Cheese whey (CW)-based growth medium efficiently protects Rhizobium loti cells during freezing and desiccation and can maintain their growth in a manner similar to that of traditional mannitol-based medium (YEM). The cheese-whey-based medium (CW) improved viability when used to re-suspend cell pellets kept at -20 degrees C and -80 degrees C and resulted in the survival of over 90% of the cells. Moreover, bacterial pellets obtained from cells grown in CW withstand desiccation better than cells grown in YEM. Survival was over 60% after 30 days at 4 degrees C. No differences were observed in nodulation efficiency between YEM-grown and CW-grown cells. Fast protein liquid chromatography (FPLC) protocols are presented for total protein profile analyses of sweet and acid cheese whey.