Read by QxMD icon Read


Yue Lu, Javier Ramiro-Garcia, Pieter Vandermeeren, Steffi Herrmann, Danuta Cichocka, Dirk Springael, Siavash Atashgahi, Hauke Smidt
Dechlorination patterns of three tetrachlorobenzene isomers, 1,2,3,4-, 1,2,3,5-, and 1,2,4,5-TeCB, were studied in anoxic microcosms derived from contaminated harbor sludge. The removal of doubly, singly, and un-flanked chlorine atoms was noted in 1,2,3,4- and 1,2,3,5-TeCB fed microcosms, whereas only singly flanked chlorine was removed in 1,2,4,5-TeCB microcosms. The thermodynamically more favorable reactions were selectively followed by the enriched cultures with di- and/or mono-chlorobenzene as the main end products of the reductive dechlorination of all three isomers...
December 1, 2016: Applied Microbiology and Biotechnology
Bipro Ranjan Dhar, Hodon Ryu, Hao Ren, Jorge W Santo Domingo, Junkseck Chae, Hyung-Sool Lee
This study systematically assessed intracellular electron transfer (IET) and extracellular electron transfer (EET) kinetics with respect to anode potential (Eanode ) in a mixed-culture biofilm anode enriched with Geobacter spp. High biofilm conductivity (0.96-1.24 mS cm(-1) ) was maintained during Eanode changes from -0.2 to +0.2 V versus the standard hydrogen electrode (SHE), although the steady-state current density significantly decreased from 2.05 to 0.35 A m(-2) in a microbial electrochemical cell...
November 21, 2016: ChemSusChem
Abid H Tanzil, Sujala T Sultana, Steven R Saunders, Alice C Dohnalkova, Liang Shi, Emily Davenport, Phuc Ha, Haluk Beyenal
The goal of this work was to synthesize gold nanoparticles (AuNPs) using electrode-respiring Geobacter sulfurreducens biofilms. We found that AuNPs are generated in the extracellular matrix of Geobacter biofilms and have an average particle size of 20nm. The formation of AuNPs was verified using TEM, FTIR and EDX. We also found that the extracellular substances extracted from electrode-respiring G. sulfurreducens biofilms reduce Au(3+) to AuNPs. From FTIR spectra, it appears that reduced sugars were involved in the bioreduction and synthesis of AuNPs and that amine groups acted as the major biomolecules involved in binding...
December 2016: Enzyme and Microbial Technology
Sara Tejedor Sanz, Jose Rodrigo Quejido, Antonio Berná, Abraham Esteve Núñez
The capacity of some microorganisms to exchange electrons with electrical conductive materials as part of their metabolism is one of the most fascinating mechanisms in the current field of microbiology. This phenomenon typically occurs in an electroactive biofilm where all bacterial layers contribute to convert oxidative metabolism into electrical current. The main drawback of this scenario is the limited number of reactive cells, which depends upon the active area of the electrode wherein the bioelectrochemical reaction is performed...
November 9, 2016: ChemSusChem
J Patrick O'Brien, Nikhil S Malvankar
Anaerobic microorganisms play a central role in several environmental processes and regulate global biogeochemical cycling of nutrients and minerals. Many anaerobic microorganisms are important for the production of bioenergy and biofuels. However, the major hurdle in studying anaerobic microorganisms in the laboratory is the requirement for sophisticated and expensive gassing stations and glove boxes to create and maintain the anaerobic environment. This appendix presents a simple design for a gassing station that can be used readily by an inexperienced investigator for cultivation of anaerobic microorganisms...
November 18, 2016: Current Protocols in Microbiology
Tom Guterman, Micha Kornreich, Avigail Stern, Lihi Adler-Abramovich, Danny Porath, Roy Beck, Linda J W Shimon, Ehud Gazit
Mimicking the multifunctional bacterial type IV pili (T4Ps) nanofibres provides an important avenue towards the development of new functional nanostructured biomaterials. Yet, the development of T4Ps-based applications is limited by the inability to form these nanofibres in vitro from their pilin monomers. Here, to overcome this limitation, we followed a reductionist approach and designed a self-assembling pilin-based 20-mer peptide, derived from the presumably bioelectronic pilin of Geobacter sulfurreducens...
