Importance of substrate availability and clay content on soil microbial EPS production

Soil health and functioning are linked to the stability of soil structure, which is in turn key to organic matter stabilisation. This study aims to evaluate the influences on macroaggregate formation and stability viz. decomposability of OM, soil texture and the microbial community and their capacity to produce extracellular polymeric substances (EPS). We investigated the effects of substrate availability and clay content on microbial production of EPS and concomitant development of stable soil aggregates. Soils were incubated with different amounts of montmorillonite (+0%, +10%) both with and without two substrates of contrasting bioavailability (starch and cellulose). Microbial communities were analysed by sequencing of 16S rRNA gene amplicons in soils after 20 days of incubation.