AN ANALYSIS OF THE POTENTIAL FOR AQUACULTURE OF N-ACYL HOMOSERINE LACTONASE FROM RHODOCOCCUS ERYTHROPOLIS BFXJ-1

The objective of this study was supplement to determine the enzymatic properties of QsdA-like AHLases and evaluate their application potentials. The gene qsda-rh5 was amplified from the Rhodococcus erythropolis BLJF-1genomevia PCR technique. After the recombinant vector pET28a/qsda-rh5 was transformed into E. coli BL21 (DE3), transformants with N-acyl-homoserine lactonase activity were screened. The purified QsdA-RH5 was obtained with Ni-NTA column. Both N-acyl-homoserine lactonase activities of QsdA-RH5 were additional characterized. The results showed that an AHL lactonase gene, qsda-rh5, of 972 base pairs, was identified from Rhodococcus erythropolis BFXJ-1. Deduced QsdA-RH5 was a metallo dependent hydrolase belonging to Phosphotriesterase (PTE) superfamily. Recombinant QsdA-RH5 was successfully expressed in Escherichia coli BL21 and purified to electrophoretic homogeneity. The enzyme maintained80% of its activity at 10-40℃, pH 8.0. QsdA-RH5 had significant resistance toproteolytic digestion. Interestingly the enzyme conferred the ability to inactivate AHLs with an acyl chain lengths ranging from six to twelve carbon atoms, without substitution at carbon three. We were the expression and characteristics of the QsdA-RH5, indicate the QsdA-RH5 has specificity of substrate. These properties make QsdA-RH5 an outstanding quorum-quenching tool for environment.