renewable options available to us. The sun is going to continue shining for billions

of years. The wind and the tide are not going anywhere, as far as we know. And there is

also another form of energy being produced all the time, all around us, which you might

not be aware of. And it's methane (CH4).

So the combustion of methane can produce large amounts of energy. It's quite popular in India.

In the UK it has not gained a foothold. So where does this energy supposed to come from?

These guys.

Cows get most of the blame for the production of methane but it is actually the microbial

communities inside it's digestive tract which are responsible. That process will continue

even after the faeces has left the cow and if one were to retrieve a sample of that and

place it into an air-tight container, with the appropriate artificial medium, the methane

production process would continue, as you can see here.

Let's take a closer look at the sample under the microscope to get a picture of what is

exactly going on.

The intestine of a cow is a very nutrient-rich environment and this allows for the existence

of hundreds to thousands of different species.

As you can see here in this image, this complexity is completely overwhelming. We can't actually

do anything with these bio cells, we have to focus in on our core interest, which is

the methane producers known as methanogens. So if we want to isolate these guys and study

them further, we have to take some very special precautions.

Methanogens are incredibly sensitive organisms. Even a tiny amount of oxygen will kill them.

So here you can see my colleague working in an anaerobic chamber where all the oxygen

has been removed.

This is what a methanogen monoculture looks like after we have successfully isolated it

from its natural community. So, of course, these guys are responsible for all the methane

production in a cow but they don't do it alone. They rely on an extensive network of other

bacteria in a food web. This is where the real science begins, you see, because now

that we have our monoculture we can mix and match different players from that food web

with this guy to find out: what does a stable community look like; what are the properties

of an efficient community; what does a weak community look like? And these design principles

can be used to tell us all sorts of things about how nature works.

Alright, so thank you very much for listening. Have a great day.