David Jung Bacteria and Fungi

I have the nutrient broth/agar (NB). I had started to observe and take pictures of the agar on September 17. I exposed the agar to the light for around 30 minutes everyday and in room temperature. I have a collection of 15 images from the very beginning and noticed its small changes everyday. 

growth of bacteria and fungi

Result #1 Growth of a Single Colony

Area of Colonies in 15 days

Result #2 Total Number of Colonies

Growth of a Single Colony


My bacteria plate is the nutrient broth/agar (NB) and I observed and analyzed the data throughout the month. During the first three days there were no sign of any significant change and continued to repeat the process of exposing the petri dish to the air and taking a picture, however starting in the fourth day it showed signs of colonies brewing. They slowly grew little colonies until one significantly larger one appeared on day 4. I would believe that my bacteria had a logistic growth example because of the activity the nutrient broth/agar had made. After these activity had been shown 3 days later (Day 7) I noticed a drastic change in its colony and size. Day 5 I began to show colonies appearing instantaneously and the consecutive days showed even more promising colonies. Then 4 days later (Day 9) I noticed the bacteria was slowly decaying and withering. The bacteria was slowly dying with the loss of nutrients. The colonies shrunk with its size. The highest possible count for colonies were in Day 6 (7.549) and the lowest count was in Day 15 (1.135). 

What I've Learned

During this experiment I've learned how a nutrient broth/agar grows and its competition. The colonies compete for nutrients to grow however, the petri dish limits how much the carrying population can carry. This may be the reason why colonies need to compete.