Explore Your Body - Microbe Magic

Fungi have been on earth for millions and millions of years. They are not a plant even though they can look like plants, nor are they an animal – fungi are actually a really ancient type of vegetable!

There are, experts think, over 1 million different species of fungi on earth to day! In a single teaspoon of earth, you could find about 120,000 fungi. You probably see fungi of some sort or other every day. The most common fungi are mushrooms and truffles (yum!), yeast that is made to make bread or molds and mildew which are useful but not so pleasant.

Although some fungi have many cells, they cannot make their own food like plants do as they do not have chlorophyll (plants use chlorophyll to make food from the light of the sun). Fungi are parasites and grow on plants, animals, humans, dead and decaying organic matter, anywhere, in fact, where it is warm and damp! They get their food by making enzymes that digest food from the surface they are growing on and absorbing the digested nutrients through their cell walls. Fungi mainly absorb water and digest sugars and starches which they use to grow.

Fungi have adapted to many different environments and can be found in the air, in the ground, in water, on plants, on you! All of these places provide the nutrients, warmth and moisture fungi need. Some fungi have adapted to grow in the desert where water is scarce, in very cold parts of the world and in fresh or seawater where there is too much or the wrong kind of water. Fungi have been around so long, they have adapted to grow almost anywhere.

Fungi, along with bacteria, are one of the best decomposers of organic material. Without them, dead plants and animals would just hang around and the nutrients from the dead material would not return to the ground. Other plants, animals and micro-organisms that rely on that food would also die and the delicate balance of the ecosystem would be lost.

Fungi are pretty simple structures really. Mushrooms, toadstools, puff balls and the hard fungus you see growing like plates on the sides of trees, all have the same structure. They grow in bunches of filaments (which look like sewing thread) called hyphae, although you cannot always see this. The hyphae grow together to form mycelium which can form a fruiting body which is the part of the mushroom you can see.

Fungi can’t move about, they stay where they grow, so how do they make more fungi? Underneath the fruiting body of the mushroom, the bit you can see that looks like an umbrella, there are rows of ‘gills’. In these gills, tiny microscopic spores are produced. Spores are the seeds for the next generation of fungi and they are carried to new places by the wind and rain. When the spores come into contact with the right growing conditions – generally somewhere there is food, moisture and warmth - they germinate (start to grow) and break through the surface and grow.

Fungal spores are spread in different ways. They can be carried by the air, on animals, on your clothing, by traffic, washed away to new places by the rain or rivers…even when you breathe, you are breathing in the tiny spores! When you cough or sneeze, it disperses the spores in new places and if the conditions are right, they will begin to grow. If the fungus doesn’t have the right conditions for growth, they hibernate (become dormant) until the right conditions come along or until they are moved to a better spot!

You may think that there are very few types of fungi but, if you think about it, you probably see fungi of some sort or other every day. The most common fungi are mushrooms and truffles (yum!), yeast that is made to make bread or molds and mildew! Yeasts like Saccharomyces cerevisiae is also called Bakers yeast and it is used in the process of fermentation to make bread. Yeasts are also involved in the fermentation of wines and beers and in brewing soy sauce which is used in Chinese cooking. Blue chesses like Cashel blue or Roquefort are injected with certain kinds of fungal spores. The mold that grows from the fungal spores gives the blue cheeses their colour and yummy taste. Don’t worry - these fungal spores and molds are not toxic to humans, so they won’t make you sick.

There are lots of things to be thankful to fungi for – besides being tasty they help to keep you and the food you eat healthy! There are some fungi that are used in medicine. They kill bacteria that invade your body and produce antibiotics like penicillin. Antibiotics made from fungi are used to treat nasty diseases like tuberculosis (TB) and leprosy. Not only that, but they can be used to fight off insects, pests and even other fungi that grow on plants!

Penicillin is the best known antibiotic and it is actually made from a mold! Penicillin was discovered by the scientist Sir Alexander Fleming in 1928. He found that mold growing with a colony (a group) of Staphylococcus aureus bacteria was killing them. It wasn’t long before scientists found out what part of the mold was killing the bacteria and they began to make lots of it and people were able to recover from bacterial infections more easily. The problem was that bacteria are really very clever. The more antibiotics that people took, the more the bacteria learnt to get around them so today, there are a lot of bacteria that penicillin used to kill but it cannot kill any more. The bacteria had adapted to the antibiotic, they are drug-resistant. New antibiotics are very difficult to find – the best way to make sure that all bacteria don’t become drug-resistant is to:

People have used fungi for a very long time to make life for humans that bit better! Fungi like mushrooms are used as food, fungi is used in the baking and brewing industries to make breads, beers and wines and in medicine to make antibiotics. But not all fungi are good for you – some are pretty bad – but why is this?

