Science Buddies: "Ask an Expert"

How do you grow bacteria quickly? I have an experiment looking at bacteia from different mouths, dog, cat and human and its due this wee!!!!

In general bacteria need food, warmth and space in order to grow.
Different types of bacteria grow better under different conditions - for example many bacteria need air (or oxygen) to grow but there are some that are anerobic and need conditions without air to grow. There are some bacteria that live in hot springs and grow at temperatures of 65C but that would kill other types of bacteria.
You can usually predict what conditions are best based on where the bacteria are found naturally. So with the mouth bacteria, although there is probably more than one kind of bacteria in the sample, they will all probably grow best at mouth temperature, so about 37C. So you will need to incubate them in a place that has a temperature control if you can. You could grow them at room temperature but they will grow slower.

There are various different kinds of media used to grow bacteria on or in that is the source of food. You can use liquid medium, that is a solution of amino acids, salts and sugars in water. Common types of medium are LB (Luria broth) and 2TY. You can also add agar to that and make it into a solid medium in a petri dish. There are also special types of medium that are used to grow specific types (or strains) of bacteria, some have extra amino acids or they can have horse blood in them. One of the tests that hospitals do is to grow bacteria on different medium as a way to tell what type of bacteria they are. (see http://web.indstate.edu/thcme/micro/hemolys.html)

Post a little bit more about what you are trying to test that is variable between the different mouth bacteria and maybe we can help you more,

best of luck
caroline