Abstract:
Metagenomicshas the potential to discover novel phenotypes that are not recognizable by DNA sequence analysis. In this study,functional metagenomic analysis of Niangua River soil detected spectinomycin (NR-YP1) and nalidixic acid (NR-YP3) resistance expressed in E. coli EPI300. Subclonesof eachwere generated and screened on spectinomycin ornalidixic acid containingmedia for NR-YP1and NR-YP3, respectively. No subclones were identified conferring resistance to either of the antibiotics. Random DNA sequencing and BLAST analysis of both NR-YP1 and NR-YP3 subclones matchedan environmental clone, termed zdt-9n2, with almost 100% sequence identity. However, proteomic analysis of zdt-9n2 yielded no proteins with the potential to conferantibiotic resistance. Thus, the two clones, NR-YP1 and NR-YP3, appear to be nearly 100% identical in their cloned DNA but yet express two different antibiotic resistance phenotypes.Genetic loci responsible for the resistance could not be identified in this study.
