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Hatada Y,
Ohta Y,
Horikoshi K,
( 2006 ) Hyperproduction and application of alpha-agarase to enzymatic enhancement of antioxidant activity of porphyran. PMID : 17177517 : DOI : 10.1021/jf0613684 Abstract >>
The nucleotide sequence of the gene for the alpha-agarase, AgaA33, from Thalassomonas sp. strain JAMB-A33 was determined. The open reading frame for AgaA33 was revealed to encode 1463 amino acid residues. We succeeded in extracellular production of recombinant -agarase (AgaA33) efficiently using Bacillus subtilis as a host. This is the first report of recombinant production of -agarase. Furthermore, we demonstrated that hydrolysis of alpha-1,3 linkages in porphyran, a sulfated polysaccharide from marine red algae, by alpha-agarase is an important step for improvement of its antioxidant activity with regard to free-radical-scavenging capacity and superoxide radical anion scavenging activity, whereas the hydrolysis of beta-1,4 linkages in porphyran by beta-agarase did not increase on the antioxidant activity markedly.
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2. |
Ohta Y,
Hatada Y,
Miyazaki M,
Nogi Y,
Ito S,
Horikoshi K,
( 2005 ) Purification and characterization of a novel alpha-agarase from a Thalassomonas sp. PMID : 15902469 : DOI : 10.1007/s00284-004-4435-z Abstract >>
An agar-degrading Thalassomonas bacterium, strain JAMB-A33, was isolated from the sediment off Noma Point, Japan, at a depth of 230 m. A novel alpha-agarase from the isolate was purified to homogeneity from cultures containing agar as a carbon source. The molecular mass of the purified enzyme, designated as agaraseA33, was 85 kDa on both SDS-PAGE and gel-filtration chromatography, suggesting that it is a monomer. The optimal pH and temperature for activity were about 8.5 and 45 degrees C, respectively. The enzyme had a specific activity of 40.7 U/mg protein. The pattern of agarose hydrolysis showed that the enzyme is an endo-type alpha-agarase, and the final main product was agarotetraose. The enzyme degraded not only agarose but also agarohexaose, neoagarohexaose, and porphyran.
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3. |
Liang SS,
Chen YP,
Chen YH,
Chiu SH,
Liaw LL,
( 2014 ) Characterization and overexpression of a novel �]-agarase from Thalassomonas agarivorans. PMID : 24206167 : DOI : 10.1111/jam.12389 Abstract >>
The agarase from Thalassomonas agarivorans BCRC 17492 was cloned and overexpressed in Escherichia coli. The characterization of the novel agarase was performed. The genomic library of T. agarivorans BCRC 17492 was constructed for screening agarase gene. The novel �]-agarase, namely AgaB1, was successfully identified and shared only 57% identity to reported agarase from Alteromonas sp. To characterize the AgaB1 protein, the recombinant AgaB1 can be obtained by heterologous expression in E. coli. The agarase activity of AgaB1 was achieved at 30�P25 U per mg at 35�XC. According to the analysis of optimal conditions, the highest activity of AgaB1 was attained at 40�XC, pH 7�P4 and 200 mmol l(-1) NaCl, and half-life of AgaB1 can be maintained for almost 1 h at 40�XC. Further determination of substrate hydrolysis indicated that AgaB1 had possession of both endo- and exolytic activity, and neoagarobiose was the major hydrolysis product by TLC and high-performance liquid chromatograph/mass spectrometer (HPLC/MS) analysis. We have successfully cloned and overexpressed the novel �]-agarase from T. agarivorans BCRC 17492 in E. coli. The high yield and detailed characterization of recombinant AgaB1 was provided. AgaB1 was the first �]-agarase that was cloned and described from Thalassomonas species. In the light of properties of AgaB1, it has the potential as the biocatalyst for industrial applications.
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