1. Bryant, M.P. (1979).J. Animal Sci., in the press.
2. Cheeseman, M.J., Toms-Wood, A., and Wolfe, R.S. (1972).J. Bacteriol. 112, 527?531.
3. McCarty, P.L., and McKinney, R.E. (1961).J. Water Pozzut. Control Fed. 33, 223?232.
4. Ristroph, D.L., Watteuw, C.M., Armiger, W.B., and Humphrey, A.E. (1977).J. Ferment. Technol. 55, 599?608.
5. Umbreit, W.W., Burris, R.H., and Stauffer, J.F. (1964). In:Manometric Techniques, p. 15. Minneapolis (Minnesota) : Burgess Publ. Co.