Question

5. You received a water from a local lake to determine the bacterial cells count, you did the count using both direct microscopic count and the plate count methods. Which methods would likely give a higher bacterial count? And Why? --- 6- Fermentation end products help in identification of bacteria. If you agree with the above statement, give a short explanation of why you agree and include an example. If you do not agree give a short explanation why you disagree? --- 7- Place an X under the pathway the following types of organism can utilize to obtain energy:- Glycolysis fermentation Krebs's cycle ETC Obligate aerobic Obligate anaerobic Go to the Next page:-

Answer 1

5. Plate count method

The individual cell count averaged 4.5 times greater than the plain agar plate count but where lactose was added this difference was reduced to 3 times. There was likewise a reduction in the variability as well as a noticeable increase in the correlation. Undoubtedly the addition of lactose to the medium would materially increase the accuracy of the plating method.

Although the microscopic group count was more variable than either the count of individual cells by the microscopic method or the agar plate count, yet the probable error of the coefficients of variability showed little or no significant difference.

6.YES, Fermentation products can give identification of bacteria.

For example, enteric bacteria are known for their ability to perform mixed acid fermentation, reducing the pH, which can be detected using a pH indicator

7.

Obligate Obligate X Glycodiysis X X fermentation Kolbe FTC ..... X. X. . ..... anaerobie