The financial impact of a nurse practitioner directed lung cancer screening and tobacco related disease program

The American Association for Thoracic Surgery Centennia

Anaerobes in Bioelectrochemical Systems

In bioelectrochemical systems (BES), the catalytic activity of anaerobic microorganisms generates electrons at the anode which can be used, for example, for the production of electricity or chemical compounds. BES can be used for various purposes, including wastewater treatment, production of electricity, fuels and chemicals, biosensors, bioremediation, and desalination. Electrochemically active microorganisms are widely present in the environment and they can be found, in sediment, soil, compost, wastewaters and their treatment plants. Exoelectrogens are microorganisms capable of donating electrons to anode electrode or accepting electrons from cathode electrode and are mainly responsible for current generation or use in BES. However, current generation from fermentable substrates often requires the presence of electrochemically inactive microorganisms that break down complex substrates into metabolites which can be further utilized by exoelectrogens. The growth and electron transfer efficiency of anaerobes depend on several parameters, such as system architecture, electrode material and porosity, electrode potential and external resistance, pH, temperature, substrate concentration, organic loading rate, and ionic strength. In this chapter, the principles and microbiology of bioelectrochemical systems as well as selective factors for exoelectrogens are reviewed. The anaerobic microorganisms and their electron transfer mechanisms at the anode and cathode are described and future aspects are briefly discussed.acceptedVersionNon peer reviewe

Bacterial Power: An Alternative Energy Source

The demand for energy and the limited supply of fossil fuels and their impact in the environment have required the development of alternative energy sources. Among the next generation of energy sources, microbial fuel cells (MFCs) have emerged as a promising technology due to their ability to recover energy from wastewaters in the form of electricity using electroactive microorganisms as catalysts. Among the various factors that affect power generation performance in MFCs, the efficiency of extracellular electron transfer (EET) is one of the most important. Several enzymes, specifically multiheme cytochromes, have been implicated in this process although the electron transfer chain organization remains to be fully understood. In this chapter, we review in detail the mechanisms that support EET from electroactive microorganisms to the anode in MFCs. We focus on the model organism Shewanella oneidensis MR-1, due to the existence of an extensive molecular characterization of its EET processes. The recent developments in the characterization of the multiheme cytochromes involved in these mechanisms will also be reviewed.authorsversionpublishe