This medium is recommended for cultivation of yeasts, moulds and aciduric microorganisms and for inactivation of β-lactam antibiotics. Lecithin and polysorbate 80 neutralizes quaternary ammonium compounds and parahydroxy benzoates. β lactamase enzyme breaks the β-lactam ring of antibiotic, deactivating the molecule's antibacterial properties thus enabling recovery of organisms from the environment of cleanrooms where production of antibiotics is carried out.