Multispecies biofilm cities and the importance of the order of colonization

Biofilms are sessile communities of cells embedded in the extracellular matrix of polysaccharides formed to protect themselves from adverse conditions and are attached to the biotic/abiotic surfaces. In the natural environment, the probability of bacteria existing in multispecies is higher than the bacteria existing in isolation. The first step to a stable multispecies biofilm formation is the attachment and colonization of the surface by one or more bacteria. This review aimed to understand the impact of sequential attachment in overall multispecies biofilm formation, its role in defining biofilm properties, and the possible challenges it could present during the removal and disinfection process. In several cases, the highest biofilm former attached to the surface first resulting in a stronger biofilm which explains the enhanced resistance to removal in multispecies biofilm. Following the formation of a stable biofilm, environmental variables (e.g. temperature, surface, nutrient availability), and metabolic exchange between the bacteria drive the properties of biofilm, finally resulting in sequential detachment, driven by the predominant bacteria. These insights are vital in understanding biofilm formation and spatial layering of pathogenic bacteria for efficient biocontrol and removal.