The different kinds of mushrooms you find in the supermarket are tasty and good for you but eating certain kinds of mushrooms from the wild can make you very ill. Only properly trained people can tell which types of wild mushrooms are safe to eat so it is wise not to eat a mushroom you find growing in the wild as it could be poisonous! Quite often the prettiest mushrooms, the ones that have bright colours like the red Amanita muscaria with the little white spots, are poisonous! The most dangerous mushroom, the Death Cap, mushroom is a plain white colour and beautiful to look at, but just a little can be lethal! Lots of people are made very sick from eating mushrooms they pick in the wild. They get a range of nasty symptoms, from a sore tummy to an allergic reaction or even total organ failure and death! Remember, its not just the ugly mushrooms that are dangerous, the toxins from pretty-looking and tasty mushrooms can kill you, even after the mushrooms have been cooked! The best rule is to never eat a mushroom if you find it growing wild. Get your mushrooms from your greengrocer or the supermarket!

The fungi you can sometimes find on your body don’t always make you sick, they are usually just annoying. Fungal infections are usually found on your skin, nails, hair – things like athletes foot which is an itchy rash that can be found between your toes or ringworm which is a scaly patch that can be found on your skin. Other fungal infections can get to your internal organs, like your lungs and nervous system, which is much more serious. Fungi like Aspergillus and Candida are often found in people who have a damaged immune system. Aspergillus spores get into the body through the respiratory system (by breathing) and isn’t normally a problem. If a person has a damaged immune system, the fungus can grow in their lungs and then use the blood stream to spread to other vital organs like the kidneys and brain. In people who are very weak, it can be extremely serious. Candida on the other hand is found in the gut of most healthy people and does not normally cause a problem. If the person has a damaged immune system, it can make them very ill and cause a lot of problems to health.

Fungi can’t make their own food, they get their food by taking nutrients from a ‘host’ – fungi are parasites. Fungi are often seen to grow on trees and sometimes the fungus doesn’t do any harm to the tree. Other fungi cause diseases like Dutch elm disease which can destroy whole populations of trees in a community or in a country! Fungi also cause rusts and smuts on plants and was the cause of the potato famine in Ireland in the 1800’s. The fungus Phytophthora infestans destroyed most of the potato crop in Ireland and about a million people starved to death. Other people travelled to countries all over the world to escape the famine and this is the reason that countries like America and Australia have such large Irish populations today.

Of the million or so types of fungi on the earth, only a very few are dangerous to humans but it pays to be safe! Remember to keep up your personal hygiene and to keep your environment clean (no damp towels hanging around your bedroom!). The best defence against fungal attack is to keep your body fit and healthy!

There are some fungi that look quite good, like the ordinary white button mushroom you eat for dinner, and some are so small that you can’t really see what they look like. Quite a lot of fungi are quite unusual and some are very ugly!

One of the most expensive types of fungi, the truffle is also one of the ugliest! The truffle is a very close relative of the mushroom but much rarer. It grows underground, close to trees, in woods and forests. Truffles look like lumps of black or white clay – in fact, the word ‘truffle’ is thought to come from the Latin word for ‘tuber’ or ‘lump’! Truffles were originally found by pigs that could smell the buried truffles as they snuffled around on the ground. More recently though, specially trained dogs have been used to dig up truffles because dogs are less likely to eat the truffles they find!

Truffles are not available to everybody because they are such an expensive delicacy. White truffles have a stronger smell and taste than black truffles, so much less of these are used. Truffles are only eaten on special occasions and in small amounts, shaved over pasta or thinly sliced as part of a stuffing for meat. It’s a good idea to eat truffles this way because it is really very ugly when it comes out of the ground!

Another type of ugly fungi that you can see growing over ground are the slime molds. Slime molds are also called Physarum olycephalum. They are a very bright yellow slimy blob that you can see growing among the flowers in your garden. They don’t start off too bad (although some people think it looks a little like a dog has been very ill!), but they soon get hard, turn a grey-ish colour and then they dry into a brown powder which are the spores that the blob uses to spread.

There are lots of different types of slime molds, most of which can move. They move very slowly, about 1millimetre each hour, so it won’t win any races! Slime molds move to find food – they can eat things like bacteria and spores from other fungi. When small slime molds move about, they leave an invisible chemical trail that attracts any other slime molds that cross the trail. The slime molds come together and join forces to become a larger slime mold blob!

One of the most annoying fungi that makes everything it touches very ugly is mildew. Mildew is a type of mold that grows on everything from clothes, paint, paper, leather, walls, any organic matter – anywhere that is damp. Mildew has a strong musty smell and looks very ugly, little black or white spots that spread over everything. You can also see a white powdery mildew or a downy mildew that grows on leaves. This is a huge problem for framers and the agriculture industry as it destroys lots of different types of crops all over the world.

The ugliest fungi of all can often look the prettiest. Lot of mushrooms that have bright colours like the red Amanita muscaria that has little white spots are great to look at but are poisonous! The most dangerous mushroom, the Death Cap, mushroom is a plain white colour and beautiful to look at, but just a little can be lethal! Lots of people are made very sick from eating mushrooms they pick in the wild, some have serious health problems for the rest of their lives and some don’t survive. Remember, its not just the ugly mushrooms that are dangerous, the toxins from pretty-looking and tasty mushrooms can kill you, even after the mushrooms have been cooked! The best thing to do is to get your mushrooms from your greengrocer or the supermarket!

Fungi are good for you and for the food you eat. Remember to love the ugly ones, but only the ones that are safe!