PURIFICATION AND CHARACTERIZATION OF L-GLUTAMINASE ENZYME FROM SYMBIONT ENDOPHYTIC BACTERIA OF MARINE PLANT Sargassum sp. AS ANTIMICROBIAL ADJUVANTS

Endophytic bacterial symbiont of marine plant seaweed is a potential source of various bioactive compounds as a raw material for drugs. This research aimed to study the antimicrobial potential of L-glutaminase enzyme isolated from seaweed bacterial symbiont collected from Cikoang Island, South Sulawesi Indonesia. The production of L-glutaminase of bacterial symbiont marine plant Sargassum sp was optimum in nutrient broth using a shaker at 37 °C for 3 d. L-glutaminase was obtained from extraction and fractionation with ammonium sulphate at increased saturation levels of 0-20%, 20-40%, 40-60% and 60-80%, continued by dialysis and column chromatography. Antimicrobial activity assessment was conducted by an agar diffusion method using paper discs. Enzyme fractions were produced by purification using DEAE-Cellulose and Sephadex G-100 column chromatography with a purity of 12.23 and 16.95 times, respectively. The enzyme characterization showed that the optimum condition was at pH 8.0 and 37oC, where at this condition, enzyme activity showed a slight increase after the addition of K+ and Na+ ions and however, significant decrease in enzyme activity after the addition of Cu2+ and Fe2+ ions. The results of the antimicrobial activity evaluation revealed that the L-glutaminase of sephadex G-100 fraction had the highest activity against Escherchia coli and Staphylococcus aureus with the inhibition zone of 12.1 ± 0.29 and 17.4 ± 0.21mm, respectively. These results demonstrated that the environmentally friendly bacterial symbiont of the marine plant Sargassum binderi could be a new alternative as a source to produce the antimicrobial L-glutaminase enzyme. This work probably provides an essential finding for further research on the antimicrobial action of protein fraction from bacterial symbiont of marine plant Sargassum sp. or the other species.