Quorum-sensing-dependent switch to butanediol fermentation prevents lethal medium acidification in Aeromonas hydrophila AH-1N.
Aeromonas hydrophila AH-1N shows biphasic growth in glucose containing broth at 30 degrees C. The first phase is characterized by strong acidification, while the second phase is accompanied by an increase in medium pH. Disruption of AHL production by knockout of ahyI did not affect the first growth phase, but resulted in further acidification which completely blocked the second growth phase and even caused cell death. The block could be relieved by addition of 5 microM (or less) synthetic N-butanoyl-L-homoserine lactone (C4-HSL), the major AHL produced by A. hydrophila AH-1N. Further analysis revealed that, as shown previously for Serratia plymuthica, butanediol fermentation is regulated by AHL-mediated quorum sensing in A. hydrophila AH-1N. These results indicate that A. hydrophila switches to butanediol fermentation to reduce medium acidification under certain conditions and to allow further growth if nutrient resources are not yet exhausted.
Van Houdt
Rob
R
Center for Food and Microbial Technology, Department of Microbial and Molecular Systems, Faculty of Bioscience Engineering, Katholieke Universiteit Leuven, Kasteelpark Arenberg 22, B-3001 Leuven, Belgium.
Aertsen
Abram
A
Michiels
Chris W
CW
D015107:4-Butyrolactone / Q000031:analogs & derivatives / Q000378:metabolism; D016980:Aeromonas hydrophila / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D002072:Butylene Glycols / Q000378:metabolism*; D015169:Colony Count, Microbial; D003470:Culture Media; D005285:Fermentation; D015964:Gene Expression Regulation, Bacterial; D005947:Glucose / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D053038:Quorum Sensing
C108088:AhyRI protein, Aeromonas; D001426:Bacterial Proteins; D002072:Butylene Glycols; D003470:Culture Media; C088386:homoserine lactone; C026978:2,3-butylene glycol; D005947:Glucose; D015107:4-Butyrolactone