TABLE 1 Summary of controlled fermentations 10 xylose Furfur

TABLE 1 Summary of controlled fermentations (10% xylose) Furfural-dependent slow growth Au (h 1) Strain Furfural concn (mM) E. coli W 0.23 0.01 E coli W 0.18 0.01 coli W 10 0.06 0.02 0.0 coli W 10 with Plasmid A Which of the following statement is true according to the data in Table 1? (A) 10 mM Furfural completely stops E. coli W to grow. (B) The plasmid A helps E. coli W to be more resistant to furfural. (C)8 mM Furfural does not influence the doubling time of E. coli W. (D) Furfural decreases the viability of coli W when cells reach stationary phase.

Solution

10mM furfural does not completely stop the E coli W to grow although there is markable reduction in the growth. The growth rate in absence of furfural and in presence of furfural was almost same if the E coli has plasmid A. So, presence of plasmid seems to impart resistance to the bacterium against furfural dependent reduction in the growth rate. Correct answer is B.