Detection of nitrate/nitrite bioavailability in wastewater using a luxCDABE-based Klebsiella oxytoca bioluminescent bioreporter.
In the present study, we have constructed a bioluminescent bioreporter for the assessment of nitrate/nitrite bioavailability in wastewater. Specifically, an approximately 500-bp DNA fragment containing a nitrate/nitrite-activated nasR-like promoter (regulating expression of genes encoding nitrite reductase in the genus Klebsiella) was fused upstream of the Vibrio fischeri luxCDABE gene cassette in a modified mini-Tn5 vector. Characterization of this strain, designated W6-1, yielded dose-dependent increased bioluminescence coincident with increased nitrate, nitrite, and ammonium added to the growth medium from 1 to 11 ppm. Bioluminescence in response to nitrogen species addition was light dependent up to 10, 7, and 8 ppm with nitrate, nitrite, and ammonium, respectively. This response was linear in the range from 1 to 8 ppm for nitrate (R2 = 0.98), 1 to 6 ppm for nitrite (R2 = 0.99), and 1 to 7 ppm for ammonium (R2 = 0.99). A significant bioluminescent response was also recorded when strain W6-1 was incubated with slurries from aged, nitrate/nitrite contaminated wastewater. Thus, bioreporter strain W6-1 can be used to elucidate factors that constrain the use of nitrate/nitrite in wastewaters.
Abd-El-Haleem
Desouky
D
Environmental Biotechnology Department, Genetic Engineering and Biotechnology Research Institute (GEBRI), Mubarak City for Scientific Research and Technology Applications, New Burg-Elarab City (Post Code: 21924), Alexandria, Egypt. abdelhaleemm@yahoo.de
Ripp
Steven
S
Zaki
Sahar
S
Sayler
Gary S
GS
D048908:Aliivibrio fischeri / Q000201:enzymology / Q000235:genetics; D019677:Artificial Gene Fusion; D004251:DNA Transposable Elements; D017930:Genes, Reporter / Q000235:genetics; D041121:Klebsiella oxytoca / Q000235:genetics* / Q000378:metabolism*; D008156:Luciferases / Q000096:biosynthesis* / Q000235:genetics; D009566:Nitrates / Q000032:analysis*; D009573:Nitrites / Q000032:analysis*; D011401:Promoter Regions, Genetic; D000644:Quaternary Ammonium Compounds / Q000032:analysis; D014867:Water / Q000737:chemistry*
D004251:DNA Transposable Elements; D009566:Nitrates; D009573:Nitrites; D000644:Quaternary Ammonium Compounds; D014867:Water; D008156:Luciferases