Biofilms, Volume 53 in the ongoing Methods in Microbiology series, highlights new advances in the field with this new volume presenting interesting chapters on a variety of timely topics, including Monospecies and polymicrobial biofilms in static and flow environment, Methods used to study biofilms, Spatial analysis of bacterial biofilms, Biofilm grown in bioreactors, Single-cell analysis of subpopulations within biofilms using microscopy, flow cytometry, and imaging flow cytometry, Microscopy analysis of biofilm-mineral interactions or mineral formation within biofilms, Bacterial biofilms as an essential component of rhizosphere plant-microbe interactions, Studying Gene Expression in Biofilms, and more.