A new fluorescent oligonucleotide probe for in situ detection of s-triazine-degrading Rhodococcus wratislaviensis in contaminated groundwater and soil samples.
A bacterial strain (FPA1) capable of using terbuthylazine, simazine, atrazine, 2-hydroxysimazine, deethylatrazine, isopropylamine or ethylamine as its sole carbon source was isolated from a shallow aquifer chronically contaminated with s-triazine herbicides. Based on its 16S rDNA sequence analysis, the strain FPA1 was identified as Rhodococcus wratislaviensis. The disappearance time of 50% of the initial terbuthylazine concentration in the presence of this strain (DT(50)) was 62days. This strain was also able to mineralise the [U-ring (14)C] triazine-ring, albeit at a slow rate. A 16S rRNA target oligonucleotide probe (RhLu) was designed, and the FISH protocol was optimised, in order to detect R. wratislaviensis in s-triazine-contaminated sites. The RhLu probe gave a positive signal (expressed as % of total DAPI-positive cells) in both the groundwater (2.19+/-0.41%) and soil (2.10+/-0.96%) samples analysed. Using the RhLu probe, R. wratislaviensis can be readily detected, and its population dynamics can be easily monitored, in soil and in water ecosystems contaminated with s-triazine. To the best of our knowledge, this is the first report showing the isolation, from groundwater, of a bacterial strain able to degrade s-triazines.
Grenni
Paola
P
Water Research Institute--National Research Council, Area della Ricerca di Roma 1-Montelibretti, via Salaria km 29,300, CP10 00016 Monterotondo, Rome, Italy. grenni@irsa.cnr.it
Gibello
Alicia
A
Barra Caracciolo
Anna
A
Fajardo
Carmen
C
Nande
Mar
M
Vargas
Raquel
R
Saccà
Maria Ludovica
ML
Martinez-Iñigo
Maria José
MJ
Ciccoli
Roberto
R
Martín
Margarita
M
D001280:Atrazine / Q000031:analogs & derivatives / Q000378:metabolism; D004275:DNA, Ribosomal / Q000235:genetics; D006540:Herbicides / Q000378:metabolism; D017404:In Situ Hybridization, Fluorescence / Q000379:methods*; D012240:Rhodococcus / Q000145:classification / Q000235:genetics* / Q000378:metabolism*; D012839:Simazine / Q000378:metabolism; D012989:Soil Pollutants / Q000378:metabolism*; D014227:Triazines / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000378:metabolism*
D004275:DNA, Ribosomal; D006540:Herbicides; D012989:Soil Pollutants; D014227:Triazines; D014874:Water Pollutants, Chemical; C446541:deethylatrazine; C037565:terbutylazine; D001280:Atrazine; D012839:Simazine