Exopolysaccharides from the Energy Microalga Strain Botryococcus braunii: Purification, Characterization, and Antioxidant Activity

Botryococcus braunii, a prestigious energy microalga, has recently received widespread attention because it can secrete large amounts of exopolysaccharides (EPS) with potential applications in food, cosmetics, and nutraceuticals. Unfortunately, the insufficiency of research on the bioactivity and structure–activity relationship of B. braunii EPS has impeded the downstream applications. In the present study, alcohol precipitation, deproteinization, and DEAE-cellulose column chromatography were used to extract and purify B. braunii SCS-1905 EPS. It was found that B. braunii SCS-1905 EPS were high-molecular-weight heteropolysaccharides containing uronic acid (7.43–8.83%), protein (2.30–4.04%), and sulfate groups (1.52–1.95%). Additionally, the EPS primarily comprised galactose (52.34–54.12%), glucose (34.60–35.53%), arabinose (9.41–10.32%), and minor amounts of fucose (1.80–1.99%), with the presence of a pyranose ring linked by a β-configurational glycosidic bond. Notably, the antioxidant activity of crude exopolysaccharides (CEPS) was stronger, and the half maximal inhibitory concentration (IC50) for ABTS and hydroxyl radicals was significantly lower than that of deproteinized exopolysaccharides (DEPS). Overall, this study indicated a potential application of B. braunii SCS-1905 EPS as a natural antioxidant. In summary, B. braunii EPS could be used as a potential feedstock for the production of antioxidant health foods.

Preparation of a Cellulose Column for Enhancing the Sensing Efficiency of the Biocide 2-n-Octyl-4-Isothiazolin-3-One

In this study, a cellulose acetate (CA) membrane with pores generated by a water pressure treatment was investigated for its ability to serve as a pretreatment filter device for the detection of 2-n-octyl-4-isothiazolin-3-one (OIT). Pores were generated by applying a water pressure of 8 bar to a membrane manufactured using a CA-based polymer solution. The CA used for the manufacturing was an environment-friendly, low-cost and highly energy-efficient material. Furthermore, since the fabricated porous CA polymeric film possessed many hydrophilic functional groups, it could strongly bind hydrophilic substances while avoiding interaction with hydrophobic substances. OIT, which comprises a hydrophobic bond that forms weak bonds over time, can break down more easily than hydrophilic impurities. The different extents of interaction occurring between either the toxic fungicide OIT or the hydrophilic impurities and the CA film were determined by Fourier-transform infrared (FT-IR) spectroscopy. The physicochemical changes in the resulting membrane, which occurred when the pores were generated, were investigated through scanning electron microscopy (SEM) and thermogravimetric analysis (TGA).

Cellulase-Assisted Extraction, Characterization, and Bioactivity against Rheumatoid Arthritis of Astragalus Polysaccharides

This study investigated the effect of cellulase on the isolation of crude Astragalus polysaccharide (APS), analyzed the monosaccharide component of deproteinized APS, detected the molecular weights of purified APS, and examined the biological activities and the preliminary mechanism against rheumatoid arthritis (RA). Compared with water extraction method, cellulase-assisted extraction increased the yield of crude APS to 154% and polysaccharide contents to 121%. Crude APS was then purified by ethanol precipitation, Sevag deproteinization, and high-performance liquid chromatography (HPLC) analysis; monosaccharide contents of APS were different after cellulase-assisted method, especially galacturonic acid content which significantly increased. DEAE-52 cellulose column chromatography isolated three polysaccharide fractions, including a neutral polysaccharide (APS-water) and two acidic polysaccharides (APS-NaCl1 and APS-NaCl2). Using high-performance gel permeation chromatography (HPGPC), the molecular weights of APS-water, APS-NaCl1, and APS-NaCl2 were identified as 67.7 kDa, 234.1 kDa, and 189.4 kDa, respectively. Then their therapeutic effects and possible mechanism against RA were explored using type II collagen-induced arthritis (CIA) rat model. APS could significantly reduce paw swelling, serum concentration of IL-1β and TNF-α, and the expression levels of NF-κB-p65 and IκBα in synovial membranes in CIA rats. Our study indicated that cellulase significantly increases the yield and polysaccharide contents of crude APS, improves the product quality, and preserves the biological features against RA in CIA rats.

