<prompt> Stalactite growth in ghee broth is due toH. influenzaC. diphtheriaY -pestisT. pallidium  <response>: Ans. is c i.e., Y. pestis Culture characteristic -Growth occurs over a wide range of temperature range 2-45degC and pH 5-9.6 optimum 7.2. The optimum temperature for growth is 27degC unlike most pathogens. - In ghee broth a characteristic growth occurs which hangs down into broth from the surface resembling stalactites - Stalactite growth. - On blood agar colonies are dark due to the hemin pigment. 