Development of Thiobacillus ferrooxidans ATCC 19859 strains tolerant to copper and zinc

A study was carried out to develop strains of Thiobacillus ferrooxidans ATCC 19859 tolerant to higher levels of heavy metal ions. Strains of T. ferrooxidans capable of growing in Cu2+ (30 g/L) and Zn2+ (60 g/L) have been obtained. The ability of strains tolerant to either copper or zinc to grow in medium containing both the metals has been examined. The copper-tolerant strain (25 g/L) grows better in the medium containing both metals (Cu2+ 25 g/L and Zn2+ 40 g/L) compared to the zinc-tolerant strain (40 g/L)

Soil Microbes are Shaped by Soil Physico-chemical Properties: A Brief Review of Existing Literature

Soil consists of very complex, inter-related community of microorganisms which interact with one another and with plants and animals, forming a complex web of biological activity. The microbes determine health and potential of soil to perform a multitude of ecosystem processes, which depend on the community composition and functioning. The microbial community structure and functions in soil are influenced by physico-chemical properties of soils. Abiotic controls like surrounding climate, environment, land use, nutrients, pH and rhizosphere control the composition of microbes in soil, which in turn modify soil properties. In this review, we investigate the existing body of research exploring studies which have explored how microbes are shaped by soil properties.</jats:p

Metabolism of carbaryl and carbofuran in soil planted to rice

In greenhouse experiments carbaryl and carbofuran disappeared more rapidly from a soil planted to rice than from an unplanted soil under both flooded and non-flooded (60% water-holding capacity) conditions. The rate of degradation was little affected by the moisture regime. The degradation of both carbamate insecticides proceeded essentially by hydrolysis. Further degradation of the hydrolysis products, 1-naphthol from carbaryl and 2,3-dihydro-2,2-dimethylbenzofuran-7-ol from carbofuran was slow in both planted and unplanted systems. A significant portion (20-38%) of the ring <SUP>14</SUP>C in carbaryl and carbofuran accumulated in the soil as the respective hydrolysis products + soil-bound residues. Evolution of <SUP>14</SUP>CO<SUB>2</SUB> from the <SUP>14</SUP>C (from both side chain and ring labels) in carbaryl and carbofuran was negligible even in soil planted to rice

Soil Microbes are Shaped by Soil Physico-chemical Properties: A Brief Review of Existing Literature

Soil consists of very complex, inter-related community of microorganisms which interact with one another and with plants and animals, forming a complex web of biological activity. The microbes determine health and potential of soil to perform a multitude of ecosystem processes, which depend on the community composition and functioning. The microbial community structure and functions in soil are influenced by physico-chemical properties of soils. Abiotic controls like surrounding climate, environment, land use, nutrients, pH and rhizosphere control the composition of microbes in soil, which in turn modify soil properties. In this review, we investigate the existing body of research exploring studies which have explored how microbes are shaped by soil properties

Degradation of carbofuran by enrichment cultures and pure cultures of bacteria from flooded soils

Enrichment cultures obtained from three flooded soils after repeated additions of carbofuran or its hydrolysis product, carbofuran phenol, effected a more rapid degradation of carbofuran in a mineral salts medium than the cultures from the respective soils never before exposed to carbofuran or carbofuran phenol. Rhizosphere soil suspension, phyllosphere suspension and guttation fluid from rice plants grown on carbofuran-treated fields were more active in degrading carbofuran than the corresponding samples from untreated fields. Bacteria isolated from carbofuran- and carbaryl-amended soils decomposed carbofuran in a mineral salts medium, but more rapidly in the absence than in the presence of an additional nitrogen source, (NH4)2HPO4. Interestingly, even enrichment cultures showed a lag in the degradation of carbofuran

Relative persistence of hexachlorocyclohexane, methyl parathion and carbofuran in an alluvial soil under flooded and non-flooded conditions

The relative persistence of the γ-isomer of hexachlorocyclohexane (γ-HCH, organochlorine), methyl parathion (O-O-dimethyl O-p-nitrophenyl phosphorothioate, organophosphate) and carbofuran (2,3-dihydro-2,2-dimethyl-7-benzofuranyl N-methylcarbamate, carbamate) in an alluvial soil was studied under flooded and non-flooded conditions. Under flooded conditions, γ-HCH was the least persistent of the three insecticides followed by methyl parathion and carbofuran, but under non-flooded conditions, γ-HCH was the most stable followed by carbofuran and methyl parathion. A major portion of the 14C in γ-HCH and methyl parathion was not accounted for, especially under flooded conditions, possibly due to the formation of volatile products. Formation of soil-bound residues from γ-HCH and methyl parathion was negligible. However, during metabolism of carbofuran, its hydrolysis product, carbofuran phenol, and bound residues accumulated in the soil in substantial quantities. The data generated from these concurrently incubated studies demonstrate that the relative persistence of insecticides with different functional groups in the soil is governed by the moisture regime