Purification and characterization of extracellular beta-glucosidase from Sinorhizobium kostiense AFK-13 and its algal lytic effect on Anabaena flos-aquae.
A beta-glucosidase from the algal lytic bacterium Sinorhizobium kostiense AFK-13, grown in complex media containing cellobiose, was purified to homogeneity by successive ammonium sulfate precipitation, and anion-exchange and gel-filtration chromatographies. The enzyme was shown to be a monomeric protein with an apparent molecular mass of 52 kDa and isoelectric point of approximately 5.4. It was optimally active at pH 6.0 and 40'C and possessed a specific activity of 260.4 U/mg of protein against 4-nitrophenyl-beta-D-glucopyranoside (pNPG). A temperature-stability analysis demonstrated that the enzyme was unstable at 50 degrees C and above. The enzyme did not require divalent cations for activity, and its activity was significantly suppressed by Hg+2 and Ag+, whereas sodium dodecyl sulfate (SDS) and Triton X-100 moderately inhibited the enzyme to under 70% of its initial activity. In an algal lytic activity analysis, the growth of cyanobacteria, such as Anabaena flos-aquae, A. cylindrica, A. macrospora, Oscillatoria sancta, and Microcystis aeruginosa, was strongly inhibited by a treatment of 20 ppm/disc or 30 ppm/disc concentration of the enzyme.
Kim
Jeong-Dong
JD
Institute of Industrial Biotechnology, Department of Biological Engineering, Inha University, Incheon 402-751, Korea.
Lee
Choul-Gyun
CG
D000645:Ammonium Sulfate / Q000378:metabolism; D046868:Anabaena cylindrica / Q000187:drug effects / Q000254:growth & development; D000900:Anti-Bacterial Agents / Q000302:isolation & purification* / Q000378:metabolism*; D005591:Chemical Fractionation; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D046869:Dolichospermum flos-aquae / Q000187:drug effects* / Q000254:growth & development; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004795:Enzyme Stability; D005960:Glucosides / Q000378:metabolism; D006046:Gold / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D007526:Isoelectric Point; D008628:Mercury / Q000494:pharmacology; D046931:Microcystis / Q000187:drug effects / Q000254:growth & development; D008970:Molecular Weight; D017830:Octoxynol / Q000494:pharmacology; D054300:Oscillatoria / Q000187:drug effects / Q000254:growth & development; D020579:Sinorhizobium / Q000201:enzymology*; D012967:Sodium Dodecyl Sulfate / Q000494:pharmacology; D013696:Temperature; D001617:beta-Glucosidase / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*
D000900:Anti-Bacterial Agents; D004791:Enzyme Inhibitors; D005960:Glucosides; C025193:4-nitrophenyl beta-D-glucoside; D012967:Sodium Dodecyl Sulfate; D006046:Gold; D017830:Octoxynol; D001617:beta-Glucosidase; D008628:Mercury; D000645:Ammonium Sulfate