| Title | Purification and Characterization of Xylanases from Alkalophilic streptomyces sp. S-510 | ||
| Author | Rhyum, Sun-Boon · Myeong-Kyu Kang · Pil-Jae Maeng · Hee-Moon Park · Young-Ha Rhee * | ||
| Address | Department of Microbiology, College of Natural Sciences, Chungnam National University | ||
| Bibliography | Korean Journal of Microbiology, 31(5),436-444, 1993 | ||
| DOI | |||
| Key Words | alkalophilic Streptomyces, xylanase, pruification | ||
| Abstract | Two xylanase components, AX-I and AX-II, were purified from alkalophilic Streptomyces sp. S-510 isolated from soil. The two enzymes were pruified to homogeneity by chromatography on sephadex G-150, DEAE-Sephadex A-50, Mono S, Mono Q, Mono P and/or Superose 12. The molecular weights of Ax-I and AX-II were estimated to be 25 kDa and 36 kDa by gel filtration on Superose 12, and the pI values to be 9.0 or higher and 3.0 or lower, respectively. The optimal temperature for enzyme activity was 60℃ for both isoenzymes, and the optimal pH 6.0~8.5 for AX-I and 8.5 for AX-II. Both enzymes were stable at the temperatures below 50℃ at least for 2 hours and considerably stable at pH 4~11. While AX-I was slightly more thermostable than AX-II, the latter showed a little higher pH stability than the former. The activity of AX-I was severely inhibited by Hg^2+ and activated by Ca^2+. On the other hand, AX-II was weakly activated by Mg^2g and inhibited by Hg^2+, Mn^2+ and Zn+2+. The K_m values of AX-I and AX-II for larchwood xylan were determined to be 6 mg/ml and 2 mg/ml, respectively. | ||
| Download PDF | Kor_310513_436-444p.pdf | ||