Pieter van Dillewijn is a Staff Scientist of the Spanish National Research Council (CSIC) and, over the last 25 years, he has been investigating the microbial biodiversity of soils to understand how microorganisms adapt to plants, environmental conditions, or pollution. These studies include the biodegradation of aromatic contaminants at laboratory and field scales by using bioaugmentation with bacterial strains to eliminate trinitrotoluene (TNT) from contaminated soils or ibuprofen from contaminated water. Currently, he is involved in projects dealing with the bioremediation of polyaromatic hydrocarbons (PAHs) and with plant–microbe interactions.