Ljubica Tasic

Metabolic Profiling of Human Blood Serum from Treated Patients with Bipolar Disorder Employing 1H NMR Spectroscopy and Chemometrics

Metabolic profiling employing hydrogen nuclear magnetic resonance (1H NMR) spectroscopy and chemometric analysis of human blood serum samples taken from the control group (n = 25) and patients with bipolar disorder (n = 25) was performed to identify molecular changes related to the disorder and to different drug treatments: lithium (n = 15) versus other medications (n = 10). This strategy showed significant potential for exploring pathophysiological and toxicological features involved in bipolar disorder. The investigated groups (control and patients with bipolar disorder under different treatments) could be distinguished according to their metabolic profiles, and the main differential metabolites found were lipids, lipid-metabolism-related molecules (acetate, choline, and myo-inositol), and some key amino acids (glutamate, glutamine). Our results suggest that some of the 24 identified metabolites may be linked to lithium- and other-medication-provoked metabolic changes or may even be directly related to the disorder. Thus, these findings may contribute to paving the way for future studies aiming at identifying potential biomarkers for bipolar disorder.

Enhanced Materials from Nature: Nanocellulose from Citrus Waste

Nanocellulose is a relatively inexpensive, highly versatile bio-based renewable material with advantageous properties, including biodegradability and nontoxicity. Numerous potential applications of nanocellulose, such as its use for the preparation of high-performance composites, have attracted much attention from industry. Owing to the low energy consumption and the addition of significant value, nanocellulose extraction from agricultural waste is one of the best alternatives for waste treatment. Different techniques for the isolation and purification of nanocellulose have been reported, and combining these techniques influences the morphology of the resultant fibers. Herein, some of the extraction routes for obtaining nanocellulose from citrus waste are addressed. The morphology of nanocellulose was determined by Scanning Electron Microscopy (SEM) and Field Emission Scanning Electron Microscopy (FESEM), while cellulose crystallinity indexes (CI) from lyophilized samples were determined using solid-state Nuclear Magnetic Resonance (NMR) and X-Ray Diffraction (XRD) measurements. The resultant nanofibers had 55% crystallinity, an average diameter of 10 nm and a length of 458 nm.

Sargassum filipendula alginate from Brazil: Seasonal influence and characteristics

The aim of this work is focused on the extraction and characterization of the Brazilian seaweed Sargassum filipendula alginate. Alginates obtained at different seasons were characterized by liquid state nuclear magnetic resonance spectroscopy and scanning electron microscopy. The alginate extraction efficiency was about 20%. Different seasons of the year and different stages in the life cycle of Sargassum sp. in southeastern Brazil influenced the M/G and, consequently, the technological properties of extracted alginates.

Advances in Chromobacterium violaceum and properties of violacein-Its main secondary metabolite: A review

Chromobacterium violaceum is important in the production of violacein, like other bacteria, such as Alteromonas, Janthinobacterium, Pseudoalteromonas, Duganella, Collimonas and Escherichia. Violacein is a versatile pigment, where it exhibits several biological activities, and every year, it shows increasing commercially interesting uses, especially for industrial applications in cosmetics, medicines and fabrics. This review on violacein focuses mainly on the last five years of research regarding this target compound and describes production and importance of quorum sensing in C. violaceum, mechanistic aspects of its biosynthesis, monitoring processes, genetic perspectives, pathogenic effects, antiparasitic and antimicrobial activities, immunomodulatory potential and uses, antitumor potential and industrial applications.

Nanocellulose and bioethanol production from orange waste using isolated microorganisms

Citrus processing waste from oranges (CPWO) was explored for the production of nanocellulose and bioethanol. After the isolation of 20 microorganisms from CPWO, their fermentation abilities were screened and two microorganisms identified as Candida parapsilosis strains IFM 48375 and NRRL Y-12969 (ATCC 22019) were selected for a further fermentation. The CPWO was steam distilled for the isolation of essential oil (1.5% g g-1 of dry CPWO) and converted into a mixture of fermentable sugars (40% g g-1 of dry CPWO) using acid or enzymes hydrolyses. Hydrolyzates were fermented with three different yeast strains, the two Candida sp. and Saccharomyces cerevisiae. Candida parapsilosis strain IFM 48375 accomplished excellent results in ethanol production (21% g g-1 of dry CPWO) from CPWO, higher when compared to other strains. Nanocellulose (2.5% g g-1 dry CPWO) and nanofibers (0.5% g g-1 dry CPWO) were isolated from solid residues obtained from enzymatically treated and fermented CPWO. To the best of our knowledge, this work reports for the first time the nanocellulose production from CPWO.

Structural and Functional Characterization of a γ-Type Phospholipase A2 Inhibitor from Bothrops jararacussu Snake Plasma

