What is L. lactis (and other bacteria)?

Lactococcus lactis is a gram-positive bacteria. Gram negative bacteria have a cell wall sandwiched in between two cell membranes. Gram positive bacteria have a thick cell wall around their membrane (Figure). Lactococcus lactis is usually shortened to L. lactis. This a bacterium is found in many food products such as cheese and beer and does not make us sick. Contrary to popular belief, most bacteria do not make us sick. In fact, many bacteria benefit us and some are necessary for us to live. Your gut is filled with bacteria that break down your food into molecules that your intestines can take up. Without these bacteria, you would not be able to eat anything! In return, our bodies are a safe home for these bacteria. Such an arrangement is called symbiosis, literally translated this means 'living together'.

We do not 'live together' with L. lactis in nature, but we can make L. lactis work for us in the bandage. Like L. lactis, Staphylococcus aureus (S. aureus for short) is gram positive. S. aureus produces toxins that are damaging to humans.

Figure 2: Bacteria are made of DNA and proteins encapsulated in a membrane. They use the proteins to multiply the DNA and make new bacteria. Gram negative bacteria have a thin cell wall and a second membrane. Gram positive bacteria have a very thick cell wall.