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 do not have an outer cell membrane found in Gram-negative bacteria. The cell wall of Gram-positive bacteria is high in peptidoglycan which is responsible for retaining the crystal violet dye.n his test, bacteria that retain the crystal violet dye do so because of a thick layer of peptidoglycan and are called Gram-positive bacteria.