Preparation of algal‐oligosaccharide mixtures by bacterial agarases and their antioxidative properties
ABSTRACT Algal-oligosaccharide-lysates (AOL), derived from six agars and four algal polysaccharide extracts (APE), were treated with 100–500 activity units (AU) of MA103-agarases or MAEF108-agarases, and their antioxidative properties evaluated. Soluble total polyphenols (TP) were between 462.2 ± 1.6 gallic acid equivalents (GAE, µg/mL) and 70.6 ± 17.4 GAE. The DPPH radical scavenging capacity of all AOL went from 68.3 ± 0.7% to 0.5 ± 0.1%. The ferrous ion chelating capacity of all AOL went from 93.1 ± 0.2% to 21.7 ± 0.9%. Evaluation of the H2O2 scavenging capacity of all AOL was between 35.9 ± 5.4% and 0.1 ± 0.2%. The reducing power of all AOL went from 51.3 ± 2.6 to 3.2 ± 6.8 expressed as µg/mL ascorbic acid. In DPPH radical scavenging capacity, ferrous ion chelating capacity and reducing power etc., the AOL derived from the APE of Porphyra dentate (digested by 500 AU of MAEF108-agarases) were highest, in all test sets. However, the AOL derived from the APE of Monostroma nitidum (digested by 500 AU of MAEF108-agarases) had the highest H2O2 scavenging capacity in all test sets. The order of antioxidative activity performance of all AOL treated in this experiment, by these four antioxidative methods, is as follows: ferrous ion chelating capacity > DPPH radical scavenging capacity > H2O2 scavenging capacity > reducing power; this may be related to their polyphenols, small molecular weight polysaccharides or simple sugar constituents. In this study, it is demonstrated that various agarases derived from algal oligosaccharide mixtures possess good potential for use as a health food, due to their antioxidative capacity.
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ABSTRACT: Agarases are the enzymes which catalyze the hydrolysis of agar. They are classified into alpha-agarase (E.C. 188.8.131.52) and beta-agarase (E.C. 184.108.40.206) according to the cleavage pattern. Several agarases have been isolated from different genera of bacteria found in seawater and marine sediments, as well as engineered microorganisms. Agarases have wide applications in food industry, cosmetics, and medical fields because they produce oligosaccharides with remarkable activities. They are also used as a tool enzyme for biological, physiological, and cytological studies. The paper reviews the category, source, purification method, major characteristics, and application fields of these native and gene cloned agarases in the past, present, and future.Marine Drugs 01/2010; 8(1):200-18. · 3.98 Impact Factor
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ABSTRACT: A sulfated polysaccharide from the green alga Monostroma latissimum was extracted in hot water and purified by ion-exchange and size-exclusion chromatography. Five sulfated polysaccharide fragments with different molecular weights were prepared from the sulfated polysaccharide by H2O2 degradation. The molecular weights of the parent sulfated polysaccharide and its fragments were 725.4, 216.4, 123.7, 61.9, 26.0 and 10.6 kDa, respectively. These sulfated polysaccharide preparations have high contents of rhamnose. Anticoagulant activities of the parent sulfated polysaccharide and its fragments were investigated by studying the activated partial thromboplastin time (APTT), thrombin time (TT) and prothrombin time (PT) using human plasma. The six sulfated polysaccharide preparations did not affect PT even at the concentration at which APTT and TT were prolonged. The sulfated polysaccharides fragments with molecular weights of 216.4–61.9 kDa had similar anticoagulant activities as the parent sulfated polysaccharide. A decrease in the molecular size of the sulfated polysaccharide fragments dramatically reduced their anticoagulant activities. The results indicated that molecular size had an important effect on the anticoagulant activity of the sulfated polysaccharide obtained from M. latissimum, and an even longer chain was necessary to achieve thrombin inhibition.Carbohydrate Polymers. 01/2008;
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ABSTRACT: This study was conducted to optimize the cultivation conditions for Bacillus subtilis to produce proteases, amylases and cellulase, and to further investigate the hydrolysis ability against mackerel and asparagus. The extracellular enzymes from B. subtilis after 2 and 4 days incubation in a modified medium, containing 1% skim milk, 1% soya meal, 0.25% starch, 0.25% K2HPO4, 0.5% NaCl and 0.05% MgCl2 were collected for the hydrolysis of asparagus and minced mackerel, respectively. Except for the α,α-diphenyl-β-picrylhydrazyl (DPPH) scavenging ability of the hydrolyzed asparagus, the trolox equivalent antioxidation capacity and DPPH scavenging ability of both samples increased significantly (P < 0.05) after 1 h hydrolysis and further increased during elongated hydrolysis at 50°C. Sodium dodecylsulfate–polyacrylamide gel electrophoresis indicated severe degradation of muscle proteins during hydrolysis. Changes in reducing sugar, soluble proteins and peptides before/after hydrolysis suggested the extracellular enzymes from B. subtilis could effectively hydrolyze the mackerel or asparagus, and subsequently improve their antioxidation ability.Fisheries Science 06/2007; 73(3):713 - 723. · 0.90 Impact Factor