NEET BIOLOGY

Detailed explanation-1: -Only a limited number of bacteria are known to produce vitamin B12, three of which-Pseudomonas denitrificans, Bacillus megaterium, and Propionibacterium freudenreichii-are used for commercial production [46–48].

Detailed explanation-2: -Vitamin B12 is produced by bacteria, not animals or plants. As such, animals, including humans, must obtain it directly or indirectly from bacteria.

Detailed explanation-3: -A vitamin B12 test is used to: Check for vitamin B12 deficiency anemia. There are several risk factors for this anemia, such as those who have had stomach or intestinal surgery, small intestine problems, or people with a family history of this anemia.

Detailed explanation-4: -delbrueckii ATCC 7830 was observed only following the addition of cytoplasmic extract (CE) obtained from L. rossiae or, alternatively, vitamin B12 to the medium, thus confirming that L. rossiae is capable of producing B12 and that this cofactor is present in its CE (Figure 4B).

Detailed explanation-5: -LAB are usually auxotrophic for several vitamins although certain strains of LAB have the capability to synthesize water-soluble vitamins such as those included in the B group.