Preliminary characterization of a novel β-agarase from Thalassospira profundimonas

BACKGROUND: The objective of this study was to characterize the agarase from a newly isolated agarolytic bacterium Thalassospira profundimaris fst-13007. RESULTS: Agarase-fst was purified to homogeneity which apparent molecular weight was 66.2 kDa. Its activity was optimal at 45 °C and pH 8 and was stable at pH 5–9 or 30–50 °C. Agarase-fst required Mn(2+) for agarase activity and inhibition by Cu(2+), Fe(3+) and EDTA. Tests of hydrolysis pattern and substrate specificity, TLC analysis and mass spectrometry of the hydrolysis products revealed that it is an endo-type β-agarase hydrolyzing agarose into neoagarobiose, neoagarotetraose and neoagarohexaose. Results of MALDI-TOF-TOF/MS indicate that it lack of homology to previously identified proteins and present conserved domain of β-agarase. CONCLUSION: Agarase-fst from T. profundimaris fst-13007 was confirmed to be a novel endo-type β-agarase.