Welcome to the inquiry with me, Tanya Beckett, one question, four expert witnesses, and an answer.

Often when we think of tackling the threat facing the climate, our minds focus on the burning of fossil fuels.

But about a sixth of greenhouse gas emissions originate from the rearing of livestock.

At the climate summit COP27 held in Charmel Shake, a bold campaign was launched by citizen-led green group called Replanet,

which claimed that the use of precision fermentation could go much of the way towards eliminating the damage to the climate from meat and dairy products.

The plan would be to replace the protein we derive from these foods with an alternative made from microorganisms, for example yeast.

But is this a realistic prospect, or does it present other risks to the environment?

This week on the inquiry we're asking, can microbes feed the world?

Fermentation is used widely in the food industry to make many everyday products such as wine, beer, bread and yogurt.

At the heart of the process of fermentation is a living microorganism which breaks down starches.

Often, but not always, these are yeasts. In the case of bread they produce carbon dioxide to make the dough rise, and in the case of wine making, they produce alcohol.

And as the microorganism chumps through the starches or sugars making these byproducts, it also gets the energy it needs to reproduce.

Hello, my name is Aphrodite Hatzifragou, and I am a social professor in the University of Reading in the UK.

The earliest record of fermentation dates back as far as 6000 BC, and nearly every civilization since has included at least one fermented food in its culinary heritage.

Well, I mean, fermentation is not something that is new. It's been with us from very, very early years. Traditionally, it has been used as a way to preserve foods.

And then, obviously, we have fermented products such as the case of cheese, for instance, on yogurt. So, it's not a very new concept.

There are a variety of microorganisms that can be used for fermentation.

So, this can be a bacterium, a yeast, or in some case, a much more complicated one, which is a fungi.

So, for instance, to give you a bit of an example, we use lactic acid bacteria when we make cheese, when we make yogurt.

We use yeast, so bake is yeast, but probably you are familiar with when we make bread, for instance.

And we use them also in wine making as well. And fungi are more often used for traditional fermented food from Asia, such as tempe.

So, we do have all these particular specific types of microorganism within our tool set.

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