Thin-layer chromatographic method for the simultaneous determination of physiological aromatic amino acids

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Odhl dephosporylation kinetics during different glutamate production processes involving Corynebacterium glutamicum

In Corynebacterium glutamicum, the activity of the 2-oxoglutarate dehydrogenase complex was shown to be controlled by the phosphorylation of a 15-kDa protein OdhI by different serine/threonine protein kinases. In this paper, the phosphorylation status and kinetics of OdhI dephosphorylation were assessed during glutamate producing processes triggered by either a biotin limitation or a temperature upshock from 33 degrees C to 39 degrees C. A dephosphorylation of OdhI in C. glutamicum 2262 was observed during the biotin-limited as well as the temperature-induced glutamate-producing process. Deletion of pknG in C. glutamicum 2262 did not affect the phosphorylation status of OdhI during growth and glutamate production phases triggered by a temperature upshock, though a 40% increase in the specific glutamate production rate was measured. These results suggest that, under the conditions analyzed, PknG is not the kinase responsible for the phosphorylation of OdhI in C. glutamicum 2262. The phosphorylation status of OdhI alone is, as expected, not the only parameter that determines the performance of a specific strain, as no clear relation between the specific glutamate production rate and OdhI phosphorylation level was demonstrated

Current views on fungal chitin/chitosan, human chitinases, food preservation, glucans, pectins and inulin: A tribute to Henri Braconnot, precursor of the carbohydrate polymers science, on the chitin bicentennial

During the 1960s and 1970s, a magni\ufb01cent cloud forest near San Francisco de Las Pampas (near Quito, Ecuador) was converted into dairy farm pastures. One endemic composite plant locally called marco yuyo and identi\ufb01ed as Munnozia pinnatipartita, has been considered an undesirable weed by dairy farming campesino communities because it negatively affects the introduced grass pasture and is unsuitable as cattle feed. Concurrently, M. pinnatipartita has also been utilized for its herbicidal properties as a deterrent to grasses in a project promoting cloud forest recovery in the Otonga natural park. The peculiarity of this endemic composite utilized as such a deterrent attracted our interest. Accordingly, we investigated its taxonomy, physiology, ecology, and ethnobiology, and managed to demonstrate its potential allelopathic effect on germinating grasses in greenhouse trials. Furthermore, gas-chromatography of potential volatile metabolites identi\ufb01ed 25 compounds and, among these, terpenes seem to be primarily responsible for the observed herbicidal effects