This medium is recommended for selective cultivation of yeasts and moulds and for inactivation of penicillins, cephalosporins of first, second, third and fourth generation and penems. Chloramphenicol inhibits a wide range of Gram-positive and Gram-negative bacteria which makes the medium selective for fungi. The low pH favours fungal growth and inhibits contaminating bacteria. β lactamase mixture added in the medium will inactivate the β-lactam antibiotics thus enabling recovery of organisms from the environment of cleanrooms where production of antibiotics is carried out.