Chemical and Structural Changes in Corn Stover After Ensiling: Influence on Bioconversion.

Production of biofuels, bioproducts, and bioenergy requires a well-characterized, stable, and reasonably uniform biomass supply and well-established supply chains for shipping biomass from farm fields to biorefineries, while achieving year-round production targets. Preserving and stabilizing biomass feedstock during storage is a necessity for cost-effective and sustainable biofuel production. Ensiling is a common storage method used to preserve and even improve forage quality; however, the impact of ensiling on biomass physical and chemical properties that influence bioconversion processes has been variable.

Field evidence for co-metabolism of trichloroethene stimulated by addition of electron donor to groundwater.

For more than 10 years, electron donor has been injected into the Snake River aquifer beneath the Test Area North site of the Idaho National Laboratory for the purpose of stimulating microbial reductive dechlorination of trichloroethene (TCE) in groundwater. This has resulted in significant TCE removal from the source area of the contaminant plume and elevated dissolved CH(4) in the groundwater extending 250 m from the injection well. The delta(13)C of the CH(4) increases from -56 per thousand in the source area to -13 per thousand with distance from the injection well, whereas the delta(13)C of dissolved inorganic carbon decreases from 8 per thousand to -13 per thousand, indicating a shift from methanogenesis to methane oxidation.

Stimulation of microbial urea hydrolysis in groundwater to enhance calcite precipitation.

Addition of molasses and urea was tested as a means of stimulating microbial urea hydrolysis in the Eastern Snake River Plain Aquifer in Idaho. Ureolysis is an integral component of a novel remediation approach for divalent trace metal and radionuclide contaminants in groundwater and associated geomedia, where the contaminants are immobilized by coprecipitation in calcite. Generation of carbonate alkalinity from ureolysis promotes calcite precipitation.

Subseafloor microbial communities in methane hydrate-bearing sediment at two distinct locations (ODP Leg204) in the cascadia margin.

The prokaryotic communities in deep subseafloor sediment collected during Ocean Drilling Program (ODP) Leg 204 from the South Hydrate Ridge (SHR) on the Cascadia Margin were analyzed by 16S rRNA gene clone sequencing and a fluorescent quantitative PCR technique. The microbial communities came from sites with contrasting geological characteristics on the SHR: sites 1244 and 1245 (located on the flank of the ridge, hydrate-rich sediment) and site 1251 (located on the slope basin of SHR, hydrate-poor sediment). The overall copy numbers of the 16S rRNA gene, and the proportion of archaeal 16S rRNA gene in all 16S rRNA gene community in sediment were larger on the slope basin than on the flank of the SHR.

Diversity of oxygenase genes from methane- and ammonia-oxidizing bacteria in the Eastern Snake River Plain aquifer.

PCR amplification, restriction fragment length polymorphism, and phylogenetic analysis of oxygenase genes were used for the characterization of in situ methane- and ammonia-oxidizing bacteria from free-living and attached communities in the Eastern Snake River Plain aquifer. The following three methane monooxygenase (MMO) PCR primer sets were used: A189-A682, which amplifies an internal region of both the pmoA gene of the MMO particulate form and the amoA gene of ammonia monooxygenase; A189-mb661, which specifically targets the pmoA gene; and mmoXA-mmoXB, which amplifies the mmoX gene of the MMO soluble form (sMMO). Whole-genome amplification (WGA) was used to amplify metagenomic DNA from each community to assess its applicability for generating unbiased metagenomic template DNA.

Microbial communities from methane hydrate-bearing deep marine sediments in a forearc basin.

Microbial communities in cores obtained from methane hydrate-bearing deep marine sediments (down to more than 300 m below the seafloor) in the forearc basin of the Nankai Trough near Japan were characterized with cultivation-dependent and -independent techniques. Acridine orange direct count data indicated that cell numbers generally decreased with sediment depth. Lipid biomarker analyses indicated the presence of viable biomass at concentrations greater than previously reported for terrestrial subsurface environments at similar depths.