Biological responses to P‐limitation in indigenous bacteria isolated from drinking water

Abstract

AbstractBiofilm formation in direct biofiltration causes operational issues such as accelerated head loss accumulation rate resulting in short filter runtime. Applying coagulant in low P level source water may impose bacteria to the P‐limited condition. It is hypothesized that the nutrient limitation, specifically P, as an essential macronutrient for bacteria causes stress and triggers excess extracellular polymeric substances (EPS). Two of the most biofilm‐producing bacteria were isolated from a full‐scale biofilter, provided the opportunity to study the indigenous biofilter bacteria. The isolated bacteria were identified using full‐length 16S rRNA and characterized. The biological behavior of the species was studied under different P‐limited conditions in a nutrient‐limited medium simulating freshwater nutrient availability. Carbohydrate and Protein‐EPS were increased when decreasing the available P in the medium, suggesting that lack of P can trigger higher EPS.Article Impact StatementThis study demonstrated that the lower P levels are directly related to excessive extracellular polymeric substances production and consequently the biofilter performance.