Distinguish between fermentation tests and respiration tests in terms of what ea
ID: 162097 • Letter: D
Question
Distinguish between fermentation tests and respiration tests in terms of what each category of test tells you about the microbes you are studying. Sketch a labeled, colored flow diagram for the nitrate test procedure, including results at each step and how to interpret the results. In a situation similar to the practicum, what would you look for to state that a particular positive for mannose fermentation? Describe in detail. In a situation similar to the practicum, what would you look for to state that a particular microbe is both oxidative and fermentative? Describe in detail.Explanation / Answer
Answer:
The respiration tests on microbes are going to summarize about the nature of microbes i.e. microbial species is going to use "either oxygen" or not for their respiration to generate energy finally it is possible to depict whether the microbe is "aerobic" or anaerobic
The fermentation tests are going to illustrate that organism are going to ferment which type of components for their metabolism either n the presence of oxygen or anoxic environment to generate energy
Mechanism
Gas production is characteristic feature with turning of red color to yellow color by oxidative fermentation of "carbohydrate containing phenol red medium" normally with bacteria. This is indicative of positive result due to presence of carbohydrates in the medium. If there is no "fermentation occurred in the medium with no gas production" even in the presence of carbohydrates in the phenol red medium in after 18 - 24 hours of incubation" is the indicative of that particular microbe is "non-fermenter" of carbohydrates. Therefore, color change & gas production (CO2) is the indicative of positive results & absence of these features in the presence of carbohydrates in the medium is the feature can you look at (within the phenol red broth tube) to ensure that this is not a false - negative result
Oxidative fermentation (OF):
In the given sample, bacteria fermented the carbohydrate (glucose, sucrose) aerobically and the result is the indicative of acid production in the open culture Durham tube (aerobic respiration occurred) and oil covered culture tube (anaerobic respiration occurred). The resultant acid produced converts, bromthymol blue PH indicator colour from green to yellow. We can assess the PH of the fermented product based on its acidic nature. We cannot determine the amount of acid produced here and we cannot predict the gas (in the form of bubbles) liberated upon OF which is significant to identify a particular unknown bacteria inside the medium. The turbidity inside the yellow broth represents bacterial motility.