Mini-Tn7 transposons for site-specific tagging of bacteria with fluorescent proteins

摘要

The mini-Tn7 transposon system is a convenient tool for site-specific tagging of bacteria in which the tagging DNA is inserted at a unique and neutral chromosomal site. We have expanded the panel of mini-Tn7 delivery plasmids expressing different fluorescent proteins (stable and unstable) from the Escherichia coli lac derived promoter, P_(A1/04/03), or from the growth-rate-dependent Escherichia coli promoter P_(rrnB P1). The mini-Tn7 transposons were inserted and tested in the soil bacterium, Pseudomonas putida KT2440. Successful and site-specific tagging was verified by Southern blots as well as by PCR. Furthermore, the effect of fluorescent protein expression on the cellular growth rate was tested by growth competition assays.