• Journal of Food Hygiene and Safety
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• v.15 no.4
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• pp.277-281
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• 2000

Agar, one of the most abundant marine products has not been utilized extensively because of low level of processing technology in Korea. This research was carried out to improve the utilization of agar and consequent increase in profit. Antibacterial activity of agarooligosaccharides were evaluated against bacteria causing putrefaction and flood poisoning. Addition of 0.4% agarooligosaccharides showed antibacterial activity toward Staphylococcus aureus and Escherichia coli O157:H7; furthermore, autoclave treatment of agarooligosaccharides solution enhanced the antibacterial activity. Agarooligosaccharides showed high stability against the pH change. Addition of amino acid(alanine, lysine, glycine, phenylalanine) in agarooligosaccharides solution enhanced antibacterial activity in E. coli O157:H7, Streptococcus mutans and Staphylococcus aureus.

• Journal of Food Hygiene and Safety
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• v.15 no.4
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• pp.282-286
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• 2000

Agarooligosaccharides were produced by $\beta$-agarase from Bacillus cereus ASK 202. LD$_{50}$ of Agarooligosaccharides was determined to be 1359 mg/kg which corresponded to GRAS material. Agarooligosaccharides at 5% level exhibited 88.3% inhibition on TA98 and 54% on TA100, indicating agarooligosaccharides to be potent antimutagenic substance. Immunologic activity of agarooligosaccharides was also confirmed by mouse spleen cell culture. Agrooligosaccharides addition of 200 $\mu$l/ml stabilized spleen cells (2.5$\times$10$^{6}$ cells/ml) as compared to control (6.4$\times$10$^4$ cells/ml).

• Journal of Food Hygiene and Safety
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• v.16 no.1
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• pp.11-15
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• 2001

This research was carried out to improve the utilization of agar by evaluating the effect of agarooligosaccharides on the intestinal microflora. Medium containing 0.2% agarooligosaccharides remarkably enhanced the growth of Bifidobacterium infanits; however, agarooligosaccharides did not influence the growth of Clostridium perflingens. Agarooligosaccharides affected intestinal microflora to different extent by various pH and NaCl concentration. The growth of B. infantis enhanced over pH 4.5. Within 1% NaCl concentration, addition of agarooligosaccharides enhanced the growth of B. infantis. In contract, NaCl did not affect the growth of Cl. perflingens at all concentrations tested. Therefore, agarooligosacchariedes improved the benevolent intestinal microflora and depressed to the level of bacteria causing putrefaction and food poisoning.

• KSBB Journal
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• v.13 no.5
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• pp.524-529
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• 1998

An agarase was partially purified from the culture broth of marine bacterium Bacillus cereus ASK202. Optimal pH and temperature of this agarase were found to be 7.0 and 40$^{\circ}C$, respectively. The maximum productivity of agarooligosaccharides was obtained from 0.3 %(w/v) agar by using of 1 unit agarase. As the results of TLC and HPLC analysis, these oilgosaccharides consisted of neoagarobiose, neoagarotetraose and neoagarohexaose. Under the optimal reaction conditions, 77.5 %(w/v) neoagarobiose and 6.2 %(w/v) neoagarotetraose were produced from agar and the conversion yield of total agarooligosaccharides was 83.7 %(w/v) after for 2 h reaction at 40$^{\circ}C$.

• Korean Journal of Food Science and Technology
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• v.32 no.2
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• pp.284-290
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• 2000

A marine bacterium Bacillus cereus ASK202 showing a high agar degrading activity, was incubated in the culture medium containing agar. After incubation for 30 hr, the productivity of agarase in the culture broth reached to maximum value (160.8 units/L). As the results of TLC and HPLC analysis, agarooligosaccharides (degrees of polymerization 2, 4 and 6) were produced from the hydrolysis of agar by using the crude agarase. Physical and chemical properties of agarooligosaccharides were compared with the manufactured products of other oligosaccharides (fructooligosaccharide; isomaltooligosaccharide; maltotetraoligosaccharide) and agarooligosaccharides showed higher viscosity, higher contents of oligosaccharides, higher stability at low pH's and higher temperatures, and lower sweetness than other oligosaccharides.

• KSBB Journal
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• v.13 no.4
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• pp.378-382
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• 1998

Agar hydorlysates or agarooligosaccharides from agar prepared by Cytophaga agarase showed eight spots on TLC plate and the degree of polymerization of the spots were in the reange of 2.5 - 6.5. Each component of the hydrolysate as tested the several functionalities such as antimicrobial activity, anticavity activity, and anticoagulant activity. The anticativity activity and anticoagulant acitvity were found in all fractions of hydrolysates and several spot on TLC, whereas the anticoagulant activity was very low.

