Performance of Some Heat-Sensitive Differential Agars Prepared and Melted by Microwave Energy

Abstract

The viable cell count performance of some heat-sensitive differential agars prepared and remelted by microwave energy was evaluated for Salmonella choleraesui, Streptococcus faecalis and Escherichia coli. The conventional boiling method was used for comparison. No significant difference was found between the microwave oven processed agar and the conventional-boiling processed agar in viable cell counts of the target bacteria. Heating and reheating of violet red bile agar, bismuth sulfite agar, and KF Streptococcus agar by both methods did not change agar performance. However, remelting of desoxycholate citrate agar by both methods resulted in a substantial lowering of viable cell counts.

COMPARISON OF MIKROCLAVETM STERILIZATION SYSTEM AND CONVENTIONAL AUTOCLAVING FOR THE STERILIZATION OF MICROBIOLOGICAL MEDIA 1

“…The effects of microwave radiation on many microorganisms in different food systems were reviewed by Fung and Cunningham (1980). The conventional microwave oven is a convenient and efficient way of preparing agars for autoclaving or melting previously sterilized agar for plating and cultivation o f bacteria (Fung and Lin 1984;Liang and Fung 1988).…”