[Cloning and expression of the detoxifying gene in cyanobacteria]

Plasmid pRL-B1 was constructed from detoxifying gene(called B1) of pesticide resistant Culex and from plasmid pRL-439 containing the strong promoter PpsbA. E. coli-cyanobacteria shuttle expression plasmid pDC-B1 was constructed from shuttle vector pDC-8 and from recombinant plasmid pRL-B1, then it was transferred into Synechococcus sp. PCC7942 by triparental conjugative transfer. The existence of B1 was detected by Southern analysis, and the expression of B1 was confirmed by enzyme activity analysis of detoxification of transgenic cyanobacteria. Experimental results indicated that the transgenic cyanobacteria could degrade beta-naphthyl acetate(beta-NA), a specific substrate of esterase. The enzyme activity of transgenic strain was higher than that of the wild type. It may be the first report on transformation of detoxify gene of pesticide resistant culex into Synechococcus strain.