Microbial Biofilms: Microbes in Social Mode

Abstract

Biofilm is a community of microorganisms embedded in extracellular polymeric substances. Organismsin their biofilm form get many advantages over their planktonic counterparts, making them prefer to existas biofilm. Biofilm formation involves adhesion of microbes on surfaces, followed by maturation stagewhich is controlled by quorum sensing (QS). Organisms present in biofilm can be 10-1000 times moreresistant to antimicrobials compared to their planktonic stage. This may be due to incomplete penetrationof antibiotics into the biofilm, slow growth rate of organisms in biofilm, or certain phenotypic changes.Biofilm forming ability of microorganisms has been a source of problems for human health, industry, andagriculture. Natural products including plant extracts, and quorum sensing inhibitors seem to be goodalternatives of conventional antibiotics against biofilms. Biofilm forming microbes can be exploited forbeneficial applications viz. waste water treatment, N2 fixation, oil degradation, and heavy metalsequestration. This review describes salient features of microbial biofilms, quorum sensing and drugresistancein biofilms, problems caused by biofilms, their potential applications, and methods availablefor their study.