Revista internacional de contaminación ambiental
Print version ISSN 0188-4999
ABURTO, Arturo and BALL, Andrew S.. Bacterial population dynamics and separation of active degraders by stable isotope probing during benzene degradation in a BTEX-impacted aquifer. Rev. Int. Contam. Ambient [online]. 2009, vol.25, n.3, pp. 147-156. ISSN 0188-4999.
The activity and diversity of a groundwater bacterial community was studied during the degradation of benzene in samples from a BTEX-contaminated aquifer (SIReN, UK) through the use of denaturing gradient gel electrophoresis (DGGE), followed by excision and sequencing of dominant bands. Rapid aerobic benzene degradation occurred in all samples, with 60-70 % degradation of benzene. DGGE analysis revealed that unique, stable bacterial communities were formed in each sample. Pseudomonas putida and Acidovorax delafieldii were identified in groundwater samples 308s and W6s respectively, suggesting they are the important taxa involved in the degradation of benzene. Further work based on stable isotope probing (SIP) of RNA using 13C benzene was carried out. Prominent bands were identified as Acidovorax and Malikia genera; the latter is very similar to the benzene-degrader Hydrogenophaga, which confirms the presence of active benzene degraders in the groundwater samples. The identification of the prominent communities provides knowledge of the bioremediation processes occurring in situ and the potential to enhance degradation. This study highlights the potential of combining community fingerprinting techniques, such as DGGE, together with SIP.
Keywords : aerobic benzene degradation; SIP; groundwater; population dynamics.