@article {724,
	title = {Trace elements affect methanogenic activity and diversity in enrichments from subsurface coal bed produced water.},
	journal = {Front Microbiol},
	volume = {3},
	year = {2012},
	month = {2012},
	pages = {175},
	abstract = {Microbial methane from coal beds accounts for a significant and growing percentage of natural gas worldwide. Our knowledge of physical and geochemical factors regulating methanogenesis is still in its infancy. We hypothesized that in these closed systems, trace elements (as micronutrients) are a limiting factor for methanogenic growth and activity. Trace elements are essential components of enzymes or cofactors of metabolic pathways associated with methanogenesis. This study examined the effects of eight trace elements (iron, nickel, cobalt, molybdenum, zinc, manganese, boron, and copper) on methane production, on mcrA transcript levels, and on methanogenic community structure in enrichment cultures obtained from coal bed methane (CBM) well produced water samples from the Powder River Basin, Wyoming. Methane production was shown to be limited both by a lack of additional trace elements as well as by the addition of an overly concentrated trace element mixture. Addition of trace elements at concentrations optimized for standard media enhanced methane production by 37\%. After 7 days of incubation, the levels of mcrA transcripts in enrichment cultures with trace element amendment were much higher than in cultures without amendment. Transcript levels of mcrA correlated positively with elevated rates of methane production in supplemented enrichments (R(2) = 0.95). Metabolically active methanogens, identified by clone sequences of mcrA mRNA retrieved from enrichment cultures, were closely related to Methanobacterium subterraneum and Methanobacterium formicicum. Enrichment cultures were dominated by M. subterraneum and had slightly higher predicted methanogenic richness, but less diversity than enrichment cultures without amendments. These results suggest that varying concentrations of trace elements in produced water from different subsurface coal wells may cause changing levels of CBM production and alter the composition of the active methanogenic community.},
	issn = {1664-302X},
	doi = {10.3389/fmicb.2012.00175},
	author = {Unal, Burcu and Perry, Verlin Ryan and Sheth, Mili and Gomez-Alvarez, Vicente and Chin, Kuk-Jeong and N{\"u}sslein, Klaus}
}
@article {752,
	title = {Tuning the hemolytic and antibacterial activities of amphiphilic polynorbornene derivatives.},
	journal = {J Am Chem Soc},
	volume = {126},
	year = {2004},
	month = {2004 Dec 8},
	pages = {15870-5},
	abstract = {Amphiphilic cationic polynorbornene derivatives, soluble in water, were prepared from modular norbornene monomers, with a wide range of molecular weights (M(n) = 1600-137 500 g/mol) and narrow polydispersities (PDI = 1.1-1.3). The antibacterial activity determined by growth inhibition assays and the hemolytic activity against human red blood cells were measured and compared to determine the selectivity of the polymers for bacterial over mammalian cells. The effects of monomer repeat unit hydrophobicity and polymer molecular weight on antibacterial and hemolytic activities were determined. The hydrophobicity of the repeat unit was observed to have dramatic effects on antibacterial and hemolytic activities. Lipid membrane disruption activities of the polymers was confirmed by measuring polymer-induced dye leakage from large unilamellar vesicles. By tuning the overall hydrophobicity of the polymer through random copolymerizations of modular norbornene derivatives, highly selective, nonhemolytic antibacterial activities were obtained. For appropriate monomer composition, selectivity against bacteria versus human red blood cells was determined to be over 100.},
	keywords = {Anti-Bacterial Agents, Bacillus subtilis, Cell Membrane, Cholesterol, Erythrocytes, Escherichia coli, Hemolysis, Humans, Liposomes, Microbial Sensitivity Tests, Molecular Weight, Norbornanes, Polymers, Structure-Activity Relationship},
	issn = {0002-7863},
	doi = {10.1021/ja045664d},
	author = {Ilker, M Firat and N{\"u}sslein, Klaus and Tew, Gregory N and Coughlin, E Bryan}
}
