Effects of short-time drying on biofilm-associated bacteria

Abstract

Microorganisms tend to form biofilms consisting of cells embedded in a highly hydrated extracellular polymeric matrix. The biofilm protects its inhabitants from antimicrobial agents, pH alterations, and confers protection against drying. It is known that biofilm-associated bacteria can survive for a while in the absence of water. When rehydrated, metabolic processes are quickly restored and microorganisms resume life. The aim of this study is to evaluate the survival of heterotrophic bacteria, sulphate-reducing bacteria and amoeba against short-time drying. Biofilms were allowed to grow for 30 and 60 days on stainless steel (316, 2B) coupons in annular biofllm reactor, which was fed with drinking water network under constant, non-turbulent shear stress and temperature. The results presented in this study indicate a role for biofilm layer in protecting biofilm-associated microorganisms from drying. The current study has provided that short-time (24 h) absence of water could not affect biofilm-associated heterotrophic microorganisms significantly, in terms of cell viability.