerance. Also, archaea do interesting biochemistry like methanogenesis (making methane) and are key components of the anaerobic digestion process used in waste water treatment sites.

  • Hi Jazz, You are correct about the mitochondria. Interestingly they also import many proteins they needs as the genes have moved onto the nuclear genome and a new mechanisms to get them back into the mitochondria had to evolve for this to happen (the Tic/Toc system).

    For the second question, this is a good idea, but in fact as the insect is small and has...

  • Hi, nice summary.
    I would consider biogas as a product (a fuel) rather than the biomass itself. Also the bioalcohols are normally what I would consider the products that are made by conversion of biomass to useful things. Alcohol (ethanol) is now getting a lot of interest not for its use as a biofuel, but as a precursor for making many other useful chemicals...

  • Yes. When you buy Quorn, this is fungal biomass (like a mushroom) and is very healthy and is grown in large fermenter on Teesside in the UK.

  • Researchers already had the idea from looking at the size and biochemical properties of mitochondria that they might have bacterial origin, but the discovery that they still contain their own DNA and that this 'looks' like bacteria DNA was the evidence that strongly supports this hypothesis.

    Yes, the symbionts we work on get their food from gut in return...

  • Great answers Bethan. For the last one the bacteria that we study in the insects are clever in that they are transmitted vertically so that new insects are born already having the symbionts in them. Your point is very true in the much longer terms however, as the symbiont's genomes eventually degrade (this is over thousands of years) and they will have to...

  • Hi Sahana. For the first question, you are right that it was by sequencing mitochondrial DNA that we could see that it was similar to certain bacteria, although some clever scientists like Lyne Margulis, had already predicted this just by looking at them and comparing their biochemical properties to bacteria.

    For the second question, the main benefit is a...

  • Jean - I am not a chemist, but the distillation that is used to removed ethanol from the growth medium, is normal distillation based on the different boiling points of ethanol compared to other components of the media (as you say, mainly water).

  • Yes - see the famous map created by Roche.
    http://biochemical-pathways.com/#/map/1

  • Biogas is methane as you say. In the UK farmers are starting to use this now - we call this anaerobic digestion. This is a more controlled process to that when methane is produced at landfill sites.

  • Microbes are excellent at making very complex antibiotics. These are small molecules and they are excellent chemists. They have problems with antibodies as microbes don't normally make these. They are proteins, which is not a problem in itself, but they are decorated in sugar (glycosylation) is patterns that are very different to get microbes to replicate....

  • You are right that they produce organic products, however, there are some very clever bugs that can precipitate metals and form nanoparticles inside them. Check out my awesome colleague Louise Horsfall from Edinburgh Uni is doing (https://horsfall.bio.ed.ac.uk/research.html).

  • Lots of blue cheeses (yum) have microbes (fungi) that make the smell and taste, but still most of the mass of the cheese in from milk. However, in Quorn for example, it really is basically the microbe you are eating (nicely packed into shapes) - its super healthy too.

  • If I understand you Jasper, you are asking why N2 fixation doesn't occur in organelles? Interesting question. This is due to the bacteria that were swallowed up in the first place (which were of course very different for the two organelles). Either neither of them had the ability to fix nitrogen in the first place (likely, as not many bugs can do it) or its...

  • Navin. Biologically the term nitrogen fixation means that biochemical conversion of nitrogen gas (N2) to ammonia - using the nitrogenase enzymes. Some bacteria (not usually the same ones) can take NH3 and convert it to nitrite and then nitrate (which is nitrification). I would consider them separate processes.

  • Tricky question Navin and not sure I have the answer. There are terms that are familiar to animal biologists that are not used at all by microbiologists (e.g. I've never heard the term amensalism before - had to Google it). Hence, although all biologists we used don't use the same language. I would suppose that any interaction between two organisms is an...

  • @GailHopkins these are what are called 'first-generation' biofuels, which have all the problems you allude to. We are interested in using biological waster materials to make bioproducts, which is of course much more difficult, but doesn't result in any competition with food production.

  • @JulieLEFRANCOIS Dear Julie, most efforts now are to try and use waste material to make bioproducts. This would not directly compete with food at all (which I agree is not a good idea). There are huge amounts of waste products which currently are either buried or burned which could be converted into some more useful. The challenges are finding and engineering...

  • Dear Jasper, there are some bacteria that are very good at secreting very large enzymes as they are used to release food from their environment and biotechnologists are trying hard to make them able to secrete a much broader range of proteins that could be more useful as therapeutics. Microbial enzymes we use in washing powder for example are secreted by the...

  • Hi Navin and Luke. You are right that secreting glycosylated proteins is something that eukaryotes do much better than bacteria and archaea, however, some bacteria can do it. However, they tend to not add the right types of sugars in the right way, so the same protein would end up with different 'surface coat' of sugars if made in a human cell compared to E....

  • Agreed. Aritha's PhD work has just been published looking at what we can do with autoclaved bin bag waste, which looks very promising.

    https://microbialcellfactories.biomedcentral.com/articles/10.1186/s12934-020-01325-0

  • There is pretty much no doubt that mitochondria were engulfed bacteria taken in by an ancestral eukaryotic cell - Lynn Margulis's theory was right.

    In terms of costs, yes there are likely costs, but presumably the benefits outweigh them. For the symbionts of aphids we have worked on they actually make nutrients for the aphids they can't get from their...

  • Dear Maggie, it is true that microbes cannot make minerals but they can certainly act on them. There are some very cool bugs called Geobacter and Shewanella that can reduce minerals by passing electrons out of the cell through electron wires (that are cytochromes) which is very cool....

  • Gavin Thomas made a comment

    Elizabeth I.

  • Gavin Thomas made a comment

    Trying to understand the relationships between religion and the state and how this changed during this period. How much did the ordinary person care about this? Interested in how science and technology also impacted on this, e.g. printing of Bibles and mapping/exploration of the world beyond England & Wales. Also, understanding more about European history and...

  • Hi Liam, Antibodies, like any other recombinant protein, could be eaten by the producing cells, and in some cases proteins do get degraded. This is normally not for the host to consume them (it takes a lot of energy to both make and break them so rather a futile process) but because the protein hasn't folded properly and the cell has many ways to removed...