Microbial exopolysaccharides: Classification, biosynthetic pathway, industrial extraction and commercial production to unveil its bioprospection: A comprehensive review

Polysaccharides, found universally in all living-species, exhibit diverse biochemical structures and play crucial roles in microorganisms, animals, and plants to defend against pathogens, environmental stress and climate-changing. Microbial exopolysaccharides are essential for cell adhesion and stress resilience and using them has notable advantages over synthetic polysaccharides. Exopolysaccharides have versatile structures and physicochemical properties, used in food systems, therapeutics, cosmetics, agriculture, and polymer industries. Immense economic and infrastructural constraints hinder its widespread commercial use, necessitating a deeper understanding of metabolic-pathways amidst changing environmental climate that influences the biomass composition of EPS-producing wild-microbes. Green and sustainable extraction of EPS from microbes followed by commercial product development has still not been exploited comprehensively. Yield of EPS production vary from 0.1 to 3 g/g of cell weight, influenced by fermentation conditions. Economic barriers, including substrate and processing costs, limit commercial viability. Key biosynthetic pathways involve glycosyltransferases enzymes, whose regulatory network gaps and substrate specificity remain areas for optimization. Addressing these could enhance yields and lower production costs. Review illustrates various microbial-exopolysaccharides, influencing factors of production, and offer valuable insights on the bioplastic, biofuel, agri-bioproduct, and biomedicine. But their bioprospecting potential is yet to be exhaustively explored, along with their pros and cons nor documented comprehensively in scientific literature.

Exploring the World of Membrane Proteins: Techniques and Methods for Understanding Structure, Function, and Dynamics

In eukaryotic cells, membrane proteins play a crucial role. They fall into three categories: intrinsic proteins, extrinsic proteins, and proteins that are essential to the human genome (30% of which is devoted to encoding them). Hydrophobic interactions inside the membrane serve to stabilize integral proteins, which span the lipid bilayer. This review investigates a number of computational and experimental methods used to study membrane proteins. It encompasses a variety of technologies, including electrophoresis, X-ray crystallography, cryogenic electron microscopy (cryo-EM), nuclear magnetic resonance spectroscopy (NMR), biophysical methods, computational methods, and artificial intelligence. The link between structure and function of membrane proteins has been better understood thanks to these approaches, which also hold great promise for future study in the field. The significance of fusing artificial intelligence with experimental data to improve our comprehension of membrane protein biology is also covered in this paper. This effort aims to shed light on the complexity of membrane protein biology by investigating a variety of experimental and computational methods. Overall, the goal of this review is to emphasize how crucial it is to understand the functions of membrane proteins in eukaryotic cells. It gives a general review of the numerous methods used to look into these crucial elements and highlights the demand for multidisciplinary approaches to advance our understanding.

Strategies for capillary electrophoresis: Method development and validation for pharmaceutical and biological applications-Updated and completely revised edition

This review is in support of the development of selective, precise, fast, and validated capillary electrophoresis (CE) methods. It follows up a similar article from 1998, Wätzig H, Degenhardt M, Kunkel A. "Strategies for capillary electrophoresis: method development and validation for pharmaceutical and biological applications," pointing out which fundamentals are still valid and at the same time showing the enormous achievements in the last 25 years. The structures of both reviews are widely similar, in order to facilitate their simultaneous use. Focusing on pharmaceutical and biological applications, the successful use of CE is now demonstrated by more than 600 carefully selected references. Many of those are recent reviews; therefore, a significant overview about the field is provided. There are extra sections about sample pretreatment related to CE and microchip CE, and a completely revised section about method development for protein analytes and biomolecules in general. The general strategies for method development are summed up with regard to selectivity, efficiency, precision, analysis time, limit of detection, sample pretreatment requirements, and validation.

