In the BIOSCHAMP project, IRNASA-CSIC has analysed the phospholipid fatty acid (PLFAs)* content for characterising microbial biomass and structure of biostimulants in peat-alternatives as casing in small-scale trials in connection and co-operation with other project partners: CTICH (project coordinator and Wageningen University.
What is the Phospholypid Fatty Acid (PLFA) profiles technique? Phospholipid fatty acid (PLFA) profiling is a technique for assessing soil or organic materials biotic diversity based on the variability of fatty acids present in cell membranes of different organisms, this allows for phenotypic fingerprinting of microbial communities and provides a snapshot of the microbial community structure and an estimate of microbial biomass (Frostegård et al., 1993).
Progress of the microbiota characterization
BIOSCHAMP has characterized at different sampling times along the mushroom cultivation cycle peat-free casing soils containing alternative materials, such as peat moss, grass fibres, green compost and spent casing (as a carrier of selected microbiota with biostimulant and biocontrol activity).
The total microbial biomass and relative abundance of microbial groups (microbial community structure) have been quantified to evaluate the presence and evolution of selected biostimulant strains. The concentrations of PLFAs of fungi and bacteria in seven alternative casings during the different Agaricus bisporus mushroom cropping stages determined this total microbial biomass and relative abundance of microbial groups.
Frostegård, A., Bååth, E., Tunlid, A., 1993. Shifts in the structure of soil microbial communities in limed forests as revealed by phospholipid fatty acid analysis. Soil Biol. Biochem. 25: 723-730.