<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Unal, Burcu</style></author><author><style face="normal" font="default" size="100%">Perry, Verlin Ryan</style></author><author><style face="normal" font="default" size="100%">Sheth, Mili</style></author><author><style face="normal" font="default" size="100%">Gomez-Alvarez, Vicente</style></author><author><style face="normal" font="default" size="100%">Chin, Kuk-Jeong</style></author><author><style face="normal" font="default" size="100%">Nüsslein, Klaus</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Trace elements affect methanogenic activity and diversity in enrichments from subsurface coal bed produced water.</style></title><secondary-title><style face="normal" font="default" size="100%">Front Microbiol</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Front Microbiol</style></alt-title></titles><dates><year><style  face="normal" font="default" size="100%">2012</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2012</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">3</style></volume><pages><style face="normal" font="default" size="100%">175</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">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.</style></abstract><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/22590465?dopt=Abstract</style></custom1></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Gomez-Alvarez, Vicente</style></author><author><style face="normal" font="default" size="100%">King, Gary M</style></author><author><style face="normal" font="default" size="100%">Nüsslein, Klaus</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Comparative bacterial diversity in recent Hawaiian volcanic deposits of different ages.</style></title><secondary-title><style face="normal" font="default" size="100%">FEMS Microbiol Ecol</style></secondary-title><alt-title><style face="normal" font="default" size="100%">FEMS Microbiol. Ecol.</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Bacteria</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA, Bacterial</style></keyword><keyword><style  face="normal" font="default" size="100%">Ecosystem</style></keyword><keyword><style  face="normal" font="default" size="100%">Genes, rRNA</style></keyword><keyword><style  face="normal" font="default" size="100%">Genetic Variation</style></keyword><keyword><style  face="normal" font="default" size="100%">Hawaii</style></keyword><keyword><style  face="normal" font="default" size="100%">Molecular Sequence Data</style></keyword><keyword><style  face="normal" font="default" size="100%">Phylogeny</style></keyword><keyword><style  face="normal" font="default" size="100%">Polymerase Chain Reaction</style></keyword><keyword><style  face="normal" font="default" size="100%">RNA, Ribosomal, 16S</style></keyword><keyword><style  face="normal" font="default" size="100%">Sequence Analysis, DNA</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil Microbiology</style></keyword><keyword><style  face="normal" font="default" size="100%">Time Factors</style></keyword><keyword><style  face="normal" font="default" size="100%">Volcanic Eruptions</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2007</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2007 Apr</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">60</style></volume><pages><style face="normal" font="default" size="100%">60-73</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">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.</style></abstract><issue><style face="normal" font="default" size="100%">1</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/17381525?dopt=Abstract</style></custom1></record></records></xml>