Moulds are a group of fungi. They’re very important in the process of decay, and they also create the ‘veins’ in blue cheeses like Stilton. But there are a few that do something far more important than giving us something tasty to put on biscuits…

In 1928 Professor Alexander Fleming went on holiday (something you could still do, back then…). He was working on the bacteria that cause sore throats, and he left some dishes with the bacteria growing in them in his notoriously untidy lab when he left.

When he returned, he noticed that one dish had mould growing in it and that the bacteria nearest it had disappeared. Intrigued, he grew the mould, tested it and found it produced a chemical that could kill many types of bacteria. The mould was called Penicillium notatum so he named the chemical penicillin. He discovered it couldn’t be stored for long, and that it didn’t harm mice if they were given a dose.

 

…But it was so difficult to extract and purify that scientists lost interest in penicillin! You’ll have to come back tomorrow to find out what happened next

Fungi are a strange and wonderful group of organisms. They’re not animals OR plants: they have  a whole Kingdom to themselves. And not all of them are microbes – that’s obvious, if you’ve ever eaten a mushroom: you didn’t need a microscope to find it on your plate. So, what are they?

If you see a mushroom growing in the ground, you are only seeing the reproductive bit of the fungus. The rest is under the soil, and is a huge network of tiny threads. In fact, the biggest organism in the world is a fungus! No, not a giant mushroom, but the underground bit – and it is truly vast.

It’s a honey fungus which lives in Oregon in the USA. It occupies an area of nearly 10 square kilometres, and is probably at least 2,400 years old, so it’s one of the oldest living things on Earth, as well as the biggest.

Lots of fungi are tiny enough to count as microbes though, and many of them are vital for the decay I wrote about last week. But there’s also one responsible for saving millions of human lives – watch out for the next post!

Still talking rot tonight… Did you realise that if you have a compost heap in your garden, or if you put food waste out for recycling, you are enlisting an army of trillions of microbes to help you?

Making compost is like magic – but it’s just biology (mind you, I find biology pretty magical). I’ve just chucked an apple core on my compost heap; what’s going to happen to it?

First, the local cats will have a sniff, sneer, and stalk off. The local fox might have a quick look, but probably won’t be interested either. Birds will come down and peck at the flesh, and quite a few insects will have a nibble. Eventually, there may only be small pieces left. If you watched them, they would start to turn a bit wrinkly or slimy, and that would show you that decay had started. If you had mega-zoom vision, you would see that what was causing the decay was a mixture of bacteria and fungi and that they were breaking down what had been the apple cells and releasing the chemicals inside them. This might only take a few days if it’s warm and not too dry, but in winter, it could take weeks or even months.

Also in the heap will be lots of other compost heroes – worms. They will be chomping up leaves and digesting them – also releasing chemical nutrients – and the worm droppings will form soil. Yes, that’s right – a lot of what we call soil is worm poo!

If you leave dead plants and kitchen waste in a compost heap for long enough, they go from being smelly bits and pieces to deliciously dark, crumbly compost with a lovely, earthy scent. Congratulations – you’ve just made some great plant food. And you couldn’t have done it without your microbe friends!

Time to meet some more of our microbe friends… the ones who make things decay . Now you may think this is NOT a helpful activity when it happens to food in your kitchen, though it can look quite entertaining if you speed it up – have a look at this.

You may also be wondering why there’s a picture of The Lion King here… It’s the Circle of Life, of course!

The only source of chemicals to build new cells – which could be part of  a carrot or a butterfly or you – is the ones that are already here on earth. But these chemicals are tied up in the organisms that already exist, so what can you use to build the new cells?

That’s where the microbes come in: as they rot dead plants and animals, they are breaking down their cells. This releases the chemicals to be re-used to build new cells, to make carrots, butterflies, humans and all the other marvellous plants and squidgy creatures on earth – and it gets rid of the old, dead ones. If it wasn’t for microbes tidying them away, the planet would be cluttered with dead dinosaurs and Romans and unicorns… Well, maybe not unicorns, but you get the idea.

 

I know this title may seem a bit strange given what we’re all girding our loins to go through, but I worry that a whole generation of children (and some adults) are going to be left with a real neurotic fear of microbes, so I thought I’d try to redress the balance a little bit.

Think of the microbe kingdom the way you think of the animal kingdom: some animals are dangerous and you would steer well clear of them, lots are harmless; some greatly enhance our lives and we would miss them hugely if they weren’t around.

Now, you may think the only connection between microbes and food is that they make it rot, but that’s not true. Your kitchen would be missing quite a few items if it wasn’t for microbes…

Yoghurt is made for us by friendly bacteria changing some of the sugars in milk into lactic acid.

Cheese takes the same process a stage further, separating the solid curds from the liquid whey, packing the soft cheese into a mould and letting it harden. You want holes in your cheese? – Add another sort of bacterium. You want blue veins? – Add a special fungus.

Yeast is a tiny fungus which we use to make bread rise, so; no yeast, no croissants, crusty rolls, sourdough – or even pre-packed white sliced.

