The extent of solubility enhancement by biosurfactant was examined at various pHs prior to the biodegradation experiments. The molar solubilization ratio (MSR) was calculated from the batch solubilization experiments and the highest MSR was detected at pH 5. The effect of the biosurfactant, rhamnolipids, on the phenanthrene mineralization in soil-water system was investigated. The strain 3Y was...

The toxicity of Pb and Cd+Pb was assessed on the Collembola F. candida in two cultivated soils (SV and AU) with low organic matter (OM) content and circumneutral to basic pH, and an acid forested soil (EPC) with high OM content. Collembola reproduction and growth as well as metal content in Collembola body, in soil, exchangeable fraction and soil solutions, pH and DOC were investigated. Pb and ...

Soil pH is a strong regulator for activity as well as for size and composition of denitrifier communities. Low pH not only lowers overall denitrification rates but also influences denitrification kinetics and gaseous product stoichiometry. N2O reductase is particularly sensitive to low pH which seems to impair its activity post-transcriptionally, leading to higher net N2O production. Little is ...

BACKGROUND Natural forest succession often affects soil physical and chemical properties. Selected physical and chemical soil properties were studied in an old-growth forest across a forest successional series in Dinghushan Nature Reserve, Southern China. METHODOLOGY/PRINCIPAL FINDINGS The aim was to assess the effects of forest succession change on soil properties. Soil samples (0-20 cm dept...

Objectives/Goals Genetically modified plants usually contain a gene of interest as well as an antibiotic marker gene, which can be transferred to soil bacteria, causing a myriad of problems. The objective of this project is to determine a soil pH that would reduce genetic transformation while being conducive to plant growth. Methods/Materials E. coli was grown in an LB broth culture, then made ...

Strontium-90 is a major hazardous contaminant of radioactive wastewater and its processing sludges at many Department of Energy (DOE) facilities. In the past, such contaminated wastewater and sludge have been disposed in soil seepage pits, lagoons, or cribs often under highly perturbed alkaline conditions (pH > 12) where 90Sr solubility is low and its adsorption to surrounding soil is high. As ...

The elevational patterns of diversity for plants and animals have been well established over the past century. However, it is unclear whether there is a general elevational distribution pattern for microbes. Changbai Mountain is one of few well conserved natural ecosystems, where the vertical distribution of vegetation is known to mirror the vegetation horizontal zonation from temperate to frig...

The reason for these questions lies in the fact that the pH, or degree of acidity of the soil, often is a symptom of some disorder in the chemical condition of the soil as it relates to plant nutrition. A measurement of soil acidity or alkalinity is like a doctor's measurement of a patient's temperature. It reveals that something naay be wrong but it does not tell the exact nature of the troubl...

Some plants are more able than others to grow on soils with low pH. This interesting ability was not well recognized until the past 20 years or so, and it still is not fully understood. Crop tolerance of low soil pH has become extremely important in the agricultural development of the humid tropics because so many of those soils have low pH (Kamprath and Foy 1985, Salinas and Sanchez 1981, Mara...

The type and amount of organic matter present in industrially contaminated soils will influence the risk they pose. Previous studies have shown the importance of humic and fulvic acids (FAs) (important components of soil organic matter) in increasing the solubility of toxic metals but were not carried out using toxic metal levels and the pH range typical of industrially contaminated soils. This...