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(22-27) Effects of potentially pollutant agents on fatty acid methyl esters profiles in agricultural soils. Puglisi, Edoardo*,1, Nicelli, Marco1, Capri, Ettore1, Trevisan, Marco1, Del Re, Attilio1, 1 Istituto di Chimica Agraria ed Ambientale, Università Cattolica del Sacro Cuore, Via Emilia Parmense 84, Piacenza, Italy ABSTRACT- The study of the effects upon the soil organisms of different potential pollutant agents is important to obtain biological indexes of soil quality in support of the chemical and physical ones which already exist. The soil composition in fatty acid methyl esters (FAMEs) is directly correlated with its content in micro-organisms and so can be used as a good 'fingerprinting' of soil microbial community structure. The FAME profiles of three soils respectively treated with sewage sludge, irrigated by saline waters and contaminated by industrial wastes were analysed and each one was compared to an adjacent control soil to find if changes in their biomass composition occurred. Five samples from each soil were taken during summer at 20 cms depth and their FAME composition was quantified using the Zelles extraction method (Zelles et al., 1992). Nineteen FAMEs, including several saturated, unsaturated and cyclopropane's ones were quantified and subjected to a multivariate discriminant analysis (Proc. Candisc; SAS, 1989). The discriminant functions associated with the first three eigenvalue accounted for a total explained variance of 91,18% and produced a good separation between the soils. Only two soils, the one treated with sewage sludge and the control for the saline irrigation treatment, accordingly to the first two eigenvectors could not be separated. Correlation of individual FAME with the first and second discriminant functions showed how the first function was highly positively correlated with C22:0, C17:0 and C18:1 (trans 9), the second with C14:0, C16:0 and cyC19:0. Key words: FAME, Discriminant analysis, Soil quality |
