Phospholipid fatty acids
- PLFA
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Phospholipid fatty acids, abbreviated as PLFAs
- Protocol for the quantification of PLFAs
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Extraction of total lipids
5 g soil (powderization, if required)
↓ + 21:0 (internal standard material, I.S.) in benzene solution
↓ + 10 ml methanol
↓ + 5 ml chloroform
↓ + 4 ml water or buffer solution (citric acid or phosphoric acid)
∇ vortex (5 min)
∇ leave at rest (5 min)
↓ + 5 ml chloroform
∇ vortex (1 min)
↓ + 5 ml water or buffer solution (1:1:0.9)
∇ vortex
∇ 3000 rpm for 5 min.In the test tube H2O/Methanol fraction Chloroform fraction ← recover lipid by a Pasteur pipette Debris (soil/litter) ↓ + 5 ml chloroform
∇ vortex
∇ ← recover chloroform fraction
↓ put the fractions together
total lipidSeparation of PLFAs from total lipids
chloroform fraction (= total lipid)
silicic acid chromatography
↓methanolysis + 2nd I.S.
↓GC
total fatty acid/g soilIdentification and quantification of PFLAs
If molecular species can not be identified, the species is determined by a gas chromatograph mass spectrometer (so-called GC mass)
- PLFAs for estimating litter decomposition
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Table 2 PLFAs used as biomarkers for microbial groups
Group PLFA group Marker PLFAs (*) Bacteria multiple group sum of the all of bacteria Gram-positive bacteria Branched PLFAs i14:0, a14:0, i15:0, a15:0, i16:0, i17:0, a17:0 Gram-negative bacteria Cyclopropyl and mono PLFAs cy17:0, cy19:0
Hydroxy (2OH-14:0, 3OH-14:0, 2OH-16:0)Actinomycetes 10Me-PLFAs 10Me16:0, 10Me18:0 AMF 16:1ω5c Fungi Polyunsaturated PLFAs 18:2ω6 Protozoan Polyunsaturated PLFAs 20:2ω6, 20:4ω6 Micro-eukaryotes Polyunsaturated PLFAs 18:3, 20:4 *: Bossio & Scow (1998), Frostegard et al. (1993), Waldrop et al. (2000)
- References
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- phosphate
- protocol
- soil
- Bossio DA, Scow KM. 1998. Impacts of carbon and flooding on soil microbial communities: phospholipid fatty acid profiles and substrate utilization pattern. Microbial Ecology 35: 265-278
- Frostegard A, Tunlid A, Baath E. 1993. Phospholipid fatty acid composition, biomass, and activity of microbial communities from two soil types experimentally exposed to different heavy metals. Applied Environmental Microbiology 59: 3605-3617
- Moore-Kucera J, Dick RP. 2008. PLFA profiling of microbial community structure and seasonal shifts in soils of a Douglas-fir chronosequence. Microbial Ecology 55: 500-511
- Waldrop MP, Balser TC, Firestone MK. 2000. Linking microbial community composition to function in a tropical soil. Soil Biology & Biochemistry 32: 1837-1846
- Wilkinson SC, Anderson JM, Scardelis SP, Tisiafoulie M, Taylor A, Wolters V. 2002. PLFA profiles of micorbial communities in decomposing conifer litters subject to moisture stress. Soil Biology & Biochemistry 34: 189-200