Wednesday, 22 June 2016

Movile - "tiny piece to the jigsaw of understanding Earth"

Rich Boden grew up in the West Midlands in the UK and moved to London to read Chemistry at King’s College London. 2 years into a 4 year programme, he realised his real love was biochemistry and - catalysed by the closure of the Department of Chemistry - he joined the Division of Life Sciences to read Biochemistry. As he had taken a lot of the courses biochemistry students were required to take, he had a lot of gaps in his timetable and was given a final year Immunology project to do instead - published in part in a 2005 publication by Alan Ebringer - this lead to him being bitten by the research bug and growing an urge to do a Ph.D! Inspired by lectures on sulfur metabolism and methylotrophy by Dr Ann Wood, he undertook a second library-based research project with her, looking at the thermodynamic possibilities of life in the putative Martian groundwaters, before taking his final year laboratory project with her, looking at amine-degrading bacteria in the River Thames sediments - published several years later with the addition of further data (Boden et al., 2008). He then did his Ph.D at the University of Warwick - a project covering both methylotrophy and sulfur metabolism - his undergraduate passions - during which he was awarded the 2008 Young Microbiologist of the Year Prize (Society of General Microbiology - now the Professor Sir Howard Dalton Prize, Society of Microbiology). After a short postdoc in biomining with Dr Paul Norris he returned to Professor Colin Murrell’s lab to work on Movile Cave. During this project he was offered a Lecturer position at the University of Plymouth, where he has lead a group working on microbial biochemistry and physiology of sulfur metabolism and developing biotechnologies including mining technologies, biomethane methods and bioremediation of heavy metals. He lives right on the sea and in his spare time enjoys watercolour painting.


Thanks for taking your time to talk with me. So how does one get to visit alien cave? How did you prepare for this exploration?

Near to 10 years ago, the laboratory I was working in at the time was contacted by a cave microbiologist in Romania (Dr Alexandra Hillebrand, Emil Racovita Institute, Bucharest) and sent some samples from the Cave to analyse - which we then published about 2008/9. Around the same time, we wrote a grant application to the Natural Environment Research Council (NERC) in the UK for about £350,000 to employ me for 3 years to work on the microbiology of the Cave. To cut a long story short, we got the grant and we had our first expedition in April 2010 and another a year later (which is the one on YouTube). I originally had no intention of going into the Cave myself but about January 2010 I decided I was turning down a once in a lifetime - once in a career - opportunity and I could not refuse that, so I did it!


How did it feel inside? How much time did you spend there? Do you have experience with similar places? Would you want to go back?

Hot! It’s only about 25 degrees centigrade but the high humidity makes it feel hotter. The air in the Cave is not air as we know it on the surface - it is only 10% oxygen (half the concentration on the surface), 3.5% carbon dioxide (100 times the surface concentration) and also contains methane, and hydrogen. That amount of carbon dioxide makes one feel out-of-breath very quickly and you become tired and slightly sluggish over time. A condition called hyperkapnea starts to happen so you can’t really spend more than 6h in the Cave safely - we limited ourselves to about a 4-5h expedition so we still had 1h to make the ascent to the surface. Getting back out involves a lot of uphill crawling whilst dragging bags and boxes of equipment and finally climbing 20 metres up a rope - which is not easy when you’re already out of breath. I had an accident the last time I went in (which is on YouTube!) where I fell 2 metres and landed on rock - as such, I don’t feel confident going back in, even though I know it would be fine.


Outside world surely helped seed life there, but how self-contained is that cave? Is it really a closed system? If something destroyed life on surface, would Movile Cave ecosystem survive?

It is really 100% sealed, yes. Movile was connected to the surface originally - it was just an ordinary cave until about 5.5 million years ago when a large section of it collapsed, sealing in the region we now call Movile Cave. “Movile” is the Romanian plural for “small hill” because the Cave is underneath a ring of small hills surrounding a depression 500 metres across called the obanul mare - “the great sinkhole” I guess - that was originally a hill too, so quite a large area collapsed, sealing in the Cave. If life was destroyed on the surface would Movile life survive? It’s very probably - as it has no interactions with the surface at all.


How did it benefit your work?

We were reliant on the expeditions to obain samples and do experiments for our work. I actually ended up getting another job about 2 years into the 3 year project so someone else took over from me after I left. In academia, you’re usually on short-term 1 or 3 year contracts until you reach a certain level of experience and you can apply for permanent positions such as being a Lecturer - which is what I did - those jobs don’t come around often so it was too good a chance to take. I still get asked about Movile even now, 5 years after my last expedition, which is always nice.


