Implications of agar and agarase in industrial applications of sustainable marine biomass

Park, Si Hyoung; Lee, Chang-Ro; Hong, Soon-Kwang

doi:10.1007/s00253-020-10412-6

Cited by 59 publications

(38 citation statements)

References 111 publications

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“…As the major biopolymer and supporting structure in seaweed, a cocktail of agarose and agaropectin constitute the molecular structure of agar [ 3 , 4 ]. Agarose, as the main component of agar, possesses a linear structure that is composed of the alternant subunit of β- d -galactose and 3,6-anhydro- l -galactose [ 5 ].…”

Section: Introductionmentioning

confidence: 99%

“…Agarases that depolymerize agarose into agarooligosaccharides (AOS) or neoagarooligosaccharides (NAOS) have been found in several gram-negative bacteria isolated from submarine sediments, seaweeds, marine organisms, and seawater [ 2 ]. Agarases are divided into two types, owing to the different hydrolysis modes, i.e., α-agarase (EC 3.2.1.158), which acts on the α-1,3 glycoside bonds and yields AOSs with 3,6-anhydro- l -galactose at the reducing ends of products, and β-agarase (EC 3.2.1.81), which cleaves the β-1,4 glycoside bonds to generate NAOS with β- d -galactose at the reducing ends of products [ 5 , 6 ].…”

Section: Introductionmentioning

confidence: 99%

“…β-agarases belong to glycoside hydrolase (GH) families, including GH 16, GH 39, GH 42, GH 50, GH 86, and GH118 [ 2 , 8 , 9 ]. Neoagarobiose (NA2), neoagarotetraose (NA4), neoagarohexaose (NA6), neoagarooctaose (NA8), neoagarodecaose (NA10), and neoagarododecaose (NA12) are the usual products of β-agarases [ 5 ]. These NAOSs possess multitudinous bioactivities, such as antioxidant, antitumor, anti-obesity, anti-diabetic, anti-inflammatory, anti-cariogenic, skin whitening, and radical-scavenging activities [ 1 , 10 , 11 , 12 ], which can be widely used in the fields of food, medicine, and cosmetics.…”

Section: Introductionmentioning

confidence: 99%

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Expression and Characterization of a Novel Cold-Adapted and Stable β-Agarase Gene agaW1540 from the Deep-Sea Bacterium Shewanella sp. WPAGA9

Wang

Yan

et al. 2021

Marine Drugs

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The neoagaro-oligosaccharides, degraded from agarose by agarases, are important natural substances with many bioactivities. In this study, a novel agarase gene, agaW1540, from the genome of a deep-sea bacterium Shewanella sp. WPAGA9, was expressed, and the recombinant AgaW1540 (rAgaW1540) displayed the maximum activity under the optimal pH and temperature of 7.0 and 35 °C, respectively. rAgaW1540 retained 85.4% of its maximum activity at 0 °C and retained more than 92% of its maximum activity at the temperature range of 20–40 °C and the pH range of 4.0–9.0, respectively, indicating its extensive working temperature and pH values. The activity of rAgaW1540 was dramatically suppressed by Cu2+ and Zn2+, whereas Fe2+ displayed an intensification of enzymatic activity. The Km and Vmax of rAgaW1540 for agarose degradation were 15.7 mg/mL and 23.4 U/mg, respectively. rAgaW1540 retained 94.7%, 97.9%, and 42.4% of its maximum activity after incubation at 20 °C, 25 °C, and 30 °C for 60 min, respectively. Thin-layer chromatography and ion chromatography analyses verified that rAgaW1540 is an endo-acting β-agarase that degrades agarose into neoagarotetraose and neoagarohexaose as the main products. The wide variety of working conditions and stable activity at room temperatures make rAgaW1540an appropriate bio-tool for further industrial production of neoagaro-oligosaccharides.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Expression and Characterization of a Novel Cold-Adapted and Stable β-Agarase Gene agaW1540 from the Deep-Sea Bacterium Shewanella sp. WPAGA9

