MAINTENANCE OF BIODEGRADATION CAPACITIES OF AEROBIC-BACTERIA DURING LONG-TERM PRESERVATION

Six strains of aerobic Gram negative bacteria degrading toluene, 2,4-d ichlorophenoxyacetate, 2,2-dichloropropionate or 3-chlorobenzoate were freeze-dried and liquid-dried in the presence or absence of a protect ive agent. Survival and maintenance of the biodegradation capability w as checked before and after drying, and after storage of the ampoules for one year at 4 degrees or 25 degrees C. In many cases, stability of the degradation potential was low although viability was high. Surviv al and stability of all strains was always highest after preservation by liquid drying in the presence of myo-inositol and activated charcoa l as protective agents. Losses of biodegradation abilities were highes t after freeze-drying using no protective agents. Cells grown on compl ex medium were less sensitive to drying than cells grown under selecti ve pressure (on mineral medium with a special compound as the sole car bon source). A choice of the most appropriate preservation method and the use of an effective protectant is recommended to avoid genetic alt erations, and to maintain biodegradation capacities during long-term p reservation.