Genomic markers for anaerobic microbial processes in marine sediments-sulfate reduction, methanogenesis, and anaerobic methane oxidation-reveal the structure of sulfate-reducing, methanogenic, and methane-oxidizing microbial communities (including uncultured members); they allow inferences about the evolution of these ancient microbial pathways; and they open genomic windows into extreme microb...

Oxidation-reduction reactions, simply referred as “redox” reactions, describe all the chemical reactions in which atoms have their oxidation state changed. This can either be a simple redox process like the oxidation of carbon (C) to carbon dioxide (CO2) or the reduction of C by hydrogen (H) to yield methane (CH4). However, in biology redox reactions are rather complex and ‘redox biology’ is fu...

Some of the most efficient homogeneous catalysts for the lowtemperature, selective oxidation of methane to functionalized products employ a mechanism involving C H activation with an electrophilic substitution mechanism. Several such systems have been reported based on the cations Hg, Pd, and Pt. These catalyst systems typically operate by two general steps that involve: A) C H activation by co...

The deep-sea vestimentiferan tubeworm Lamellibrachia luymesi forms large aggregations at hydrocarbon seeps in the Gulf of Mexico that may persist for over 250 y. Here, we present the results of a diagenetic model in which tubeworm aggregation persistence is achieved through augmentation of the supply of sulfate to hydrocarbon seep sediments. In the model, L. luymesi releases the sulfate generat...

an experiment was conducted to evaluate the effect of lime application on the mass and sugar losses reduction from 2004 to 2005 in karaj. four lime concentrations of 0, 3, 4 and 5 percent (factor a) and storage durations of 30 and 60 days (factor b) were arranged as factorial experiment in rcbd with four replications. the commercial variety of shirin was drilled in early may and storage roots w...

A unique set of geochemical pore-water data, characterizing the sulfate reduction and uppermost methanogenic zones, has been collected at the Blake Ridge (offshore southeastern North America) from Ocean Drilling Program (ODP) Leg 164 cores and piston cores. The δ13C values of dissolved CO2 (ΣCO2) are as 13C-depleted as –37.7‰ PDB (Site 995) at the sulfate-methane interface, reflecting a substan...

The Pennsylvania region hosts numerous oil and gas reservoirs and the presence of hydrocarbons in groundwater has been locally observed. However, these methane-containing freshwater ecosystems remain poorly explored despite their potential importance in the carbon cycle. Methane isotope analysis and analysis of low molecular weight hydrocarbon gases from 18 water wells indicated that active met...