Wang

Yan

et al. 2021

Marine Drugs

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“…Marine agar-degrading organisms produce agarases to utilize agar as a convenient carbon source. Therefore, most of the reported agarases were isolated from marine bacteria [2].…”

Section: Introductionmentioning

confidence: 99%

A new neoagarobiose-producing agarase from Vibrio sp. LA1

Lin¹,

Zheng²,

Huang³

et al. 2021

ScienceAsia

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An agarolytic bacterium was isolated from the sea coast of Shantou in China and identified as Vibrio sp. LA1. The agarase gene agaA was cloned from Vibrio sp. LA1 by using degenerate oligonucleotide-primed PCR and genome walking technique. Gene agaA consists of a 2913 bp open reading frame encoding 970 amino acids; and the predicted molecular mass and isoelectric point were 108 kDa and 4.46, respectively. Based on the amino acid sequence similarity, the encoded protein (AgaA) of gene agaA should be an agarase of glycoside hydrolase family GH50 with a catalytic domain of glycoside hydrolase family GH42. Soluble expression of AgaA in Escherichia coli was obtained and investigated. The optimal temperature and pH for the activity of the purified recombinant agarase were 35°C and pH 6, respectively. The reducing reagent β-mercaptoethanol could increase the activity of agarase AgaA by more than 80%. AgaA showed exo-lytic activity on agarose degradation. It decomposed agarose to yield neoagarobiose as the sole product, which was different from the agarase Aga41A from Vibrio sp. CN41 that showed 95% identities of amino acid sequence to agarase AgaA. With single end product, purification procedure is easier than that with multi-products. Therefore, agarase AgaA could be a useful tool for producing the bioactive neoagarobiose.

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“…Agar is called 'agarose' when agarobiose is the main component, and 'porphyran' when porphyrobiose is the main component [1,3].Agar has been widely used as a food, food additive, culturing medium, and support material for techniques like electrophoresis and chromatography [2]. Moreover, as the various biological activities of agar-derived oligosaccharides and agar decomposition products are discovered, the industrial use of agar is expected to expand [4]. Agarose, in nature, is mainly hydrolyzed by microbial beta-agarases into neoagarobiose (3,6-anhydro-Lgalactosyl-α-1,3-D-galactose), which is further hydrolyzed by neoagarooligosaccharide (NAOS) hydrolase into monomers D-galactose (D-Gal) and 3,6-anhydro-L-galactose (L-AHG) [5].…”

mentioning

confidence: 99%

NADP⁺-Dependent Dehydrogenase SCO3486 and Cycloisomerase SCO3480: Key Enzymes for 3,6-Anhydro-L-Galactose Catabolism inStreptomyces coelicolorA3(2)

