Under conditions supporting rapid growth, γ-[6-hydroxy-(3-pyridyl)]-γ-oxobutyric acid appeared to be the last major pyridine-containing intermediate formed within twelve hours by the non-blue-pigment-forming nicotine-degrading bacterial isolate No. 3. When isolated, it was readily oxidized without any time lag by other non-blue-pigment-forming cultures. The rate of its formation was enhanced noticeably by as yet unidentified components of Chicago tap water, Pseudooxynicotine appeared to be the intermediate preceding its formation. The isolates which formed blue pigment were unable to oxidize it and there was no indication of its formation during their incubation cycle.

(Full article published with kind permission from "Tobacco International")