Concentrating microorganisms in water samples by super-absorbent polymer beads

Abstract

Detection and quantification of pathogens in water is crit. for the protection of human health and for drinking water safety and security. When the pathogen concns. are low, large sample vols. (several liters) are needed to achieve reliable quant. results. However, most microbial identification methods utilize relatively small sample vols. As a consequence, a concn. step is often required in order to detect pathogens in natural waters. Herein, we introduce a novel water sample concn. method based on superabsorbent polymer (SAP) beads. When SAP beads swell with water, small mols. can be sorbed within the polymer beads, but large particles are excluded and, thus, concd. in the residual non-sorbed water. To illustrate this approach, millimeter-sized poly(acrylamide-co-itaconic acid) (P(AM-co-IA)) beads are synthesized and successfully applied to conc. water samples contg. two model microorganisms: Escherichia coli (E. coli) and bacteriophage MS2. This new water sample concn. procedure is very fast, effective, scalable, and low-cost with no need for complex instrumentation.