November 17, 2016: Nature Communications
Agathe Paitier, Alexiane Godain, Delina Lyon, Naoufel Haddour, Timothy M Vogel, Jean-Michel Monier
In order to optimize energy production in MFCs, a better understanding of anodic communities is essential. Our objective was to determine the taxonomic structure of the bacterial communities present at the surface of the anode during the formation and development of electro-active biofilms in MFCs inoculated with fresh primary clarifier overflow. Quantitative microbial community dynamics were evaluated as a function of time and electrical performance using 16S rRNA gene-based phylogenetic microarrays and flow cytometry...
November 2, 2016: Biosensors & Bioelectronics
Hong-Wei Luo, Xiangping Yin, Aaron M Jubb, Hongmei Chen, Xia Lu, Weihua Zhang, Hui Lin, Han-Qing Yu, Liyuan Liang, Guo-Ping Sheng, Baohua Gu
Atmospheric deposition of mercury (Hg) to surface water is one of the dominant sources of Hg in aquatic environments and ultimately drives methylmercury (MeHg) toxin accumulation in fish. It is known that freshly deposited Hg is more readily methylated by microorganisms than aged or preexisting Hg; however the underlying mechanism of this process is unclear. We report that Hg bioavailability is decreased by photochemical reactions between Hg and dissolved organic matter (DOM) in water. Photo-irradiation of Hg-DOM complexes results in loss of Sn(II)-reducible (i...
November 8, 2016: Environmental Pollution
Matthew D Yates, Sarah M Strycharz-Glaven, Joel P Golden, Jared Roy, Stanislav Tsoi, Jeffrey S Erickson, Mohamed Y El-Naggar, Scott Calabrese Barton, Leonard M Tender
No abstract text is available yet for this article.
November 8, 2016: Nature Nanotechnology
Nikhil S Malvankar, Vincent M Rotello, Mark T Tuominen, Derek R Lovley
No abstract text is available yet for this article.
November 8, 2016: Nature Nanotechnology
Godwin E Oyiwona, James Ogbonna, Chukwudi Uzoma Anyanwu, So Ishizaki, Zen-Ichiro Kimura, Satoshi Okabe
OBJECTIVE: To investigate a syntrophic interaction between Geobacter sulfurreducens and hydrogenotrophic methanogens in sludge-inoculated microbial fuel cell (MFC) systems running on glucose with an improved electron recovery at the anode. RESULTS: The presence of archaea in MFC reduces Coulombic efficiency (CE) due to their electron scavenging capability but, here, we demonstrate that a syntrophic interaction can occur between G. sulfurreducens and hydrogenotrophic methanogens via interspecies H2 transfer with improvement in CE and power density...
November 3, 2016: Biotechnology Letters
Allison M Speers, Bryan D Schindler, Jihwan Hwang, Aycin Genc, Gemma Reguera
The metal-reducing bacterium Geobacter sulfurreducens requires the expression of conductive pili to reduce iron oxides and to wire electroactive biofilms, but the role of pilus retraction in these functions has remained elusive. Here we show that of the four PilT proteins encoded in the genome of G. sulfurreducens, PilT3 powered pilus retraction in planktonic cells of a PilT-deficient strain of P. aeruginosa and restored the dense mutant biofilms to wild-type levels. Furthermore, PilT3 and PilT4 rescued the twitching motility defect of the PilT-deficient mutant...
2016: Frontiers in Microbiology
Hyung-Sool Lee, Bipro Ranjan Dhar, Junyeong An, Bruce E Rittmann, Hodon Ryu, Jorge W Santo Domingo, Hao Ren, Junseok Chae
We experimentally assessed the kinetics and thermodynamics of electron transfer (ET) from the donor substrate (acetate) to the anode for a mixed-culture biofilm anode. We interpreted the results with a modified biofilm-conduction model consisting of three ET steps is series: (1) intracellular ET, (2) non-Ohmic extracellular ET (EET) from an outer membrane protein to an extracellular cofactor (EC), and (3) ET from the EC to the anode by Ohmic-conduction in the biofilm matrix. The steady-state current density was 0...
October 31, 2016: Environmental Science & Technology
Mengning Ding, Hui-Ying Shiu, Shiue-Lin Li, Calvin K Lee, Gongming Wang, Hao Wu, Nathan O Weiss, Thomas D Young, Paul S Weiss, Gerard C L Wong, Kenneth H Nealson, Yu Huang, Xiangfeng Duan
The electrical conductivity measured in Shewanella and Geobacter spp. is an intriguing physical property that is the fundamental basis for possible extracellular electron transport (EET) pathways. There is considerable debate regarding the origins of the electrical conductivity reported in these microbial cellular structures, which is essential for deciphering the EET mechanism. Here, we report systematic on-chip nanoelectronic investigations of both Shewanella and Geobacter spp. under physiological conditions to elucidate the complex basis of electrical conductivity of both individual microbial cells and biofilms...
