Question

1) Why was the Micrococcus at the bottom of the broth tube?

2) What growth pattern(s) would be most beneficial for survival if bacteria were growing in a pond for many years? Explain your answer.

Answer 1

1. Mcrococcus is a genus of bacteria belongs to micrococcaceae family. In these genus approx 13-18 species are identified.

Most commonly occuring species is Micrococcus luteus.

As researchers gave the idea that Micrococcus are aerobic bacteria.

Thioglycolate broth: it is a special broth medium used for the identification of aerobic and unaerobic bacteria. In this process, a broth medium is prepared and then sample of bacteria are allowed for growth. After a period of growth we observe the presence of bacteria in different locations of tube.

Few of the bacteria appear at the upper most region of the broth: These are aerobic bacteria requires more oxygen for their survival. in the absence of oxygen they are not able to grow.

Few of the bacteria appears at the bottom of the tube so we can say that these are anaerobic bacteria and they don't need oxygen for their survival. To avoid oxygen they move towards the bottom of the tube.

So, as I mentioned above most of the micrococcus bacteria are obligate aerobic bacteria. But few of them appears in the bottom of the thioglycolate broth tube which indicates that these are anaerobic bacteria.

2. The pond system have very low change in the nutrient components of that region. The growth pattern of bacteria is determined by the nutrients available for their consumption and growth. In the pond, bacteria grow normally and show normal growth curve but the duration of each phases may vary.

All the duration of growth stages are different depends upon the nutrient supplement available in pond.

Mostly in ponds, bacteria grow normally and have long exponential phase but after the period of time the nutrient availability will decreases which leads to a stable growth phase. In this phase bacteria not able to devide they just manage themself in low nutrient condition for survival. Then after 2 possibilities occurred: One in which they got nutrients they will start doubling again and another condition in which they didn't get sufficient nutrients they will die. But in some cases bacteria does not get that much affect of nutrient availability because they shows cannabalism process. So, when some of the bacterial cell die due to low nutrient availability, the rest of the bacteria eat them and Fullfill their nutrietion requirements.

So we can say that pond bacteria newer dies completely.