Difference between gram positive and gram negative bacteria: Bacteria are classified into Gram-positive and Gram-negative

Bacteria are classified into Gram-positive and Gram-negative based on their cell wall structure and their reaction to Gram staining. This distinction, first described by Hans Christian Gram (1884), remains one of the most important principles in microbiology. Gram-positive species like Lactobacillus and Bifidobacterium help ferment food and maintain gut health. Gram-negative species like Bacteroides break down complex carbohydrates and regulate immune tolerance. Gram staining is an approach that employs violet dye to differentiate between gram positive and gram negative bacteria. In the case of bacteria that are gram positive the thick proteinoglycan layer inside the cell walls will hold the dye, and they’ll stain with violet. If the bacteria are not gram-positive, the dye will escape out of the peptidoglycan layer and the bacteria will be stained red. Gram-positive bacteria show blue or purple after Gram-staining in a laboratory test. They have thick cell walls. Gram-negative bacteria show pink or red on staining and have thin walls.