Vitamin B12 is a crucial water-soluble vitamin involved in key metabolic processes, including serving as a cofactor for enzymes in DNA synthesis, promoting red blood cell formation, and supporting healthy nerve tissue and brain function. While plants cannot synthesize vitamin B12, it can be found in certain plants and mushrooms through microbial interaction. Additionally, vitamin B12 is abundant in animal tissues, making the meat and milk of ruminant’s valuable dietary sources. Due to its essential role in human health and the growing demand, there has been significant interest in industrial-scale production of vitamin B12 using microbes. Commonly utilized microorganisms include Sinorhizobium meliloti, Propionibacterium shermanii, and Pseudomonas denitrificans. The production process often employs inexpensive, carbon-rich substrates derived from agro-industrial waste, providing a cost-effective solution for microbial cultivation. Both solid-state and submerged fermentation methods are optimized for vitamin B12 yield, with specific culture conditions tailored to different microbial strains. This review offers a comprehensive overview of vitamin B12, highlighting its natural sources, cost-effective substrates for microbial production, and the optimized culture conditions necessary for efficient purification and extraction. Future prospects in this field include enhancing production yields and exploring novel microbial strains and substrates to meet the increasing global demand for vitamin B12.

Keywords: Cobalamin production, Sources, Optimized conditions, Heterologous pathway development.