Production, purification, and characterization of a major penicillium glabrum xylanase using brewer's spent grain as substrate

In recent decades, xylanases have been used in many processing industries. This study describes the xylanase production by Penicillium glabrum using brewer's spent grain as substrate. Additionally, this is the first work that reports the purification and characterization of a xylanase using this agroindustrial waste. Optimal production was obtained when P. glabrum was grown in liquid medium in pH 5.5, at 25 ��C, under stationary condition for six days. The xylanase from P. glabrum was purified to homogeneity by a rapid and inexpensive procedure, using ammonium sulfate fractionation and molecular exclusion chromatography. SDS-PAGE analysis revealed one band with estimated molecular mass of 18.36 kDa. The optimum activity was observed at 60 ��C, in pH 3.0. The enzyme was very stable at 50 ��C, and high pH stability was verified from pH 2.5 to 5.0. The ion Mn2+ and the reducing agents ��-mercaptoethanol and DTT enhanced xylanase activity, while the ions Hg2+, Zn2+, and Cu2+ as well as the detergent SDS were strong inhibitors of the enzyme. The use of brewer's spent grain as substrate for xylanase production cannot only add value and decrease the amount of this waste but also reduce the xylanase production cost. �� 2013 Adriana Knob et al.

Supplementation of soft drinks with metallic ions reduces dissolution of bovine enamel

Funda����o de Amparo �� Pesquisa do Estado de S��o Paulo (FAPESP)

Determination of in situ speciation of manganese in treated acid mine drainage water by using multiple diffusive gradients in thin films devices

Acid mine drainage (AMD) is a serious environmental problem that creates acidic solution with high Mn concentrations. The speciation of residual Mn from AMD after an active treatment involving the addition of a neutralizing agent can reliably evaluate the treatment efficiency and provide knowledge of the Mn species being inputted into the environment. The aim of this study was to evaluate the in situ lability and speciation of Mn using the diffusive gradients in thin films (DGT) technique with treated drainage water from a uranium mine (TAMD). DGT devices with different binding phases (Chelex-100 and P81 and DE81membranes) were used to perform the in situ speciation of Mn. A comparison of the results from deploying DGT in the laboratory and in situ shows that the speciation of Mn in TAMD should be performed in situ. Linear deployment curves (from in situ experiments) indicate that the DGT device containing the Chelex-100 binding phase can be used to evaluate Mn lability in TAMD. The labile Mn fraction (from in situ measurements) obtained using the device containing the Chelex-100 resin ranged from 63 to 81% of the total Mn concentration and, when compared to the speciation obtained using the CHEAQS software, indicated that this device was capable of uptaking the free Mn2+ and a portion of the MnSO4(aq). The values obtained using the DGT technique were compared to those from on site solid phase extraction, and a good agreement was found between the results. The amount of negative Mn species sampled by DE81 device was insignificant (<1.5%) for all of the sites. Sites containing a relatively small amount of Ca (<40mgL-1) and measured using devices containing the P81 membrane agreed with the concentration predicted by the CHEAQS software for positive Mn species (Mn2+ and Mn(OH)+). Nevertheless, the speciation obtained using the CHEAQS software indicated that the concentrations of positive Mn species were underestimated for sites with relatively high Ca concentrations (>150mgL-1), which take place due to the saturation of binding sites in the P81 membrane. �� 2013 Elsevier B.V.

Atividade coagulante e da toxidade da giroxina nativa e irradiada com Cobalto-60 isolada do veneno de Crotalus durissus terrificus

Coordena����o de Aperfei��oamento de Pessoal de N��vel Superior (CAPES)

Caracteriza����o f��sico-qu��mica de pectinases extracelulares purificadas de Aspergillus giganteus

Funda����o de Amparo �� Pesquisa do Estado de S��o Paulo (FAPESP)

Estudo da dopagem no ��xido de mangan��s tipo espin��lio nanoestruturado no desempenho de um sensor potenciom��trico para ��ons l��tio

Coordena����o de Aperfei��oamento de Pessoal de N��vel Superior (CAPES)

'Beta'-D-frutofuranosidases de Fusarium graminearum: produ����o, purifica����o, imobiliza����o e determina����o das propriedades bioqu��micas de enzimas sol��veis e secas em Spray dryer

P��s-gradua����o em Biotecnologia - IQ

Estudos estruturais com miotoxinas do tipo fosfolipases A2 hom��logas do veneno de serpentes do g��nero Bothrops: avan��os no entendimento da rela����o estrutura-fun����o

Coordena����o de Aperfei��oamento de Pessoal de N��vel Superior (CAPES)

Purifica����o e caracteriza����o bioqu��mica da ��-glicosidase termoest��vel produzida por Thermoascus aurantiacus CBMAI 756

Funda����o de Amparo �� Pesquisa do Estado de S��o Paulo (FAPESP)

Purifica����o e caracteriza����o bioqu��mica de poligalacturonases termoest��veis produzidas pelo fungo Thermoascus aurantiacus atrav��s de fermenta����o submersa e fermenta����o em estado s��lido

Funda����o de Amparo �� Pesquisa do Estado de S��o Paulo (FAPESP)

Produ����o, isolamento e caracteriza����o de 'beta'-galactosidades de Trichoderma reesei: intera����o de ��ons met��licos na atividade enzim��tica

