231L AA1 Dilution Assignment (1)

Assessment Activity 1: Dilution Assignment Micro231L Fall 2023 10. You are testing two different types of media (Medium A & Medium B) that contain different types of nutrients. Your goal is to see which media will provide optimal growth for microbes found in prairie soil. You perform a viable plate count before and after incubation in the two different types of media to compare viable cells before and after incubation. The results are given in Table 1. Table 1: The growth of the viable microbial population from prairie incubated in two different media Medium A Medium B Plate Dilution Time 0 hour (CFU) Time 12 hour (CFU) Time 0 hour (CFU) Time 12 hour (CFU) 10 -1 TNTC TNTC TNTC TNTC 10 -2 322 TNTC 667 2221 10 -3 41 TNTC 80 623 10 -4 8 1154 6 48 10 -5 0 188 0 8 10 -6 0 20 0 0 10 -7 0 5 0 0 a) What is the original concentration (CFU/g) of viable cells found in the prairie soil at time 0 before incubated in medium A? b) What is the original concentration (CFU/g) of viable cells found in the prairie soil at time 12 before incubated in medium A? c) What is the original concentration (CFU/g) of viable cells found in the prairie soil at time 0 before incubated in medium B? d) What is the original concentration (CFU/g) of viable cells found in the prairie soil at time 12 before incubated in medium B? e) Based on the results, which medium promotes optimal growth for the prairie soil microbes?