Impact of manganese on the production of a biomass associated B-D-lucosidase activity using a thermophilic Bacilllus licheniformis strain

The â-Glucosidase (EC 3.2.1.21) constitutes a group of well-studied hydrolases. This enzyme catalyzes the hydrolysis of arylglucosides, alkylglucosides, cellobiose, and cellooligosaccharides. The interest in this biocatalyst centers on its roles in the enzymatic hydrolysis of cellulose. The rate of cellulose hydrolysis can be improved by supplementing commercial cellulases with immobilized â-D-glucosidase, which usually has high stability and can be recovered and reused. In addition, for industrial saccharification of cellulosic materials, â-glucosidases from thermophilic bacteria are also of particular interest due to their increased stability. In this work, we study the influence of manganese on the production of a biomass associate â-D-glucosidase activity using a thermophilic Bacillus licheniformis strain. Assays were performed at 45 °C in 500 ml Erlenmeyer containing 200 ml of LB medium supplemented with 0 - 1.0 mM MnCl2. The â-D-glucosidase activity was also determined at 45 °C using 3.6 mM p-nitrophenyl-â -D-glucopyranoside (Sigma) as substrate. Cells were harvested by centrifugation and washed twice with 100 mM Tris-HCl buffer (pH 7). The pellet was resuspended in the same buffer, and it was directly used as the â-D-glucosidase source. The mixture was shaken at 1000 rpm. Then, the absorbance of the supernatant was measured at 405 nm and the enzyme activity calculated and related to the biomass dry weight. One unit of the enzyme was defined as the amount needed to release 1 µmol p-nitrophenol per min. Thus, dose-response experiments showed that in the presence of 0.3 mM MnCl2 the enzyme production was increased by about 20%. Under this culture condition, a specific activity value of 19.99 U per mg of dry weight was obtaining after 4 h of cultivation. Finally, these results could be of relevance to the bioethanol industry where lignocellulosic material is used as feedstock for fermentation and, which should be treated enzymatically. The use of naturally bound enzymes is an important immobilization technique. This type of biocatalyst system is potentially cost-effective because the biomass can be directly utilized in the treatment.Fil: Abdulhamid, María Belén. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Baigorí, Mario Domingo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Pera, Licia Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaXI Congreso Argentino de Microbiología GeneralCórdobaArgentinaSociedad Argentina de Microbiología Genera

Estudio del efecto de iones metálicos en el tratamiento de vinaza para la obtención de productos de interés biotecnológicos

La vinaza es un subproducto final resultante de la producción de bioetanol a partir de cultivos azucareros. La disposición inadecuada e indiscriminada de la vinaza ha generado problemas ambientales. Se han desarrollado técnicas de biorremediación para el tratamiento de este efluente, entre estos encontramos el empleo de microorganismos oleaginosos con interés biotecnológico, para la obtención de biomasa y lípidos con fines energéticos. En el presente trabajo se evaluó el efecto de diferentes concentraciones de sales inorgánicas en vinaza para el desarrollo de Rhodotorula mucilaginosa y Rhodotorula glutinis. Se observó un incremento en el diámetro mayor y menor de las levaduras oleaginosas con el agregado de FeCl 3 y MnCl 2 sin embargo el aumento no fue significativo en la obtención de biomasa y lípidos. A su vez, se logró una remoción de la carga de la vinaza del 66% para R. mucilaginosa y 67% para R. glutinis.Vinasse is a final by-product resulting from the production of bioethanol from sugarcane crops. Inadequate and indiscriminate disposal of vinasse in soils and bodies of water has generated environmental problems. Bioremediation techniques have been developed for the treatment of this effluent, among them we find the use of oleaginous microorganisms with biotechnological interest. It is an interesting option for obtaining biomass and lipids for energy purposes. In the present work the effect of different concentrations of inorganic salts in vinasse was evaluated for the development of oleaginous yeasts, using vinasse as the culture medium. It was observed an increase in the major and minor diameter of Rhodotorula mucilaginosa and Rhodotorula glutinis, with the addition of salts in different concentrations of FeCl 3 and MnCl 2 , however the increase was not significant in obtaining biomass and lipids. A removal of the enriched vinasse load was achieved with 66% and 67% salts for R. mucilaginosa and R. glutinis respectively.Fil: Reyes, Sarita Isabel. Consejo Nacional de Investigaciones Científicas y TécnicasFil: Alfaro, Juan Manuel. Consejo Nacional de Investigaciones Científicas y TécnicasFil: Martearena, María Rita. Consejo Nacional de Investigaciones Científicas y TécnicasFil: Blanco, Silvia. Consejo Nacional de Investigaciones Científicas y TécnicasFil: Baigorí, Mario. Consejo Nacional de Investigaciones Científicas y TécnicasFil: Pera, Licia. Consejo Nacional de Investigaciones Científicas y Técnica

Proizvodnja pektinaza, aktivnih pri niskim temperaturama, pomoću psihrotolerantnih mikroorganizama

