Challenging the impact of consortium diversity on bioaugmentation efficiency and native bacterial community structure in a freshly PAH-contaminated soil

Abstract

Polycyclic aromatic hydrocarbons (PAHs) are priority pollutants. We studied the effect of 20 bioaugmentation with three allochthonous bacterial consortia with increasing diversity, SC AMBk, SC1 21 and SC4, in the structure and functionality of an acutely PAH-contaminated soil microbiome. The PAH 22 supplementation increased the resource availability and the inocula were able to: efficiently degrade 23 the PAHs supplemented after 15 days of incubation, become temporary established, and modify the 24 number of total interactions with soil residents. Sphingobium and Burkholderia, both member of 25 inoculants, were the major contributors to KO linked to degradation and to differentially abundant 26 genera in inoculated microcosms, indicating their competitiveness in the soil. Bioaugmentation 27 efficiency relayed on them, while further degradation, could be carried out by native microorganism. 28 This is the one of the first works which applied three inocula, designed from naturally occurring 29 bacteria and study their effect on the soil native community through the ANCOM-BC. We revealed that 30 when a resource that can be use by the inoculant is added to the soil, it is not necessary a high-diversity 31 inoculant to interact with native community and establish itself. This result has implications in the 32 design of microbiome engineering for bioremediation processes