Our current exhibition, Atmospheric Encounters, covers the work of the High Altitude Bioprospecting (HAB) team, a group with an extraordinary broad skillset between them, including biochemistry, technology, engineering, robotics, mathematics and art. Bought together by a shared interest in microbiology, they use their considerable talents to search for life in the outer reaches of Earth’s atmosphere and to disseminate what they find out to the rest of us.

It was only during the exhibition’s installation that some of us learned of the airborne drifts of aeroplankton, chemically communicating with each other as they travel the stratosphere. So for myself, in my role in gallery visitor services, for our visitors and for everyone else not blessed with a working knowledge of high altitude dwelling life forms, I’ve asked the biochemist, High Altitude Bioprospecting team member and BOM Fellow, Dr Melissa Grant to respond to some of the questions we’ve been asked in the gallery.

CD: You’re aware of the surprise the general public have had to the existence of aeroplankton since the exhibition opened, for a great many of us this is new news. How did you become drawn to these tiny specks of life in the first place?

MG: I have had a long fascination of the way life works (biochemistry is the science of life) and it still provokes a sense of wonder for me. I remember vividly being given ‘homework’ to do in the summer between my ‘A’ level years on biochemistry and from that moment onwards I was hooked. At university I studied biochemistry and have experienced working with viruses, bacteria, plants and animals. The underlying way things work in terms of how the molecules interact with each other is very similar between organisms.
Then in 2008 I applied to become part of a programme run by NESTA* called Crucible. The idea was to throw together 30 young scientists and see what innovations we came up with by exploring different disciplines. This is where I met Oliver de Peyer and Paul Shepherd. One night in the bar I asked Oliver what he would really like to study and he said he’d like to discover microbes in the stratosphere and so HAB began in earnest. I also happened to be working in a lab where Kira O’Reilly was artist in residence. She introduced me to bioart and Anna Dumitriu and Alex May. So then we had the first six members of the HAB team.

CD: We’ve seen close up footage of oceanic plankton on Natural History documentaries, we’ve possibly held jars of pond water to the light to see the tiny creatures living in our fresh water. Do these images prepare us for what air borne life might look like if we happened to be floating around the stratosphere with suitable bit of magnifying kit? Are there similar densities of life and are they as varied?

MG: Our atmosphere has layers – we for instance live in the troposphere. This is the place on Earth where there is the most abundance of life, where the conditions are easiest to flourish for most species. The atmosphere in the troposphere is also thicker or denser, that is there are more molecules of air than further away from the surface of the Earth. Between the troposphere and stratosphere there is the tropopause, a thicker barrier of the atmosphere that makes it harder to get into the stratosphere. It takes big events, such as volcanic eruptions or space rockets, to get there. It is not impossible but it means that we expect the density of life in the stratosphere to be much lower than in the troposphere. Information collected so far suggests that there is a variety to the organisms that make it into the stratosphere, but it is likely to be far less than in the troposphere.

CD: If it’s a known that these small organisms can seed cloud, rain and snow formation, do we know how great or small their impact on our climate is?

MG: The field of meteorological microbiology is growing but I don’t think we know all the answers to this yet.

CD: We know that the density of airborne insect life closer to earth has seen huge reductions in recent years, is there likely to be a similar trajectory of loss within the high altitude microscopic communities that you are researching?

MG: The number of experiments that have been done and that they have only happened sporadically means we don’t have much data on this yet.

CD: Do we know how aeroplankton is being affected by climate change?

MG: To answer this, we would need to set up some very specific experiments to monitor the microbes in the atmosphere. Some groups have started to look at variations over time – some have looked at what happens in clouds over mountain weather stations and others have looked at what happens in laboratories situated next to rainforests. More experiments will be under way and we’ll need to keep up with the scientific communications to learn more.

CD: In the gallery notes on Till Bovermann and Hannah Imlach’s piece, ‘Flock’, there’s mention of a conversation that needs to be had about whether it’s ethical to bioprospect at all. What are the ethical concerns that should be addressed? Do these concerns shape the direction of your research as a team?

MG: Bioprospecting is a term that describes the finding and gathering of biological entities – in this case microbes, but it could also be molecules from plants for medical treatment. The word prospecting carries a lot of colonial connotations and the potential for stripping something from the environment.  So, the ethical concerns could be associated with how the bioprospecting happens and what happens with the microbes found afterwards. Other questions could be around, who do the microorganisms belong to and how can they be used for human gain – that is exploitation. Other questions then arise such as can you exploit a microbe? We have been using, for instance, yeast for a very long time for making bread and beer – is that OK? As a team we are discussing these issues – other ethical questions are coming up now around the use of helium as it is a natural resource with a finite quantity. Alternatives such as hydrogen may be better as it can be made but it is highly flammable, so has the potential to be riskier to use. These kinds of considerations are all part of being a scientist and considering the pros and cons of experiments and end points.

CD: Could as yet undiscovered aero plankton be useful in some way? Could they be farmed and would that be sustainable and or ethical?

MG: Yes, this is exactly what we hope for. Surviving in the stratosphere is hard: there are extreme quantities of sunlight (ultraviolet light to be specific) and the quantity of oxygen can be low. Microbes found there may have specialised to be able to cope with these and other conditions. If we can identify and understand these then we could perhaps make use of them. The easiest example to think of is could a microbe that can withstand high UV being used to find novel sunscreens?

In terms of keeping microbes and ‘farming’ them – this is usually not too difficult. Culturing microbes is if the correct conditions can be found allows for them to be grown in laboratories and then they can be harvested for the desired purpose. It is also possible to adapt easy to grow laboratory microbes with knowledge and molecules from biosprospected microbes to help this to happen too.

CD: When you have finished growing cultures from the samples you find, what happens to them, do you throw them away?

MG: Microbes are amazing in that they can often be frozen and kept in storage in a freezer. This means that there can always be some of the daughter cells of those found in HAB expeditions kept stored if they are not being examined at a particular time.

CD: Is there microscopic life beyond our atmosphere?

MG: A good question that NASA**, ESA*** and others are putting a lot of effort into solving. The hunt for life on other planets is looking for exoplanets that have the Goldilocks conditions (not too hot, not too cold….) to allow life as we know it to flourish. Most of these exoplanets are a very long way from Earth and so scientists look for signatures of chemicals that suggest life rather than actual microbes themselves. Closer to home there have been efforts to look for traces of life on other planets, moons and comets in our solar system. Nobody can say that there is life anywhere else yet – as they say there is no planet B.

CD: If the HAB team had unlimited funding and time to pursue a new project, what might that project be?

MG: We’ve tried many things with developing the HAB device but I think we have yet to get the sweet spot, so the first thing would be to get the best HAB device. Then we would fly it to get a much better idea of the microbes in the atmosphere in general and definitely the stratosphere, without contaminating the places we’d like to go (that’s actually a big challenge). Making this a robust scientific endeavour with multiple flights, from multiple locations, exploring the daily and seasonal variation would tell us a lot more about this little explored but often viewed part of our planet. If we can make it accessible through a citizen science approach I think that would spread the excitement we all feel with the HAB project.

CD: Finally, and very importantly, we’d like your thoughts on the best cake to order in BOM’s Café…

MG: I had the privilege of being in the BOM café the day before reopening and got to sample a lot of different cakes. My favourite is the Bara Brith – this is super fruity and not too sweet. It also brings back lots of memories as Bara Brith is the first cake that I learnt to make on my own.


* NESTA https://www.nesta.org.uk

**NASA https://www.nasa.gov

***ESA http://www.esa.int