USE OF AN S-TRIAZINE NITROGEN-SOURCE TO SELECT FOR AND ISOLATE A RECOMBINANT CHLOROBENZOATE-DEGRADING PSEUDOMONAS

A novel mating system, which uses the s-triazine nitrogen source (cyan uric acid, CA) as a selective nutritional marker, was developed to eva luate mobility and facilitate identification of chlorobenzoate (CBA) d egradation genes in Pseudomonas o aeruginosa strain JB2. Matings were done between strain JB2, which is unable to grow with CA, and a CA-uti lizer Pseudomonas sp. strain D on 2-CBA-CA and 3-CBA-CA media. Isolate s were recovered only from the 2-CBA-CA and were all identified as str ain D derivatives. Subtractive hybridization analysis of genomic DNAs from the parental strains and a selected isolate, Pseudomonas sp. stra in JPL, was used to determine that the latter organism had acquired ap prox. 16.1 kb of DNA from strain JB2.