Bacillus megaterium on an agar slant. Bacillus is a gram +, rod shaped bacteria.
Non-pathogenic E. coli on agar slant. E. coli is a gram negative bacteria.
Live culture on agar slant. R. rubrum is a gram negative, spiral shaped bacterium. "rubrum" refers to the purple color this bacteria showns when grown.
Serratia marcescens culture on agar slant. S. marcescens is a gram negative, rod shaped bacteria.
Staphylococcus Epidermidis on an agar slant. S. epidermidis is a gram positive, cocci shaped bacteria.
Gram positive bacteria have a plasma membrane and a thick peptidoglycan layer. They appear purple when gram stained.Gram negative bacteria have a plasma membrane, thin peptidoglycan layer and an outer lipopolysaccharide layer. They appear pink when gram stained.
All living organisms require energy. They can get their energy from multiple sources: organic chemicals(carbon containing compounds), inorganic chemicals and light. Bacteria use organic chemicals, such as, sugars, starch, protiens and fats to grow. Bacteria are called heterotrophs.
Most bacteria grow best at normal, human body temperature (98-99 degrees F). When growing the bacteria, incubate at a temperature as close to this as possible. The bacteria will grow slower at lower temperatures.
Aseptic technique is the process of growing and transferring bacteria without contaminating the culture by touching or breathing on the sample.
Nutrient agar is a general purpose prepared media and grows many types of bacteria and fungi. If you have a specific bacteria culture, you can spread the bacteria on the plate using a sterile swab or innoculating loop. The bacteria will grow and become visible in 24-48 hrs. If you would like to determine the types of bacteria growing on a sink, chair, table or other areas, a sterile swab can be used to rub across the area you would like to test. After the sample is taken, you can transfer the bacteria to the nutrient agar plate by swiping the swab across the surface of the agar plate. After 24-48 hrs, you may find many, different looking colonies growing on the nutrient agar plate. Each type of bacteria look a little different (color, shape, size) when they grow.
- Bacillus Megaterium
- Escherichia coli K12
- Rhodospirillum Rubrum
- Serratia Marcescens
- Staphylococcus Epidermidis