RT Journal Article SR Electronic(1) A1 Kilkenny, Carol A. A1 Berger, David K. A1 Rawlings, Douglas E.YR 1994 T1 Isolation of the Thiobacillus ferrooxidans ntrBCgenes using a T. ferrooxidans nifH-lacZfusion JF Microbiology, VO 140 IS 10 SP 2543 OP 2553 DO https://doi.org/10.1099/00221287-140-10-2543 PB Microbiology Society, SN 1465-2080, AB An agar plating technique was developed in which the activation of expressior of a Thiobacillus ferrooxidans nifH-lacZgene fusion was used to isolate the ntrBCgenes from a T. ferrooxidansgene library. An Escherichia coli ntrCmutant containing the nifH-lacZfusion was transformed and plated on a low-nitrogen medium so that on flooding with ONPG, the production of yellow colonies indicated the presence of the cloned T. ferrooxidans ntrBCgenes. A 4.47 kb region from the T. ferrooxidanschromosome was sequenced. Analysis of the sequence revealed that the ntrBand ntrCgenes were closely linked to a third ORF of unknown function. Analysis of the 900 bp region upstream of the T. ferrooxidans ntrBCgenes and Southern hybridization experiments confirmed that in T. ferrooxidansATCC 33020, the glnAand ntrBCgenes are unlinked. Expression of the T. ferrooxidans nifH-lacZfusion in E. coliwas activated in the presence of the T. ferrooxidans ntrBCgenes and regulated by nitrogen., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-140-10-2543