Question

How can you identify the Gram status of Proteobacteria and what is their Gram status?

Answer 1

Gram status classifies bacteria into two large groups. It is done by Grams method, a method of staining to classify bacteria into either gram positive or gram negative. The name comes from the Danish bacteriologist Hans Christian Gram, who developed the technique. Gram staining differentiates bacteria by the chemical and physical properties of their cell walls. Gram-positive cells have a thick layer of peptidoglycan in the cell wall that retains the primary stain, crystal violet. Gram-negative cells have a thinner peptidoglycan layer that allows the crystal violet to wash out.

They are stained pink or red by the counterstain, commonly safranin or fuchsine. The Gram stain is almost always the first step in the preliminary identification of a bacterial organism. The Proteobacteria are a major group of bacteria. They include a wide variety of pathogens, such as Escherichia, Salmonella, Vibrio, Helicobacter, and many other notable genera. Others are free-living, and include many of the bacteria responsible for nitrogen fixation. Gram-negative bacteria are bacteria that do not retain crystal violet dye in the Gram staining protocol.