Budget Amount *help |
¥4,550,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥1,050,000)
Fiscal Year 2013: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2012: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2011: ¥2,470,000 (Direct Cost: ¥1,900,000、Indirect Cost: ¥570,000)
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Outline of Final Research Achievements |
Under osmotic stress, bacterial cells uptake compatible solutes such as glycine-betaine to maintain homeostasis. It is unknown whether there are incompatible solutes that are similar in structure to compatible solutes but have adverse physiological effects on bacterial physiology. The objective of this study was to evaluate solute incompatibility of various amino acids against bacterial growth. Twenty-three amino acids with L and/or D isomers were examined for the effect of bacterial growth inhibition. Among the various amino acids examined, D-tryptophan (~40 mM) in PYG broth supplemented with 0 to 4% (w/v) salt inhibited the growth of Listeria monocytogenes, Salmonella enterica, and Escherichia coli O157:H7 at 25°C. These results demonstrate that the uptake of D-tryptophan as an incompatible solute during osmotic stress may inhibit bacterial growth. The antibacterial effect of D-tryptophan demonstrated in this study suggests that D-tryptophan could be used as a novel preservative.
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