Determination of traces of iron in indium phosphide by electrothermal atomic absorption spectrometry combined with solvent extraction.

An electrothermal atomic absorption (ETAAS) method for the determination of traces of iron (0.1-1.0 microgram g-1) in Fe-doped indium phosphide (InP) has been developed.

Adhesion to hyphal matrix and antifungal activity of Pseudomonas strains isolated from Tuber borchii ascocarps.

Pseudomonas spp. isolates from Tuber borchii ascocarps, known to be able to produce phytoregulatory and biocontrol substances in pure culture, were used to perform studies on their possible physiological role in nature. Antimycotic activity was confirmed against fungal contaminants isolated from the ascocarps, suggesting that populations associated with Tuber borchii fruit bodies may play a role in the maintenance of ascocarp health.

Effects of the antimycotic molecule Iturin A2, secreted by Bacillus subtilis strain M51, on arbuscular mycorrhizal fungi.

A new system, devised for the study of early stages of arbuscular mycorrhizal infection, was used to test the effect of the biological control agent Iturin A2, secreted by the strain M51 of Bacillus subtilis, on the development of arbuscular mycorrhizal fungi. The saprophytic growth of the fungus Glomus mosseae was inhibited by Iturin A2 concentrations higher than 100 micrograms/g of sand; whereas, in the presence of the tomato host plant, both, pre-infection events and intraradical growth were not negatively influenced by the antifungal compound; furthermore, the development of arbuscular mycorrhizal symbiosis was not impeded by the biocontrol agent in field conditions, while Fusarium oxysporum f. sp.