DIN CEN ISO/TS 29843-1:2014-12

This part of ISO/TS 29843 defines an extended method for the extraction and determination of phospholipid fatty acids (PLFA) and phospholipid ether lipids (PLEL) from soils. ISO/TS 29843-2 describes a simple procedure for the extraction of PLFA from soils only. Phospholipids are essential components of membranes of all living cells, and their fatty acids (PLFA: phospholipid fatty acids) or ether-bound isoprenoid side chains (PLEL: phospholipid ether lipids) enable taxonomic differentiation within complex microbial communities. This approach is currently a common method in soil ecology and serves as a phenotypic and thus complementary instrument to genotypic (= molecular genetic) approaches for the determination of microbial diversity. There are different methods for determining fatty acids in soil. These methodologies represent different degrees of complexity and provide different degrees of resolution in the description of microbial communities in soil. The determination of the total contents of PLFA and PLEL provides a quantitative measure of the viable biomass of soil: microorganisms from all three areas of the biosphere (bacteria, fungi and archaebacteria). Viable microorganisms have an intact membrane containing phospholipids. Within minutes or hours after cell death, cellular enzymes lead to the hydrolysis and release of phosphate groups. In addition to taxonomic descriptions, the PLFA method allows the determination of physiological changes within microorganism communities. The committee responsible for this document is NA 119-01-02-04 UA "Biologische Verfahren" ("Biological Processes") at DIN.