This gene controls the operator gene in cooperation with a chemical substance called inducer present in the cytoplasm. A regulator gene is not necessarily adjacent to the operator gene which it controls. The regulator gene codes for and produces a protein called repressor.
The Gram-positive bacteria include staphylococci (staph), streptococci (strep), pneumococci, and the bacterium responsible for diphtheria (Cornynebacterium diphtheriae) and anthrax (Bacillus anthracis). The Danish bacteriologist J.M.C. Gram (1853-1938) devised a method of staining bacteria using a dye called crystal (gentian) violet. Gram's method helps distinguish between different types of bacteria. The gram-staining characteristics of bacteria are denoted as positive or negative, depending upon whether the bacteria take up and retain the crystal violet stain or not.
Gram positive bacteria have a single thick cell wall made of peptidoglycan (50-90% of cell wall). This thick wall stains purple and remains purple throughout the gram staining test. Gram negative bacteria have a thinner layer of peptidoglycan (10% of cell wall), and an additional outer membrane which contains lipids.The outer membrane of gram negative bacteria will stain purple also but it falls off during the gram stain test. Its 2nd wall is what gets stained pink.he trick to remembering the difference between gram positive and gram negative bacteria is to first understand where their naming convention comes from. I have an article follow by a mini game to teach you the difference between gram positive and gram negative bacteria.