Extracellular polymeric substances from soil-grown bacteria delay evaporative drying

When soils dry, water flow and nutrient diffusion cease as the hydraulic microenvironments vital for soil life become fragmented. To delay drying locally related adverse effects, bacteria plants modify their surroundings by releasing extracellular polymeric substances (EPS). As a result, physical properties of hotspots like biological crusts or rhizosphere differ from those surrounding bulk soil. Specifically, presence EPS delays evaporative drying. Despite evidence reduced evaporation EPS-amended soils, mechanisms controlling content dynamics remain elusive. Thus, our study aimed to elucidate potential local environment when exposed oscillations in induced We incubated sand microcosms with two contrasting strains Bacillus subtilis one week cabinet. At end incubation period, loss was quantified spatially resolved using time-series neutron radiography. Strain NCIB 3610, complex biofilm producer steadily modified during period resulting substantial due decoupling front surface. Evaporation remained largely unaltered inoculated domesticated strain 168 trp+ compared control treatment. The mechanism 3610 verified estimates diffusive fluxes position plane microcosm. Additionally, role confirmed an experiment xanthan analogue.