RESUMO
Conjugated linoleic acid (CLA) has been the subject of numerous studies in recent decades because of its associated health benefits. CLA is an intermediate product of the biohydrogenation pathway of linoleic acid (LA) in bacteria. Several bacterial species capable of efficiently converting LA into CLA have been widely reported in the literature, among them Lactobacillus delbrueckii subsp. bulgaricus LBP UFSC 2230. Over the last few years, a multicomponent enzymatic system consisting of three enzymes involved in the biohydrogenation process of LA has been proposed. Sequencing the genome of L. delbrueckii subsp. bulgaricus LBP UFSC 2230 revealed only one gene capable of encoding an oleate hydratase (OleH), unlike the presence of multiple genes typically found in similar strains. This study investigated the biological effect of the OleH enzyme of L. delbrueckii subsp. bulgaricus LBP UFSC 2230 on the hydration of LA and dehydration of ricinoleic acid (RA) and its possible role in the production of CLA. The OleH was cloned, expressed, purified, and characterized. Fatty acid measurements were made by an internal standard method using a gas chromatography-coupled flame ionization detector (GC-FID) system. It was found that the enzyme is a hydratase/dehydratase, leading to a reversible transformation between LA and RA. In addition, the results showed that L. delbrueckii subsp. bulgaricus LBP UFSC 2230 OleH protein plays a role in stress tolerance in Escherichia coli. In conclusion, the OleH of L. delbrueckii subsp. bulgaricus LBP UFSC 2230 catalyzes the initial stage of saturation metabolism of LA, although it has not converted the substrates directly into CLA. IMPORTANCE This study provides insight into the enzymatic mechanism of CLA synthesis in L. delbrueckii subsp. bulgaricus and broadens our understanding of the bioconversion of LA and RA by OleH. The impact of OleH on the production of the c9, t11 CLA isomer and stress tolerance by E. coli has been assisted. The results provide an understanding of the factors which influence OleH activity. L. delbrueckii subsp. bulgaricus LBP UFSC 2230 OleH presented two putative fatty acid-binding sites. Recombinant OleH catalyzed both LA hydration and RA dehydration. OleH was shown to play a role in bacterial growth performance in the presence of LA.
Assuntos
Hidroliases/metabolismo , Lactobacillus delbrueckii/enzimologia , Lactobacillus delbrueckii/metabolismo , Ácido Linoleico/metabolismo , Ácidos Ricinoleicos/metabolismo , Genoma Bacteriano/genética , Hidroliases/genética , Hidrogenação , Lactobacillus delbrueckii/genética , Estresse Fisiológico/fisiologia , Sequenciamento Completo do GenomaRESUMO
In the late nineteenth century, Mexico's Superior Health Council devised a consistent and assertive international strategy around alignment with international scientific standards, the control of disease certification on Mexican soil by Mexican experts, transparent disease reporting, internationally demonstrated competence in campaigns against tropical disease, and participation in multilateral health agreements. The council came to command a central role in the regime of Porfirio Díaz (18771911), mainly because this international strategy enabled a successful defense of Mexican sovereignty. In the arena of public health, the council, led by Eduardo Licéaga, came close to realizing the Científicos' dream of Mexican development "without U.S. investment." This was largely because the council obtained independent access to European ideas and technologies prior to its engagement with the United States, which began in 1890 when the first Mexican delegation attended the annual meeting of the American Public Health Association (APHA). Through a persistent and creative diplomatic campaign, taking advantage of relationships cultivated through the APHA, Porfirio Díaz's sanitary advisors persuaded many of their American counterparts that Mexican experts could be trusted partners in defending the health of the western hemisphere. The article describes the Atlantic world of Mexican medicine in the nineteenth century, the significance of public health within a context shaped by rising U.S. imperialism, the key role played by Licéaga, and Mexico's participation in the APHA. (AU)