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The effects of acetaldehyde, benzaldehyde, cinnamaldehyde, ethanol, benzyl alcohol, nerolidol, 2-nonanone, beta-ionone, and ethyl formate vapors on the growth of Rhizopus stolonifer, Penicillium digitatum, Colletotrichum musae, Erwinia carotovora, and Pseudomonas aeruginosa on agar medium were evaluated. The aldehydes were found to be the strongest growth inhibitors and the most lethal to the fungal spores and mycelia and bacterial cells. The average minimum inhibitory concentrations (MICs) of aldehydes that were germicidal to decay microorganisms were 0.28, 0.49, and 0.88 mmol per Petri dish, for cinnamaldehyde, benzaldehyde, and acetaldehyde, respectively. Ethanol also inhibited growth completely, but the MIC, which was 14.6 mmol per Petri dish, was significantly higher than those of the aldehydes. Ethanol can be considered germistatic because the alcohol does not inhibit germination of spores completely; it completely controlled only mycelial growth. The ketones tended to be effective only on P. digitatum and C. musae, whereas ethyl formate was not effective except on P. digitatum. The concentration of a volatile compound in the headspace of the Petri dish and its diffusion into the medium largely determined its efficacy against decay microorganisms.

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The effects of mycorrhizae on growth and uptake of N, P, Zn, and Pb by plants were investigated in a greenhouse trial using vetiver grass (Vetiveria zizanioides) as host. Inoculation of the host plants with arbuscular mycorrhizal fungi (AMF), Glomus mosseae and G. intraradices spores, significantly increased the growth and P uptake. Mycorrhizal colonization increased Pb and Zn uptake by plants under low soil metal concentrations (at 0 and 10 mg/kg of Pb or Zn), whereas under higher concentrations (at 100 and 1,000 mg/kg of Pb or Zn), it decreased Pb and Zn uptake. P concentration in soil was negatively correlated with mycorrhizal colonization as well as Zn or Pb concentrations. The results showed that inoculation of the host plants with AMF protects them from the potential toxicity caused by increased uptake of Pb and Zn, but the degree of protection varied according to the fungus and host plant combination. The potential of arbuscular mycorrhizae in phytoremediation of the Zn-or the Pb-contaminated soils is discussed in this article.