October 27, 2016: ACS Nano
Paul Kavanagh, Catherine H Botting, Partha S Jana, Donal Leech, Florence Abram
Geobacter sulfurreducens is a dissimilatory metal-reducing bacterium capable of forming thick electron-conducting biofilms on solid electrodes. Here, we employ for the first time comparative proteomics to identify key physiological changes involved in G. sulfurreducens adaptation from fumarate-respiring planktonic cells to electron-conducting biofilms. Increased levels of proteins involved in outer membrane biogenesis, cell motility and secretion are expressed in biofilms. Of particular importance to the electron-conducting biofilms are proteins associated with secretion systems of Type I, II, V and Type IV pili...
October 10, 2016: Journal of Proteome Research
Yan Dang, Yuqing Lei, Zhao Liu, Yiting Xue, Dezhi Sun, Li-Ying Wang, Dawn E Holmes
A considerable amount of leachate with high fulvic acid (FA) content is generated during the municipal solid waste (MSW) incineration process. This incineration leachate is usually processed by downstream bio-methanogenic treatment. However, few studies have examined the impact that these compounds have on methanogenesis and how they are degraded and transformed during the treatment process. In this study, a laboratory-scale expanded granular sludge bed (EGSB) reactor was operated with MSW incineration leachate containing various concentrations of FA (1500 mg/L to 8000 mg/L) provided as the influent...
September 23, 2016: Water Research
Milán Farkas, Sándor Szoboszlay, Tibor Benedek, Fruzsina Révész, Péter Gábor Veres, Balázs Kriszt, András Táncsics
Dissimilatory iron-reducing bacteria are commonly found in microbial communities of aromatic hydrocarbon-contaminated subsurface environments where they often play key role in the degradation of the contaminants. The Siklós benzene, toluene, ethylbenzene, and xylene (BTEX)-contaminated area is one of the best characterized petroleum hydrocarbon-contaminated sites of Hungary. Continuous monitoring of the microbial community in the center of the contaminant plume indicated the presence of an emerging Geobacter population and a Rhodoferax phylotype highly associated with aromatic hydrocarbon-contaminated subsurface environments...
September 28, 2016: Folia Microbiologica
Hui Yun, Deyong Kong, Bin Liang, Minhua Cui, Zhiling Li, Aijie Wang
Chloramphenicol (CAP) is a frequently detected environmental pollutant. In this study, an electroactive biofilm for CAP reduction was established by initially in the anode and then inverting to the cathode. The established biocathode could enhance the reduction of CAP to the nitro-group reduced CAP (AMCl2) and further dechlorinated form (AMCl), both had lost the antibacterial activity. The phylogenetic diversity of the acclimated biofilm was decreased after the polar inversion. Proportions of functional bacterial genera, including Geobacter, Desulfovibrio and Pseudomonas responsible for the bidirectional electron transfer and nitroaromatics reduction, had increased 28%, 104% and 43% in the cathode...
December 2016: Bioresource Technology
Toshiyuki Ueki, Kelly P Nevin, Trevor L Woodard, Derek R Lovley
Physiological studies and biotechnology applications of Geobacter species have been limited by a lack of genetic tools. Therefore, potential additional molecular strategies for controlling metabolism were explored. When the gene for citrate synthase, or acetyl-CoA transferase, was placed under the control of a LacI/IPTG regulator/inducer system, cells grew on acetate only in the presence of IPTG. The TetR/AT system could also be used to control citrate synthase gene expression and acetate metabolism. A strain that required IPTG for growth on D-lactate was constructed by placing the gene for D-lactate dehydrogenase under the control of the LacI/IPTG system...
November 2016: Journal of Industrial Microbiology & Biotechnology
T P Delforno, D Y Okada, C V Faria, M B A Varesche
The objective of this study was to evaluate the removal of linear alkylbenzene sulfonate (LAS) associated with Fe(III) supplementation using an expanded granular sludge bed (EGSB) reactor. The reactor was inoculated with a granular sludge and fed with synthetic wastewater containing a specific LAS load rate (SLLR) of 1.5 mg gVS(-1) d(-1) (∼16.4 mgLAS L(-1) influent) and supplied with 7276 μMol L(-1) of Fe(III). The biomasses from the inoculum and at the end of the EGSB-Fe operation (127 days) were characterized using 16S rRNA Ion Tag sequencing...
December 1, 2016: Journal of Environmental Management
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"