Periplasmic space is seen in ?

Ans. is 'b' i.e., Gram negative bacteria Periplasmic space is a narrow space between cytoplasmic membrane (plasma membrane) and cell wall. Periplasmic space has been more frequently and better recorded in gram-negative bacteria as compared to gram-negative. "At present most gram positive bacteria are thought to have only periplasm, but not periplasmic space".