Purification and characterization of β-agarase from Paenibacillus sp.

beta-Agarase produced by Paenibacillus sp. WL (agarase WL) was purified using a combination of ammonium sulfate precipitation, DEAE-ion exchange, and gel-filtration chromatography. The purity of the agarase was increased by 11.9x with a recovery of 5.1% and a specific activity of 4,670.1 U/mg of protein. The molecular mass of the purified agarase was approximately 30 kDa (SDS-PAGE). The agarase was stable at temperature below 50A degrees C and the favorable agar-hydrolysis activity was at 40A degrees C. The agarase was active in the range of pH 5.0 to 8.0, and the optimal agar-hydrolysis pH value was approximately 6.0. Metal ions normally found in seawater (Na+, K+, Ca2+, Mg2+, and Al3+) could activate agarase WL. The Michaelis-Menten constant K (m) and maximal reaction velocity V (max) of purified agarase WL were 3.22 mg/mL and 41.5 mu g/mL center dot min, respectively. The agarase WL was highly agar specific.