关键词: Cupriavidus metalliduransCH34, 苯酚, 基因簇, 基因组, 细菌人工染色体文库

Abstract: Cupriavidus metallidurans (C.metallidurans) CH34 is a kind of heavy metalresistant bacterium, whose genome own two phenoldegrading gene clusters and can grow on the medium that has phenol, cresol, benzoic acid, aniline as sole carbon and energy source. By using vector pIndigoBAC 5, a bacterial artificial chromosome (BAC) library of C.metallidurans CH34 was constructed and thirty thousand clones were obtained, from which 98% of the clones had an insertion fragment with average size of 30 kb. It was deduced that the whole BAC library size is about 1 240 times of the genome size. More than 3 000 clones were screened with PCR and nine positive clones were obtained: five with longer gene clusters and four with shorter clusters. Two clones with total length of phenoldegrading gene cluster were used to study its expression in Escherichia coli (E.coli) on the medium using phenol as the sole carbon source. The results indicate that both clones have the ability to degrade phenol, and the one carrying a shorter cluster shows stronger ability than that of the one with longer cluster.

Key words: Cupriavidus metallidurans CH34, bacterial artificial chromosome (BAC) library, gene cluster, genome, phenol