Environmental microbial biofilms

In natural settings, microbes live mainly in interactive communities known as biofilms and aggregates. These microbial communities are associated with a copious amount of extracellular polymeric substances matrix and behave differently from their planktonic counterparts. Biofilms are a serious concern in the medical field because they tend to grow on tissues and implants and exhibit higher tolerance to antimicrobials. In industrial settings, biofilms profoundly affect material deterioration, heat transfer efficiency, maritime activities, aquaculture equipment, and sensors. Microbial biofilms also have beneficial roles in the environment in many ways, including primary productivity in aquatic environments, biogeochemical cycling of elements, natural attenuation of pollutants, water treatment, bioremediation, and wastewater treatment. Microbes inhabiting biofilms or aggregates/granules confer higher tolerance to harsh environmental conditions and toxic pollutants and thus are suitable for effective water and wastewater treatment. Microbial biofilms or aggregates have been successfully employed in engineered settings, including in the activated sludge process and in upflow anaerobic sludge blanket reactors, moving bed biofilm reactors, aerobic granular sludge reactors, and bioelectrochemical systems for wastewater treatment and resource recovery. In this chapter, several aspects of environmental biofilms, such as their formation, life cycle, and related attributes, their distribution in different settings and their impacts and their biotechnological applications for sustainable development are covered in detail.