The aerobic decomposition of choline by microorganisms

Summary

• 1. The ability to decompose choline is widespread among aerobic microorganisms since representatives of the genera Agrobacterium, Arthrobacter, Micrococcus, Pseudomonas, Rhizobium, and Streptomyces and a large number of coryneform bacteria were found to grow with choline as the sole C- and N-source.

• 2. Almost all the coryneforms isolated from soil and dairy waste activated sludge displayed this ability in contrast to those isolated from cheese and, be it to a less extent, those from the phyllosphere. The significance of choline utilization in the taxonomy of coryneform bacteria is discussed.

• 3. All the choline-utilizing bacteria tested were found to be able to grow with betaine, N,N-dimethylglycine, or sarcosine as the sole C- and N-source. Choline-grown cells, as contrasted to those grown with yeast extract and glucose, of Pseudomonas fluorescens and Arthrobacter S₃ respired the latter three compounds at a rate similar to that of choline.

• 4. About 30% of the 50 choline-utilizing coryneform bacteria tested grew also with N,N-dimethylethanolamine and N-monomethylethanolamine. Choline-grown cells, in contrast to those grown with yeast extract and glucose, of a representative of this group, Arthrobacter S₃, also respired these two compounds at a rate somewhat lower than that of choline.