Enumeration and Identification of Enteric and Pseudomonad Proteobacteria from Agriculture-Impacted Rivers and an Exploration of Fecal Viruses and Protozoa
In this exercise, students analyze water samples from two local rivers, emphasizing MacConkey-selected gram-negative proteobacteria. They use lactose and oxidase testing to sort observed colonies into Enterics (both lactose positive and lactose negative) and Pseudomonads. While Enterics are typically associated with transient fecal contamination, Pseudomonads represent natural soil and water dwellers that play important roles in decomposition and bioremediation. Each student subcultures and identifies river-derived and provided enteric controls using a standard array of biochemical tests. Each student also analyzes waterborne and fecal-associated protozoa and viruses, using provided slides and online Centers for Disease Control and Prevention resources.