Phospholipases A2 (PLA2s) from snake venoms comprise a group of 14-18 kDa proteins, responsible for several toxic effects induced by the whole venom. Considering this, studies aiming at the search for natural inhibitors of these proteins are very important. The present work had as objectives the isolation and functional/structural characterization of a γ-type phospholipase A2 inhibitor (PLI) from Bothrops jararacussu snake plasma, named γBjussuMIP. This acidic glycoprotein was isolated in a high purity level through affinity chromatography on CNBr-Sepharose 4B coupled with BthTXII, showing a pI ∼ 5.5 and molecular weight of 23,500 for the monomer (determined by SDS-PAGE), and 160,000 for the oligomer (determined by molecular exclusion chromatography on Sephacryl S-200). The interaction between γBjussuMIP (MIP) and Phospholipase A2 (PLA2) was confirmed using circular dichroism (CD) and emission fluorescence techniques. The helical content of the 1:1 molar mixture was higher than that calculated for the addition of the spectra of the unbound proteins indicating binding. The emission fluorescence experiments pointed that Trp residues in PLA2 participate in proteins interaction as blue shift of 4 nm was observed. The γBjussuMIP cDNA, obtained by PCR of the liver of B. jararacussu snake, revealed 543 bp codifying for a mature protein of 181 amino acid residues. Alignment of its amino acid sequence with those of other snake γPLIs showed 89-94% of similarity. γBjussuMIP mainly inhibited the pharmacological properties of Asp49 PLA2s, such as phospholipase, anticoagulant, myotoxic, edema inducing, cytotoxic, bactericidal and lethal activities. In addition, it showed to be able to supplement Bothrops antivenom, potentiating its antimyotoxic effect. The aspects broached in this work will be able to provide complementary information on possible mechanisms of action, relating structure and function, which could result in a better understanding of the inhibitory effects induced by γBjussuMIP.

Topography-driven bionano-interactions on colloidal silica nanoparticles

We report here that the surface topography of colloidal mesoporous silica nanoparticles (MSNs) plays a key role on their bionano-interactions by driving the adsorption of biomolecules on the nanoparticle through a matching mechanism between the surface cavities characteristics and the biomolecules stereochemistry. This conclusion was drawn by analyzing the biophysicochemical properties of colloidal MSNs in the presence of single biomolecules, such as alginate or bovine serum albumin (BSA), as well as dispersed in a complex biofluid, such as human blood plasma. When dispersed in phosphate buffered saline media containing alginate or BSA, monodisperse spherical MSNs interact with linear biopolymers such as alginate and with a globular protein such as bovine serum albumin (BSA) independently of the surface charge sign (i.e. positive or negative), thus leading to a decrease in the surface energy and to the colloidal stabilization of these nanoparticles. In contrast, silica nanoparticles with irregular surface topographies are not colloidally stabilized in the presence of alginate but they are electrosterically stabilized by BSA through a sorption mechanism that implies reversible conformation changes of the protein, as evidenced by circular dichroism (CD). The match between the biomolecule size and stereochemistry with the nanoparticle surface cavities characteristics reflects on the nanoparticle surface area that is accessible for each biomolecule to interact and stabilize any non-rigid nanoparticles. On the other hand, in contact with variety of biomolecules such as those present in blood plasma (55%), MSNs are colloidally stabilized regardless of the topography and surface charge, although the identity of the protein corona responsible for this stabilization is influenced by the surface topography and surface charge. Therefore, the biofluid in which nanoparticles are introduced plays an important role on their physicochemical behavior synergistically with their inherent characteristics (e.g., surface topography).

Orange waste as a biomass for 2G-ethanol production using low cost enzymes and co-culture fermentation

The successful conversion of orange waste into a mixture of fermentable sugars was achieved using low cost enzymes obtained from the citrus-canker bacterium Xanthomonas axonopodis pv. citri strain 306 (IBSBF 1594). Then, fermentable sugars were converted into 2G-ethanol using Saccharomyces cerevisiae in combination with one of the two isolated yeast strains, Candida parapsilosis strains IFM 48375 and NRRL Y-12969 (ATCC 2219), in independent submerged co-culture fermentations. The co-culture fermentations enabled reducing fermentation time to 6 h. Pure ethanol in excellent yield with C-6 sugars conversion of 98.9% was obtained. Therefore, diminished costs of enzyme biomass processing and reduced fermentation time could make the 2G-ethanol production from orange waste even more feasible, cost-effective and an environmentally friendly process.

Analytical approaches for lipidomics and its potential applications in neuropsychiatric disorders.

Abstract Objectives: In this review, the authors discuss an overview of lipidomics followed by in-depth discussion of its application to the study of human diseases, including extraction methods of lipids, analytical techniques and clinical research in neuropsychiatric disorders. Methods: Lipidomics is a lipid-targeted metabolomics approach aiming at the comprehensive analysis of lipids in biological systems. Recent technological advancements in mass spectrometry and chromatography have greatly enhanced the development and applications of metabolic profiling of diverse lipids in complex biological samples. Results: An effective evaluation of the clinical course of diseases requires the application of very precise diagnostic and assessment approaches as early as possible. In order to achieve this, “omics” strategies offer new opportunities for biomarker identification and/or discovery in complex diseases and may provide pathological pathways understanding for diseases beyond traditional methodologies. Conclusions: This review highlights the importance of lipidomics for the future perspectives as a tool for biomarker identification and discovery and its clinical application.

Bacterial secretion chaperones.

Many Gram-negative bacteria are able to invade hosts by translocation of effectors directly into target cells in processes usually mediated by two very complex secretion systems (SSs), named type III (T3) and type IV (T4) SSs. These syringe-needle injection devices work with intervention of specialized secretion chaperones that, unlike traditional molecular chaperones, do not assist in protein folding and are not energized by ATP. Controversy still surrounds secretion chaperones primary role, but we can say that these chaperones act as: (i) bodyguards to prevent premature aggregation, or as (ii) pilots to direct substrate secretion through the correct secretion system. This family of chaperones does not share primary structure similarity but amazingly equal 3D folds. This mini review has the intent to present updated structural and functional data for several important secretion chaperones, either alone or in complex with their cognate substrates, as well to report on the common features and roles of T3, T4 and flagellar chaperones.