Karakterisasi Bakteri Isolat Bacillus sp. NTT 3a dan Bacillus sp. NTT 3e.

Abstract

Quorum sensing (QS) is a bacterial communication mechanism controled by bacterial population and mediated by autoinducer (AI) molecule. AI molecule of Gram-negative bacteria generally is Acyl Homoserine Lactone (AHL). Acyl Homoserine Lactone Lactonase (AHL-lactonase) enzyme encoded by aiiA gene is an enzyme that can hydrolyze the lactone ring so that inhibiting QS process. This study aimed to characterize the AHL-Lactonase producing bacteria i.e. Bacillus sp. NTT 3a dan Bacillus sp. NTT 3e. the characterization is based on colony morphology, characteristics of growth in NB medium (growth curve, specific growth rate and generation time), and activity of AHL-lactonase. AHL-lactonase activity was observed using bioindicator Chromobacterium violaceum. Colonies of Bacillus sp. NTT 3a and Bacillus sp. NTT 3e are round, have a convex elevation and slippery ledges. The colony color of Bacillus sp. NTT 3a is white, while Bacillus sp. NTT 3e is beige. The maximum specific growth rate of Bacillus sp. NTT 3a and Bacillus sp. NTT 3e was 0,005 minute-1 and 0,0042 minute-1 respectively. The highest activity of AHL-lactonase in both of bacterial culture reached the age of 42 hours (stationary phase). Protein content of Bacillus sp. NTT 3a (0,539 mg/ml) lower than Bacillus sp. NTT 3e (0,578 mg/ml) at the 48 hours. However, the activity of AHL-lactonase in Bacillus sp. NTT 3a is higher than Bacillus sp. NTT 3e