Performance of malolactic fermentation by inoculation of selected Lactobacillus plantarum and Oenococcus oeni strains isolated from Rioja red wines

Malolactic fermentations (MLF) of wines inoculated with selected lactic acid bacteria strains of the species Oenococcus oeni and Lactobacillus plantarum were studied and compared with spontaneous MLF. Bacterial populations were monitored along the whole process of MLF and bacteria identifications were carried out at species and strain level. Macrorestriction analysis with SfiI endonuclease and subsequent PFGE was carried out in order to identify O. oeni individual strains. L. plantarum active lyophila did not survive competing with the indigenous microbiota in a wine with 15.3 % (vol/vol) alcohol, whereas the selected O. oeni strains carried out wine MLF. The highest production of histamine took place during MLF in those wines that underwent spontaneous MLF with a mixed population of indigenous strains. The lowest levels of histamine were obtained with the selected commercial O. oeni strain that succeeded 100 % over the indigenous microbiota. Results indicate that development of MLF leaded by selected O. oeni active lyophila provides negligible histamine levels in red wines of quality that can be submitted to subsequent ageing in wood.

Characterization and winemaking application of a novel pectin-degrading enzyme complex from Aspergillus sojae ATCC 20235

A novel pectin-degrading enzyme complex produced by Aspergillus sojae ATCC 20235 (PC-AS) using lowcost substrates was characterised in terms of its enzyme activities relevant in winemaking. This novel PC-AS was applied at the maceration/fermentation stage during the elaboration of 'Tempranillo' red wines to study its effect on colour development and the phenolic and amino acid wine composition. PC-AS polygalacturonase activity was the major enzyme activity detected and quantified under winemaking conditions (pH 3.5, 20 °C) and proved being stable and active in the presence of sulfur dioxide. Xylanase activity, albeit in lesser amounts, was also present in PC-AS, and neither pectinesterase, which produces methanol, nor β-glucosidase, which is detrimental to wine colour, were detected in PC-AS. This pectin-degrading complex promoted a faster colour extraction since maximum colour intensity of the enzyme treated wines was reached earlier compared to their controls. After 6 months of storage under winery conditions, wines elaborated with PC-AS presented higher concentrations of caffeic acid, coumaric acid and aspartic acid (p ˂ 0.05), suggesting an improved extraction of grape cell components. In conclusion, the application of PCAS yielded results that showed that it can be used in red winemaking to shorten the maceration time needed to reach high CI values and to improve the extraction of some phenolics and other compounds that enhance the quality of the final product.Facultad de Ciencias ExactasCentro de Investigación y Desarrollo en Fermentaciones Industriale

Characterization and winemaking application of a novel pectin-degrading enzyme complex from Aspergillus sojae ATCC 20235

A novel pectin-degrading enzyme complex produced by Aspergillus sojae ATCC 20235 (PC-AS) using lowcost substrates was characterised in terms of its enzyme activities relevant in winemaking. This novel PC-AS was applied at the maceration/fermentation stage during the elaboration of 'Tempranillo' red wines to study its effect on colour development and the phenolic and amino acid wine composition. PC-AS polygalacturonase activity was the major enzyme activity detected and quantified under winemaking conditions (pH 3.5, 20 °C) and proved being stable and active in the presence of sulfur dioxide. Xylanase activity, albeit in lesser amounts, was also present in PC-AS, and neither pectinesterase, which produces methanol, nor β-glucosidase, which is detrimental to wine colour, were detected in PC-AS. This pectin-degrading complex promoted a faster colour extraction since maximum colour intensity of the enzyme treated wines was reached earlier compared to their controls. After 6 months of storage under winery conditions, wines elaborated with PC-AS presented higher concentrations of caffeic acid, coumaric acid and aspartic acid (p ˂ 0.05), suggesting an improved extraction of grape cell components. In conclusion, the application of PCAS yielded results that showed that it can be used in red winemaking to shorten the maceration time needed to reach high CI values and to improve the extraction of some phenolics and other compounds that enhance the quality of the final product.Facultad de Ciencias ExactasCentro de Investigación y Desarrollo en Fermentaciones Industriale

Aplicación de una preparación pectinolítica de <i>Aspergillus sojae</i> en la elaboración de vino blanco

Se estudió el efecto del un preparado pectinolítico de Aspergillus sojae (PP-AS) en la elaboración de vinos blancos. Se adicionó PP-AS al mosto de uva blanca para estudiar el efecto clarificante del mismo durante el desfangado (proceso de ―limpieza‖ del mosto antes de fermentar), y posteriormente se utilizaron los mostos desfangados para elaborar vinos blancos secos y analizar su composición química final desde el punto de vista enológico. Un gramo de PP-AS presentó igual número unidades de actividad pectinolítica, determinada sobre pectina en condiciones similares a las utilizadas durante el desfangado (pH 3,5 y 20° C), que un preparado comercial utilizado como testigo en los ensayos. Según los resultados obtenidos, los mostos tratados con PP-AS disminuyeron su turbidez significativamente respecto a los mostos control, y hasta valores considerados óptimos (100-250 NTU) para su posterior uso en la elaboración de vinos blancos de calidad. Los vinos blancos elaborados con PP-AS exhibieron un mayor contenido de ácido L-málico y un menor contenido de ácido L-láctico respecto a los vinos elaborados sin enzimas, efectos buscados en la elaboración ciertos tipos de vinos blancos secos.Centro de Investigación y Desarrollo en Fermentaciones Industriale

