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SECTION I: MOLECULAR GENETIC ENGINEERING AND BIOCHEMICAL TECHNOLOGY 833.3. Antimicrobial activity As shown in Table 2, the isolates 1-2 showed antimicrobial activities at different levels. They established the same MIC value of 128 mg/mL against the growth of the Gram (+) bacterium B. subtilis, and two Gram (%u2013) bacteria E. coli and P. aeruginosa. Compounds 1-2 also exerted the MIC values of 256 and 128 mg/mL against the Gram (+) bacterium S. aureus, respectively. Especially, they strongly suppressed the proliferation of the fungus A. niger with the same MIC value of 64 mg/mL. the MIC values of 64 and 128 mg/mL were assigned to compounds 1-2 in assay against the fungus F. oxysporum, respectively. However, they failed to control the yeasts C. albicans and S. cerevisiae (MIC > 256 mg/mL).Table 2. Antimicrobial activity of the isolated flavonoids 1 - 2Microbial strainsMinimum Inhibitory Concentration (MIC: mg/mL)1 2 Streptomycin Tetracycline NystatinGram (+)B. subtilis 128 128 4S. aureus 256 128 8Gram (%u2013)E. coli 128 128 4P. aeruginosa 128 128 8FungiA. niger 64 64 16F. oxysporum 64 128 8YeastsC. albicans > 256 > 256 4S. cerevisiae > 256 > 256 8Accumulative evidence has been documented regarding the uses of green propolis extracts and their isolated metabolites in antimicrobial treatments. For instance, new prenylated flavonoids propolis C, D, F, and G extracted from Taiwanese green propolis were reported to inhibit the growth of the Gram (+) bacterial strains S. aureus, B. subtilis, Listeria monocytogenes, and Paenibacillus larvae[13]. The volatile oil of green propolis showed the same MIC