ANTIBACTERIAL EFFECT OF GLUCOSE-OXIDASE ON GROWTH OF PSEUDOMONAS-FRAGI AS RELATED TO PH

The effect of glucose oxidase (GOX) catalyzed reaction with glucose on Pseudomonas fragi was analyzed in nutrient broth and fish extract med ia. Growth of P. fragi in nutrient broth was clearly suppressed by 1.0 , 2.0 and 4.0 mg/mL glucose when combined with 0.5-2.0 U/mL GOX. The s ame GOX/glucose combinations inhibited P. fragi growth in fish extract media. Viable cell numbers in fish media showed clear growth inhibiti on with combinations of 1.0-2.0 U/mL GOX and 8.0-16.0 mg/mL glucose. H igher GOX and glucose rapidly produced 2.0-2.5 unit decreases in pH, b ut produced enough gluconic acid to precipitate fish proteins. Use of 0.5 U/mL GOX in fish extract media resulted in slow, sustained activit y with potential for inhibition of microbial growth in foods without e xcessive acidity.