Molecular cloning, characterization and enzymatic properties of a novel βeta-agarase from a marine isolate Psudoalteromonas sp. AG52

Abstract

An agar-degrading Pseudoalteromonas sp. AG52 bacterial strain was identified from the red seaweed Gelidium amansii collected from Jeju Island, Korea. A β-agarase gene which has 96.8% nucleotide identity to Aeromonas β-agarase was cloned from this strain, and was designated as agaA. The coding region is 870 bp, encoding 290 amino acids and possesses characteristic features of the glycoside hydrolase family (GHF)-16. The predicted molecular mass of the mature protein was 32 kDa. The recombinant β-agarase (rAgaA) was overexpressed in Escherichia coli and purified as a fusion protein. The optimal temperature and pH for activity were 55 °C and 5.5, respectively. The enzyme had a specific activity of 105.1 and 79.5 unit/mg toward agar and agarose, respectively. The pattern of agar hydrolysis demonstrated that the enzyme is an endo-type β-agarase, producing neoagarohexaose and neoagarotetraose as the final main products.Since, Pseudoalteromonas sp. AG52 encodes an agaA gene, which has greater identity to Aeromonas β-agarase, the enzyme could be considered as novel, with its unique bio chemical characteristics. Altogether, the purified rAgaA has potential for use in industrial applications such as development of cosmetics and pharmaceuticals.

Cloning and Characterization of a Novel Agarase from a Newly Isolated Bacterium Simiduia sp. Strain TM-2 Able to Degrade Various Seaweeds

“…Further characterization of these products by mass spectrum will be discussed in future studies. This result suggests that AgaTM2 might be an interesting candidate for industrial applications in several fields including cosmetics and medicines, given the various uses of bacterial agarase-derived oligosaccharides for their whitening and antioxidant activities [40,41].…”

A Novel Neoagarotriose-Producing Agarase from the Marine Bacterium Gilvimarinus Agarilyticus JEA5

“…To determine the biochemical properties of rGaa16Bc, we performed enzyme assays to assess the optimum temperature and pH for enzyme activity, as well as protein thermostability, and the effects of metal ions and chelators. The enzyme activities were measured using modi ed DNS methods [29]. The reaction conditions were as follows: 100 µL of 1% agarose (Lonza, Switzerland), 95 µL of proper buffer and 5 µL of diluted enzyme, incubated for 5 min at 55 °C.…”

Molecular Cloning, Overexpression, and Enzymatic Characterization of Glycosyl Hydrolase Family 16 β-Agarase from Marine Bacterium Saccharophagus sp. AG21 in Escherichia coli

“…SY12 [38], Microbulbifer [34], Pseudoalteromonas sp. AG52 [35], Saccharophagus [12], Vibrio [9], and Zobellia [21]. In contrast, the GH50 and GH86 families consist of β-agarases only, and presently contain 74 and 32 members, respectively (http://www.cazy.org).…”