This is the transcript of an interview broadcast Saturday 3/06/00 on Australia’s ABC.
Last year Dr Philippa Uwins discovered a group of organisms in limestone from off-shore Western Australia that are the smallest ever discovered. Since then, Dr Uwins has been doing some further investigations into the bacteria she named Nanobes.
Robyn Williams: At another part of Queensland University they were waiting to show me the world’s deepest rock – deepest ever discovered anyway. But on the way I went to see Phillipa Uwins. Do you remember her from last year, when they claimed to have found Nanobes. Life so small it seemed impossible.
Philippa Uwins: Yes nanobes are a group of organisms which we’ve discovered growing in some sandstone samples that came from outer western Australia and the interesting thing about the nanobes is that they’re in a size range that’s argued, on a current understanding of biological theory to be too small to exist. And the other interesting aspect of the nanobes is that they’re in the same size range as the controversial Martian nanobe bacteria that were found in a meteorite some years ago.
Robyn Williams: Well that’s the summary of what you found a year ago and caused a huge amount of fuss and travelled around the world. What have you found since?
Philippa Uwins: Well when we first published the work we showed ultra structure, morphology, DNA staining at an optical level. And what we’ve since been doing is re-processing the samples to actually improve on the ultra structural detail that we’ve seen, so that we can now see that these are clearly membrane bound structures. They have a nuclear area of dense cytoplasm, and we’ve also now been able to label DNA and RNA within individual cells.
Robyn Williams: So there’s no-one come up and said you were wrong, that they’re not really living things that small?
Philippa Uwins: Not yet, no. It’s generated an amazing amount of enthusiasm, and nobody has come up to us and said, no we don’t agree with your results.
Robyn Williams: Has anyone gone to look, and found similar objects?
Philippa Uwins: Yes I’ve had a number of people written to me said, we’ve been working on similar things but we weren’t game to publish at the time, and now it’s really exciting because we can actually now start looking at this sort of size range. So it has generated a lot of enthusiasm, and we’re now looking in different environments for in situ organisms, and I’m beginning to find some which I know now are actually coming out of these rocks.
Robyn Williams: Have any people who understand microbiology and where these creatures may have come from, given you some kind of lineage as to what sort of life form they may be and where they came from?
Philippa Uwins: Not yet, we’re still working on the sequencing. We got held up last year. So we’re not actually sure exactly what they are yet. Morphologically they look very similar to fungi, only sort of fifty times smaller. And also they are quite unusual in the environments that they grow in, and they sort of fit into some of the theories about the deep hot biospheres, some of these organisms that can actually live in the deep rocks. So they could be related to Archeae because we know that they withstand extreme temperatures, or they be some sort of new organism that we just have to start working on.
Robyn Williams: Archeae that live deep, deep down where it’s hot?
Philippa Uwins: Yes, and around the hydrothermal vents in the mid oceanic ridges.
Robyn Williams: Now I’m sitting here at the University of Queensland, Microscopy Department, in front of your scanning electro microscope. You’ve got a few very pretty growths on your screen here. Those aren’t nanobes are they?
Philippa Uwins: Some of them are. These are some of the larger organisms that are associated with the nanobes which may represent some sort of fruiting or reproductive structures. But in amongst the clay minerals, if I sort of move around in the sample, will see the very small cells in actually in between the clay platelets and the particles.
Robyn Williams: Well how small are they, the things I’m looking at?
Philippa Uwins: The smaller ones in the background that you can see some of these little ones; they’d be in roughly 100 nanometres and smaller. This sample’s been coated with platinum so we have to take off 20 nanometres from the dimensions. So a lot of those cells will be below 100 nanometres in diameter and it’s currently argued, organisms smaller, well with an internal volume smaller than a 200 nanometre sphere can’t exist. So a lot of these cells are about 50% smaller than what’s currently accepted.
Robyn Williams: If they’re much smaller they wouldn’t be able to do anything. They couldn’t actually live, reproduce.
Philippa Uwins: That’s one of the main questions about these organisms. We know that we have larger cells in the samples and we also have these cells that are smaller than 200 nanometres going down to in the order of 20 nanometres. So it’s now to try and find out what are these small structures – what do they represent? Are these organisms some sort of communal organisms, and smaller ones join up with the larger ones. So this is all the sorts of things that we’re trying to do as we monitor growth over time.
Robyn Williams: And you started off talking about the Martian Meteorite. Any luck looking in space, or other meteorites?
Phillippa Uwins: Interestingly we’re starting to collaborate with the astrobiology initiatives of NASA and the European Space Agency. And so we’re looking at the properties of the organisms that we have and then comparing them with some of the samples that will be returned or they are apparently working on now. So we’re working in with these programs which is incredibly exciting.
Robyn Williams: Well I wish you the best of luck. It’s very exciting stuff, and I’m glad to see that after this time it isn’t like one of these science stories that was exciting one minute and gone the next – like the Marsh Meteorite for example.
Philippa Uwins: No, since the initial announcement last year the enthusiasm and interest around the world has just got bigger and bigger. In fact there’s more articles coming out in Germany, in Der Spiegel next week. It’s just really from school children to specific people working in different areas, they’re really interested in finding out exactly what these are. I think just the geological implications of it are really fascinating.
Robyn Williams: You mean that there might be life down there?
Philippa Uwins: I believe there is. Yeah.