How we grow bacteria from the environment!
Did you know there are between millions and one trillion species of bacteria living on Earth? Does this make you curious? When scientists want to learn more about their surroundings, we may collect environmental samples and culture them. In microbiology(the study of bacteria and other tiny organisms), to culture means to grow microbes in a lab. We can find interesting bacteria practically anywhere in the environment. They hang out in places including soil, on plants or trees, and in streams or lakes!
One simple method is to get a cotton swab, and rub it on the surface of where we want to collect the bacteria. Once we have collected the sample, we can rub the swab in a zig-zag pattern across a plate with agar (a gel that "feeds" our bacteria). We can use nutrient agar(NA) or trypticase soy agar(TSA) plates. These are helpful because they have a lot of different nutrients for almost any bacteria to use! A nutrient is something that an organism can eat, so it can grow and live. Next, we’d place the plate somewhere safe and wait a few days. This is so the bacteria can get nutrients from the plate, and make more copies of themselves!
When we come back to check on the plate, we should see bacterial colonies, or clumps and patches. This means that the bacteria multiplied by large enough numbers that we can see them all together. We would write down observations, or details on what they look like. They might be different sizes, shapes, and colors. Now that we have bacteria growing on our plates, we can learn more about them, by seeing them under the microscope!
E.coli growth in Agar plates
Picture Source: researchgate.net