In winemaking, low temperatures are favourable for the production and retention of flavour and colour components, requiring the use of cold-active enzymes. For this reason, \u27psychrotolerant\u27 microorganisms have been isolated and selected based on their ability to produce pectinolytic enzymes with satisfactory activity at low temperatures. Different mature grape varieties with designation of origin were sampled from the region of San Rafael (Mendoza, Argentina), and pectinolytic bacterial, fungal and yeast strains were isolated. The pectinolytic activity was measured by cup-plate assay, quantification of released reducing sugars and viscosity reduction of pectin solution. Two bacteria (Bacillus sp. SC-G and SC-H) and two yeast strains were selected for their good pectinase activity at low temperatures. Among them, the strain with the highest activity, Bacillus sp. SC-H, was selected. According to their 16S rRNA profiles, Bacillus sp. SC-G and SC-H can be classified as members of Bacillus subtilis. Among the assayed techniques, the rotary evaporation was found to be the most appropriate to obtain enzymatic extracts with highest activity. The optimal conditions for the enzymatic activity were 30 °C and pH=5.0 for the concentrated extract, and 45 °C and pH=6.0 for the filtered supernatant. The concentrated extract presented good activity at 3 °C, confirming that it was a cold-active enzyme. Natural extraction and enzymatic preparation were used to extract pigments and polyphenols from Malbec grapes. Better results were obtained for the enzymatic extract with regard to index, shade, CIELab coordinates, CIELab colour differences and polyphenols (measured using Folin-Ciocalteu).Da bi se dobili što boji okus i boja vina, u vinarstvu se primjenjuju enzimi aktivni pri niskim temperaturama. Izolirani su psihrotolerantni mikroorganizmi sposobni da sintetiziraju pektinolitičke enzime aktivne pri niskim temperaturama. Zrelo grožđe različitih sorata s oznakom podrijetla prikupljeno je s područja San Rafael (Mendoz, Argentina), pa su izolirani pektinolitički sojevi bakterija, kvasaca i plijesni. Njihova je učinkovitost ispitana utvrđivanjem aktivnosti pektinaze na agaru (tzv. „cup-plate assay“), određivanjem udjela reducirajućih šećera što nastaju djelovanjem enzima i praćenjem smanjenja viskoznosti otopine pektina. Odabrana su dva soja bakterija (Bacillus sp. SC-G i SC-H) i dva soja kvasaca što luče pektinaze aktivne pri niskim temperaturama. Najveću aktivnost imao je soj Bacillus sp. SC-H. Određivanjem profila 16S rRNA utvrđeno je da su obje bakterije sojevi Bacillus subtilis. Najučinkovitiji enzimski ekstrakti dobiveni su u rotacijskom isparivaču. Optimalni uvjeti za aktivnost enzima bili su: 30 ºC i pH=5,0 za koncentrirani ekstrakt, te 45 ºC i pH=6,0 za filtrirani supernatant. Koncentrirani je ekstrakt imao dobru aktivnost i pri 3 °C, što potvrđuje njegovu učinkovitost pri niskim temperaturama. Prirodnom i enzimskom ekstrakcijom iz grožđa sorte Malbec izdvojeni su pigmenti i polifenoli. Enzimska je ekstrakcija bila učinkovitija, što potvrđuju indeks boje, CIELab koordinate, razlika boje prema CIELab sustavu i udjel polifenola određen Folin-Ciocalteu metodom

Biodiesel a partir de aceite usado de locales gastronómicos: efecto de la temperatura de reacción

El objetivo del trabajo fue evaluar la producción de biodiesel mediante transes- terificación alcalina de aceites usados (AU) recolectados en tres locales gastronómicos, a diferentes temperaturas de reacción. Los AU utilizados como materia prima provienen: bar-comedor de la UNSE-sede central(AUU), rotisería Santa Cruz(AUR) y bar-comedor de Villa Zanjón(AUZ). El índice de acidez de los aceites AUR y AUZ fue menor al 1% mientras que el del AUU fue de 1,4%. La humedad se disminuyó a valores menores al 1%. La obtención del biodiesel se realizó mediante transesterifi- cación alcalina utilizando metanol e KOH, a 120min de reacción variando la temperatura entre 25, 45 y 65°C. Con los tres tipos de aceites y a las tres temperaturas de reacción el rendimiento fue superior al 95% en casi todas las producciones. El punto de inflamación fue aumentando con la temperatura de reacción desde 98°C a 208°C. Las características fisicoquímicas determinadas a los biodiesel cumplen con los parámetros aconsejados por las legislaciones vigentes. La utilización de ALT en la cocción de alimentos para la producción de biodiesel permitiría producir biocombustible y resolver el problema ambiental que generan estos AU cuando son vertidos en cauces de agua o en pozos absorbentes sin un tratamiento previo adecuado.

Selection of Psychrotolerant Microorganisms Producing Cold-Active Pectinases for Biotechnological Processes at Low Temperature

In winemaking, low temperatures are favourable for the production and retention of flavour and colour components, requiring the use of cold-active enzymes. For this reason, 'psychrotolerant' microorganisms have been isolated and selected based on their ability to produce pectinolytic enzymes with satisfactory activity at low temperatures. Different mature grape varieties with designation of origin were sampled from the region of San Rafael (Mendoza, Argentina), and pectinolytic bacterial, fungal and yeast strains were isolated. The pectinolytic activity was measured by cup-plate assay, quantification of released reducing sugars and viscosity reduction of pectin solution. Two bacteria (Bacillus sp. SC-G and SC-H) and two yeast strains were selected for their good pectinase activity at low temperatures. Among them, the strain with the highest activity, Bacillus sp. SC-H, was selected. According to their 16S rRNA profiles, Bacillus sp. SC-G and SC-H can be classified as members of Bacillus subtilis. Among the assayed techniques, the rotary evaporation was found to be the most appropriate to obtain enzymatic extracts with highest activity. The optimal conditions for the enzymatic activity were 30 °C and pH=5.0 for the concentrated extract, and 45 °C and pH=6.0 for the filtered supernatant. The concentrated extract presented good activity at 3 °C, confirming that it was a cold-active enzyme. Natural extraction and enzymatic preparation were used to extract pigments and polyphenols from Malbec grapes. Better results were obtained for the enzymatic extract with regard to index, shade, CIELab coordinates, CIELab colour differences and polyphenols (measured using Folin-Ciocalteu)