explanation could be that high molecular weight compounds which are partially responsible for antibacterial activity interfere with the diffusion through the agar (Cagri, Ustunol, & Ryser, 2001). Moreover, Ps. aeruginosa and S. Choleraesuis showed similar or lower MICs than B. subtilis and C. albicans. The data showed that amounts ranging from 5 to 80 mg/mL of spent coffee were capable of inhibiting the growth of a broad range of microorganisms with concentrations of 106 cfu/mL; however, the most resistant bacteria (E. coli) required larger quantities