@article {736,
	title = {Hydrogenotrophic denitrification and perchlorate reduction in ion exchange brines using membrane biofilm reactors.},
	journal = {Biotechnol Bioeng},
	volume = {104},
	year = {2009},
	month = {2009 Oct 15},
	pages = {483-91},
	abstract = {Halophilic (salt loving), hydrogenotrophic (H(2) oxidizing) denitrifying bacteria were investigated for treatment of nitrate (NO3-) and perchlorate (ClO4-) contaminated groundwater and ion exchange (IX) brines. Hydrogenotrophic denitrifying bacteria were enriched from a denitrifying wastewater seed under both halophilc and non-halophilc conditions. The cultures were inoculated into bench-scale membrane biofilm reactors (MBfRs) with an "outside in" configuration, with contaminated water supplied to the lumen of the membranes and H(2) supplied to the shell. Abiotic mass transfer tests showed that H(2) mass transfer coefficients were lower in brines than in tap water at highest Reynolds number, possibly due to increased transport of salts and decreased H(2) solubility at the membrane/liquid interface. An average NO3- removal efficiency of 93\% was observed for the MBfR operated in continuous flow mode with synthetic contaminated groundwater. Removal efficiencies of 30\% for NO3- and 42\% for ClO4- were observed for the MBfR operated with synthetic IX brine in batch operating mode with a reaction time of 53 h. Phylogenetic analysis focused on the active microbial community and revealed that halotolerant, NO3- -reducing bacteria of the bacterial classes Gamma-Proteobacteria and Sphingobacteria were the metabolically dominant members within the stabilized biofilm. This study shows that, despite decreased H(2) transfer under high salt conditions, hydrogenotrophic biological reduction may be successfully used for the treatment of NO3- and ClO- in a MBfR.},
	keywords = {Bacteroidetes, Biofilms, Cluster Analysis, DNA, Bacterial, DNA, Ribosomal, Gammaproteobacteria, Hydrogen, Ion Exchange, Membranes, Molecular Sequence Data, Nitrites, Oxidation-Reduction, Perchloric Acid, Phylogeny, RNA, Ribosomal, 16S, Sequence Analysis, DNA, Water Pollutants, Chemical, Water Purification},
	issn = {1097-0290},
	doi = {10.1002/bit.22414},
	author = {Sahu, Ashish K and Conneely, Teresa and N{\"u}sslein, Klaus and Ergas, Sarina J}
}
@article {743,
	title = {Arsenic sequestration by nitrate respiring microbial communities in urban lake sediments.},
	journal = {Chemosphere},
	volume = {70},
	year = {2007},
	month = {2007 Dec},
	pages = {329-36},
	abstract = {Changes in microbial community composition and activity were related to geochemical conditions favoring arsenic sequestration in sediments collected from the urban, arsenic-contaminated Upper Mystic Lake. After amendment with nitrate, >94\% total soluble arsenic is sequestered by Fe(III)-(oxy)hydroxides generated in live sediments. Of this sequestered arsenic, >75\% existed as As(III), indicating As redox state alone is not responsible for changes in mobility. Arsenic sequestration was concurrent with the microbial respiration of nitrate as indicated by steady state hydrogen concentration and the presence of organisms similar to nitrate-reducing, iron-oxidizing bacteria belonging to the genus Dechloromonas in 16S rDNA clone libraries.},
	keywords = {Arsenic, Betaproteobacteria, Biodegradation, Environmental, DNA, Bacterial, DNA, Ribosomal, Fresh Water, Geologic Sediments, Massachusetts, Nitrates, Oxidation-Reduction, RNA, Ribosomal, 16S, Urbanization, Water Microbiology, Water Pollutants, Chemical},
	issn = {0045-6535},
	doi = {10.1016/j.chemosphere.2007.05.094},
	author = {Gibney, Brian P and N{\"u}sslein, Klaus}
}
@article {746,
	title = {Comparative bacterial diversity in recent Hawaiian volcanic deposits of different ages.},
	journal = {FEMS Microbiol Ecol},
	volume = {60},
	year = {2007},
	month = {2007 Apr},
	pages = {60-73},
	abstract = {Volcanic activity creates new landforms that can change dramatically over time as a consequence of biotic succession. Nonetheless, volcanic deposits present severe constraints for microbial colonization and activity. We have characterized bacterial diversity on four recent deposits at Kilauea volcano, Hawaii (KVD). Much of the diversity was either closely related to uncultured organisms or distinct from any reported 16S rRNA gene sequences. Diversity indices suggested that diversity was highest in a moderately vegetated 210-year-old ash deposit (1790-KVD), and lowest for a 79-year-old lava flow (1921-KVD). Diversity for a 41-year-old tephra deposit (1959-KVD) and a 300-year-old rainforest (1700-KVD) reached intermediate values. The 1959-KVD and 1790-KVD communities were dominated by Acidobacteria, Alpha- and Gammaproteobacteria, Actinobacteria, Cyanobacteria, and many unclassified phylotypes. The 1921-KVD, an unvegetated low pH deposit, was dominated by unclassified phylotypes. In contrast, 1700-KVD was primarily populated by Alphaproteobacteria with very few unclassified phylotypes. Similar diversity indices and levels of trace gas flux were found for 1959-KVD and 1790-KVD; however, statistical analyses indicated significantly different communities. This study not only showed that microorganisms colonize recent volcanic deposits and are able to establish diverse communities, but also that their composition is governed by variations in local deposit parameters.},
	keywords = {Bacteria, DNA, Bacterial, Ecosystem, Genes, rRNA, Genetic Variation, Hawaii, Molecular Sequence Data, Phylogeny, Polymerase Chain Reaction, RNA, Ribosomal, 16S, Sequence Analysis, DNA, Soil Microbiology, Time Factors, Volcanic Eruptions},
	issn = {0168-6496},
	doi = {10.1111/j.1574-6941.2006.00253.x},
	author = {Gomez-Alvarez, Vicente and King, Gary M and N{\"u}sslein, Klaus}
}
