Further studies of Mycoplasma gallisepticum serum plate agglutination antigen grown in medium with artificial liposomes substituting for serum.

Frey's medium supplemented with artificial liposomes substituting for serum was evaluated for Mycoplasma gallisepticum (MG) serum plate agglutination (SPA) antigen. Antigens prepared in batch (static) culture were compared with antigens grown in a fermenter. All batch-grown MG liposome antigens were highly sensitive, specific, and resulted in a greater yield compared with fermenter-grown liposome antigens. Compared with antigens prepared in Frey's medium with 12% swine serum (regular FMS) or with commercial SPA antigens, liposome antigens had a higher degree of specificity; however, they were similar in sensitivity and antigen yield. The only growth parameter to affect the yield per liter of batch-grown liposome antigen was the concentration of liposomes in the growth medium. The reduced yield and sensitivity of antigens grown in a fermenter may have been due to autoclaving the medium instead of sterilizing by filtration. There was no obvious difference between patterns of serum-medium-grown, liposome-medium-grown, or commercial SPA antigens upon sodium dodecyl sulfate-polyacrylamide gel electrophoresis.