Use of aiiA gene amplification for AHL-lactonase production from endophytic bacterium Enterobacter species.

AHL-lactonase has gained renewed interest due to biotechnological applications such as antiquorum sensing, antibiofilm strategies, biofouling, etc. In our study, the production of AHL-lactonase from endophytic bacteria Enterobacter aerogenes VT66 was optimized by response surface methodology (RSM) using central composite design (CCD) for four different cultural conditions. The relative activity of AHL-lactonase was correlated with amplification of aiiA homologous gene amplification with respect to cultural conditions. Statistical analysis by ANOVA of the quadratic regression model showed that the RSM model constructed is highly significant, as indicated by F-test with a low probability value (p(model) < 0.0001) and high regression coefficient (0.9997) as well as lower coefficient of variation (1.86%) indicate that suitability of variable parameters. The quadratic regression model of AHL-lactonase production in terms of relative activity was built and the optimal cultural conditions for maximum enzyme production were determined as 32.5 °C temperature, pH 7.0, 350 μM of substrate concentration and 33 h of incubation time. The enhanced AHL-lactonase yielded 1.33 fold increases in relative activity and it positively correlated with the amplification of aiiA gene.