bacillus sp. guf8, isolated from acidic soil samples of a tea farm was identified as bacillus cereus, based on 16s rdna sequencing and standard bacterial identification methods. following optimization of enzyme production, the resulting α-amylase was purified by acetone precipitation and ion exchange chromatography. consequently, thermostability and kinetic parameters of the purified enzyme wer...

plants and soil microbes are the main sources of most enzymes available in the environment. it is, therefore, anticipated that any change in the growth of soil biota in response to salinity, may reduce the synthesis and production of extra- and intra- cellular enzymes. as a result, a reduction in the growth of plants and the activity of soil microbes in saline environments may lessen the level ...

background: we aimed at evaluating the toxicity effects of low (subtoxic) concentrations of silver nanoparticles (agnp, 5-10 nm) in human hepatoblastoma (hepg2) cell line after and during a period of about one month. methods: xtt and mtt assays were used to draw a dose-response curve ic50 (half maximal inhibitory concentration) value of the agnp on hepg2 cells was calculated to be 2.75-3.0 mg/l...

this research has focused on isolation and characterization of a strain of bacillus sp. from alkaline soil, which was able to produce extracellular alkaline protease at phs ranging from 8 to 11 and temperatures of 20 to 50ºc. also the impact of different carbon andnitrogen sources were investigated. the yield and fold of enzyme purification was 24% and 50 times, respectively. molecular weight o...

Present study assessed the effect of heavy metals on soil enzyme activities like amylase, invertase, dehydrogenase and urease of open shrub lands present at 1 km, 1.5 km, 2 km and 2.5 km distance away from Bhushan sponge iron industry, in Rengali block of Sambalpur district, Odisha. The heavy metals studied were Cd, Ni, and Cr, whose concentrations in the above sites were much more than the saf...

Differentiating intracellular from extracellular enzyme activity is important in soil enzymology, but not easy. Here, we report on an adjusted sonication method for the separation of intracellular from extracellular phosphatase activity in soil. Under optimal sonication conditions [soil:water ratio  =  1/8 (w/v) and power density  =  15 watt ml(-1)], the activity of alkaline phosphomonoesterase...

β-glucosidase (E.C. 3.2.1.21), an enzyme involved in cellulose degradation, plays an important role in the soil organic carbon cycle. Cellulose is the most abundant organic compound in the biosphere so a product of its enzymatic hydrolysis is important as an energy source for soil microorganisms. Since β-glucosidase is very sensitive to different factors, determination of its activity might be ...

Soil microbial biomass and enzyme activities have an important influence on nutrient cycling. The temporal variation in soil microbial biomass C, N, and enzyme activities during the growing season were determined under three different alpine grasslands in Northern Tibet. The results showed that soil microbial biomass C, and N contents and enzyme activities of the alpine meadow (AM) and the alpi...

phosphorus is one of the most important nutrients for plant growth and development. chemical pi fertilizer is used to provide the phosphorus for the plants, but it is mostly fixed in the soil into insoluble form and become unavailable to the plants. phosphate-solubilizing bacteria have lots of application in agriculture as biological fertilizer. consumption of biofertilizers instead of chemical...