Let's take advantage of bacterial adaptability to environmental stress: High quality and safe food production by using uptake incompatible solute into bacterial cell

• Project/Area Number: 23780150
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Food science
• Research Institution: Hokkaido University (2013-2014); National Agriculture and Food Research Organization (2011-2012)
• Principal Investigator: KOSEKI Shigenobu 北海道大学, (連合)農学研究科(研究院), 准教授 (70414498)
• Project Period (FY): 2011-04-28 – 2015-03-31
• Project Status: Completed (Fiscal Year 2014)
• Budget Amount: ¥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)
• Keywords: 適合溶質 / アミノ酸 / ストレス応答 / 浸透圧ストレス / Dトリプトファン / 増殖阻害 / 代謝阻害 / 予測モデル

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.

Research Products

• [Journal Article] Growth Inhibition of Listeria monocytogenes, Salmonella enterica, and Escherichia coli O157:H7 by D-Tryptophan as an Incompatible Solute (2015)
  • Author(s): SHIGENOBU KOSEKI, NOBUTAKA NAKAMURA, AND TAKEO SHIINA
  • Journal Title: Journal of Food Protection Volume: 78 Issue: 4 Pages: 819-824
  • DOI: 10.4315/0362-028x.jfp-14-374
  • Peer Reviewed / Acknowledgement Compliant
• [Presentation] Tryptophan Acts as an Incompatible Solute: Growth Inhibition of Listeria monocytogenes, Salmonella enterica, and Escherichia coli O157:H7 (2014)
  • Author(s): Shige Koseki
  • Organizer: International Association for Food Protection
  • Place of Presentation: Indianapolis Convention Center (USA)