Trichoderma bio-fertilizer is widely used to improve soil fertility and carbon (C) sequestration, but the mechanism for increasing C accumulation remains unclear. In this study, effects of on mineralization aggregate-associated organic were investigated in a field experiment with five treatments (bio-fertilizer substitute 0 (CF), 10% (BF10), 20% (BF20), 30% (BF30) 50% (BF50) chemical fertilizer...

Soil microbial communities play an important role in nutrient cycling and nutrient availability, especially in unimproved soils. In grazed pastures, sheep urine causes local changes in nutrient concentration which may be a source of heterogeneity in microbial community structure. In the present study, we investigated the effects of synthetic urine on soil microbial community structure, using ph...

The description of soil microbial community structure by phospholipid fatty acid (PLFA) profiles is based on the relationship between the phylogeny of microorganisms and their PLFA profiles. Based on this relationship, two community based microbiological measurements, namely, potential C source utilization patterns in Biolog microtiter plates and PLFA profiles were used to examine metabolic fin...

Microorganisms that oxidize atmospheric methane in soils were characterized by radioactive labelling with (14)CH(4) followed by analysis of radiolabelled phospholipid ester-linked fatty acids ((14)C-PLFAs). The radioactive fingerprinting technique was used to compare active methanotrophs in soil samples from Greenland, Denmark, the United States, and Brazil. The (14)C-PLFA fingerprints indicate...

Phospholipid-derived fatty acids (PLFA) and respiratory quinones (RQ) are microbial compounds that have been utilized as biomarkers to quantify bacterial biomass and to characterize microbial community structure in sediments, waters, and soils. While PLFAs have been widely used as quantitative bacterial biomarkers in marine sediments, applications of quinone analysis in marine sediments are ver...

The relationship between microbial communities, salinity, soil depth, and time was evaluated using phospholipid fatty acids (PLFA) collected from coastal wetlands in Louisiana post hurricanes Katrina and Rita. The three marsh types studied included freshwater and intermediate marshes from the Jean Lafitte Preserve as well as two brackish marsh sites from the Caernarvon Basin. The Caernarvon Bas...

To better understand how water stress and availability affect the structure of microbial communities in soil, I measured the change in phospholipid fatty acids (PLFA) and the incorporation of C-labeled glucose into the PLFA following exposure to water stress. Overlaid on the laboratory water stress treatment, samples were collected from drought-prone and irrigated (11 years) tallgrass prairie s...

Repeated fertilizer applications to cultivated soils may alter the composition and activities of microbial communities in terrestrial agro-ecosystems. In this study, we investigated the effects of different long term fertilization practices (control (CK), three levels of mineral fertilizer (N1P1K1, N2P2K2, and N3P3K3), and organic manure (OM)) on soil environmental variables and microbial commu...

Possible enhancement of biodegradation of petroleum hydrocarbons in agricultural soil after tank truck accident (~5000 mg/kg dry soil initial concentration) by bioaugmentation of diesel degrading Pseudomonas fluorescens strain and addition of abiotic additives (humates, zeolite) was studied in a 9-month pot experiment. The biodegradation process was followed by means of analytical parameters (h...

Marine sediment slurries enriched for anaerobic, sulfate-reducing prokaryotic communities utilizing glucose and acetate were used to provide the first comparison between stable-isotope probing (SIP) of phospholipid fatty acids (PLFA) and DNA (16S rRNA and dsrA genes) biomarkers. Different 13C-labelled substrates (glucose, acetate and pyruvate) at low concentrations (100 microM) were used over a...