Cloning and Characterization of a Novel Oligoalginate Lyase from a Newly Isolated Bacterium Sphingomonas sp. MJ-3

Abstract

A bacterium possessing alginate-degrading activity was isolated from marine brown seaweed soup liquefied by salted and fermented anchovy. The isolated strain was designated as Sphingomonas sp. MJ-3 based on the analyses of 16S ribosomal DNA sequences, 16S-23S internal transcribed spacer region sequences, biochemical characteristics, and cellular fatty acid composition. A novel alginate lyase gene was cloned from genomic DNA library and then expressed in Escherichia coli. When the deduced amino acid sequence was compared with the sequences on the databases, interestingly, the cloned gene product was predicted to consist of AlgL (alginate lyase L)-like and heparinase-like protein domain. The MJ-3 alginate lyase gene shared below 27.0% sequence identity with exolytic alginate lyase of Sphingomonas sp. A1. The optimal pH and temperature for the recombinant MJ-3 alginate lyase were 6.5 and 50°C, respectively. The final degradation products of alginate oligosaccharides were analyzed by electrospray ionization mass spectrometry and proved to be alginate monosaccharides. Based on the results, the recombinant alginate lyase from Sphingomonas sp. MJ-3 is regarded as an oligoalginate lyase that can degrade oligoalginate and alginate into alginate monosaccharides.

Alginate lyase: Review of major sources and classification, properties, structure-function analysis and applications

“…), and a wide range of marine and terrestrial bacteria. In addition, some lyases have been isolated from fungi and viruses ( This classification has been widely accepted, but some enzymes show activities toward both polyM and polyG, [30][31][32][33] which may degrade alginate more effectively. In terms of the mode of action, alginate lyase can be grouped into endolytic and exolytic alginate lyase.…”

“…13 Endolytic alginate lyase cleaves glycosidic bonds inside alginate polymer and releases unsaturated oligosaccharides (di-, tri-, and tetra-saccharides) as main products, 30 while exolytic alginate lyase can further degrade oligosaccharides into monomers. [31][32][33] Based on the analysis of hydrophobic cluster of primary structures, alginate lyases can be grouped into 7 families of Polysaccharide Lyase (PL) family ( Table 2), PL-5, -6, -7, -14,-15, -17, and -18. 34 Most of endolytic bacterial alginate lyases are assigned to PL-5 and PL-7.…”

Screening of Alginate Lyase-Producing Bacteria and Optimization of Media Compositions for Extracellular Alginate Lyase Production

“…Faster growth rates and the appearance of colonies were observed at low concentrations of alginate (0.4%). Park et al [24] isolated strain MJ-3 and reported that the growth rate of the isolate is significant in M9 medium containing 0.8% alginate. However, the growth rates of the isolates were increased with higher sodium alginate concentrations in LB broth (Fig.…”

Enhancing the Alginate Degrading Activity of Streptomyces sp. Strain M3 Alginate Lyase by Mutation

“…3). Alginate lyases beloning to polysaccharide lyase group could be structurally classified to seven families, PL-5 ((α/α)6 barrel) [26], PL-6 (parallel β-helix) [7], PL-7 (β-jelly roll) [18], PL-14 (glove-like β-jelly roll) [17], PL-15 (pocket-like structure involving an α/α barrel + anti-parallel β-sheet-fold) [15], PL-17 (another pocket-like structure involving an α/α barrel + anti-parallel β-sheet-fold) [19] and PL18 (another β-jelly roll) [20]. ALY-PG, A1-II' and PA1167 involved in a PL-7 family but they showed different substrate specificities.…”