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Submitted to: Meeting Abstract
Publication Type: Abstract Only Publication Acceptance Date: 5/1/2003 Publication Date: 8/1/2003 Citation: Bayles, D.O. 2003. A method for evaluating changes to uvm for improving the growth of listeria monocytogenes. Meeting Abstract. P074. Interpretive Summary: Technical Abstract: A microplate-based method was developed for evaluating the efficacy of additives for improved growth of L. monocytogenes in UVM. Essential compounds for L. monocytogenes growth or compounds that have demonstrated ability to improve bacterial growth under stressful conditions were tested by two-fold serially diluting the compounds across the length of a microplate inoculated with L. monocytogenes. Multiple replicates were run with two strains of L. monocytogenes and were read hourly at 595nm using a microtiter plate reader. The repeated measures data for each concentration of the compounds tested were averaged down each column of the microplate and analyzed using SAS Institute software. The osmoprotectants glycine betaine and carnitine did not improve the growth of L. monocytogenes in UVM. Also, the iron containing compound, hemin, was ineffective at improving the growth of L. monocytogenes in UVM. Alpha-ketoglutarate (alpha-KG) at concentrations of 0.1 to 3.1 g/L was found to improve the growth of L. monocytogenes in UVM. Above 3.1 g/L, alpha-KG was found to be inhibitory to growth. Sodium pyruvate at concentrations of 0.1 to 6.3 g/L was found to improve the growth of L. monocytogenes. Pyruvate was inhibitory to growth at 12.5 g/L and greater concentrations. Growth was also improved with the addition of a minor elements solution providing a final concentration of 400 ug/L FeSO4 × 7H2O, 15 ug/L MnSO4 × 2H2O, and 15 ug/L NaMoO4 × 2H2O. These media changes accelerate the growth and improve the recovery of L. monocytogenes from UVM enrichments. |