All you hipsters who love your fermented foods would have to say goodbye to sauerkraut, kimchi, soy sauce, kefir, miso…

Vegetarians wouldn’t be able to cook with Quorn any more, since it’s made from a fungus.

And we would have to bid a sad farewell to alcohol: beer, wine, cider, spirits… even those sickly-sweet liqueurs.

 

 

I know, it’s been a while… I’ve been busy having a non-online life, doing school visits, taking part in the Newcastle heat of Kids Lit Quiz, tracking my son’s progress as he travels round South America, organising our annual bonfire party (and clearing up after it…). Oh yes – and writing. I’ve been doing a bit of an edit on my book on Mary Queen of Scots, and have dived into writing the first draft of a book about exploration.

I haven’t been completely off line though: in a moment of madness I gave my cat an Instagram account (yes, drink had been taken first), so he is now online as lenthecatsays.

Much more significantly though, I’ve just done a blog on A Secret Diary of the First World War for Reading Force, a splendid charity which works with service families to use books to bring them together when parents are posted overseas. You can read it here.

It’s always a gamble going to see a film adaptation of a book you love… I took a deep breath, crossed my fingers and did it twice in the last week.

First I went to see The Goldfinch. Now this really is one of my favourite books. It’s a long, leisurely read which was criticised in some reviews for meandering too much. I loved the meandering, but I did think that the plot would squash down fairly readily into a two and a half hour movie.

Turns out the meandering was vital. I did enjoy the film, but it was hugely flawed and the relationships never had a chance to build up in a convincing way. Finn Wolfhard (best name ever!) and Aneurin Barnard were both excellent as young/older Boris, and Nicole Kidman was perfectly cast, but I was less convinced by Anselm Elgort as Theo, the central character. Hmmm… Great source, disappointing film.

I spent a lot of time as a child with my nose in DC and Marvel comics, which could hardly be described as high art, but I’m not a huge fan of superhero films. However, I decided to give Joker a try. Wow! It’s a disturbing, dystopian art house movie, with a mesmerising central performance from Joaquim Phoenix. Forget any comic book movie you have ever seen: this is something entirely different. Dodgy source, great film.

It’s been a busy few days in world of books, with visits to Airdrie Academy and Perth. In Airdrie, I was talking to the S3 history group about my research for A Secret Diary of the First World War. I haven’t done that before, and it was really enjoyable being able to share some of the unexpected gems that I unearthed while down the research rabbit hole. Thanks, Airdrie Academy!

On Saturday I was at the Black Watch Musuem in Perth to take part in the very first Words of War Book Festival. The museum itself is fascinating, and occupies a lovely building and has its own replica WW1 trench, which I visited with the children I’d been talking to about Secret Diary.

We also got to have a good look at some bits of kit: webbing, entrenching tools, gas masks – fascinating for me as I’d written about these things without actually seeing them before. The museum is well worth a visit.

I also got chatting to Fiona Maxwell, Scottish ambassador for Reading Force. Reading Force, which I must admit I hadn’t heard of before, is a charity which uses reading to keep Service families connected even when they can’t all be together, by encouraging children to read, talk and scrapbook about books with absent family members. Having read a bit about it now, it sounds like an excellent idea to help children cope with the separation involved. I hope I can work with them sometime soon.

Well, it serves me right for trying to keep fit, I suppose… I’ve cracked a metatarsal while attempting to do Couch to 5K. I’m really cheesed off as I’d got to the stage of running (albeit pretty slowly) for 25 minutes non-stop, and was beginning to enjoy it. (And there’s a sentence I never expected to write.) So at the moment, I’m pretty immobile.

However, this does have its advantages when you’re an author who’s trying to research the next non-fiction book and at the same time edit a new draft of a novel. It’s much harder to procrastinate when you can’t go out for a walk…

For the past couple of days I’ve been reading a fascinating book about shipwrecks and wreck divers, which has been most diverting and full of amazing facts. (And strangely appropriate that I should be reading about wrecks, I’ve just realised.) Did you know, for instance, that a Roman wreck has been found off the coast of Brazil? Or that one of the ships from the Spanish Armada lies wrecked in Tobermory Bay on the Isle of Mull?

I can remember the excitement when the Mary Rose was raised from the seabed. Until then I hadn’t even realised there was such a thing as marine archaeology, but my goodness, it sounds fascinating. And dangerous…

Edinburgh has reverted to normal: most of the tourists have headed home and you can now walk along pavements in the centre of town again without ending up in someone’s photo album. Autumn has also, rather abruptly, arrived and it’s definitely time to get back to work.

I’ve been looting the library for books on such topics as shipwrecks and submarines as I disappear down the research rabbit hole. It’s great fun to learn about something new and I’m always on the look out for the bizarre facts that make a non-fiction book come alive. At the moment I’m boggling at the fact that there are estimated to be 3 million shipwrecks out there. It’s a wonder there’s room for any water in the sea, what with all that and the whales.

For a bit of contrast, in the evenings I’m editing a novel. It’ s good to have two such different things on the go at once: each one acts as light relief for the other. So far, anyway…

And of course, school events are revving up for the autumn term: look out Mary Erskine, Dalziel and Braidhurst high schools – I’m coming your way this week.