@article {1561, title = {4-methylphenol produced in freshwater sediment microcosms is not a bisphenol A metabolite.}, journal = {Chemosphere}, volume = {117}, year = {2014}, month = {2014 Dec}, pages = {521-6}, abstract = {

4-Methylphenol (4-MP), a putative bisphenol A (BPA) degradation intermediate, was detected at concentrations reaching 2.1 mg L(-1) in anoxic microcosms containing 10 mg L(-1) BPA and 5 g of freshwater sediment material collected from four geographically distinct locations and amended with nitrate, nitrite, ferric iron, or bicarbonate as electron acceptors. 4-MP accumulation was transient, and 4-MP degradation was observed under all redox conditions tested. 4-MP was not detected in microcosms not amended with BPA. Unexpectedly, incubations with (13)C-labeled BPA failed to produce (13)C-labeled 4-MP suggesting that 4-MP was not derived from BPA. The detection of 4-MP in live microcosms amended with lactate, but not containing BPA corroborated that BPA was not the source of 4-MP. These findings demonstrate that the transient formation of 4-MP as a possible BPA degradation intermediate must be interpreted cautiously, as microbial activity in streambed microcosms may generate 4-MP from sediment-associated organic material.

}, keywords = {Anaerobiosis, Benzhydryl Compounds, Biodegradation, Environmental, Chromatography, High Pressure Liquid, Cresols, Environmental Monitoring, Fresh Water, Gas Chromatography-Mass Spectrometry, Geologic Sediments, Phenols, Water Pollutants, Chemical}, issn = {1879-1298}, doi = {10.1016/j.chemosphere.2014.09.008}, author = {Im, Jeongdae and Prevatte, Carson W and Lee, Hong Geun and Campagna, Shawn R and L{\"o}ffler, Frank E} } @article {1565, title = {Guided cobalamin biosynthesis supports Dehalococcoides mccartyi reductive dechlorination activity.}, journal = {Philos Trans R Soc Lond B Biol Sci}, volume = {368}, year = {2013}, month = {2013 Apr 19}, pages = {20120320}, abstract = {

Dehalococcoides mccartyi strains are corrinoid-auxotrophic Bacteria and axenic cultures that require vitamin B12 (CN-Cbl) to conserve energy via organohalide respiration. Cultures of D. mccartyi strains BAV1, GT and FL2 grown with limiting amounts of 1 {\textmu}g l(-1) CN-Cbl quickly depleted CN-Cbl, and reductive dechlorination of polychlorinated ethenes was incomplete leading to vinyl chloride (VC) accumulation. In contrast, the same cultures amended with 25 {\textmu}g l(-1) CN-Cbl exhibited up to 2.3-fold higher dechlorination rates, 2.8-9.1-fold increased growth yields, and completely consumed growth-supporting chlorinated ethenes. To explore whether known cobamide-producing microbes supply Dehalococcoides with the required corrinoid cofactor, co-culture experiments were performed with the methanogen Methanosarcina barkeri strain Fusaro and two acetogens, Sporomusa ovata and Sporomusa sp. strain KB-1, as Dehalococcoides partner populations. During growth with H2/CO2, M. barkeri axenic cultures produced 4.2 {\textpm} 0.1 {\textmu}g l(-1) extracellular cobamide (factor III), whereas the Sporomusa cultures produced phenolyl- and p-cresolyl-cobamides. Neither factor III nor the phenolic cobamides supported Dehalococcoides reductive dechlorination activity suggesting that M. barkeri and the Sporomusa sp. cannot fulfil Dehalococcoides{\textquoteright} nutritional requirements. Dehalococcoides dechlorination activity and growth occurred in M. barkeri and Sporomusa sp. co-cultures amended with 10 {\textmu}M 5{\textquoteright},6{\textquoteright}-dimethylbenzimidazole (DMB), indicating that a cobalamin is a preferred corrinoid cofactor of strains BAV1, GT and FL2 when grown with chlorinated ethenes as electron acceptors. Even though the methanogen and acetogen populations tested did not produce cobalamin, the addition of DMB enabled guided biosynthesis and generated a cobalamin that supported Dehalococcoides{\textquoteright} activity and growth. Guided cobalamin biosynthesis may offer opportunities to sustain and enhance Dehalococcoides activity in contaminated subsurface environments.

