Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

Microorganisms can be grown in batch culture or chemoStats for the industrial pr

ID: 209031 • Letter: M

Question

Microorganisms can be grown in batch culture or chemoStats for the industrial production of metabolites or foods (such as ethanol, glutamic acid, or v ine). Both methods have advantages and disadvantages. Briefly compare and contrast these two neral methods. 1. This gel shows the results of several PCR reactions. In each of these reactions, the PCR is used to target particular genes. The samples represent total environmental DNA from river sediment. Two different genes that are involved in the nitrogen cycle were targeted, nosZ and nrfA. The outcome of these PCRs is obviously quite different. Speculate aboyt why these differences exist. Remember, your primers are supposed to target one type of gene. What would you do to improve some of these PCR reactions? Your answer does not require specific information about these genes -Iam not asking you to do research on these genes. The issue is the PCR reactions themselves. (Lane 1, ladder; lanes 2-7, nosZ gene; lanes 8-12 nrfA gene) 2.

Explanation / Answer

Answer:

1. Batch culture: Advantages- less risk of infection, complete substrate conversion possible, different reactions possible. Disadvantages- skill labor required, a lot of idle time, safety problems may arise

Chemostats: efficient, appealing automation, low labor cost. Disadvantages- failure in months of continuous culture, and inflexible.

In batch culture there is always a new environment and substrate utilization terminate whereas, in chemostats, cells can remain in chemostats as long as we want.

2. Methods to improve PCR reactions:

Increase the annealing time as well as extension time. Annealing temperature has to be 5 degrees lower than melting temperature.

Addition to 5% DMSO to decrease the non-specific banding and increase the band intactness.

Improvement in the working stocks of the primer.