Exercise 21: Enumeration Count colonies (30-300 plates) and share data Lab 19 Goals and Objectives: Exercise 21: Enumeration Count colonies (30-300 plates) and share data (Sample data/explanations in supplemental packet pages 79-80) Exercise 57: Bacterial Counts on Foods Plate pre-made dilutions of foods Use pre-poured solid plates and spread with beads Each pair needs: 1:10 of each: meat, spinach, milk (no blending: done!) 1:1000 of each: meat, spinach, milk (no diluting: done!) 9 BHIA plates and 9 tubes of beads Exercise 59: The Membrane Filter Method Each pair use one clear environmental water sample Perform according to directions pg 397 except skip step 4, Filter 100ml of sample Each pair needs: Filter apparatus, Grid filter disc, Absorbent pad, Petri dish, Endo MF broth

0.4 0.3 0.2 0.1 CFU/ml 2.55 X 105 3.4 X 106 y = mx+b Once you can assign real CFU/ml numbers to the OD readings, you have a standard curve and the equation of the line can be used to determine the CFU/ml concentration in a sample from the OD reading

Fig 57.1 Dilutions already made, you just plate

From Introduction to Exercise 58 Coliform: gram-negative, facultative, non-endospore forming rods that ferment lactose to produce acid and gas e.g. Intestinal Bacteria: Escherichia & Enterobacter Used as indicators for Vibrio cholerae: cholera Salmonella typhi: typhoid fever Shigella dysenteriae: bacillary dysentery

Fig 59.1

Exercise 21: Enumeration Count colonies (30-300 plates) and share data Lab 19 Goals and Objectives: Exercise 21: Enumeration Count colonies (30-300 plates) and share data (Sample data/explanations in supplemental packet pages 79-80) Exercise 57: Bacterial Counts on Foods Plate pre-made dilutions of foods Use pre-poured solid plates and spread with beads Each pair needs: 1:10 of each: meat, spinach, milk (no blending: done!) 1:1000 of each: meat, spinach, milk (no diluting: done!) 9 BHIA plates and 9 tubes of beads Exercise 59: The Membrane Filter Method Each pair use one clear environmental water sample Perform according to directions pg 397 except skip step 4, Filter 100ml of sample Each pair needs: Filter apparatus, Grid filter disc, Absorbent pad, Petri dish, Endo MF broth