TWENTY-THIRD ANNUAL EASTERN FISH HEALTH WORKSHOP JOHN CARVER INN, PLYMOUTH, MA 30 MARCH - 2 APRIL, 1998 Evaluation Of Different Serum-Free Broth Media For Growth Of Renibacterium salmoninarum. Clifford E. Starliper1, William B. Schill1, and Jay Mathias2 1U.S. Geological Survey, Biological Resources Division, Leetown Science Center, National Fish Health Research Lab, Kearneysville, WV 25430; 2The Conservation Fund, Freshwater Institute, Shepherdstown, WV 25443. Growth of Renibacterium salmoninarum was evaluated in various serum free media, and compared to the serum containing KDM2+M. Fourteen different media were prepared in each trial and included 12 that were pairwise comparisons of 6 formulations prepared with and without supplementation with 1% v/v R. salmoninarum MCO4M filtered metabolite. Fifty mL cultures were shaken (at 100 rpm)in 250 mL flasks at 15 C and medium performance was evaluated by enumeration of viable cells on days 10, 20, and 30 post inoculation. Three trials were done using starting cell concentrations of 1.13 X 106 cfu/mL per flask (trial 1), 1.23 X 105 cfu/mL (trial 2) and 2.68 X 104 cfu/mL (trial 3). In trials 2 and 3, the pH was estimated using test papers at the same times as cell counts were done. The day that the mean cell yield for each medium was highest (peak day) increased as inoculum cell concentration was decreased. Eleven of 14 media in trial 1 had a mean peak day on day 10; 9 of the 14 peaked on day 10 in trial 2; and only 2 of 14 in trial 3. For most media, a simple pH determination could be used as a means to check that growth has occurred, particularly useful if charcoal was added directly to media and visual inspection could not be done to detect growth. In general, all media performed well and the choice of which to employ might depend on considerations such as ease of preparation and presence of certain ingredients that might affect subsequent assays.   Return to 23rd Annual Eastern Fish Health Workshop Return to Leetown Science Center Home Page