Methodical progress of microbial biomass determination with classical fumigation-extraction method - further possible improvement in soil microbial ecotoxicology
| Authors | |
|---|---|
| Year of publication | 2000 |
| Type | Article in Proceedings |
| Conference | Symposium Program of Prague 2000: Fifth International Symposium and Exhibition on Environmental Contamination in Central and Eastern Europe; 12-14 September 2000, Prague, Czech Republic |
| MU Faculty or unit | |
| Citation | |
| Field | Ecology |
| Description | Fumigation-extraction method (FEM) is one of the main methodical implements of current soil microbiology. FEM serves to quantify microbial biomass as carbon immobilized in microorganisms - Cbio. Principle of the method is dispatching of soil microorganism cells with fumigant (redestilled chloroform). Biomass is obtained from 0.5M K2SO4 extractable carbon difference from fumigated and non-fumigated samples. Study was focused on biochemical specification of soil organic matter extracted 0.5M K2SO4 before and after fumigation. Colorimetric analytical methods were found to be the most suitable alternative for this purpose. The organic C (Cox), phenol-, anthrone- and orcinol-reactive organic compounds (PRC, ARC and ORC), ninhydrin-reactive nitrogen (NRN), Folin-Ciocalteu's reagent-reactive compounds (FRC) and diphenylamine-reactive compounds (DRC) were evaluated using extracts from 48 different soils. All of the used methods were quick, simple and cheap. Parameters obtained from such measurements for fumigated and non-fumigated extracts were found to be good approach for FE method validation. Index expressions of measured parameters were found as the most suitable for evaluation and investigation of relationships between microbial biomass and soil organic matter. Indices were found to be sensitive indicators for soil matter composition and microbial biomass mineralization activity changes. Furthermore, indices discriminated measured soils more sensitively than Cbio measures only. The possibility of characterizing soil organic matter and microbial biomass by adopting suitable colorimetric methods is another advantage of fumigation-extraction method and could show a possible course of improvement in soil microbial ecotoxicology. |
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