Carotenoids' influence on radiotolerance of Pantoea agglomerans, a plant pathogen.
OBJECTIVE
The aim of this study was to evaluate the effect of gamma radiation on the carotenoid content of two strains of the Enterobacteriaceae: Pantoea agglomerans.


RESULTS
Pantoea agglomerans strains ATCC 49174 and RL1 were used for this study. Successive radiation treatments were performed to study the radiotolerance. Total carotenoids were obtained by multiple extraction using chloroform/methanol (2 : 1), quantified by measuring the optical density at 453 nm and their antioxidant activity measured by a colorimetric method. The D(10) studies were conducted using a UC-15A irradiator loaded with 60Co. Bacterial counts from various dilutions were carried out after irradiation. Strain ATCC 49174 irradiated at 1 kGy produced 4.3 times more carotenoids than the control, whereas carotenoid synthesis increased by 2.9-fold in the strain RL1. However, there was no significant difference in the D(10) values.


CONCLUSIONS
Carotenoid increased production is influenced by gamma radiation but does not modify the tolerance to radiations.


CONCLUSIONS
To our knowledge, this is the first study to demonstrate the effects of gamma radiation on carotenoid production levels.
Dussault
D
D
Canadian Irradiation Centre and Research Laboratories in Sciences Applied to Food, INRS-Institut Armand-Frappier, Laval, Quebec, Canada.
Caillet
S
S
Le Tien
C
C
Lacroix
M
M
D000975:Antioxidants / Q000378:metabolism; D002338:Carotenoids / Q000096:biosynthesis*; D020636:Pantoea / Q000378:metabolism / Q000528:radiation effects*; D011836:Radiation Tolerance; D017382:Reactive Oxygen Species / Q000378:metabolism
D000975:Antioxidants; D017382:Reactive Oxygen Species; D002338:Carotenoids