A good while ago I decided to revisit my publications and attempt to make them more accessible and (hopefully) more interesting with some background information on what actually went into them.  This is my first attempt at that with my very first publication.  It’s mainly to see whether I can do it and to practise writing in different ways.  If you’re a scientist reading this, please let me know if I’ve dumbed down to the point of inaccuracy; if you’re a real person, is it interesting, do you care, what else do you want to know that I’ve missed?  The original publication is embedded below in all it’s slightly dry (but look - pictures!) glory.

The sea is a soup of bacteria, viruses and algae. In a teacup of seawater you can find thousands of algae, millions of bacteria, and thousands of millions of viruses.  They form complex ecosystems of organisms competing for food, preying upon each other and reproducing in near invisibility that belies their importance to life on the planet.

In 1999 I was a student studying microbiology and spotted an advert for an eight-week summer placement at the Marine Biological Association laboratory in Plymouth.  Figuring that it sounded much more interesting than my usual summer job of serving cream teas and pasties to coach-loads of tourists (for American readers pasties are like empanadas, not the things that attach tassels to strippers’ nipples) I applied and got the position.

It was with Willie Wilson, a fellow at the MBA and I was supposed to study viruses that infect algae, particularly Emiliania huxleyi* and Phaeocystis pouchetii. Both these algae form large blooms of organisms and then die off; Phaeocystis blooms are thought to be responsible for the for the foam that you can sometimes see along the seashore.  In the summer of 1999 there was a large bloom of E.hux (as there frequently is) off the coast of Plymouth in the English Channel looking, from satellite images, something like this:

The turquoise patches of sea are light being reflected by the coccoliths, shield-like constructions of the mineral calcite, that E.hux surrounds itself with.  When E.hux dies these are released into the water and sparkle.

Willie was particularly interested in how these blooms die, and suspected that viruses played a role, though no viruses to coccolithophores (the group of organisms that E.hux belongs to) had been isolated.  He and a student of his had been out to the bloom in a boat, collected seawater from various areas of living and dead algae within the bloom and brought these back to the lab.  My job was to use these samples to attempt to kill E.hux that had been grown in the laboratory.  This was a good thing as I’ve always been bad at keeping things alive, particularly houseplants and pets. 

First the water was passed through fine filters to exclude everything except viruses and then this filtrate added to cultures of different types of E.hux.  I would then monitor them to see whether they died or not.  Luckily for me it’s really easy to tell when an E.hux culture has died, it goes from being a milky green flask to a clearer flask with fine white dust at the bottom and releases a strong seaside smell (a chemical called dimethyl sulfide or DMS).  I would take samples from any cultures that died and reinfect fresh cultures, building up the numbers of viruses I had and also purifying them.

I also got to take some pictures of samples from dead cultures with an electron microscope (which I only broke once) revealing, to our relief, large numbers of particles that looked like viruses.  Only one of my pictures made it to the publication, it’s figure 5 B in the paper and shows what is presumably a single E.hux cell that has burst apart from the mass of viruses that have been multiplying inside it. You can tell it’s my image as it’s so heavily over-stained, black and blobby compared to the others in the paper.

At the time these were extremely large viruses (christened coccolithoviruses), around 170 nanometres in diameter, some of the largest ever found, and I’d been lucky that they passed through the filter at all. Since then some truly enormous viruses, the mimiviruses have been discovered that are at least four times the size (though thousands would sit comfortably in neat line across the head of a pin).

This was the first time that a virus that infected E.hux had been isolated, and other peoples’ experiments reported in the paper provided evidence that they may have been responsible for the demise of the E.hux bloom.  Since then EHV86 (Emiliania huxleyi virus 86, clever name huh? There were a lot more than 86, I can’t remember why we focused on it…must have been the best at killing E.hux) has had its genome sequenced revealing some unusual genes including those for making ceramide (erm, because they’re worth it?), and methods have been developed to track it in the environment so that its role in killing blooms can be more deeply investigated.

One question that I haven’t yet addressed, and probably a valid one is: who cares?  Sometimes phrased as “why should we give you money to study this?”.  E.hux viruses may have a significant affect on the world around them.  This goes back to that seaside-smelling chemical I mentioned above produced by the dead E.hux cultures. When viruses kill E.hux, DMS is released into the atmosphere where it is converted to other compounds called cloud condensation nuclei. These increase the number of water droplets in clouds, which then reflect more sunlight and have a greater cooling effect…something as minuscule (or in this case, slightly larger than minuscule) as a virus potentially affecting the Earth’s climate. 

EHV86

*I’ve just noticed that the E.hux wikipedia article actually uses a figure from this paper as its main picture. Fame and fortune!