Microbes - The unsung hero of food production.
There is no questioning the fact that all four elements, earth, air, water and fire, individually and collectively, play a fundamental role in our very existence. However, when it comes to our food system, it is air to which we humans really should salute, and not just because we breathe it. Maybe it’s because we can’t see it, perhaps because it’s always just there, but we all owe a debt of gratitude and respect to the air we breathe for centuries of service to the food system and, in the process, helping shape us as a species.
Invisible to our naked eye, the air we breathe provides a dense and stable environment that allows trillions of microscopic bacteria to float around in the air amongst us. They latch onto, feed and rapidly multiply on whatever they goddamn well please. And we are goddamn lucky that they do.
This planet belongs to bacteria. It is quite literally their domain. Bacteria are some of the first life forms to appear on Earth and can be found everywhere, from soil to acidic hot springs and from the sea floor to radioactive waste. To put into context just how prolific these little critters are, there are around 40 million bacterial cells in a gram of soil and around a million in a millilitre of fresh water - their biomass exceeds that of all plants and animals combined. And they ‘ain’t just around us either, they’re all over us, and in us. On you and in you, there are around 39 trillion bacterial cells. This is about 30% more bacterial cells than actual human cells. Statistically, you are more bacteria than you are human.
We all know there are good bacteria and bad, but there are a few strains of bacteria that, quite frankly, deserve a medal for their unwavering service to food production. The king of the microbes, or at least to humans, is undoubtedly Lactobacillus. These little legends break down sugars into lactic acid and can be found in their trillions in your digestive and urinary systems and the fun parts of the body; the genitalia. While these simple, microscopic organisms go about their business, the lactic acid they produce makes for something truly magical for us humans; fermentation. They are the ultimate secret ingredient. So secret an ingredient were these microbes and the role they played in food production that for millennia, we had no idea of their existence or just what the fuck was going on, but we liked the end product, so we kept doing it.
These microbes are responsible for many of the foods we consume today. Bread, cheese, alcohol, chocolate, salami and kimchi are only a few direct results of airborne microbes playing a critical role in fermentation and making these foods palatable and delicious. Without microbes and the carbon dioxide and lactic acid they produce, these foods would not exist as we know them. Just try to imagine a world without wine. No thanks. Now, while the thought of a world without wine is unimaginable, take into consideration how humans have literally evolved with bread. The humble loaf. The staple of many cultures worldwide and possibly the invention of which may have changed the course of our human evolution forever. Bread has been a cornerstone of our diet since the dawn of agriculture, and still today, in many cultures around the world, the thought of a meal without bread is unthinkable.
There are many speculative stories about how we first learned to make bread. Evidence suggests that our prehistoric ancestors experimented with baking using gruel from foraged starches and roots, mixed with water to form a paste, and cooked on hot rocks. But it wasn’t until around 5000 years ago the Egyptians took it to the next level and began to leaven bread. While there is no direct evidence as to exactly when or exactly how the Egyptians invented the first leavened loaf of bread, one of the most plausible explanations is that way, way back, in the region around Egypt that is fittingly known as the Fertile Crescent and The Cradle of Civilisation, some fool (food was scarce back then) left their bowl of wheat-grain porridge under the bed, only to find it a few days later bubbling away with a hive of bacterial activity. The original ‘mother’ to bread as we know it today. The fermentation happened as a result of the yeasts and lactobacillus bacteria producing carbon dioxide and lactic acid, respectively, leavening the bread and, also unbeknownst to the founders, creating a product that not only was bigger than its original form than what they had started with, it was, perhaps more importantly, more nutritional than the sum of its parts.
To this end, wheat very quickly became the best thing before sliced bread, and since then has gone on to take the title of the most widely cultivated crop in history. Some may argue wheat is the agricultural crop that has enabled the human race to evolve and advance to where we find ourselves today, but introducing microbes to this wheat is what really changed the game for us.
These days we call it sour-dough, and it has made a comeback with more and more artisan bakers returning to the old ways of bread production, and we are all the luckier for it. The gluten found within the flour traps the carbon dioxide produced by the yeasts as gas bubbles, and the lactic acid produced by lactobacillus gives a slightly sour flavour to the bread, which, when compared to the mass-produced supermarket bread, is like comparing chalk and cheese. A pretty simple process, but without the presence of microbes, Melbournians would be eating flatbreads under those smashed avocados.
Now while these microbes have quietly gone about changing the course of human evolution and given us the cornerstone of our diets, they also have had our back with some of our other favourite foods. A close second (arguably more important than the facilitation of bread) is their Oscar-worthy performance in helping produce alcohol—beautiful, sweet booze. For centuries humans have been using fermentation to make wine and beer, and for almost as long, the brewers didn’t understand what was happening to the mix - but the end product was magnificent, and it got you drunk, so they just rolled with it.
Cheese is another by-product of microbial bacteria at work. Lactic acid bacteria convert milk sugar and lactose into lactic acid, which lowers cheese pH and makes the cheese inhospitable to many other potential spoilage bacteria. At the same time, make it equal measures of stinky and tasty.
The bacteria known as ‘Propionobacter shermanii’ play a vital role in the cheese-making process as they can digest acetic acid and turn it into that distinct sharp, sweaty foot-smelling propionic acid and carbon dioxide. It is these same propionic bacteria that can be found on the human body and are responsible for producing that unpleasant stench that can emanate from the body’s ’ sweet spots.
Most of the moulds that grow on cheese are a species of Penicillium. It is just two species of bacterium, P.roqueforti and P.glaucum, responsible for creating the blue moulds that give the unique flavour and texture to hundreds of blue cheese varieties such as Stilton, Roquefort and gorgonzola, which are some of the most revered cheeses around the world. These unique bacteria can live in shallow oxygen environments, and the cracks of these style cheeses make for a perfect home.
Soft-ripened cheeses, such as camembert, are produced by the presence of a mould called, you guessed it, P.camemberti. These microbes have an enzyme that breaks down the milk proteins and gives rise to the characteristic ‘rind’ that encases the firm interior.
When it comes to cheese, there is a well-known saying ‘the stinkier, the better’, and it is once again microbes that are responsible for creating the room-clearing pong of cheeses like Munster, Limburger and Raclette. In these cases, brevibacter linens are present, also called smear bacteria. Not surprisingly, given the stench it produces in cheese, it is the same bacteria in the human body that causes foot odour.
To quote the late American poet John Ciardi; ‘fermentation and evolution are inseparable’, and he couldn’t be more right, but the day we indeed bow down in homage to microbes may not be too far into the future; scientists in Finland have created a batch of single-cell protein out of thin air using nothing but electricity and carbon dioxide. The food-creating system uses a bio-reactor to create electrolysis of the water. With the carbon dioxide captured from the air and our little heroes, microbes, the reaction results in a powdery, edible compound of around 50% pure protein and 25% carbohydrates. At the same time, the remainder is various fats and acids. Now I’m going to take a guess and say it probably tastes like shit. Still, the simple fact that the United Nations estimate that there are currently around 900 million undernourished people around the world, and with this number to increase to somewhere about 2 billion by 2050, well, it might just be that microbes quite literally save our asses, again.
So take a moment over your next beer or slice of sourdough bread to say a little thank-you to these little troopers of food production. So many microbes gave their life so you could enjoy that beer, so you owe it to them to drink more of it. Cheers.
