Biofilms are group or micro-organisms in which microbes produced an extracellular polymeric substances (EPS) such as proteins (<1-2%) including enzymes), DNA (<1%), polysaccharides (1-2%) and RNA (<1%), and in addition to these components, water (up to 97%) is the major part of biofilm which is responsible for the flow of nutrients inside biofilm matrix. The architecture of biofilm consists of two main components i.e. water channel for nutrients transport and a region of densely packed cells having no prominent pores in it. The microbial cells with in biofilms are arranged in way with significant different physiology and physical properties. Bacterial biofilms are normally beyond the access of antibiotics and human immune system.
Microorganisms that produce biofilm have enhanced potential to bear and neutralize antimicrobial agents and result in prolonged treatment. Biofilm forming bacteria switch on some genes that activate the expression of stress genes which in turn switch to resistant phenotypes due certain changes e.g. cell density, nutritional or temperature, cell density, pH and osmolarity. When the biofilm water channels are compared with system of circulations showed that biofilms are considered primitive multi-cellular organisms. Various components of biofilms are shown in Table1 signify the biofilm integrity and making it resistant against various environmental factors.