New quality of assessment of microbial diversity in arable soils using molecular and biochemical methods

摘要

AbstractNew molecular and biomarker approaches allow now a better understanding of the microbial diversity in soils. Examples are presented to demonstrate the new performance of these approaches and the quality of results. Investigations of the diversity of a bacterial indicator genus as well as studies of the whole microbial community structure are presented. Genotypes ofOchrobactrumwere isolated by immunotrapping and characterized by PCR — fingerprinting. On a fallow land no significant changes in the intragenus diversity of this indicator bacterium was observed over a period of one year. In contrast, crop rotation was accompanied by a shift in the dominant genotypes ofOchrobactrum, while the genetic potential was not affected.Phospholipid fatty acid (PLFA)‐pattern revealed significant shifts in the structure of the whole microbial community in a soil of a hop plantation as compared to a similar soil with crop rotation. The quantity of anaerobic bacteria, represented by the non‐ester linked fatty acids were lower in soil samples derived from crop rotation as compared to a former hop plantation soil, which was contaminated with copper. In contrast, the ester linked fatty acids which are present in a wide range of Gram‐negative and Gram‐positive bacteria, exhibited a reverse relation. Soil samples of the hop plantation contained low amounts of saturated ester linked fatty acids branching on the 10thC atom. This indicates that actinomycetes are present in relative small proportions in the hop planta