Functional and phylogenetic diversity of anaerobic BTEX-degrading microorganisms in contaminated aquifers

摘要: Microbial communities involved in anaerobic BTEX degradation contaminated groundwater, and factors which control limit their metabolic activities are poorly understood. Within this thesis, microbes toluene at a number of impacted sites across Germany investigated using tools molecular microbial ecology. This is done to circumvent known pitfalls cultivation-based environmental microbiology, provide better understanding the true key players natural attenuation processes. Due phylogenetic dispersal degraders, specific detection via ribosomal marker genes (e.g. 16S rRNA) not possible. Therefore, catabolic gene assay was developed thesis targeting enzyme degradation, benzylsuccinate synthase (Bss). With newly PCR assay, sitespecific clusters bssA sequences were shown for three different (Pasing, Flingern, Testfeld Sud). At Pasing site, geobacterial sequence types exclusively detected, whereas retrieved from other formed distinct so far unidentified clusters, named due site Flingern cluster “F1” “F2” Sud “T1” “T2”, respectively. The F1 F2 showed only remote affiliation proteobacterial lineages T1/T2 deeply branching, indicating relevance non-proteobacterial degraders first glance. Via DNA-stable isotope probing (DNA-SIP) applied sediments, breakdown identified as Desulfosporosinus related organisms (Clostridia), surprisingly carrying any previously detected types. these closely cluster, therefore assumed represent “true” clostridial bssA. Further sequencing efforts cultured spp. may prove hypothesis. branching thus putative bssA-homologues, be fumarate-adding reactions hydrocarbon degradation. Furthermore, quantification quantitative (qPCR) site. this, it possible characterise detail spatial distribution over depth transect contaminant plume. high-resolution sampling made by Anneser colleagues, plume compartments redox gradients could prevail very small scales. highest absolute relative abundance within sulfidogenic gradient zone underneath core. primary field data strongly supports validity “plume fringe concept”, predicts that occurring fringes plumes. Bauer coworkers have established concept laboratory experiments with two-dimensional (2D) flow-through systems. Depth-resolved characterisation total rRNA targeted T-RFLP analyses revealed pronounced shifts community structure between compartment.