Characterization and winemaking application of a novel pectin-degrading enzyme complex from Aspergillus sojae ATCC 20235

A novel pectin-degrading enzyme complex produced by Aspergillus sojae ATCC 20235 (PC-AS) using lowcost substrates was characterised in terms of its enzyme activities relevant in winemaking. This novel PC-AS was applied at the maceration/fermentation stage during the elaboration of 'Tempranillo' red wines to study its effect on colour development and the phenolic and amino acid wine composition. PC-AS polygalacturonase activity was the major enzyme activity detected and quantified under winemaking conditions (pH 3.5, 20 °C) and proved being stable and active in the presence of sulfur dioxide. Xylanase activity, albeit in lesser amounts, was also present in PC-AS, and neither pectinesterase, which produces methanol, nor β-glucosidase, which is detrimental to wine colour, were detected in PC-AS. This pectin-degrading complex promoted a faster colour extraction since maximum colour intensity of the enzyme treated wines was reached earlier compared to their controls. After 6 months of storage under winery conditions, wines elaborated with PC-AS presented higher concentrations of caffeic acid, coumaric acid and aspartic acid (p ˂ 0.05), suggesting an improved extraction of grape cell components. In conclusion, the application of PCAS yielded results that showed that it can be used in red winemaking to shorten the maceration time needed to reach high CI values and to improve the extraction of some phenolics and other compounds that enhance the quality of the final product.Facultad de Ciencias ExactasCentro de Investigación y Desarrollo en Fermentaciones Industriale

Glycation does not modify bovine serum albumin (BSA)-induced reduction of rat aortic relaxation: The response to glycated and nonglycated BSA is lost in metabolic syndrome

The effects of nonglycated bovine serum albumin (BSA) and advanced glycosylation end products of BSA (AGE-BSA) on vascular responses of control and metabolic syndrome (MS) rats characterized by hypertriglyceridemia, hypertension, hyperinsulinemia, and insulin resistance were studied. Albumin and in vitro prepared AGE-BSA have vascular effects; however, recent studies indicate that some effects of in vitro prepared AGEs are due to the conditions in which they were generated. We produced AGEs by incubating glucose with BSA for 60 days under sterile conditions in darkness and at 37°C. To develop MS rats, male Wistar animals were given 30% sucrose in drinking water since weanling. Six month old animals were used. Blood pressure, insulin, triglycerides, and serum albumin were increased in MS rats. Contraction of aortic rings elicited with norepinephrine was stronger. There were no effects of nonglycated BSA or AGE-BSA on contractions in control or MS rats; however, both groups responded to L-NAME, an inhibitor of nitric oxide synthesis. Arterial relaxation induced using acetylcholine was smaller in MS rats. Nonglycated BSA and AGE-BSA significantly diminished relaxation in a 35% in the control group but the decrease was similar when using nonglycated BSA and AGE-BSA. This decrease was not present in the MS rats and was not due to increased RAGEs or altered biochemical characteristics of BSA. In conclusion, both BSA and AGE-BSA inhibit vascular relaxation in control artic rings. In MS rats the effect is lost possibly due to alterations in endothelial cells that are a consequence of the illness

Decoding the Folding of Burkholderia glumae Lipase: Folding Intermediates En Route to Kinetic Stability

The lipase produced by Burkholderia glumae folds spontaneously into an inactive near-native state and requires a periplasmic chaperone to reach its final active and secretion-competent fold. The B. glumae lipase-specific foldase (Lif) is classified as a member of the steric-chaperone family of which the propeptides of α-lytic protease and subtilisin are the best known representatives. Steric chaperones play a key role in conferring kinetic stability to proteins. However, until present there was no solid experimental evidence that Lif-dependent lipases are kinetically trapped enzymes. By combining thermal denaturation studies with proteolytic resistance experiments and the description of distinct folding intermediates, we demonstrate that the native lipase has a kinetically stable conformation. We show that a newly discovered molten globule-like conformation has distinct properties that clearly differ from those of the near-native intermediate state. The folding fingerprint of Lif-dependent lipases is put in the context of the protease-prodomain system and the comparison reveals clear differences that render the lipase-Lif systems unique. Limited proteolysis unveils structural differences between the near-native intermediate and the native conformation and sets the stage to shed light onto the nature of the kinetic barrier

Rents, knowledge and neo-structuralism: transforming the productive matrix in Ecuador

This paper explores the relationship between ground rent, production and knowledge in Ecuador’s neo-structuralist, state-led project to transform the productive matrix. Based upon insights from the Marxian approach to the critique of political economy, we interrogate how neo-structuralism has conceptualised the relationship between ‘natural resource income’ and ‘knowledge-based’ economic development. The paper argues that a rent-theoretical perspective, which takes seriously the regional unfolding of uneven geographical development in Latin America, can highlight the limits of a national development plan conceived according to the logic of Schumpeterian efficiency. In doing so, the paper identifies the contradictory relationship between natural resource exports, state-led ‘knowledge’-based development and capital accumulation. On this basis the paper offers a historically and empirically informed critical analysis of selective import substitution industrialisation and vanguard science and technology strategies designed to transition Ecuador away from primary resource dependence