• Journal of Life Science
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• v.22 no.2
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• pp.266-280
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• 2012

Agar is a cell wall component of macro red algae that can be hydrolyzed by agarase. Agarases are classified into ${\alpha}$-agarase (E.C. 3.2.1.158) and ${\beta}$-agarase (E.C. 3.2.1.81), in accordance with their cleavage pattern, and can be grouped in the glycoside hydrolase (GH)-16, -58, -86, -96, and -118 family according to the amino acid sequences of the proteins. Many agarases and/or their genes have been detected, isolated, and recombinantly expressed from bacteria, and metagenomes have their origins in sea and terrestrial environments. Products of agarases, agarooligosaccharides and neoagarooligosaccharides, represent wide functions such as antitumor, immune stimulation, antioxidation, prebiotic, hepa-protective, antibacterial, whitening, and moisturizing effects; hence, broad applications would be possible in the food industry, cosmetics, and medical fields. In addition, agarases are also used as a tool enzyme for research. This paper reviews the sources, purifications and detection methods, and application fields of agarases. The role of agarases in agar metabolism and the function of their enzymatic products are also surveyed.

• KSBB Journal
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• v.31 no.2
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• pp.113-119
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• 2016

A novel agar-degrading marine bacterium, SH-1 strain, was isolated from seashore of Namhae at Gyeongnam province, Korea. The SH-1 strain exhibited 98% similarity with Alteromonas species based on 16S rDNA sequencing and named as Alteromonas sp. SH-1. Alteromonas sp. SH-1 showed agarase activity of 348.3 U/L (1.67 U/mg protein). The molecular masses of the enzymes were predicted as about 85 kDa and 110 kDa by SDS-PAGE and zymogram. The enzymatic activity was optimal at $30^{\circ}C$ and the relative agarase activity was decreased as temperature increase from $30^{\circ}C$ and thus about 90% and 70% activities were shown at $40^{\circ}C$ and $50^{\circ}C$, respectively. The optimum pH was 6.0 for agarase activity in 20 mM Tris-HCl buffer and activities were less than 70% and 85% activity at pH 5.0 and pH 7.0, respectively, compared with that at pH 6. Agarase activity has remained over 90% at $20^{\circ}C$ after 1.5 hour exposure at this temperature. However, its activity was less than 60% at $30^{\circ}C$ after 0.5 h exposure at this temperature. The enzymes produced agarooligosaccharides such as agaropentaose and agarotriose from agarose, indicating that the agarases are ${\alpha}$-agarases. Thus, Alteromonas sp. SH-1 and its agarases would be useful for the industrial production of agarooligosaccharides which are known as having anticancer and antioxidation activities.

• KSBB Journal
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• v.16 no.4
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• pp.398-402
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• 2001

Enzymatic hydrolysis of agar was carried out continuously to produce agarooligosaccharides by immobilized agarase in Packed-Bed Reactor. The reactor was constructed using a acryl tube with an internal diameter of 10 mm and a useful height of 140 mm. The Packed-Bed Reactor was 11 mL reactor volume as its length : diameter ratio was 14 : 1. The operation condition of reaction was performed with an 1 g/L agar concentration at 40$^{\circ}C$, 10 mM MOPS buffer(pH 7.0) and with the flow rate 3 mL∼48 mL/h at a dilution rate of 1.09∼5.45 h$\^$-1/. The hydrolysis products was identified DP6, DP4 and DP2 by HPLC. The conversion rate of agar was about 80% and amount of total agarooligosaccharide was 0.88 mg/mL at Packed-Bed Reactor.

• Microbiology and Biotechnology Letters
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• v.27 no.3
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• pp.208-214
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• 1999

The condition for immobilization of the partially purified agarase from Bacillus cereus ASK202 and the properties of the immobilized enzyme have been investigated. Agarase was immobilized on various supports by entrapment method. The enzyme immobilized on Na-alginate bead showed the highest activity among those studied. The optimal reaction conditions of the immobilized agarase were obtained in 3%(w/v) Na-alginate for the matrix, bead diameter of 2.5mm, 1 unit of agarase solution and 1.0%(w/v) calcium chloride solution. The optimum pH and temperature of the immobilized agarase were pH and temperature of the immobilized agarase were pH 7.0 and 4$0^{\circ}C$, respectively. Km and Vmax values were 0.5mg/ml.min, respectively. The immobilized agarase conerted agar to agarobiose, and their total conversion ratio under the optimal condition was 89%.