It is a process for which interest is frequently renewed due to the requirement to use new feedstocks and the application of more severe environmental legislation, for example, the need to reduce sulfur levels in fuels.
Orem et al. (2011) and Corrales et al. (2011) provide detailed information on sulfur sources in EPA and offer potential management strategies to achieve reduced sulfur levels.
In 2005, George W. Bush's EPA issued the Clean Air Interstate Rule, aimed at achieving the largest reduction in air pollution in more than a decade, including reducing sulfur dioxide emissions by a further 70percentt from their 2003 levels.
Reducing sulfur content to half of one percent worldwide would cut that number by about 41,000, they said.
Members of Congress tried repeatedly to introduce legislation to reduce sulfur-dioxide levels, but the Reagan Administration (as well as many elected officials, both Democratic and Republican, from regions where sulfur-rich coal is mined) opposed any controls, fearing that they would harm the economy.
Adequate levels of reduced sulfur compounds, such as Cys and GSH, would repress gene expression through a negative feedback loop preventing excessive sulfate uptake and reduction; vice versa a contraction of GSH pools would de-repress gene transcription allowing sulfate to enter the pathway.
Mr. Manning of Keyspan disputed the assertion, saying more than $60 million was spent over the last 10 years to reduce sulfur dioxide and nitrous oxide emissions to levels far below state and national averages.
The Environmental Protection Agency recently proposed a sound new regulation, which aims, over the next four years, to reduce sulfur dioxide emissions by about 70 percent from 2005 levels and cut nitrogen oxide emissions in half.
The ability of A. ferrooxidans to obtain energy and electrons from sulfur and reduced sulfur compounds has been investigated at the biochemical level.
Murray is lobbying Congress to stop rules including one from the Office of Surface Mining (OSM) aimed at protecting streams from the adverse effects of coal mining; a Mine Safety and Health Administration MSHAA) proposal for stricter requirements on the dust levels allowed in mines; and EPA rules to reduce sulfur dioxide and nitrogen oxide emissions.
