Abstract
Active, thermostable Microbispora bispora Bgl B Beta-D-glucosidase was expressed in Streptomyces lividans TK24 cells transformed with plasmid pIJ702 carrying the bg/B coding sequence under the control of Streptomyces longisporus STI-II trypsin inhibitor promoter. The recombinant enzyme, SlBgl B, has a molecular weight of 54 kDa, an isoelectric pH of 5.0, shows resistance to glucose inhibition,and is optimally active on omicron-nitrophenyl Beta-D-glucopyranoside at 57 degrees C. This recombinant Beta-D-glucosidase was more active on aryl-glycosides than on cellobiose. We also report a successful mutagenesis strategy used to achieve increased levels of SlBgl B expression in this host organism. Screening mutants created by low fidelity PCR using Taq polymerase in the presence ofmanganese ion revealed a series of up-regulated clones, one yielding 235 mg/L of SlBgl B.
| Original language | American English |
|---|---|
| Title of host publication | Fuels and Chemicals from Biomass |
| Subtitle of host publication | ACS Symposium Series 666 |
| Editors | B. C. Saha, J. Woodward |
| Pages | Cha 9: 154-171 |
| State | Published - 1997 |
Bibliographical note
Developed from a symposium sponsored by the Division of Biochemical Technology at the 211th National Meeting of the American Chemical Society, 24-29 March, 1996, New Orleans, Louisiana.NREL Publication Number
- NREL/CH-580-20775