Immunoaffinity Capillary Electrophoresis in the Era of Proteoforms, Liquid Biopsy and Preventive Medicine: A Potential Impact in the Diagnosis and Monitoring of Disease Progression

Over the years, multiple biomarkers have been used to aid in disease screening, diagnosis, prognosis, and response to therapy. As of late, protein biomarkers are gaining strength in their role for early disease diagnosis and prognosis in part due to the advancements in identification and characterization of a distinct functional pool of proteins known as proteoforms. Proteoforms are defined as all of the different molecular forms of a protein derived from a single gene caused by genetic variations, alternative spliced RNA transcripts and post-translational modifications. Monitoring the structural changes of each proteoform of a particular protein is essential to elucidate the complex molecular mechanisms that guide the course of disease. Clinical proteomics therefore holds the potential to offer further insight into disease pathology, progression, and prevention. Nevertheless, more technologically advanced diagnostic methods are needed to improve the reliability and clinical applicability of proteomics in preventive medicine. In this manuscript, we review the use of immunoaffinity capillary electrophoresis (IACE) as an emerging powerful diagnostic tool to isolate, separate, detect and characterize proteoform biomarkers obtained from liquid biopsy. IACE is an affinity capture-separation technology capable of isolating, concentrating and analyzing a wide range of biomarkers present in biological fluids. Isolation and concentration of target analytes is accomplished through binding to one or more biorecognition affinity ligands immobilized to a solid support, while separation and analysis are achieved by high-resolution capillary electrophoresis (CE) coupled to one or more detectors. IACE has the potential to generate rapid results with significant accuracy, leading to reliability and reproducibility in diagnosing and monitoring disease. Additionally, IACE has the capability of monitoring the efficacy of therapeutic agents by quantifying companion and complementary protein biomarkers. With advancements in telemedicine and artificial intelligence, the implementation of proteoform biomarker detection and analysis may significantly improve our capacity to identify medical conditions early and intervene in ways that improve health outcomes for individuals and populations.

Rapid Structural, Kinetic, and Immunochemical Analysis of Alpha-Synuclein Oligomers in Solution

Oligomers comprised of misfolded proteins are implicated as neurotoxins in the pathogenesis of protein misfolding conditions such as Parkinson's and Alzheimer's diseases. Structural, biophysical, and biochemical characterization of these nanoscale protein assemblies is key to understanding their pathology and the design of therapeutic interventions, yet it is challenging due to their heterogeneous, transient nature and low relative abundance in complex mixtures. Here, we demonstrate separation of heterogeneous populations of oligomeric α-synuclein, a protein central to the pathology of Parkinson's disease, in solution using microfluidic free-flow electrophoresis. We characterize nanoscale structural heterogeneity of transient oligomers on a time scale of seconds, at least 2 orders of magnitude faster than conventional techniques. Furthermore, we utilize our platform to analyze oligomer ζ-potential and probe the immunochemistry of wild-type α-synuclein oligomers. Our findings contribute to an improved characterization of α-synuclein oligomers and demonstrate the application of microchip electrophoresis for the free-solution analysis of biological nanoparticle analytes.

A Two-Dimensional Affinity Capture and Separation Mini-Platform for the Isolation, Enrichment, and Quantification of Biomarkers and Its Potential Use for Liquid Biopsy

