POTENTIAL OF RICE STRAW AS A NATURAL FIBER MATERIAL FOR COMMERCIAL PRODUCTS

Cellulose is a material used in producing natural fibers, which is more environmentally friendly than synthetic fibers. Rice straw waste contains much cellulose and has potential as natural fiber. However, before the natural cellulose fiber is extracted from the rice straw, it must pass through several processes, such as chemicals or nuclear radiation, especially during the pretreatment process. Furthermore, the resulting natural fibers are utilized to replace synthetic fibers for use as raw materials in manufacturing several commercial products. This review describes a process that can be applied to manufacture natural fibers from rice straw and commercial products made from natural cellulose fibers.

Effect of Alkali Treatment on the Mechanical Property of Natural Fiber in a Concrete-A Mini Review

Ongoing studies show that an effective demand for using natural fibers as a substitution of an artificial fiber in fiber-reinforced composites formation has increased their applicability in an industrial area worldwide. The hydrophobic nature of natural fiber makes week adhesion among the cellulose fiber and matrix components; these problems are usually encountered in fiber-reinforced composites production. To overcome such a limitation of a cellulose fiber, specific physical and chemical treatment strategies were advised by researchers around the world for surface modification of natural cellulose fibers. One of the most basic and efficient surface modification approaches adopted today by the researchers was alkali treatment, widely used in natural fiber composites formation. This technique effectively improved the Mechanical property of natural cellulose fiber, such as tensile strength and flexural properties, while the impact strength result was reduced.

Epoch-Making Discovery for CO2 Characteristics: “Pseudo Osmosis” in the Gas Phase

Recently, unprecedented torrential rains have deluged the globe, resulting in disastrous floods. These disasters were caused by climate changes because of an increase in carbon dioxide (CO2) concentration in the atmosphere since the industrial revolution. Therefore, atmospheric accumulation of CO2 should be reduced to avoid a future climate crisis. Many methods to fix CO2 have been developed, but a practical method has not been established, except for the method using amines based on moderate plant constructions. However, the membrane method has not yet been established because of the conflicting relationship between penetrability and specificity, although membrane technology can be used for CO2 separation. Epoch-making discoveries for CO2 characteristics have been presented as follows: 1) the high penetrability of CO2 in the gas phase caused “pursued osmosis” against polymer elasticity; 2) highly penetrable CO2 passed through polymer membranes such as authentic polymers and natural cellulose, whereas neither O2 nor N2 penetrates these polymers examined; 3) CO2 is absorbed by plastics; 4) H2 and CH4 gases penetrate through polymer membranes, but their penetration was completely blocked in the presence of water; and 5) using a polytunnel made of polymer sheets (an artificial forest or positive green house), which allows CO2 penetration, instead of hard chamber, steel, or plastic could be cost effective. Therefore, polymer membranes could be practically and economically useful for CO2 separation from the exhaust gas and atmosphere.

PSI-6 Characterization of in vitro stability for two multi-functional processive endoglucanases as exogenous biocatalysts in pig nutrition

Poor efficiency of dietary fibre utilization limits global pork production profit margins and mitigation of footprint on environment. The objective of this study was to characterize in vitro stability for two unique processive endoglucanases of tCel5A1 and p4818Cel5_2A that are reported to hydrolyze natural cellulose and have multi-functionality towards hemicelluloses (Basit and Akhtar, Biotechnology and Bioengineering, 2018, 115:1675; Wang et al., Scientific Reports 2019, 9:13630). Both tCel5A1 and p4818Cel5_2A were modelled with the SWISS-MODEL online server and analyzed and visualized by PyMOL2.4.1. These two cellulases were overexpressed in ClearColi®BL21(DE3). Their endoglucanase activities were determined using 0.70 % sodium carboxymethyl cellulose and 5 mM dithiothreitol (DTT) with or without N2 gas purging; and incubated at pH 6.5–7.0 and 37 °C for 15 min. The three-dimensional models showed 1 and 4 Cys residues on the surfaces of tCel5A1 and p4818Cel5_2A, respectively, suggesting their susceptibility to auto-oxidation by air-borne O2. This prediction was tested by comparing the activities of N2-purged and non-purged enzyme preparations as well as their processing and incubation handling. Both tCel5A1 and p4818Cel5_2A activities were enhanced (P < 0.01) by 50% when 5-mM DTT and N2-purging were adopted. Furthermore, after incubating both tCel5A1 and p4818Cel5_2A enzyme preparations under the porcine gastric pH (3.5) and pepsin (274 U/mL) as well as intestinal trypsin (78 U/mL) and chymotrypsin (20 U/mL) activities at pH 6.5 during 0–5 h, Eadie-Hofstee inhibition kinetic analyses showed that tCel5A1 and p4818Cel5_2A respectively lost 18 and 68% (P < 0.01) of their initial activities after 2 h under the gastric conditions and more than 90% (P < 0.01) of their initial activities after 2–3 h under the intestinal conditions. Therefore, further enzyme protein engineering and/or post-fermentation treatments, such as coating for by-passing the gastric-intestinal environment, will be required to enable these two processive endoglucanases as efficacious exogenous fibre enzymes.

Facile Fabrication of Polysaccharide Nanocomposites Using Ionic Gelation Method

Polysaccharide-based nanomaterials with significant biocompatibility and physiochemical features have been widely analyzed in modern biomedical nanotechnology. Chitosan-coating is an advantageous procedure to provide several pharmacological characteristics of chitosan on the reinforcement. Here, we fabricated polysaccharide nanocomposites using the facile ionic gelation method and sodium tripolyphosphate (TPP) cross-linker. The polysaccharide nanocomposites comprised natural cellulose and chitosan as reinforcement and coating agents, respectively. From the image of the scanning electron microscope, the nanocomposites indicated almost spherical dimensions with sizes below 60 nm. Results from X-ray powder diffraction and Fourier-transform infrared spectroscopy showed multifunctional properties of the nanocomposites related to both cellulose and chitosan. Therefore, the ionic gelation method is potentially appropriate to synthesize the polysaccharide nanocomposites for medically-related applications.