v4n4doi10.4322/sc.2012.018en
https://dx.doi.org/10.4322/sc.2012.018
Determination of fatty acid of Vibrio bacteria by gas chromatography
Fernández, Rodrigo Valenzuela; Silva, René Cortez; Garay, Miguel Zazopulos; Karmy, Jaime Carmi
Palavras-chave: Fatty acids, Vibrio, gas liquid chromatography, bacteria.
Resumo: The genus Vibrio includes several species of clinical importance, many of them related to foodborne diseases. It is desirable to have alternative techniques to support the identification of bacterial genera and sanispecies of Vibrio. Capillary gas Chromatography can be used to determine GLC profile for the methyl esters of the fatty acids present in the cellular structure of the microorganisms. The objective of this study is to determine and quantify the profile of methyl esters of fatty acids present in Vibrio vulnificus, Vibrio parahaemolyticus, Vibrio cholerae and Vibrio alginolyticus, and other species such as Escherichia coli and Staphylococcus aureus, in order to determine the fatty most relevant acids present in microorganisms, as well as any relationship between them. For this identification, each Vibrio strain is grown in trypticase soy broth (TSB) with 1% sodium chloride, after incubation the culture is centrifuged to separate the broth microbial mass. The bacterial mass obtained was subjected to an breakage with high-frequency waves, a 0.5 Normal potassium hydroxide solution in metanol is added, the unsaponifiable is extracted, the residue was acidified and the fatty acids were extracted and methylated, injecting in a chromatograph equipped with a BPX-70 column of 0.22 mm diameter and flame ionization detector, FID. The results indicate that the fatty acid profile is unique to each species analyzed and therefore significantly different for each species of Vibrio bacteria and for other consideration. Stand as indicators of differentiation fatty acids myristic, palmitic, oleic cis-, trans-oleic acid, cis-linoleic and arachidonic. ω-9/ω-6 relationship is also significantly different for each species tested. Consequently, the fatty acid profile may be an alternative test for the identification of Vibrio at low cost and relative time.
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