Vitamin B12 Production by Microorganisms Isolated from Poultry House Litter and Droppings

Abstract

Only 2.8% of 142 isolations of microorganisms from poultry house litter and droppings which were studied for vitamin B₁₂ production produced no detectable quantity (less than 0.01 mµg per milliliter of broth) of vitamin B₁₂ activity as determined by microbiological assay with Lactobacillus leichmannii (A.T.C.C. 4797); 32.3% produced between 0.01 and 0.10; 22.5% between 0.1 and 0.4; and 42.2% more than 0.4 mµg per milliliter of broth. Vitamin B₁₂ production studies at 30° to 37°C. showed that 62.3% of the isolated organisms produced better at 30°C. than at 37°C., and 37.7% produced better at 37°C. The addition of 0.2% of choline chloride to the vitamin B₁₂ production medium reduced the total production of vitamin B₁₂ of 14 of the organisms studied by 33%. Only two of the 14 produced better (but only slightly) with the addition of choline chloride. Thirty-three organisms, which were selected as being the better vitamin B₁₂ producers, produced an average change in the vitamin B₁₂ production medium from an original pH of 7.0 to 6.0 after incubation for 72 hours at 30°C. and to 6.3 after incubation for the same period at 37°C. Only 9 of the organisms produced an alkaline reaction at one or both temperatures. The lowest pH recorded was 3.1 and the highest was 7.7. Among the better vitamin B₁₂-producing organisms isolated from poultry house litter and droppings were yeast, molds, and many classes of bacteria. One organism was isolated which produced more vitamin B₁₂ as measured microbiologically than either Bacillus megatherium, Streptomyces aureofaciens or Streptomyces griseus under our test conditions. This organism has been tentatively identified as a strain of Aerobacter aerogenes.