LACTOBACILLUS BULGARICUS is a rod shaped bacteria.

As you can see in the image above, Lactobacillus Bulgaricus (as well as most other Lactobacilli) form straight chains, varying in length. However, with this being said, Lactobacillus bulgaricus can form into *cocci and spiral shaped bacteria under certain conditions.

*What is a cocci? A round bacterial cell.

Due to the fact that Lactobacillus Bulgaricus is GRAM POSITIVE (distinguished from gram-negative through differences in cell-wall), the structure of the cell wall is very interesting. The Lactobacillus Bulgaricus cell wall is composed of: A *cytoplasmic membrane, a *peptidoglycan layer, and many *capsule polysaccharides.

*What is a cytoplasmic membrane? A lipid bilayer found in all cells.

*What is a peptidoglycan layer? A layer of different amino acids and sugars, formed on top of the cytoplasmic membrane.

*What is a capsule polysaccharide? The layer outside of a cell wall in bacteria, usually formed of polysaccharides, used to protect the bacteria from harsh or changing conditions.

Internal structure of Lactobacillus Bulgaricus?

Like all cells, the Lactobacillus Bulgaricus cell is internally composed of mainly cytoplasmic fluids. It contains a nucleus, which in itself contains the RNA and DNA, and the nucleolus. However, it is also internally composed of lactic acids which are produced inside it. This explains Lactobacillus Bulgaricus' low pH (4-5), and why Lactobacilli are labelled as lactic acid bacteria.

Lactobacillus Bulgaricus can range from  0.5-0.8 x 2.0-9.0 mm.

Lactobacillus Bulgaricus does not have a *flagellum.

*What is a flagellum? A flagellum is an organelle of a cell, protruding outside the outside membranes. It is used to propel the cell.

Lactobacillus Bulgaricus is non-spore forming, which means that it does not form *endospores.

What is an endospore?

An endospore is a structure which is created by a very few bacteria in the Firmicutes (includes Lactobacillus Bulgaricus) phylum. It is dormant and non-reproductive. They are generally released by these select few bacteria when the integral proteins in the cytoplasmic membrane recognize a distressful environment or environmental change. Due to this fact, they are resistant to temperature, starvation, disinfectant and other harmful factors. This is why these cells release them - to protect themselves. The creation of endospores, or sporulation takes about eight hours, and it all starts within the cells DNA.