Production and Purification of Amylase from Bacillus subtilis Isolated from Soil

In spite of progress in biotechnology and enzymology, the enzymes have been industrialized in recent years for the mounting up the product development in various arena. The ultimate goal of this study comprises the production and purification the amylase enzyme from the bacterial strain. A powerful amylase producer, Bacillus subtilis ISOLATE-4 was isolated, screened and identified from the soil sample. In order to produce extracellular amylase, various physico-chemical parameters were optimized. During optimization, the maximal production of amylase by the isolate at 48 hrs of incubation in 100 rpm was found to be 6.93U/ml, 5.94U/ml, 6.0U/ml at 45ºC, pH 6 with 1% substrate concentration respectively. Ammonium sulphate fractionation was done for rapid precipitation of the amylase at a concentration of 60% and exposed to dialysis showed the 25% purification fold of an enzyme. The dialyzed product was further subjected to DEAE-Cellulose column chromatography resulted in an increase up to 75% purification fold than crude enzyme. The amylase enzyme might be suitable for the liquefaction of starch, detergent, textile and several additional industrial applications.

Leaf proteins in five varieties of red clover cultivated in Poland

Protein fractions: albumins, globulins, gluteins and prolamins were extracted from the leaves of 5 varieties of red clover. 'Skrzeszowicka' and 'Hruszowska' showed the highest content of total protein, 'Rotra' however – the highest globulin level. Globulins were fractionated on DEAE cellulose column into 3 fractions. Globulins from 'Rotra' and 'Hruszowska' varieties were separated into 4 fractions.

Chemical Analysis and Antioxidant Activities In Vitro of Polysaccharide Extracted from Corn Silk

Corn silk polysaccharide (CSP) was investigated for the treatment of different kinds of diseases. In order to characterize the chemical properties and antioxidant activities of CSP, the CSP was isolated from corn silk and purified by DE-52 cellulose column chromatography. Four components were separated, and the highest one named CSP-A. The CSP-A was characterized by FTIR and the monosaccharide components were analyzed by HPLC. The FTIR spectra indicated that CSP-A was characteristic of β-glucosidic bond and α-glycosidic bond. The CSP-A mainly comprised of glucose, galactose, arabinose, mannose, rhamnose. The antioxidant activities of CSP were determined by hydroxyl radical (•OH) and DPPH radicals scavenging assays. When the concentration of CSP was 10mg/mL, the scavenging capacity of •OH and DPPH could reach to 40% and 48%, respectively.

Characterization of Activity of a Potential Food-Grade Leucine Aminopeptidase from Kiwifruit

Aminopeptidase (AP) activity in ripe but firm fruit of Actinidia deliciosa was characterized using L-leucine-p-nitroanilide as a substrate. The enzyme activity was the highest under alkaline conditions and was thermolabile. EDTA, 1,10-phenanthroline, iodoacetamide, and had inhibitory effect while a low concentration of dithiothreitol (DTT) had stimulatory effect on kiwifruit AP activity. However, DTT was not essential for the enzyme activity. The results obtained indicated that the kiwifruit AP was a thiol-dependent metalloprotease. Its activity was the highest in the seeds, followed by the core and pericarp tissues of the fruit. The elution profile of the AP activity from a DEAE-cellulose column suggested that there were at least two AP isozymes in kiwifruit: one unadsorbed and one adsorbed fractions. It is concluded that useful food-grade aminopeptidases from kiwifruit could be revealed using more specific substrates.