You don't have to even check. Everything on the planet is covered in bacteria. It may be growing, or just waiting for the right conditions for it to multiply. And even before you see anything like changes in color or oder, they have already multiplied into the thousands, and even millions. Unless it was just sterilized in a autoclave oven at the right temperature for the correct length of time, it already has bacteria that only time and available food supply that keep them from growing into what you can see or smell, but just remember, they are already everywhere.
Technically, the only way to tell is by visual examination, and the only way to do that is with a microscope.
The white fuzzy stuff on top of your bacteria culture is likely mold. Mold can grow on top of bacteria cultures due to contamination. It's important to discard the culture to prevent further contamination and start a new culture.
Bacterial generation time is the time is takes for a bacteria to double in quantity. An example of slow growing would be Mycobacterium Tuberculosis (24 hours) and fast growing would be E. Coli (about 20 minutes).
The rapid growth of the fastest-growing bacteria is influenced by factors such as favorable environmental conditions, availability of nutrients, and efficient cellular processes.
The medical term for spherical bacteria growing in pairs is "diplococci." These bacteria typically arrange themselves in pairs and are commonly associated with certain infections, such as pneumonia and meningitis.
Bacteria growth can be detected by an increase in turbidity (cloudiness) of the culture, formation of colonies on agar plates, or by changes in pH or color of the medium due to metabolic byproducts. Additionally, observing the presence of a pellicle, sediment, or turbidity in a liquid culture can indicate bacterial growth.
by growing on suitable media.
the bacteria growing in tomato paste is microbe
A container that has growing bacteria must be closed and/or sealed to prevent contamination by other bacteria.
agar
It takes less than 72 hours for an onion to start growing bacteria.
Overuse is to use or repeat something for too long. The Medical profession is warning that the overuse of antibiotics is leading to growing resistance in bacteria.
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by killing them, or by creating a surface that is undesirable for the bacteria.
The white fuzzy stuff on top of your bacteria culture is likely mold. Mold can grow on top of bacteria cultures due to contamination. It's important to discard the culture to prevent further contamination and start a new culture.
Just tell her to be mature and patient. Tell your little sister to think about something very carefully before you do it.