Human demand for meat and dairy products requires hordes of methane-spewing ruminants, the source of a major greenhouse gas. Therefore, the possible solution described in your News story “Vaccine targets gut reaction to calm livestock wind” (Nature 429, 119; 200410.1038/429119b) is exciting.
Yet, while we wait for a vaccine to be perfected, there is no excuse for wanton methanogenesis. A chemical remedy has been known since 1967, when Thomas Bauchop of the University of California, Davis, found the answer (J. Bacteriol 94, 171–175; 1967).
Bauchop collected the fore-stomach contents of cattle into flasks and studied methane production by the bacteria responsible. The work was fraught with troublesome foam, so an anti-foaming agent was sprayed into the flasks. The foaming stopped, but so did the methane production. It turned out that the aerosol propellant, a Freon (CCl2F2), inactivated methane-producing enzymes. This popular chlorofluorocarbon (CFC) was used as a coolant in refrigeration as well as an aerosol propellant, until its ozone-depleting activities were discovered during the 1970s.
Researchers at the University of Illinois determined that the Freon propellant attaches covalently to the cobalt ion of the vitamin B12 cofactor that is required by methane-yielding enzymes (J. M. Wood, F. S. Kennedy and R. S. Wolfe Biochemistry 7, 1707–1713; 1968).
So, before the cinematically illustrated global-warming disaster of The Day After Tomorrow becomes reality, let us go forth and spray the cows with Freon.