How can science benefit from studying such exotic and alien environment. What does the inside tell us about the outside?

The point of our work was to try and understand how the complex microbial populations interact with one another and the environment so that the macrobiologists could understand what the nematodes and mites were eating. Our work was a mix of ecology and eco-physiology. All such studies (regardless of the environment studied) add another tiny piece to the jigsaw of understanding Earth and how the various chemical elements cycle around and how life interacts with them.


Biorefinery, bioenergetics and biohydrometallurgy what exactly is that?

That’s a totally unrelated set of work. I lead a research group now working mostly on microbial bioenergetics - how they obtain their energy and, at protein level, how organisms differ at this very basic level. My research group also works on applied microbiology, specifically the use of microorganisms to extract metals from ores (biohydrometallurgy) and then refining and processing the metals into products we can use (biorefinery) - this is cheaper as well as cleaner and greener than current methodologies.


If I’m correct, your research is at least partially connected with ongoing climate change, could you tell my readers something about it?

Only a little connected! I have two postgraduate students jointly with colleagues Dr Mick Hanley (who works on plant-insect interactions and how environmental changes impact these critical relationships) and Prof Camille Parmesan (who works on climate change impacts on insect populations and shares the 2006 Nobel Peace Prize as part of the IPCC). One has been working on how sea-level rises and storm surges impact coastal grasslands - we have looked at every scale from soil chemistry to soil microbiology, plant-microbe interactions, toxicity of salt to plants and how pollenating insect populations changes when plants get damaged by salt - my input to this work is largely the soil chemistry and microbiology. We have another who has been working on the environmental impact of bioenergy crop growth - these are plants that grow really fast and can be burnt to generate electricity or can be fermeted into biomethane - and again, my relationship with the work concerns soil microbiology and chemistry.


Let’s get back to the cave. Is there anything about Movile Cave you’d say was most strange or surprising?

It’s so long ago now it’s honestly hard to remember. We did use a hand-held gas monitor whilst down there and found 0.2% hydrogen in the air - that was totally unexpected - and I remember seeing the insects etc down there and how they totally ignore people or light etc. Sitting in total darkness down there with our helmet lamps turned off was an enjoyable, if sobering, experience. You literally are in another world and totally cut off from Earth as we know it.


This sure is some strange life, but as a Carbon Chauvinist I gotta ask - can you imagine extraterrestrial life that is not carbon based? Or life that is complex but makes it without oxygen?

Well, there are probably more organisms on Earth that operate without oxygen than those that do - don’t forget humans can use pyruvate instead of oxygen, producing lactate, which is what makes your muscles feel heavy when exerted. Microbes using sulfate, nitrate, uranium (VI), ferric iron, manganese (IV), pyruvate, formate and so on as their terminal electron acceptors all exist. There are metazoa and protozoa that can metabolise anaerobically too - Spinoloricus for example. We don’t know how widespread these organisms are yet - you don’t need a very extreme environment for a total lack of oxygen - 0.05mm into dental plaque and there is no oxgen - and your entire large intestine is lacking in oxygen, which is why so many methane-producing Archaea can live there.

As for life without carbon - who knows. I would find it pretty coincidental that all life on Earth that is known uses carbon when there’s so much silicon around but direct homologs just wouldn’t work - respiration producing silicon dioxide (sand), for example! Sounds painful! There was a study a few years ago suggesting an organism used arsenic instead of phosphorus in both DNA and ATP (ATAs, as it became) - not a single lab around the world has been able to replicate that, however. If life ever came along during evolution that used something other than phosphorus, it presumably got out-competed by those that do use as it as they’re more efficient, which is why it’s the norm on Earth. I do believe there must be life elsewhere in the universe, just based on the simplicity of the chemistry that gave rise to Krebs’ cycle on clay surfaces (the work of Gunter W√§chtersh√§user) - that could easily happen elsewhere - and several variations of the Miller-Urey experiment have shown the building blocks of life could form under the conditions of a variety of planets now.


Thank you for your time!

You can follow dr. Boden’s work on Twitter: @bodenlab or YouTube: bodenrich


Top picture - Copyright (c) 2013 Plymouth University
Rest - Credit: Patrick Landmann/SPL