Isolation and characterization of a marine agarase

Abstract:

Abstract: [Objective] This study was carried out to isolate and characterize an agarase from a marine bacterium Agarivorans albus QM38. [Methods] SDS-PAGE grade agarase was obtained from the fermentation broth after removing the bacteria by centrifugation, ammonium sulfate precipitation, DEAE- sepharose fast flow anion exchange chromatography and Sephacryl S-100 gel filtration. Enzyme’s molecular weight was determined with SDS-PAGE. The catalysates of the isolated enzyme were determined with mass spectrography. [Results] Agarase A was isolated. The molecular weight of agarase A was 127.80 kDa. More characterizations of agarase A were studied and the results showed that the optimal reaction condition for agarase A was at 35 ℃, pH 7.6, and agar concentration of 0.9% (w/v), while most of the metal ions inhibited the activity of it. The catalysates of agarase A were mainly tetrose and hexose. [Conclusion] Agarase A was purified from the medium. It could hydrolyze jellied agar and yield simple catalysates. Its molecular weight is different from all the agarases reported so far.

Key words:Keywords: agarase; purification; characterization; analysis of catalysate