(21) Although only few bacterial species produce vitamin B12, most aerobic bacteria do require vitamin B12 to grow. (22) Furthermore, the mechanisms of vitamin B12 uptake in bacteria are quite well characterized, (23) especially in Escherichia coli.
To survive the bacteria must be able to accumulate the following elements from the host: Carbon, Hydrogen, Oxygen, Nitrogen and Sulfur. These can be found in water, macromolecules, or macromolecules.
The recombinant E. coli strain harboring these three plasmids produced vitamin B12 under both anaerobic and aerobic conditions. Via optimizing the culture conditions, the engineered strain produced 0.65 ± 0.03 μg/g cdw of coenzyme B12.
Besides its role as a cofactor for MetH and MCM, cobalamin is also used by many bacteria as a cofactor for additional processes, including metabolism and gene regulation. Cobalamin impacts host–microbe interactions by altering host and bacterial physiology at intestinal and extraintestinal sites.
Anaerobic bacteria need their vitamin B12 to digest estrogen.
One organism that is associated with vitamin B12 deficiency is Helicobacter pylori, found in over half of all patients. Adequate treatment of this infection has been shown to result in an increase in the concentration of the vitamin.
We now show that at least two groups of organisms in the small bowel, Pseudomonas and Klebsiella sp., may synthesise significant amounts of the vitamin.
B12 is synthesized by only certain bacteria and archaeon, but not by plants or animals. The synthesized B12 is transferred and accumulated in animal tissues, even in certain plant tissues via microbial interaction. Meats and milks of herbivorous ruminant animals are good sources of B12 for humans.
Vitamin B12 is needed to form red blood cells and DNA. It is also a key player in the function and development of brain and nerve cells.
Vitamin B12 can help balance immune responses to better fight viral infections.
Indeed, E. coli benefits its host in a number of ways. It produces vitamin K and vitamin B12, both of which are required by mammalian hosts (Bentley and Meganathan, 1982; Lawrence and Roth, 1996).
We have shown that vitamin B12–PNA conjugates inhibit the growth of E. coli at 5 μM concentration and are stable in the presence of bacterial media up to 168 h. Modifications of vitamin B12 structure influence the use of such vitamin B12 derivatives as essential coenzymes in E. coli.
Out of 100 E. coli isolates, 15 isolates were inhibited by vitamin C at a concentration of 0.625 mg/ml, 70 isolates were inhibited by vitamin C at a concentration of 1.25 mg/ml and 15 isolates were inhibited by vitamin C at a concentration 2.5 mg/ml.
Pathogenic E. coli strains can survive in open environments. The ability to use nutrients and to attach to surfaces plays a crucial role in their survival in open environments. Escherichia coli O157:H7 is found in soil, manure, and irrigation water or contaminated seeds.
E. coli make energy from formate and consume carbon dioxide in order to produce biomass.
Upon starvation for any of the three nutrients—carbon, phosphorus, or nitrogen—E. coli activates the RpoS response and enters stationary phase for survival. However, each type of starvation is sensed differently, and activation of the RpoS regulon occurs in a unique way with each type of starvation (Fig.
Vitamin B12 is required for the development, myelination, and function of the central nervous system; healthy red blood cell formation; and DNA synthesis [1,4,5]. Vitamin B12 functions as a cofactor for two enzymes, methionine synthase and L-methylmalonyl-CoA mutase [1-3,5].
Adults need around 2.4 micrograms (mcg) of vitamin B12 a day, and people who are pregnant or breastfeeding need more. The amount of vitamin B12 babies and children need varies based on age.
Key points about vitamin B12 deficiency anemia
Without enough red blood cells, your tissues and organs don't get enough oxygen. Without enough oxygen, your body can't work as well. Symptoms include weak muscles, numbness, trouble walking, nausea, weight loss, irritability, fatigue, and increased heart rate.
Small bowel bacterial overgrowth can also cause megaloblastic anemia, which results from vitamin B12 deficiency. Binding of vitamin B12 to bacteria in the upper small intestine can prevent absorption of the vitamin in the distal ileum.
Churning Out Vitamins
In humans, gut bacteria secrete vitamin B12 and a less familiar micronutrient called vitamin K.
Pernicious anemia is a relatively rare autoimmune disorder that causes diminishment in dietary vitamin B12 (cobalamin) absorption, resulting in B12 deficiency and subsequent megaloblastic anemia. It affects people of all ages worldwide, particularly those over 60.
And probiotics have been shown in clinical trials to positively impact the absorption of some vitamins and minerals: One 2021 systematic review of clinical trials found probiotics improved micronutrient levels in healthy people, specifically vitamin B12, folate (vitamin B9), calcium, iron, and zinc [2].