Effect of Ammonium Ion Concentrations on ​Tetrahymenathermophila​ Growth

  • Justin Kim
  • Fareez Sanif
  • Yury Onikashvili


Following action against an ammonia spill into a tributary of the Fraser River by CIMCO Refrigeration and the University of British Columbia, this study looks to characterize the effect of varying ammonium ion concentrations on the growth rate of the protist, Tetrahymena thermophila. T. thermophila populations were placed in 4 cell cultures of differing ammonium ion concentrations (0, 5, 50, and 500 mg/L) and allowed to incubate for 24 hours at 35oC, respectively. These treatments were fixed and the cells were counted at intervals of 0, 2, 4, 6, 8 and 24 hours, in order to determine their growth rate. Kruskal-Wallis rank sum test showed that ammonium ions do not impact T. thermophila growth rate (p = 0.07487), with post-hoc tests all showing a p-value > 0.05. Our results were inconclusive on whether the growth rate of T. thermophila is directly impacted by differing ammonium ion concentrations, thus more research must be done in order to come to a definite conclusion.