Genetic transfer of the mcd gene in soil.
OBJECTIVE
To investigate the role of horizontal gene transfer of mcd (methylcarbamate-degrading) gene in high genetic diversity of carbofuran-degrading bacteria.


RESULTS
The actuality of genetic transfer from degraders to an Agrobacterium tumefaciens strain was determined in liquid medium. The mcd gene was chosen for transfer experiments. Transconjugants were obtained irrespective of the type of the donor strain (Gram-positive or Gram-negative), size of the inoculum, or nature and concentration of the pesticide in the medium. Soil microcosms, inoculated with or without the donor and/or recipient strains were used. The size of the initial degrading population (treated or untreated soil) and the nature of the inoculated donor strains were considered. More transconjugants were isolated in the previously treated soil than in the untreated soil. Agrobacterium transconjugants were isolated even when the donor strain was not inoculated, probably as a result of gene transfer from indigenous degrading population to the recipient strain. Moreover, potential transconjugants belonging to the Pseudomonas genus were isolated.


CONCLUSIONS
Our results seem to demonstrate that the mcd gene is transferable in soil among bacterial populations.


CONCLUSIONS
The transfer of the mcd gene is partly responsible for the high genetic diversity of micro-organisms able to catabolize carbofuran.
Desaint
S
S
Laboratoire de Microbiologie des Sols, Centre de Microbiologie du Sol et de l'Environnement, INRA, Dijon Cedex, France.
Arrault
S
S
Siblot
S
S
Fournier
J-C
JC
D016960:Agrobacterium tumefaciens / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D001673:Biodegradation, Environmental; D002219:Carbamates / Q000378:metabolism* / Q000494:pharmacology; D002235:Carbofuran / Q000378:metabolism; D003227:Conjugation, Genetic / Q000235:genetics; D004587:Electrophoresis, Agar Gel / Q000379:methods; D022761:Gene Transfer, Horizontal / Q000235:genetics*; D005798:Genes, Bacterial / Q000235:genetics*; D011549:Pseudomonas / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D012988:Soil Microbiology
D002219:Carbamates; C036868:methyl carbamate; D002235:Carbofuran