Write a note on microbes in industrial vitamin production.

↵Vitamin B12 which forms an important part of the vitamin B complex is produced commercially on a large scale . It was  recovered  for the first time in active crystalline form from actinomycete Streptomyces griseus. Different methods are employed for its production and these are as follows:

• Direct fermentation: In this method , Streptomyces griseus is grown on a culture medium under controlled conditions. Then Fermentation is carried out at 27˚C with aeration for about 5 days. The growth is harvested before mycelial autolysis and vitamin destruction. The vitamin is recovered from broth by filtration. .Bacillus megaterium, Propionibacterium freudenreichii, Propionibacterium shermanii and Pseudomonas has also been used for commercial production of vitamin B12
• Indirect production: It is obtained as byproduct of antibiotic fermentation processes such as Streptomycin production
• Genetic engineering: Genetic approaches like shuffling of genome have also been employed in Propionibacterium shermanii to improve yields of vitamin B12.