The effective microorganism fermentation extract (EM-X) is a refreshment beverage widely consumed in East Asia. Due to the antioxidant property of the health beverage, EM-X has potential benefits for the human immune system and has been generally accepted in clinical practice. In search of new functions of EM-X, another version of EM-X, named EM-YU in this study, which is fermented from rice bran, seaweed, and kiwifruit with effective microorganisms demonstrates high antioxidant, antibacterial, tyrosinase inhibition activities, and biofilm inhibition activity of pathogenic bacteria. The antioxidant activity of 1.8% EM-YU was equivalent to that of 0.01 mg/mL vitamin C. Also, EM-YU clearly inhibited the cell growth of two pathogenic bacteria, Escherichia coli O157:H7 and Pseudomonas aeruginosa PAO1; and EM-YU broth (6.7%) inhibited (55${pm}$1%) the activity of mushroom tyrosinase. Moreover, the ethyl acetate extract of EM-YU, called EM-YU-EX (0.6 mg/mL), 7-fold reduced the biofilm formation of E. coli O157:H7 without affecting its cell growth. It is the first report that EM-X variant possess antibacterial, tyrosinase inhibitory, and biofilm inhibitory activities. These results support other beneficial properties of the natural health product EM-X variant (EM-YU).