Biomarker detection for disease diagnosis, prognosis, and therapeutic response is becoming increasingly reliable and accessible. Particularly, the identification of circulating cell-free chemical and biochemical substances, cellular and subcellular entities, and extracellular vesicles has demonstrated promising applications in understanding the physiologic and pathologic conditions of an individual. Traditionally, tissue biopsy has been the gold standard for the diagnosis of many diseases, especially cancer. More recently, liquid biopsy for biomarker detection has emerged as a non-invasive or minimally invasive and less costly method for diagnosis of both cancerous and non-cancerous diseases, while also offering information on the progression or improvement of disease. Unfortunately, the standardization of analytical methods to isolate and quantify circulating cells and extracellular vesicles, as well as their extracted biochemical constituents, is still cumbersome, time-consuming, and expensive. To address these limitations, we have developed a prototype of a portable, miniaturized instrument that uses immunoaffinity capillary electrophoresis (IACE) to isolate, concentrate, and analyze cell-free biomarkers and/or tissue or cell extracts present in biological fluids. Isolation and concentration of analytes is accomplished through binding to one or more biorecognition affinity ligands immobilized to a solid support, while separation and analysis are achieved by high-resolution capillary electrophoresis (CE) coupled to one or more detectors. When compared to other existing methods, the process of this affinity capture, enrichment, release, and separation of one or a panel of biomarkers can be carried out on-line with the advantages of being rapid, automated, and cost-effective. Additionally, it has the potential to demonstrate high analytical sensitivity, specificity, and selectivity. As the potential of liquid biopsy grows, so too does the demand for technical advances. In this review, we therefore discuss applications and limitations of liquid biopsy and hope to introduce the idea that our affinity capture-separation device could be used as a form of point-of-care (POC) diagnostic technology to isolate, concentrate, and analyze circulating cells, extracellular vesicles, and viruses.

Dual-opposite injection capillary electrophoresis: Principles and misconceptions

Dual-opposite injection capillary electrophoresis (DOI-CE) is a separation technique that utilizes both ends of the capillary for sample introduction. The electroosmotic flow (EOF) is suppressed to allow all ions to reach the detector quickly. Depending on the individual electrophoretic mobilities of the analytes of interest and the effective length that each analyte travels to the detection window, the elution order of analytes in a DOI-CE separation can vary widely. This review discusses the principles, applications, and limitations of dual-opposite injection capillary electrophoresis. Common misconceptions regarding DOI-CE are clarified.

A fully automated microfluidic micellar electrokinetic chromatography analyzer for organic compound detection

An integrated microfluidic chemical analyzer utilizing micellar electrokinetic chromatography (MEKC) is developed using a pneumatically actuated Lifting-Gate microvalve array and a capillary zone electrophoresis (CZE) chip. Each of the necessary liquid handling processes such as metering, mixing, transferring, and washing steps are performed autonomously by the microvalve array. In addition, a method is presented for automated washing of the high resistance CZE channel for device reuse and periodic automated in situ analyses. To demonstrate the functionality of this MEKC platform, amino acids and thiols are labeled and efficiently separated via a fully automated program. Reproducibility of the automated programs for sample labeling and periodic in situ MEKC analysis was tested and found to be equivalent to conventional sample processing techniques for capillary electrophoresis analysis. This platform enables simple, portable, and automated chemical compound analysis which can be used in challenging environments.

"Getting the best sensitivity from on-capillary fluorescence detection in capillary electrophoresis" - A tutorial

Capillary electrophoresis with Laser-Induced Fluorescence (CE-LIF) detection is being applied to new analytical problems which challenge both the power of CE separation and the sensitivity of LIF detection. On-capillary LIF detection is much more practical than post-capillary detection in a sheath-flow cell. Therefore, commercial CE instruments utilize solely on-capillary CE-LIF detection with a Limit of Detection (LOD) in the nM range, while there are multiple applications of CE-LIF that require pM or lower LODs. This tutorial analyzes all aspects of on-capillary LIF detection in CE in an attempt to identify means for improving LOD of CE-LIF with on-capillary detection. We consider principles of signal enhancement and noise reduction, as well as relevant areas of fluorophore photochemistry and fluorescent microscopy.

