• Journal of Microbiology and Biotechnology
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• v.13 no.6
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• pp.976-983
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• 2003

Seven Escherichia coli cells defective with aerobic growth were isolated by the insertion of ${\lambda}placMu53$, a hybrid bacteriophage of ${\lambda}$ and Mu, which created a transcriptional fusion to lacZY. These insertion mutant cells were tested on an XG ($5-bromo-4-chloro-3-indolyl-{\beta}-D-galactopyranoside$) medium for anaerobic expression of lacZ by fusion to a promoter. The chromosomal DNA from these strains were digested by EcoRI, and the EcoRI fragments that contained the fused gene and lacZ sequence were identified by Southern hybridization, using lacZ containing plasmid as a probe. The EcoRI fragment from each strain was cloned and sequenced. The sequence data were compared with the GenBank database. The mutated gene of three strains, CYT4, CYT5, and OS11, was found to be identical, and it was nrdAB that encoded ribonucleoside diphosphate reductase. The gene nrdAB was at min 50.5 on the Escherichia coli linkage map and 2,348,084 on the physical map, and is involved in hemAe-related reduction-oxidation reaction. OS6 and OS14 mutant strains had insertion at min 8.3 and the mutated gene was hemB. The hemB encodes 5-aminolevulinate dehydratase or porphobilinogen synthase. The OS3 mutant had insertion in cydB at min 16.6. The cydAB encodes cytochrome d oxidase. In the case of OS1, the fusion was made with sucA, the E1 component of ${\alpha}-ketoglutarate$ dehydrogenase.

• Journal of Plant Biotechnology
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• v.35 no.2
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• pp.141-145
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• 2008

In this study, glucose-inducible intergenic sequences were used to generate bioreporters of the cyanobacterium Synechocystis sp. PCC 6803 that could monitor environmental pollutants. Luciferase genes LuxAB from the marine bacterium Vibrio fischeri under the control of glucose-inducible intergenic seqeucens of eight genes (atpI, ndbA, ctaD1, tkt, pgi, pdh, ppc, and cydA) were successfully expressed in the cyano-bacterial transformants, showing 5-25 fold increases in biolumeniscence upon exposure to glucose. In addition, glucose-inducible cyanobacterial bioreporters were very sensitive to various chemicals such as heavy metals ($Hg^{2+}$, $Cu^{2+}$, $Zn^{2+}$), electron transport inhibitors (DCMU, DBMIB, $CN^-$), and antibiotics (chloramphenicol and rifampicin). These glucose-inducible cyanobacterial bioreporters would be useful to develop biosensors for rapid screening of environmental samples.