Tsevelkhorloo

Kim

Kang

et al. 2021

J. Microbiol. Biotechnol.

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Marine red algal cells contain high amounts of cellular carbohydrates and low amounts of lignin, and thus have gained attention as a sustainable next-generation biomass resource. Red algae-derived carbohydrates can replace fossil fuels, which are expected to be depleted in the near future, and can be converted into chemical feedstocks and bioenergy [1,2].Consisting mainly of carbohydrates that make up the majority of red algal cells, agar is a copolymer of the agarobiose unit (4-O-β-D-galactopyranosyl-3,6-anhydro-L-galactose) and the porphyrobiose unit (4-O-β-Dgalactopyranosyl-L-galactose-6-sulfate), linked by alpha-1,3 glycosidic bonds. The composition ratio of the two units varies depending on the species of red algae. Agar is called 'agarose' when agarobiose is the main component, and 'porphyran' when porphyrobiose is the main component [1,3].Agar has been widely used as a food, food additive, culturing medium, and support material for techniques like electrophoresis and chromatography [2]. Moreover, as the various biological activities of agar-derived oligosaccharides and agar decomposition products are discovered, the industrial use of agar is expected to expand [4]. Agarose, in nature, is mainly hydrolyzed by microbial beta-agarases into neoagarobiose (3,6-anhydro-Lgalactosyl-α-1,3-D-galactose), which is further hydrolyzed by neoagarooligosaccharide (NAOS) hydrolase into monomers D-galactose (D-Gal) and 3,6-anhydro-L-galactose (L-AHG) [5]. D-Gal is a valuable chemical feedstock that can be converted into bioenergy or other useful chemicals [4]. Additionally, L-AHG is a rare monosaccharide Agarose is a linear polysaccharide composed of D-galactose and 3,6-anhydro-L-galactose (AHG). It is a major component of the red algal cell wall and is gaining attention as an abundant marine biomass.However, the inability to ferment AHG is considered an obstacle in the large-scale use of agarose and could be addressed by understanding AHG catabolism in agarolytic microorganisms. Since AHG catabolism was uniquely confirmed in Vibrio sp. EJY3, a gram-negative marine bacterial species, we investigated AHG metabolism in Streptomyces coelicolor A3(2), an agarolytic gram-positive soil bacterium. Based on genomic data, the SCO3486 protein (492 amino acids) and the SCO3480 protein (361 amino acids) of S. coelicolor A3(2) showed identity with H2IFE7.1 (40% identity) encoding AHG dehydrogenase and H2IFX0.1 (42% identity) encoding 3,6-anhydro-L-galactonate cycloisomerase, respectively, which are involved in the initial catabolism of AHG in Vibrio sp. EJY3. Thin layer chromatography and mass spectrometry of the bioconversion products catalyzed by recombinant SCO3486 and SCO3480 proteins, revealed that SCO3486 is an AHG dehydrogenase that oxidizes AHG to 3,6-anhydro-L-galactonate, and SCO3480 is a 3,6-anhydro-L-galactonate cycloisomerase that converts 3,6-anhydro-L-galactonate to 2-keto-3-deoxygalactonate. SCO3486 showed maximum activity at pH 6.0 at 50°C, increased activity in the presence of iron ions, and activity against various a...

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Implications of agar and agarase in industrial applications of sustainable marine biomass

Cited by 59 publications

References 111 publications

Expression and Characterization of a Novel Cold-Adapted and Stable β-Agarase Gene agaW1540 from the Deep-Sea Bacterium Shewanella sp. WPAGA9

Expression and Characterization of a Novel Cold-Adapted and Stable β-Agarase Gene agaW1540 from the Deep-Sea Bacterium Shewanella sp. WPAGA9

A new neoagarobiose-producing agarase from Vibrio sp. LA1

NADP⁺-Dependent Dehydrogenase SCO3486 and Cycloisomerase SCO3480: Key Enzymes for 3,6-Anhydro-L-Galactose Catabolism inStreptomyces coelicolorA3(2)

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Implications of agar and agarase in industrial applications of sustainable marine biomass

Cited by 59 publications

References 111 publications

Expression and Characterization of a Novel Cold-Adapted and Stable β-Agarase Gene agaW1540 from the Deep-Sea Bacterium Shewanella sp. WPAGA9

Expression and Characterization of a Novel Cold-Adapted and Stable β-Agarase Gene agaW1540 from the Deep-Sea Bacterium Shewanella sp. WPAGA9

A new neoagarobiose-producing agarase from Vibrio sp. LA1

NADP+-Dependent Dehydrogenase SCO3486 and Cycloisomerase SCO3480: Key Enzymes for 3,6-Anhydro-L-Galactose Catabolism inStreptomyces coelicolorA3(2)

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NADP⁺-Dependent Dehydrogenase SCO3486 and Cycloisomerase SCO3480: Key Enzymes for 3,6-Anhydro-L-Galactose Catabolism inStreptomyces coelicolorA3(2)