Isolation and characterization of rhizobacteria and their effects on root extracts of Valeriana officinalis.

Plant growth promoting rhizobacteria (PGPR) are a group of microorganisms which can enhance growth parameters of host plants and can be used as biofertilizers. Valerian (Valeriana officinalis) is a perennial herb which is used as a medicinal plant. In the current study 40 colonies of bacteria were isolated from the rhizosphere of valerian by growing in various enriched and selective media including S1 and King B, crystal violet agar and methyl red agar.

Cleaning heavy metal contaminated soil by soluble humic substances instead of synthetic polycarboxylic acids

Soils contaminated with heavy metals constitute a serious and widespread ecological problem but to clean such soils requires
strong chemicals such as polycarboxylates; frequently ethylenediaminetetraacetic acid and nitrilotriacetic acid are used.
However, these compounds are synthetic and toxic and their replacement by natural products such as soluble humic
substances as washing agents for cleaning heavy metal polluted soils would be environmentally very attractive. In fact, such a

Evaluation of copper bioaccumulation and translocation in Jatropha curcas grown in a contaminated soil

Contamination of soils with copper (Cu) has become a serious problem in the environment.
Phytoremediation is an emerging green technology that uses green plants to remediate heavy
metal contaminated areas. This study was conducted to evaluate the potential of Jatropha
curcas for remediation of soils contaminated with Cu. Seedlings were planted in soils spiked
with Cu in amount of 0, 50, 100, 200, 300, and 400 mg kg–1 (Cu0, Cu50,Cu100,Cu200,Cu300,
and Cu400) for a period of five months. The maximum height and number of leaves were

Evaluation of copper bioaccumulation and translocation in Jatropha curcas grown in a contaminated soil

Contamination of soils with copper (Cu) has become a serious problem in the environment.
Phytoremediation is an emerging green technology that uses green plants to remediate heavy
metal contaminated areas. This study was conducted to evaluate the potential of Jatropha
curcas for remediation of soils contaminated with Cu. Seedlings were planted in soils spiked
with Cu in amount of 0, 50, 100, 200, 300, and 400 mg kg–1 (Cu0, Cu50,Cu100,Cu200,Cu300,
and Cu400) for a period of five months. The maximum height and number of leaves were

Comparison of natural humic substances and synthetic EDTA and NTA as washing agents of a heavy metal polluted soil.

Ethylenediaminetetraacetic acid (EDTA), nitrilotriacetic
acid (NTA), and other synthetic polycarboxylic acids have
been shown to possess substantial capacity as washing agents
of heavy metal–polluted soils, but they are environmentally
problematic. Th erefore, a sample of natural soluble humic
substances (HS) was tested as a possible substitute. Th e
effi ciency of HS to extract cadmium (Cd), copper (Cu), and
lead (Pb) from a strongly polluted calcareous urban soil was
compared with that of EDTA and NTA. Th e infl uence of