}, keywords = {Bacteriological Techniques, Benzimidazoles, Biodegradation, Environmental, Chloroflexi, Chromatography, High Pressure Liquid, Coculture Techniques, Culture Media, Dichloroethylenes, Halogenation, Oxidation-Reduction, Trichloroethylene, Vitamin B 12}, issn = {1471-2970}, doi = {10.1098/rstb.2012.0320}, author = {Yan, Jun and Im, Jeongdae and Yang, Yi and L{\"o}ffler, Frank E} } @article {688, title = {Stress-induced synthesis of phosphatidylinositol 3-phosphate in mycobacteria.}, journal = {J Biol Chem}, volume = {285}, year = {2010}, month = {2010 May 28}, pages = {16643-50}, abstract = {Phosphoinositides play key roles in regulating membrane dynamics and intracellular signaling in eukaryotic cells. However, comparable lipid-based signaling pathways have not been identified in bacteria. Here we show that Mycobacterium smegmatis and other Actinomycetes bacteria can synthesize the phosphoinositide, phosphatidylinositol 3-phosphate (PI3P). This lipid was transiently labeled with [(3)H]inositol. Sensitivity of the purified lipid to alkaline phosphatase, headgroup analysis by high-pressure liquid chromatography, and mass spectrometry demonstrated that it had the structure 1,2-[tuberculostearoyl, octadecenoyl]-sn-glycero 3-phosphoinositol 3-phosphate. Synthesis of PI3P was elevated by salt stress but not by exposure to high concentrations of non-ionic solutes. Synthesis of PI3P in a cell-free system was stimulated by the synthesis of CDP-diacylglycerol, a lipid substrate for phosphatidylinositol (PI) biosynthesis, suggesting that efficient cell-free PI3P synthesis is dependent on de novo PI synthesis. In vitro experiments further indicated that the rapid turnover of this lipid was mediated, at least in part, by a vanadate-sensitive phosphatase. This is the first example of de novo synthesis of PI3P in bacteria, and the transient synthesis in response to environmental stimuli suggests that some bacteria may have evolved similar lipid-mediated signaling pathways to those observed in eukaryotic cells.}, keywords = {Cell-Free System, Chromatography, High Pressure Liquid, Leishmania, Lipids, Mass Spectrometry, Mycobacterium smegmatis, Nucleotides, Oxalic Acid, Phosphatidylinositol Phosphates, Phosphatidylinositols, Phospholipids, Phosphorylation, Salts, Signal Transduction}, issn = {1083-351X}, doi = {10.1074/jbc.M110.119263}, author = {Morita, Yasu S and Yamaryo-Botte, Yoshiki and Miyanagi, Kana and Callaghan, Judy M and Patterson, John H and Crellin, Paul K and Coppel, Ross L and Billman-Jacobe, Helen and Kinoshita, Taroh and McConville, Malcolm J} } @article {518, title = {The proteome of dissimilatory metal-reducing microorganism Geobacter sulfurreducens under various growth conditions.}, journal = {Biochim Biophys Acta}, volume = {1764}, year = {2006}, month = {2006 Jul}, pages = {1198-206}, abstract = {The proteome of Geobacter sulfurreducens, a model for the Geobacter species that predominate in many Fe(III)-reducing subsurface environments, was characterized with ultra high-pressure liquid chromatography and mass spectrometry using accurate mass and time (AMT) tags as well as with more traditional two-dimensional polyacrylamide gel electrophoresis (2-D PAGE). Cells were grown under six different growth conditions in order to enhance the potential that a wide range of genes would be expressed. The AMT tag approach was able to identify a much greater number of proteins than could be detected with the 2-D PAGE approach. With the AMT approach over 3,000 gene products were identified, representing about 90\% of the total predicted gene products in the genome. A high proportion of predicted proteins in most protein role categories were detected; the highest number of proteins was identified in the hypothetical protein role category. Furthermore, 91 c-type cytochromes of 111 predicted genes in the G. sulfurreducens genome were identified. Differences in the abundance of cytochromes and other proteins under different growth conditions provided information for future functional analysis of these proteins. These results demonstrate that a high percentage of the predicted proteins in the G. sulfurreducens genome are produced and that the AMT tag approach provides a rapid method for comparing differential expression of proteins under different growth conditions in this organism.}, keywords = {Bacterial Proteins, Bacteriological Techniques, Chromatography, High Pressure Liquid, Cytochrome c Group, Electrophoresis, Gel, Two-Dimensional, Ferric Compounds, Fumarates, Geobacter, Peptide Fragments, Proteome, Spectrometry, Mass, Electrospray Ionization}, issn = {0006-3002}, doi = {10.1016/j.bbapap.2006.04.017}, author = {Ding, Yan-Huai R and Hixson, Kim K and Giometti, Carol S and Stanley, Ann and Esteve-N{\'u}{\~n}ez, Abraham and Khare, Tripti and Tollaksen, Sandra L and Zhu, Wenhong and Adkins, Joshua N and Lipton, Mary S and Smith, Richard D and Mester, T{\"u}nde and Lovley, Derek R} }