Resumo

ROZO, Catalina  e  DUSSAN, Jenny. Analysing horizontal gene transfer in bioremediation trials using recalcitrant grease. Rev. colomb. biotecnol [online]. 2010, vol.12, n.1, pp.22-31. ISSN 0123-3475.

Using microorganisms as a tool for mineralising organic pollutants is a practice which has begun to gain strength due to its efficiency and low cost. Horizontal gene transfer (HGT) by conjugation is important for optimising bioremediation processes. The metabolic diversity of catabolic pathways must thus be studied; however, the microbial interactions occurring in bioremediation consortia must also be understood. This will lead to improving bioremediation in the field. This study was aimed at evaluating HGT potential in vitro and in soil microcosms from bacterial strains isolated from grease samples obtained from a disposal site situated in the Cerrejon coal mine. The isolates were initially grouped by selective markers: ampicillin, chloramphenicol, gentamicin, tetracycline and kanamycin. The Vlf4, Ot3, Ot6, Pgt4, Blf11 and Vlf13 strains’ HGT potential was evaluated in vitro on Luria-Bertani LB agar. New phenotypes were obtained from mating between Vlf13xOt6 and Pgt4xOt6. The new phenotype indicated resistance to both antibiotic markers and its morphology suggested that isolate Ogt6 was the receptor in both cases. Vlf13, Pgt4 and Ot6 parental strains were identified by RNAr 16S as being Pseudomonas sp. Pseudomonas sp. and Chryseobacterium sp., respectively; the transconjugants were identified as being Chryseobacterium sp. Soil microcosms were subsequently constructed with Vlf13xOt6 and Pgt4xOt6 and new phenotypes were detected at a lower rate but having the same possible receptor. These results suggested that the selected isolates had HGT potential which could lead to formulating a bacterial consortium having an adaptive advantage in future studies.

Palavras-chave : Conjugation; transconjugant; replica plating.

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