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Biological systems are being developed all over EU countries to protect water-bodies from pesticide contamination at farm level. A laboratory experiment was carried out to test the efficiency of a mixture of compost and straw in bio-degrading different mixtures of fungicides usually applied in vineyards. At the same time the effects of fungicide applications on microbial community of biomixture were also evaluated. Results showed that the biomixture had a good capability of degrading pesticides. Indeed, at the end of the experiment (112 days), the concentration of most of the pesticides was close to complete degradation. Denaturing gradient gel electrophoresis (DGGE) analysis showed an evident modification of microbial diversity after the addition of fungicides. However, at the end of degradation process, no significant changes in the composition of microbial community were seen. In this specific substrate used in the biomixture, yeast flora and ascomycete filamentous fungi seemed to be involved in the degradation activity., (Copyright © 2011 Elsevier B.V. All rights reserved.)

The co-composting of olive mill wastewater with a variety of agricultural wastes was investigated. To reduce the toxicity of the phenolic fraction and to improve the degree of maturity of the compost, inoculation with the white-rot fungus Phanerochaete chrysosporium was carried out during the maturation phase. The results showed that agricultural wastes that contain high levels of lignin-related compounds, such as the residue from trimmings, improved the microbial activity and thus reduced the soluble phenols residue. The inoculation of P. chrysosporium during compost maturation reduced and modified the phenolic fraction, allowing a reduction in the time to reach compost maturity with the improvement in the germination index of 100% after 36 days in two of three trials performed.

Abstract: A laboratory procedure using a simple respirometric technique was evaluated to determine the microbial toxicity in soil of three toxicant compounds: two pesticides, chlorpyrifos and glyphosate; and diesel oil. The microbial toxicity was tested using the specific oxygen uptake rate (SOUR) method, evaluating the soil samples for both the reduction in maximum SOUR (SOURmax) and the cumulative oxygen demands after 20h (OD20). Consumption rate curves were produced for the lowest concentrations assessed: diesel (2460ppm), chlorpyrifos (62.5ppm), and glyphosate (250ppm) (limiting amounts considered as local soil contamination). In comparison with the control, these showed drastic reductions in SOURmax, demonstrating the high sensitivity of this SOUR method. The SOURmax provides a better indication of the microbial toxicity of these contaminants compared to the OD20 because of the different effects of these toxic compounds on microbial communities in the soil. Increasing concentrations of these toxic compounds resulted in different responses, evaluated as percentage inhibition by these different xenobiotic compounds. For these reasons, the microbial toxicity of xenobiotic compounds can be better recognized with SOURmax as compared to other respirometric methodologies. [ABSTRACT FROM AUTHOR]