Thirty-two chemoheterotrophic bacteria were isolated from unsaturated subsurface soil samples obtained from ca. 70 m below land surface in a high desert in southeastern Idaho. Most isolates were gram positive (84%) and strict aerobes (79%). Acridine orange direct counts of microbes in one subsurface sample showed lower numbers than similar counts performed on surface soils from the same locatio...

Lipases have many applications in biotechnology, thanks to their ability of acylglycerides hydrolysis. They alsp possess the unique feature of acting at the lipid-water interface, which distinguishes them from esterases. Commercially useful lipases are produced by microorganisms with the extracellular lipase being produced by many bacteria including Pseudomonas. The greatest production of lipas...

Alkaline phosphatase (ortho phosphate, monoester hydrolase phosphoinositide E. C. 3.1.3.1) is a non-specific metalloproteinase enzyme that is located inside periplasmic space of bacteria. This enzyme is used to measure freshwater sediment in genetic engineering for cleaning water. Isolation and molecular identification of the bacteria producing alkaline phosphatase and comparison of its product...

The objective of this work was to evaluate the transport of Escherichia coli cells in undisturbed cores of a brown leached soil collected at La Côte St André (France). Two undisturbed soil cores subjected to repeated injections of bacterial cells and/or bromide tracer were used to investigate the effect of soil hydrodynamics and ionic strength on cell mobility. Under the tested experimental con...

Water availability is the main limiting factor in arid soils; however, few studies have examined the effects of drying and rewetting on nitrifiers from these environments. The effect of water availability on the diversity of ammonia-oxidizing bacteria (AOB) and archaea (AOA) from a semiarid soil of the Chilean sclerophyllous matorral was determined by microcosm assays. The addition of water eve...

to isolate and detect anthrax spores form soil in different regions of iran in order to find the anthrax foci‚ a total of 668 environmental specimens were collected during 2003-2004. bacterial endospores were extracted from soil specimens via flotation in distilled water, incubation at room temperature, filtration, heat shock and culture on blood agar and selective plet media. bacillus anthraci...

To improve the feasibility of soil-aquifer remediation using bioaugmentation, more efficient methods are needed to widely disperse pollutant-degrading bacteria in porous media. Under water-saturated conditions, bacteria readily adhere to soil particles, but under unsaturated conditions, bacteria preferentially accumulate at the air-water interface. Air sparging a saturated porous medium produce...

Moisture may limit microbial activity in a wide range of environments including salt water, food, wood, biofilms, and soils. Low water availability can inhibit microbial activity by lowering intracellular water potential and thus reducing hydration and activity of enzymes. In solid matrices, low water content may also reduce microbial activity by restricting substrate supply. As pores within so...

Global change may be a severe threat to natural and agricultural systems, partly through its effects in altering soil biota and processes, due to changes in water balance. We studied the potential influence of changing soil water balance on soil biota by comparing existing sites along a natural water balance gradient in the Qinghai-Tibetan Plateau. In this study, the community structure of bact...

abstract in this study, evaluation of swap model in simulating crop yield, water and salt movement in soil were investigated in the wheat- fodder maize cultivated units. the research was conducted in the voshmgir network, golestan province. the crop yield, soil humidity and moisture data in different times of agriculture year of 2007-2008 were measured. the measured and simulated data were anal...