Advanced oxidation processes applied for color removal of textile effluent using a home-made peroxidase from rice bran

Bioprocess and Biosystems Engineering - Enzymes are becoming tools in industrial processes because of several advantages, including activity in mild environmental conditions, and high specificity....     

Cellulolytic enzyme production from agricultural residues for biofuel purpose on circular economy approach

This study evaluated the production of cellulolytic enzymes from different agricultural residues. The crude enzyme extract produced was characterized and applied for saccharification of some agricultural residues. Maximum cellulolytic activities were obtained using soybean hulls. All enzymatic activities were highly stable at 40 °C at a pH range of 4.5–5.5. For stability at low temperatures, the enzyme extract was stored at freezing temperature and cooling for about 290 days without major loss of activity. The K_m values found for total cellulase (FPase), endoglucanase (CMCase), and xylanase were 19.73 mg ml⁻¹, 0.65 mg ml⁻¹, and 22.64 mg ml⁻¹, respectively, and V_max values were 0.82 mol min⁻¹ mg⁻¹, 0.62 mol min⁻¹ mg⁻¹, and 104.17 mol min⁻¹ mg⁻¹ to cellulose, carboxymethyl cellulose, and xylan, respectively. In the saccharification tests, the total amount of total reducing sugars (TRS) released from 1 g of soybean hulls catalyzed by the enzymes present in the crude enzyme extract was 0.16 g g⁻¹ dry substrate.

     

Genetic variability in G2 and F2 region between biological clones of human respiratory syncytial virus with or without host immune selection pressure

Human respiratory syncytial virus (HRSV) is an important respiratory pathogens among children between zero-five years old. Host immunity and viral genetic variability are important factors that can make vaccine production difficult. In this work, differences between biological clones of HRSV were detected in clinical samples in the absence and presence of serum collected from children in the convalescent phase of the illness and from their biological mothers. Viral clones were selected by plaque assay in the absence and presence of serum and nucleotide sequences of the G2 and F2 genes of HRSV biological clones were compared. One non-synonymous mutation was found in the F gene (Ile5Asn) in one clone of an HRSV-B sample and one non-synonymous mutation was found in the G gene (Ser291Pro) in four clones of the same HRSV-B sample. Only one of these clones was obtained after treatment with the child''s serum. In addition, some synonymous mutations were determined in two clones of the HRSV-A samples. In conclusion, it is possible that minor sequences could be selected by host antibodies contributing to the HRSV evolutionary process, hampering the development of an effective vaccine, since we verify the same codon alteration in absence and presence of human sera in individual clones of BR-85 sample.     

3,4‐Dihydroxyphenylethanol and 3,4‐dihydroxyphenylacetic acid affect the aggregation process of E46K variant of α‐synuclein at different extent: Insights into the interplay between protein dynamics and catechol effect

Parkinson''s disease (PD) is a chronic multifactorial disease, whose etiology is not completely understood. The amyloid aggregation of α‐synuclein (Syn) is considered a major cause in the development of the disease. The presence of genetic mutations can boost the aggregation of the protein and the likelihood to develop PD. These mutations can lead to early onset (A30P, E46K, and A53T) or late‐onset (H50Q) forms of PD. The disease is also linked to an increase in oxidative stress and altered levels of dopamine metabolites. The molecular interaction of these molecules with Syn has been previously studied, while their effect on the pathological mutant structure and function is not completely clarified. By using biochemical and biophysical approaches, here we have studied the interaction of the familial variant E46K with two dopamine‐derived catechols, 3,4‐dihydroxyphenylacetic acid and 3,4‐dihydroxyphenylethanol. We show that the presence of these catechols causes a decrease in the formation of amyloid fibrils in a dose‐dependent manner. Native‐ and Hydrogen/deuterium exchange‐mass spectrometry (HDX‐MS) provide evidence that this effect is strongly conformation dependent. Indeed, these molecules interact differently with the interconverting conformers of Syn and its familial variant E46K in solution, selecting the most prone‐to‐aggregation one, confining it into an off‐pathway oligomer. These findings suggest that catechols could be a molecular scaffold for the design of compounds potentially useful in the treatment of Parkinson''s disease and related conditions.