Multiple choice

Vitamin B12 production can be enhanced by employing modern techniques of genetic engineering. Which of the following strains were used to obtain a high yielding strain for vitamin B12 production?

  1. Bacillus megaterium and Rhodopseudomonas spheroides

  2. Propionibacterium freudenreichii and Propionibacterium shermanii

  3. Protaminobacter rubber and Rhodopseudomonas spheroides

  4. Pseudomonas denitrificans and Streptomyces olivaceus
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A protoplast fusion technique between Protaminobacter rubber and Rhodopseudomonas spheroides resulted in a hybrid strain called Rhodopseudomonas protamicus. This is the highest yielding strain of vitamin B12. This new strain can produce as high as 135 mg/l of vitamin B12 utilising a carbon source.

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