Fig. 3
Biochemical characteristics of the recombinant alginate lyases AlyPB1 and AlyPB2. a Effects of temperature. The enzyme activities of AlyPB1 and AlyPB2 were each measured using sodium alginate as substrate in the 50 mM NaH2PO4–Na2HPO4 buffer (pH 8.0) at various temperatures (0–70 °C) for 1 h. Data are shown as the percentage of the activity of that obtained at 30 °C for AlyPB1 and at 20 °C for AlyPB2 (100%). b Effects of pH values. The enzyme activities of AlyPB1 and AlyPB2 against sodium alginate were individually measured in buffers with varying pH values from 5.0 to 10.0 for 1 h at 30 °C of AlyPB1 and at 20 °C of AlyPB2. Data are shown as the percentage of the activity of that obtained in 50 mM NaH2PO4–Na2HPO4 buffer (pH 8.0) (100%). c, d Thermostability of AlyPB1 and AlyPB2. The enzymes were preincubated for 0–24 h under temperatures ranging from 0 to 70 °C, and the residual activities against sodium alginate were estimated at 30 °C of AlyPB1 and at 20 °C of AlyPB2. Data are shown as the activity relative to that of untreated AlyPB1 and AlyPB2. e, f Effects of various compounds on the enzyme activity of AlyPB1 and AlyPB2. The enzyme activities of AlyPB1 and AlyPB2 against sodium alginate were individually measured in the NaH2PO4–Na2HPO4 buffer (pH 8.0) containing a 1 mM or 10 mM concentration of various compounds for 1 h at 30 °C of AlyPB1 and at 20 °C of AlyPB2. Data are shown as the percentage of the activity of obtained in the buffer without tested compounds. Error bars represent mean values of triplicates ± SD