Entity

Time filter

Source Type


Adachi O.,Yamaguchi University | Hours R.A.,Research and Development Center for Industrial Fermentation | Akakabe Y.,Yamaguchi University | Tanasupawat S.,Chulalongkorn University | And 4 more authors.
Bioscience, Biotechnology and Biochemistry | Year: 2010

Production of 4-keto-D-arabonate (4KAB) was confirmed in a culture medium of Gluconacetobacter liquefaciens strains, newly isolated from water kefir in Argentina. The strains rapidly oxidized D-glucose, Dgluconate (GA), and 2-keto-D-gluconate (2KGA), and accumulated 2,5-diketo-D-gluconate (25DKA) exclusively before reaching the stationary phase. 25DKA was in turn converted to 4KAB, and 4KAB remained stable in the culture medium. The occurrence of 4KAB was assumed by Ameyama and Kondo about 50 years ago in their study on the carbohydrate metabolism of acetic acid bacteria (Bull. Agr. Chem. Soc. Jpn., 22, 271-272, 380-386 (1958)). This is the first report confirming microbial production of 4KAB. Source


Adachi O.,Yamaguchi University | Hours R.A.,Research and Development Center for Industrial Fermentation | Shinagawa E.,National Institute of Technology, Ube College | Akakabe Y.,Yamaguchi University | And 2 more authors.
Bioscience, Biotechnology and Biochemistry | Year: 2011

4-Keto-D-arabonate (D-threo-pent-4-ulosonate) and 4-keto-D-ribonate (D-erythro-pent-4-ulosonate) were prepared from D-arabinose and D-ribose by two successive reactions of membrane-bound enzymes, D-aldopentose 4-dehydrogenase and 4-keto-D-aldopentose 1-dehydrogenase of Gluconobacter suboxydans IFO 12528. Alternatively, they were prepared from D-arabonate and D-ribonate with another membrane-bound enzyme, Dpentonate 4-dehydrogenase. Analytical data confirmed the chemical structures of the 4-pentulosonates prepared. This is the first report of successful enzymatic synthesis of 4-pentulosonates. Source


Adachi O.,Yamaguchi University | Hours R.A.,Research and Development Center for Industrial Fermentation | Akakabe Y.,Yamaguchi University | Shinagawa E.,National Institute of Technology, Ube College | And 3 more authors.
Bioscience, Biotechnology and Biochemistry | Year: 2013

D-Ribose and 2-deoxy-D-ribose were oxidized to 4- keto-D-ribonate and 2-deoxy-4-keto-D-ribonate respectively by oxidative fermentation, and the chemical structures of the oxidation products were confirmed to be as expected. Both pentoses are important sugar components of nucleic acids. When examined, purine nucleosidase activity predominated in the membrane fraction of acetic acid bacteria. This is perhaps the first finding of membrane-bound purine nucleosidase. Source


Butiuk A.P.,Research and Development Center for Industrial Fermentation | Martos M.A.,National University of Misiones | Adachi O.,Yamaguchi University | Hours R.A.,Research and Development Center for Industrial Fermentation
Journal of Applied Research on Medicinal and Aromatic Plants | Year: 2015

Chlorogenic acid (CGA) is a fine chemical used in different food and pharmaceutical industries. CGA is currently extracted from various plant materials, particularly green coffee beans. Yerba mate (Ilex paraguariensis St. Hil.) contains significant amounts of CGA with very low levels of extraction interfering substances (fatty materials). Both of these reasons prompted us to evaluate yerba mate as a novel source for extraction of this compound.CGA content was quantified in various yerba mate fractions during different processing steps, and in samples taken from two companies at early and late harvesting seasons. Samples were exhaustively extracted with hot water and total CGA content (including its three isomeric compounds) was determined by HPLC. Total CGA content (on a dry weight basis) ranged from 45.8±0.4 to 80.8±1.0g CGA kg-1 of leaves and from 31.6±0.6 to 78.9±5.3g CGA kg-1 of stems. A substantial reduction in CGA content was found along the processing steps. The highest CGA content was found in samples from freshly harvested (green) yerba mate, for both leaves and stems; with no significant differences in their CGA content (P <0.05). CGA content at the early harvesting season was substantially higher to that obtained at the end of the harvesting season, for both green leaves and stems.Green stems, a residue from yerba mate processing obtained at the early harvesting season, could be considered as a promising and valuable raw material for the production of CGA-enriched extracts. © 2015 Elsevier GmbH. Source


Zapata Zapata A.D.,National University of Colombia | Zapata Zapata A.D.,Research and Development Center for Industrial Fermentation | Gaviria Montoya C.A.,National University of Colombia | Cavalitto S.F.,Research and Development Center for Industrial Fermentation | And 2 more authors.
LWT - Food Science and Technology | Year: 2012

Protopectinase-SE was used to macerate the albedo layer from sour orange (Citrus aurantium). The effect of agitation on the process was evaluated and then, antioxidant activity of the resulting preparation was determined by mean of the methodologies DPPH, ABTS, and ferric reducing antioxidant power. The following parameters were assayed: the levels of total phenols, reducing sugars, vitamin C, total flavonones, naringin, and galacturonic acid as well as the preparation's total acidity. It was found that the use of either a reciprocal or orbital system of agitation, the latter feature achieved with flasks having internal deflectors, yielded similar maceration levels (33 g/100 g). Moreover, the antioxidant activity, as well as the concentrations of vitamin C and total flavonones was the highest with the greatest degree of tissue maceration. These results confirm the effectiveness of the method of maceration for obtaining a form of cellular disruption that result in a maximum conservation of the nutritional characteristics of the processed tissue. © 2011 Elsevier Ltd. Source

Discover hidden collaborations