Bonus: A bioengineer is running fermentation experiments to produce a new biofue
ID: 87964 • Letter: B
Question
Bonus: A bioengineer is running fermentation experiments to produce a new biofuel. The biofuel is produced as a byproduct of normal metabolism of lactose by a newly identified fecal coliform bacterial species. Currently the yield of biofuel is half the expected amount. The engineer suspects that there may be another bacterial species contaminating the recent fermentation. Use the information below to answer the following: Design an experiment using only what we have learned in class to determine A) If there is another bacterial species contaminating the fermentation and B) how to determine if the contaminating bacterium is affecting the biofuel yield.Explanation / Answer
The bacteria showing green metallic sheen on an eosin methylene blue plate is an E.coli, giving green colonies. The bacteria does not seem to show any contamination in the first day of incubation. To determine if the fermentation is interfered with another bacteria, we need to perform an MPN test, the most probable number test that would identify between fecal coliforms.
Since the bacteria after a week , contaminating the source is giving a colourless colony, I.e. Beta colony, it would mean that the bacteria is non lactose fermenting but Gram negative, as EMB is selective from Gram negative bacteria.
It can be tested by isolating the bacteria and then growing it on a separate plate and carrying out its morphological identity tests.
---> to determine if the contaminating bacteria is lowering the biofuel yield, we need to isolate a pure strain of the bacteria used in fermentation and then check its growth and subsequently the biofuel yield.