Fermentation is a chemical metabolic process that is used to produce multiple types of food products and beverages. Alcoholic beverages, yogurt, cheese, chocolate, and several other food products go through stages of lacto-fermentation to achieve the pleasant taste many people enjoy. Through this process one of the primary bacteria produced is Lactobacillus. For this experiment, we used freshly shredded white cabbage and a salt solution to make our sauerkraut. Without oxygen present in the container, Lactobacillus, Leuconostoc, and Pediococcus began to convert carbohydrates into lactic acid. Throughout this experiment, we monitored the pH, CFU count, …show more content…
We added our cabbage to a brine solution of 3% NaCl and then compressed the cabbage and let a watch glasses rest on top of the compressed cabbage to keep it submerged beneath the brine. The last and most crucial step performed was the removal of oxygen from a gas chamber attached to the container. On the same day, we performed a 1:10 serial dilution to get a plate count of the growing microorganisms. We used a p1000 pipet to collect 3 mL of our brine solution to use as our source for the dilutions. We then used the p1000 pipet again to pipet 900 ul of 0.1% peptone into five epitubes. The peptone would serve as a nutrient solution to aid in the growth of bacteria. After completing the 1:10 serial dilutions in the five epitubes, we plated out 100 uL out onto the nutrient agar and MacConkey agar. We plated out 10^-4 on the nutrient agar and 10^-5 on the MacConkey agar. We used a MacConkey ager because it only allows the growth of gram-negative bacteria, so it was meant to identify any grow of gram-negative colonies. This initial plating of