Metagenomic approach for the analysis of nematode diversity in soils with different health status

Nematodes are widely recognised as bioindicators of the soil environment health. Analysis of soil nematode community is increasingly used to calculate various ecological indices related to enrichment and trophic status of nematofauna. The soil nematode community from three selected relatively undisturbed and disturbed sites in the Apulia region (Italy) was comparatively studied through both morpho-taxonomic and molecular analysis. Nematodes for both analyses were extracted from 100 g sub-samples from composite soil samples collected at each site. Nematodes were fixed in a 2.5% formaldehyde solution and then identified at family and genus level under an optical microscope. The maturity and trophic diversity indices were determined. For the molecular study, total DNA was extracted from the nematode community of each soil subsample and PCR amplification was performed by using the small subunit (18S) rDNA, as diagnostic marker, for nematode species discrimination. The 300 sequences available at this moment are still under characterisation. Sequencing of further 18S amplicons is also in progress.