Carbohydrate and Protein Catabolism
Jessica Ware
Lab MW 11AM
Procedure: * In this experiment carbohydrate catabolism was first tested under aerobic conditions. We began this by drawing three sections on the bottom of the petri plate, dividing it into three sections. Using a sterile loop, we streaked a single line of each culture Bacillus subtilis, Pseudomonal aeruginosa, and Escherichia coli, to each of the separate sections. The plate was incubated until the next lab period, where we then flooded the plate with Iodine and were able to observe and record starch Hydrolysis. (Table 1) * In order to test carbohydrate catabolism under anaerobic conditions we tested cultures of Pseudomonas aerugenosa, Escherichia coli, and Alcaligenes faecalis in tubes containing a glucose medium. After inoculating each tube with each of the bacteria 5mm of mineral oil was poured into one of the tubes containing bacteria to observe anaerobic respiration and while one remained without mineral oil. (Table 2) * We then observed protein catabolism in Entrobacter aerogenes and Proteus vulgaris. We inoculated tubes with each bacteria, one containing a nutrient gelatin and one a urea agar medium and incubated the tubes, at room temperature and observed the growth and the color to determine whether hydrolysis took place. (Table 3) * To observe protein catabolism we also inoculated one tube with Enterobacter aerogenes and the another Proteus vulgaris, allowed them to incubate and observed the growth and color changes after adding phenylalanine deaminase. (Table 4.)
Results:
Table 1. Carbohydrate Catabolism
Starch Hydrolysis (Aerobic) Organism | Growth | Color after Iodine | Starch Hydrolysis | Bacillus subtilis | Yes | Clear | Yes (uses starch) | Pseudomonas aeruginosa | yes | brown | No | Escherichia coli | yes | brown | No |
Table 2. OF-Glucose (Anaerobic) Organism | Growth | Color | Fermenter (F), Oxidizer (O), Neither (-) |