Nanomaterials in consumer products: a challenging analytical problem

Many products used in everyday life are made with the assistance of nanotechnologies. Cosmetic, pharmaceuticals, sunscreen, powdered food are only few examples of end products containing nano-sized particles (NPs), generally added to improve the product quality. To evaluate correctly benefits vs. risks of engineered nanomaterials and consequently to legislate in favor of consumer's protection, it is necessary to know the hazards connected with the exposure levels. This information implies transversal studies and a number of different competences. On analytical point of view the identification, quantification and characterization of NPs in food matrices and in cosmetic or personal care products pose significant challenges, because NPs are usually present at low concentration levels and the matrices, in which they are dispersed, are complexes and often incompatible with analytical instruments that would be required for their detection and characterization. This paper focused on some analytical techniques suitable for the detection, characterization and quantification of NPs in food and cosmetics products, reports their recent application in characterizing specific metal and metal-oxide NPs in these two important industrial and market sectors. The need of a characterization of the NPs as much as possible complete, matching complementary information about different metrics, possible achieved through validate procedures, is what clearly emerges from this research. More work should be done to produce standardized materials and to set-up methodologies to determine number-based size distributions and to get quantitative date about the NPs in such a complex matrices.

Gold-nanoparticle extraction and reversed-electrode-polarity stacking mode combined to enhance capillary electrophoresis sensitivity for conjugated nucleosides and oligonucleotides containing thioether linkers

We present a capillary electrophoresis method for determining two different C8-conjugated deoxyadenosines, and for oligonucleotides containing them, in which a psoralen or an acridine molecule is bonded to the base via a short alkyl chain containing sulfur ethers at both ends. The sensitivity of the micellar electrokinetic chromatography (MEKC) method was increased by using two preconcentration techniques, micro solid-phase extraction (μSPE) followed by reversed-electrode-polarity stacking mode (REPSM). Variables that affect the efficiency of the extraction in μSPE and preconcentration by REPSM, including the type and volume of extraction nanoparticle, concentration, and injection time, were investigated. Under the optimum conditions, enrichment factors obtained were in the range 360-400. The limits of detection (LODs) at a signal-to-noise ratio of 3 ranged from 2 to 5 nmol L(-1). The relative recoveries of labelled adenosines from water samples were 95-103%. The proposed method provided high enrichment factors and good precision and accuracy with a short analysis time. On the basis of the advantages of simplicity, high selectivity, high sensitivity, and good reproducibility, the proposed method may have great potential for biochemical applications.

Phenolic characterization and antimicrobial activity of folk medicinal plant extracts for their applications in olive production

Phytophthora spp is important in plant pathology due to the importance of the diseases it causes. In olive trees, severe damages are caused by the disease known as "dry branch" occasioned by Phytophthora nicotianae, P. citrophthora and P. palmivora. Much effort has been made to find efficient methods of control, with a low negative impact on environment. In this regard, treatment with plant extracts is a valid strategy. The aims of the present study are (i) to determine the polyphenol composition of extracts of Thymus vulgaris, Origanum vulgare, Matricaria recutita, and Larrea divaricata by CZE, (ii) correlate the analytical composition of these extracts with the inhibition on the mycelial growth, and (iii) determine the individual antimicrobial activity of the most active ingredients. A simple methodology was developed for the determination of catechin, naringenin, cinnamic acid, syringic acid, chlorogenic acid, apigenin, vanillic acid, luteolin, quercetin, and caffeic acid in plant extracts by CZE. The extraction of phenolic compounds in extract was performed by a miniaturized solid phase extraction using a home-made minicolumn packed with suitable filtering material (C18 , 50 mg). The optimized analyses conditions were: 30 mM boric acid buffer, pH 9.50; capillary, 57 cm full length, 50 cm effective length, 75 μm id, hydrodynamic injection 30 mbar, 2 s; 25 kV; 25°C, detection by UV absorbance at 290 nm. Sample results suggest that phenolic composition seems to have a great influence on inhibition of pathogens. The highest inhibitions of mycelial growth were observed for cinnamic acid and naringenin.

Capillary isotachophoresis for separation of silver nanoparticles according to size

Capillary isotachophoresis was used for the separation of Ag nanoparticles stabilized by gelatin according to their size.