Bacterial and protistan communities of the lettuce rhizosphere upon protist inoculation

We studied the impact of individual inoculation of six well-characterized protists on lettuce growth, with Cercomonas sp. S24D2 emerging as the strain with the largest impact on plant growth. In a second step, we created a three-protist species mixture inoculant by adding two protist species (Acanthamoeba sp. C13D2 and a heterolobosean isolate S18D10), based on differences in their feeding patterns.We then inoculated Cercomonas sp. either individually or in the protist mixture to lettuce plants one week before, simultaneously with or one week after seedling transfer.We monitored plant growth and nutrient content, as well as impacts on the resident soil and rhizosphere microbiome composition via 16S rRNA and 18S rRNA genes amplicon sequencing.