Question

What is correct about Escherichia coli and Rhizobium japonicum?
A. E. coli is gram negative and R. japonicum is gram positive
B. Both gram positive
C. Both gram negative
D. E. coli is gram positive and R. japonicum is gram negative

Answer 1

Hint: The coliform bacteria Escherichia coli, also known as E. coli, is a Gram-negative, facultatively anaerobic, rod-shaped bacteria found in the lower intestine of warm-blooded animals.
Rhizobium is a bacterium that lives in a symbiotic relationship with leguminous plants' root nodules. Nitrogen fixation is not possible on its own. Rhizobium requires a plant host for this reason. Rhizobium is an important supplier of nitrogen for agricultural soils, especially in arid areas. Nitrogen is converted to ammonia by them.

Complete answer:
Option A: Gram-negative, rod-shaped facultative anaerobic bacteria, E. coli. Rhizobium japonicum is a nitrogen-fixing gram-negative rod-shaped bacteria that forms a symbiotic relationship with the soybean plant. Glycine maxima is a Glycine species. R. japonicum belongs to the Rhizobiaceae family, which also includes other nitrogen-fixing bacteria that work with legumes in a symbiotic relationship.
So option A is not correct.
Option B: Rhizobium are nitrogen-fixing bacteria that live in the soil as free-living bacteria or in association with the roots of leguminous plants.
So option B is not correct
Option C: E. coli is a facultative anaerobic bacteria that is Gram-negative and rod-shaped.. Rhizobium japonicum is a nitrogen-fixing gram-negative rod-shaped bacteria that forms a symbiotic relationship with the soybean plant. Glycine maxima is a species of Glycine. R. japonicum is a member of the Rhizobiaceae family, which also includes other nitrogen-fixing bacteria that form symbiotic relationships with legumes.
So option C is correct.
Option D: E. coli is a facultative anaerobic bacteria that is Gram-negative and rod-shaped.
So option D is not correct.

So option C is the correct answer.

Note:

GRAM POSITIVE BACTERIA	GRAM NEGATIVE BACTERIA
A single-layered, smooth cell wall	A double-layered, wavy cell-wall
It's a thick layer that can be stacked as well.	It is a thin layer/ often single-layered.
The outer membrane is absent	The outer membrane is present (mostly)
More susceptible to antibiotics	More resistant to antibiotics
Eg. Staphylococcus, Streptococcus, etc.	Eg. Escherichia, Salmonella, etc.
Even after being cleaned with acetone or alcohol, these bacteria retain their crystal violet colour and look purple-colored when inspected under the microscope following gramme staining.	Even after being cleaned with acetone or alcohol, these bacteria do not retain the stain colour and look pink-colored when inspected under the microscope following gramme staining.