The main objective of this work was to study the ecology of enterococci and related bacteria in raw and treated wastewater from a treatment plant rece

Summary: Microbial and functional diversity were assessed, from a serpentinization‐driven subterrestrial alkaline aquifer – C abeço de V ide A quifer ( CVA ) in P ortugal. DGGE analyses revealed the presence of a stable microbial community. By 16 S rRNA gene libraries and pyrosequencing analyses, a diverse bacterial composition was determined, contrasting with low archaeal diversity. Within B acteria the majority of the populations were related to organisms or sequences affiliated to class C lostridia , but members of classes A cidobacteria , A ctinobacteria , A lphaproteobacteria , B etaproteobacteria , D einococci , G ammaproteobacteria and of the phyla B acteroidetes, C hloroflexi and N itrospira were also detected. Domain A rchaea encompassed mainly sequences affiliated to E uryarchaeota . Only form I RuBisCO – cbb L was detected. Autotrophic carbon fixation via the rTCA , 3‐ HP and 3‐ HP /4 H ‐ B cycles could not be confirmed. The detected APS reductase alpha subunit – aprA sequences were phylogenetically related to sequences of sulfate‐reducing bacteria belonging to C lostridia , and also to sequences of chemolithoautothrophic sulfur‐oxidizing bacteria belonging to B etaproteobacteria . Sequences of methyl coenzyme M reductase – mcrA were phylogenetically affiliated to sequences belonging to A naerobic M ethanotroph group 1 ( ANME ‐1). The populations found and the functional key markers detected in CVA suggest that metabolisms related to H ₂ , methane and/or sulfur may be the major driving forces in this environment.

Groundwater samples (111) from six different boreholes located in two geographical areas were examined for the presence of legionellae over a 7-year period. The number of Legionella isolates detected was generally low. The colonization of the aquifers was not uniform, and the persistence of Legionella was independent of the hydraulic pumps and the plumbing system present in the borehole. A total of 374 isolates identified by fatty acid methyl ester analysis belonged to Legionella pneumophila , L. oakridgensis , L. sainthelensi , and L. londiniensis . In area 1, L. oakridgensis constituted the major population detected, exhibiting only one random amplified polymorphic DNA (RAPD)-PCR profile. L. sainthelensi strains were less frequently isolated and also displayed a single RAPD profile, while L. pneumophila was only sporadically detected. In contrast, L. pneumophila comprised the vast majority of the isolates in area 2 and exhibited six distinct RAPD patterns, indicating the presence of different genetic groups; three L. londiniensis RAPD types were also detected. Two of the L. pneumophila and one of the L. londiniensis RAPD types were persistent in this environment for at least 12 years. The genetic structure of L. pneumophila groundwater populations, inferred from rpoB and dotA gene sequences, was peculiar, since the majority of the isolates were allied in a discrete group different from the lineages containing most of the type and reference strains of the three subspecies of L. pneumophila . Furthermore, gene exchange events related to the dotA allele could be envisioned.

A low-G+C-content Gram-positive bacterium, designated CV53^T, phylogenetically related to species of the genus Bacillus, was isolated from a highly alkaline non-saline groundwater environment (pH 11.4). This organism comprised rod-shaped cells, was aerobic, did not display spore formation, was catalase- and oxidase-negative, had an optimum growth temperature of 40 °C and had an optimum pH of approximately 7.0–8.5. Optimal growth was observed in the absence of NaCl, but growth did occur at NaCl concentrations up to 3.0 %. The strain possessed an A1γ-type peptidoglycan cell wall and the major respiratory quinone was MK-7. The predominant fatty acids were anteiso-C_15 : 0, iso-C_15 : 0 and anteiso-C_17 : 0. The G+C content of the DNA was 43.1 mol%. Phylogenetic analyses of the 16S rRNA gene sequence revealed that the novel isolate is closely related to the type strain of Bacillus jeotgali, forming a coherent cluster supported by bootstrap analysis at a confidence level of 90 %. The pairwise similarity of the 16S rRNA gene sequences of the two strains is 97.7 %. On the basis of the phylogenetic analyses and the distinct phenotypic characteristics, strain CV53^T represents a novel species within the genus Bacillus, for which we propose the name Bacillus foraminis sp. nov. The type strain is CV53^T (=LMG 23174^T=CIP 108889^T).