No chemist worth his salt can fail to be fascinated by the chemistry carried out with such exquisite control in living systems. That a humble microorganismcan construct a molecule having the complexity of vitamin B12, the antipernicious anemia vitamin, is quite amazing. The influence of some fermentation parameters on vitamin B12 formation by actinomycetes isolated from different soil samples and contaminated fruits and vegetables were investigated. All the 34 Actinomycetes organisms which were isolated from soil, fruits and vegetables are producing vitamin B12. Eight isolates are potential for the production cyanocobalamin (vitamin B12). contaminated 6 fruits and 17 vegetableswere screened for the determination of vitamin B12. Apple among the fruits and potato among the vegetables were known to contain relativelymore amount of vitamin B12.For the determination of vitamin B12, bioassay was followed by using Lactobacillus delbrueckii sub sp. lactis ATCC 7830.