Changes in phosphorylation of adenosine phosphate and redox state of nicotinamide-adenine dinucleotide (phosphate) in Geobacter sulfurreducens in response to electron acceptor and anode potential variation
Rose N.D.,Pennsylvania State University |
Regan J.M.,Pennsylvania State University |
Regan J.M.,First Environment Inc.
Bioelectrochemistry | Year: 2015
Geobacter sulfurreducens is one of the dominant bacterial species found in biofilms growing on anodes in bioelectrochemical systems. The intracellular concentrations of reduced and oxidized forms of nicotinamide-adenine dinucleotide (NADH and NAD+, respectively) and nicotinamide-adenine dinucleotide phosphate (NADPH and NADP+, respectively) as well as adenosine triphosphate (ATP), adenosine diphosphate (ADP), and adenosine monophosphate (AMP) were measured in G. sulfurreducens using fumarate, Fe(III)-citrate, or anodes poised at different potentials (110, 10, -90, and -190mV (vs. SHE)) as the electron acceptor. The ratios of CNADH/CNAD+ (0.088±0.022) and CNADPH/CNADP+ (0.268±0.098) were similar under all anode potentials tested and with Fe(III)-citrate (reduced extracellularly). Both ratios significantly increased with fumarate as the electron acceptor (0.331±0.094 for NAD and 1.96±0.37 for NADP). The adenylate energy charge (the fraction of phosphorylation in intracellular adenosine phosphates) was maintained near 0.47 under almost all conditions. Anode-growing biofilms demonstrated a significantly higher molar ratio of ATP/ADP relative to suspended cultures grown on fumarate or Fe(III)-citrate. These results provide evidence that the cellular location of reduction and not the redox potential of the electron acceptor controls the intracellular redox potential in G. sulfurreducens and that biofilm growth alters adenylate phosphorylation. © 2015 Elsevier B.V.
Clarke A.J.,First Environment Inc.
Environmental Claims Journal | Year: 2011
In December 2010, Federal Rule of Civil Procedure 26 (FRCP 26) was amended to protect certain communications between a litigating counsel and its experts from discovery. The rule protects communications and draft expert reports and lays out new disclosure requirements for the so-called " treating physician " expert. Attorneys and experts who first read the rule commonly agreed that the rule would make expert discovery more streamlined and cost-effective while preserving an opposing party's right to obtain facts and data that were considered by the expert in formulating its opinion. However, many commentators on the amended FRCP 26 warned practitioners not to fully embrace the literal meaning of the rule until it was field tested by litigating attorneys and the courts had the opportunity to interpret a number of loosely defined terms during the course of resolving federal discovery disputes. Now, almost a year after the rule's first official publication, several courts have interpreted the key terms that appear in the rule and have expressed their interpretations in written opinions. The judicial holdings of these cases cover different aspects of the rule, and it is still too early to determine how the majority of federal courts will ultimately interpret it. However, a review of current case law indicates that the courts have, thus far, taken a practical and literal view of the amended rule and have not expanded or limited its scope beyond what was generally believed to be the intent of the rule. As a result, practitioners are still hopeful that the rule will make working with an expert more efficient and less cumbersome, to the benefit of experts, attorneys, and ultimately their clients. © First Environment, Inc.
Kymer R.I.S.,First Environment Inc.
Environmental Claims Journal | Year: 2010
Although the United Nations Climate Change Conference, held recently in Copenhagen, fell short of expectations by failing to achieve a legally binding agreement to fill the gap when the Kyoto Protocol expires in 2012, there were some positive outcomes. A negotiating gridlock limited the resulting Copenhagen Accord to a nonlegally binding treaty drafted in part by the United States. The Accord was not adopted. This article discusses key elements of the Accord, identifies those countries that have committed to greenhouse gas emission reduction targets, and offers insights into the positive outcomes, shortcomings, and business implications of the Accord. © Taylor & Francis Group, LLC.
Schiffman-Kymer R.I.,First Environment Inc. |
Demarco D.,First Environment Inc. |
Campbell M.P.,First Environment Inc.
Environmental Claims Journal | Year: 2010
On September 22, 2009, the U.S. Environmental Protection Agency issued its Mandatory Greenhouse Gas (GHG) Reporting Rule, which will require over 10,000 U.S. facilities to report their GHG emissions annually. The Rule generally applies to facilities that emit more than 25,000 metric tons of carbon dioxide equivalent (mtCO2e) or more per year, although some sources with lower emissions in specific sectors of the economy will also be subject. Recordkeeping and reporting requirements are significant and will warrant processes to ensure a consistent, defensible approach. The article discusses the background, purpose, and organization of the Rule; applicability, emissions accounting, reporting, recordkeeping, and emission verification; and presents a potential implementation plan. © Taylor & Francis Group, LLC.