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Full-Text Articles in Biological Engineering

Proteomic Analysis Of 17Β-Estradiol Degradation By Stenotrophomonas Maltophilia, Zhongtian Li May 2012

Proteomic Analysis Of 17Β-Estradiol Degradation By Stenotrophomonas Maltophilia, Zhongtian Li

Z Li

Microbial degradation plays a critical role in determining the environmental fate of steroid hormones, such as 17β-estradiol (E2). The molecular mechanisms governing the microbial transformation of E2 and its primary degradation intermediate, estrone (E1), are largely unknown. The objective of this study was to identify metabolism pathways that might be involved in microbial estrogen degradation. To achieve the objective, Stenotrophomonas maltophilia strain ZL1 was used as a model estrogen degrading bacterium and its protein expression level during E2/E1 degradation was studied using quantitative proteomics. During an E2 degradation experiment, strain ZL1 first converted E2 to E1 stoichiometrically. At 16 h …


Securing Foreign Oil: A Case For Including Military Operations In The Climate Change Impact Of Fuels, Adam Liska, Richard Perrin May 2012

Securing Foreign Oil: A Case For Including Military Operations In The Climate Change Impact Of Fuels, Adam Liska, Richard Perrin

Richard K Perrin

Military operations are major industrial activities that use massive amounts of fuel and materials that significantly contribute to climate change. In this article, we assert that military activity to protect international oil trade is a direct production component for importing foreign oil— as necessary for imports as are pipelines and supertankers—and therefore the greenhouse gas (GHG) emissions from that military activity are relevant to U.S. fuel policies related to climate change. Military security for protection of global maritime petroleum distribution is part of the acquisition process, but in addition, recent Middle Eastern wars may also be related to securing petroleum …


Energy And Climate Implications For Agricultural Nutrient Use Efficiency, Adam J. Liska, Richard K. Perrin May 2012

Energy And Climate Implications For Agricultural Nutrient Use Efficiency, Adam J. Liska, Richard K. Perrin

Richard K Perrin

Energy and climate change are beginning to dominate the global political agenda and will drive policy formation that will shape the future of agriculture. Energy issues threaten national security and economic stability, as well as access to low-cost nutrient inputs for agriculture. Climate change has the potential to cause serious disruption to agricultural productivity. Paradoxically, nutrient use in agriculture to increase crop yields has the potential to negatively impact climate. This chapter will discuss recent and future energy and climate trends, the relationships between agricultural nutrient use efficiency and biofuels, and how global land limitations will shape agriculture in the …


Indirect Land Use Emissions In The Life Cycle Of Biofuels: Regulations Vs. Science, Adam Liska, Richard Perrin May 2012

Indirect Land Use Emissions In The Life Cycle Of Biofuels: Regulations Vs. Science, Adam Liska, Richard Perrin

Richard K Perrin

Recent legislative mandates have been enacted at state and federal levels with the purpose of reducing life cycle greenhouse gas (GHG) emissions from transportation fuels. This legislation encourages the substitution of fossil fuels with “low-carbon” fuels. The burden is put on regulatory agencies to determine the GHG-intensity of various fuels, and those agencies naturally look to science for guidance. Even though much progress has been made in determining the direct life cycle emissions from the production of biofuels, the science underpinning the estimation of potentially significant emissions from indirect land use change (ILUC) is in its infancy. As legislation requires …


Robust Dynamic Balance Of Ap-1 Transcription Factors In A Neuronal Gene Regulatory Network., Gregory M Miller, Babatunde A Ogunnaike, James S Schwaber, Rajanikanth Vadigepalli May 2012

Robust Dynamic Balance Of Ap-1 Transcription Factors In A Neuronal Gene Regulatory Network., Gregory M Miller, Babatunde A Ogunnaike, James S Schwaber, Rajanikanth Vadigepalli

Rajanikanth Vadigepalli

BACKGROUND: The octapeptide Angiotensin II is a key hormone that acts via its receptor AT1R in the brainstem to modulate the blood pressure control circuits and thus plays a central role in the cardiac and respiratory homeostasis. This modulation occurs via activation of a complex network of signaling proteins and transcription factors, leading to changes in levels of key genes and proteins. AT1R initiated activity in the nucleus tractus solitarius (NTS), which regulates blood pressure, has been the subject of extensive molecular analysis. But the adaptive network interactions in the NTS response to AT1R, plausibly related to the development of …


Removing 17Β-Estradiol From Drinking Water In A Biologically Active Carbon (Bac) Reactor Modified From A Granular Activated Carbon (Gac) Reactor, Zhongtian Li Mar 2012

Removing 17Β-Estradiol From Drinking Water In A Biologically Active Carbon (Bac) Reactor Modified From A Granular Activated Carbon (Gac) Reactor, Zhongtian Li

Z Li

Estrogenic compounds in drinking water sources pose potential threats to human health. Treatment technologies are needed to effectively remove these compounds for the production of safe drinking water. In this study, GAC adsorption was first tested for its ability to remove a model estrogenic compound, 17β-estradiol (E2). Although GAC showed a relatively high adsorption capacity for E2 in isotherm experiments, it appeared to have a long mass transfer zone in a GAC column reactor, causing an early leakage of E2 in the effluent. With an influent E2 concentration of 20 μg/L, the GAC reactor was able to bring down effluent …


Kinetic Modeling Of Photoautotropic Growth And Neutral Lipid Accumulation In Terms Of Ammonium Concentration In Chlamydomonas Reinhardtii, Yasar Demirel, R. Tevetia, P. Blum Dec 2011

Kinetic Modeling Of Photoautotropic Growth And Neutral Lipid Accumulation In Terms Of Ammonium Concentration In Chlamydomonas Reinhardtii, Yasar Demirel, R. Tevetia, P. Blum

YASAR DEMIREL

This study focuses on the cell growth and the neutral lipid production modeling of Chlamydomonas reinhardtii in terms of different ammonium concentrations. Autotrophy was maintained during growth in a double walled bioreactor, using Tris Phosphate (TP medium) with only CO2 and NH4Cl as sole sources of carbon and nitrogen, respectively. Nitrogen depletion results in an increase in neutral lipid production with an indirect effect on the growth of algal cells. Modified Baranyi–Roberts and logistic equations were used to describe the cell growth whereas Luedeking–Piret equation was used for neutral lipid production kinetics. Sensitivity analysis shows that the model equations satisfactorily …