Chromosomal integration of the Vitreoscilla hemoglobin gene in Burkholderia and Pseudomonas for the purpose of producing stable engineered strains with enhanced bioremediating ability.
Using the pUT-miniTn5 vector system developed by the laboratory of K.N. Timmis, the Vitreoscilla hemoglobin gene (vgb) was integrated into the chromosomes of Pseudomonas aeruginosa and Burkholderia cepacia; Vitreoscilla hemoglobin (VHb) was expressed at 8.8 and 0.8 nmol/g wet weight of cells in the respective engineered strains. The vgb-bearing P. aeruginosa outgrew wild-type P. aeruginosa and degraded benzoic acid faster than the latter strain at both normal and low aeration. In contrast, the vgb-bearing B. cepacia strain had a growth advantage over the wild-type strain at ca. 90 ppm, but not at ca. 120 ppm 2,4-dinitrotoluene (DNT); no difference in DNT degradation was seen between the two strains at either normal or low aeration. The results demonstrate the practicality of enhancing bioremediation with vgb stably integrated into the chromosome, but also suggest that a minimal level of VHb expression is required for its beneficial effects to be seen.
Chung
J W
JW
Biology Division, Department of Biological, Chemical, and Physical Sciences, Illinois Institute of Technology, IIT Center, Chicago, IL 60616, USA.
Webster
D A
DA
Pagilla
K R
KR
Stark
B C
BC
D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D019817:Benzoic Acid / Q000378:metabolism*; D001673:Biodegradation, Environmental; D015139:Blotting, Southern; D019117:Burkholderia / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D002876:Chromosomes, Bacterial / Q000235:genetics*; D003227:Conjugation, Genetic; D004251:DNA Transposable Elements / Q000235:genetics; D004136:Dinitrobenzenes / Q000378:metabolism*; D005818:Genetic Engineering / Q000379:methods; D005822:Genetic Vectors; D006454:Hemoglobins / Q000235:genetics / Q000378:metabolism*; D010957:Plasmids / Q000235:genetics; D016133:Polymerase Chain Reaction; D011549:Pseudomonas / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D054793:Truncated Hemoglobins; D020589:Vitreoscilla / Q000235:genetics / Q000378:metabolism
D001426:Bacterial Proteins; D004251:DNA Transposable Elements; D004136:Dinitrobenzenes; D006454:Hemoglobins; D054793:Truncated Hemoglobins; C082613:hemoglobin protein, Vitreoscilla; C016403:2,4-dinitrotoluene; D019817:Benzoic Acid