Coordena����o de Aperfei��oamento de Pessoal de N��vel Superior (CAPES)

Effect of divalent metal ions on the activity and stability of ��-galactosidase isolated from Kluyveromyces lactis

In this study, it was demonstrated that ��-galactosidase can be deactivated and reactivated with EDTA and divalent metal ions. The enzyme was deactivated after 20 minutes in EDTA solution. Maximal deactivation at the lowest EDTA concentration (10-3 mol.L-1) occurred in the presence of Tris-HCl buffer (pH 7.0). The enzyme recovered 50% of its initial activity after 10 minutes at Mg2+concentrations higher than 0.1 mmol.L-1. Experimental concentrations of 0.1 mmol.L-1 Mn2+ and 1.0 mmol.L-1 Co2+ were sufficient to reactivate the enzyme to around 300% of the control activity for the Mn2+ ion and nearly 100% for the Co2+ ion. The enzyme gradually lost its activity when the Co2+ concentration was 10-2 mol.L-1. Ni2+ and Zn2+ were unable to restore the catalytic activity. Km app and Vmax app were 1.95 �� 0.05 mmol.L-1 and 5.40 �� 0.86x10-2 mmol.min-1.mg-1, with o-NPG as substrate. Optimal temperature and pH were 34oC and 7.5. The half-life (t1/2) at 30��C was 17.5 min for the holoenzyme and 11.0 min for the apoenzyme. With respect to pH variation, the apoenzyme proved to be more sensitive than the holoenzyme. Keywords: ��-galactosidase. Divalent metallic ions. Enzyme activity. Stability. RESUMO Efeito de ��ons met��licos divalentes na atividade e estabilidade da ��-galactosidase isolada de Kluyveromyces lactis Este estudo demonstra como a ��-galactosidase pode ser desativada e reativada usando EDTA e ��ons met��licos divalentes. A enzima foi desativada ap��s 20 minutos na presen��a de EDTA. Desativa����o m��xima para a menor concentra����o de EDTA (10-3 mol.L-1) ocorreu na presen��a do tamp��o Tris-HCl. A enzima recuperou 50% de sua atividade inicial ap��s 10 minutos na presen��a de Mg2+ em concentra����es superiores a 0,1mmol.L-1. Concentra����es de 10-4 e 10-3mol.L-1 de Mn2+ e Co2+ foram suficientes para reativar a enzima em 300% comparado ao controle de ��ons Mn2+ e aproximadamente 100% para ��ons Co2+. A enzima perdeu gradualmente a sua atividade quando a concentra����o foi de 10-2 mol.L-1. Ni2+ e Zn2+ foram incapazes de restabelecer a atividade catal��tica. Km app e Vmax app foram 1,95 �� 0,05 mmol.L-1 e 5,40 �� 0,86 x 10-2 mmol.min-1.mg-1. A temperatura e pH ��timos foram 34��C e 7,5. A meia vida da holoenzima foi de 17,5 min a 30��C e para a apoenzima foi de 11,0 min a 30��C. Quanto �� varia����o de pH, a apoenzima provou ser mais sens��vel que a holoenzima. Palavras-chave: ��-galactosidase. ��ons met��licos divalentes. Atividade enzim��tica. Estabilidade.

Processamento e propriedades magn��ticas de manganitas multiferr��icas = Mise en forme et propri��t��s magn��tiques de manganites multiferr����ques

P��s-gradua����o em Ci��ncia e Tecnologia de Materiais - FC

Improvement of the photocatalytic activity of magnetite by Mn-incorporation

Coordena����o de Aperfei��oamento de Pessoal de N��vel Superior (CAPES)

Characterization of the co-purified invertase and beta-glucosidase of a multifunctional extract from Aspergillus terreus

The filamentous fungus Aspergillus terreus secretes both invertase and beta-glucosidase when grown under submerged fermentation containing rye flour as the carbon source. The aim of this study was to characterize the co-purified fraction, especially the invertase activity. An invertase and a beta-glucosidase were co-purified by two chromatographic steps, and the isolated enzymatic fraction was 139-fold enriched in invertase activity. SDS-PAGE analysis of the co-purified enzymes suggests that the protein fraction with invertase activity was heterodimeric, with subunits of 47 and 27 kDa. Maximal invertase activity, which was determined by response surface methodology, occurred in pH and temperature ranges of 4.0-6.0 and 55-65 A degrees C, respectively. The invertase in co-purified enzymes was stable for 1 h at pH 3.0-10.0 and maintained full activity for up to 1 h at 55 A degrees C when diluted in water. Invertase activity was stimulated by 1 mM concentrations of Mn2+ (161 %), Co2+ (68 %) and Mg2+ (61 %) and was inhibited by Al3+, Ag+, Fe2+ and Fe3+. In addition to sucrose, the co-purified enzymes hydrolyzed cellobiose, inulin and raffinose, and the apparent affinities for sucrose and cellobiose were quite similar (K-M = 22 mM). However, in the presence of Mn2+, the apparent affinity and V-max for sucrose hydrolysis increased approximately 2- and 2.9-fold, respectively, while for cellobiose, a 2.6-fold increase in V-max was observed, but the apparent affinity decreased 5.5-fold. Thus, it is possible to propose an application of this multifunctional extract containing both invertase and beta-glucosidase to degrade plant biomass, thus increasing the concentration of monosaccharides obtained from sucrose and cellobiose.