Polysaccharides, known as the most abundant biopolymers in the world, are macromolecules of carbohydrate nature obtained by enchainment of monosaccharides through glycosidic bonds. The biodegradability behavior and the mechanical properties of polysaccharides are significantly controlled by their crystalline content and the crystallite size of crystals. The crystalline structure of these polymers stem in their chemical structure and inter-/intramolecular interactions. Semi-crystalline polysaccharides have been utilized to reinforce the polymer composites for various applications ranging from packaging uses to biomedical applications. This chapter discusses the crystallization behavior of polysaccharides and technique used in measuring their crystallization. Applications of crystalline polysaccharides for various uses, especially packaging and biomedical, are specifically outlined.

α-amylase, 265 α-glucans, 254 α-l-iduronic acid (IdoA), 710 β-amylase, 265 β-D-galactose, 25 1,1-dihpenyl-2-picrylhydrazyl (DPPH) radicals, 431 2-methacryloyloxyethylphosphorylchlorine, 595 3D frameworks,

Lignocellulosic residues have been receiving growing interest as a promising source of polysaccharides, which can be converted into a variety of compounds, ranging from biofuels to bioplastics. Most of these can replace equivalent products traditionally originated from petroleum, hence representing an important environmental advantage. Lignocellulosic materials are theoretically unlimited, cheaper and may not compete with food crops. However, the conversion of these materials to simpler sugars usually requires cellulolytic enzymes. Being still associated with a high cost of production, cellulases are commonly considered as one of the main obstacles in the economic valorization of lignocellulosics. This work provides a brief overview of some of the most studied strategies that can allow an important reduction of cellulases consumption, hence improving the economy of lignocellulosics conversion. Cellulases recycling is initially discussed regarding the main processes to recover active enzymes and the most important factors that may affect enzyme recyclability. Similarly, the potential of enzyme immobilization is analyzed with a special focus on the contributions that some elements of the process can offer for prolonged times of operation and improved enzyme stability and robustness. Finally, the emergent concept of consolidated bioprocessing (CBP) is also described in the particular context of a potential reduction of cellulases consumption.

This study aimed to produce modified cellulose extracted from oat hulls by an esterification reaction with citric acid (CA) employing ultrasonication and reactive extrusion assisted processes. Modified samples were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (DRX), scanning electron microscopy (SEM), wettability, oil and water absorption capacities, water adsorption capacity, and thermal stability. From FTIR results it can be observed a new band for all modified samples at 1735 cm−1, confirming the esterification. The morphology and crystallinity pattern of fibers were not affected by esterification, and crystallinity indexes ranged from 43% (unmodified cellulose) to 44–49% in modified samples. Both groups of samples, obtained by ultrasonication and reactive extrusion, showed decreases in water absorption capacities (1.63–1.71 g/g) compared to unmodified cellulose (9.38 g/g). It was observed an increase in oil retention capacity from 1.80 g/g (unmodified cellulose) to 4.57–7.31 g/g after esterification, and also the modified samples presented higher affinity by a non-polar solvent in the wettability test. The new properties of modified cellulose expand its use in the industry and prove that ultrasonication and reactive extrusion can be used to obtain esterified cellulose, being eco-friendly, simple, and convenient processes with short reaction times.

Bacterial transformation and gene transfection can be understood as being the results of introducing specific genetic material into cells, resulting in gene expression, and adding a new genetic trait to the host cell. Many studies have been carried out to investigate different types of lipids and cationic polymers as promising nonviral vectors for DNA transfer. The present study aimed to carry out a systematic review on the use of biopolymeric materials as nonviral vectors. The methodology was carried out based on searches of scientific articles and applications for patents published or deposited from 2006 to 2020 in different databases for patents (EPO, USPTO, and INPI) and articles (Scopus, Web of Science, and Scielo). The results showed that there are some deposits of patents regarding the use of chitosan as a gene carrier. The 16 analyzed articles allowed us to infer that the use of biopolymers as nonviral vectors is limited due to the low diversity of biopolymers used for these purposes. It was also observed that the use of different materials as nonviral vectors is based on chemical structure modifications of the material, mainly by the addition of cationic groups. Thus, the use of biopolymers as nonviral vectors is still limited to only a few polysaccharide types, emphasizing the need for further studies involving the use of different biopolymers in processes of gene transfer.

In the last decades, many studies have been conducted on new materials to meet a growing industrial demand and to move scientific research forward. Superabsorbents are good examples of materials that have generated special attention in many fields for their ability to absorb and retain water up to 1000 times of their dry weight. They found many applications in hygiene products and other products, for a fast growing market of USD 9.58 Billion in 2019. Most of them are composed of synthetic polymers, which are often not environmentally friendly. Therefore, natural superabsorbents and particularly those based on polysaccharides have received a recent increased interest for their biodegradability, biocompatibility, and renewability. This review focuses on polysaccharide-based superabsorbents, on their properties, synthesis methods, and characterization. Their potential applications in many fields, such as biomedical and hygiene, agriculture, water treatment, and the building sector, are also reported with an interest in products already marketed.

GC-MS-based metabolomics were used to investigate metabolic changes in prawn shell waste during fermentation. Microbial strains Lactobacillus plantarum and Bacillus subtilis were co-fermented in a shake flask comprising of 5% (w/v) prawn shell waste and 20% (w/v) glucose as a carbon source. Analysis of the prawn shell waste fermentation showed a total of 376 metabolites detected in the culture supernatant, including 14 amino acids, 106 organic acids, and 90 antimicrobial molecules. Results show that the liquid fraction of the co-fermentation is promising for harvesting valuable metabolites for probiotics application.

Biotic, abiotic stresses and their unpredictable combinations severely reduce plant growth and crop yield worldwide. The different chemicals (pesticides, fertilizers, phytoregulators) so far used to enhance crop tolerance to multistress have a great environmental impact. In the search of more eco-friendly systems to manage plant stresses, chitin, a polysaccharide polymer composed of N-acetyl-D-glucosamine and D-glucosamine and its deacetylated derivative chitosan appear as promising tools to solve this problem. In fact, these molecules, easily obtainable from crustacean shells and from the cell wall of many fungi, are non-toxic, biodegradable, biocompatible and able to stimulate plant productivity and to protect crops against pathogens. In addition, chitin and chitosan can act as bioadsorbents for remediation of contaminated soil and water. In this review we summarize recent results obtained using chitin- and chitosan-based derivatives in plant protection against biotic and abiotic stresses and in recovery of contaminated soil and water.