0.02-0.5 mcg/100 mcg in barley malt syrup, sourdough bread and more

[Korn]

From http://www.pubmedcentral.nih.gov/art...i?artid=193752

We found that Lactobacillus reuteri CRL1098, a lactic acid bacterium isolated from sourdough, is able to produce cobalamin. The sugar-glycerol cofermentation in vitamin B12-free medium showed that this strain was able to reduce glycerol through a well-known cobalamin-dependent reaction with the formation of 1,3-propanediol as a final product. The cell extract of L. reuteri corrected the coenzyme B12 requirement of Lactobacillus delbrueckii subsp. lactis ATCC 7830 and allowed the growth of Salmonella enterica serovar Typhimurium (metE cbiB) and Escherichia coli (metE) in minimal medium. Preliminary genetic studies of cobalamin biosynthesis genes from L. reuteri allowed the identification of cob genes which encode the CobA, CbiJ, and CbiK enzymes involved in the cobalamin pathway. The cobamide produced by L. reuteri, isolated in its cyanide form by using reverse-phase high-pressure liquid chromatography, showed a UV-visible spectrum identical to that of standard cyanocobalamin (vitamin B12).

[Korn]

According to this source, small amounts of B12 has been found in ie.in barley malt syrup and sourdough bread:

There has been a long history of misconceptions about which, if any, plant foods are good sources of B12. Much of this stems from the use of unreliable methods that measure B12 analogue rather than B12. Other confusion stems from the fact that bacterial contamination may occur in some foods in certain countries but not in others. Below is a survey of the scientific literature on B12 in plant foods, some of which appears to have contradictory information.

Herbert & Drivas43 (1982, USA) reported an analysis of 3 brands of spirulina sold in health food stores. 80% of the B12 shown with the microbiological assay that at the time was used by US Pharmacopoeia (L. leichmanni) was shown to be analogue using IF.

van den Berg et al.101 (1988, Netherlands) analyzed the B12 content of various foods using IF as well as microbiological assay. There was no measurable B12 found using either method for fermented foods such as tempeh, tofu, shoyu, tamari, rice miso, barley miso, amesake rice, or umeboshi prunes.

Some B12 (0.02-0.5 mcg/100 mcg) was found in barley malt syrup, sourdough bread, parsley, and shitake [presumably shiitake mushrooms]. Some algae were rich in B12 using IF, including spirulina, kelp, kombu, wakame, dulse, and various species of nori (which contained 12.0-68.8 mcg/100mcg; a very large amount).

Miller et al.68 (1991, USA) found that B12 status appeared to be unrelated to consumption of several vegetarian foods, including wakame, kombu, other sea vegetables, tempeh, or miso in macrobiotic children and adults.

Dagnelie et al.21 (1991, Netherlands) say, "It seems unjustified to advocate algae and other plant foods as a safe source of vitamin B12 because its bioavailability is questionable".

[grant]

I thought the O. Malhamensis (spelled wrong?) assay was the best one for ascertaining whether the "b12" was active or analogue? I'd like to see ALL sources of vitamin b12 (including supplements and animal products) analysed using this method if so.