Efficient synthesis of octyl-β-d-galactopyranoside by Bacillus spore-displayed β-galactosidase using an amphiphilic 1,2-dimethoxyethane co-solvent
| Autor: | Jungdon Bae, Eun Hwa Choi, Jae-Gu Pan |
|---|---|
| Rok vydání: | 2010 |
| Předmět: |
Glycosylation
Bioconversion Bioengineering Lactose Bacillus subtilis Applied Microbiology and Biotechnology Biochemistry Micelle chemistry.chemical_compound Hydrolysis Enzyme Stability Organic chemistry Spores Bacterial biology fungi technology industry and agriculture Galactosides 1-Octanol biology.organism_classification beta-Galactosidase Dimethoxyethane Recombinant Proteins Solvent Ethyl Ethers chemistry Yield (chemistry) Solvents lipids (amino acids peptides and proteins) Nuclear chemistry Biotechnology |
| Zdroj: | Enzyme and microbial technology. 48(3) |
| ISSN: | 1879-0909 |
| Popis: | For enzymatic synthesis of octyl-β-d-galactopyranoside (octyl-gal) from lactose and n-octanol, Escherichia coli β-galactosidase (β-Gal) was expressed and displayed on the surfaces of Bacillus subtilis spores. The spore-displayed β-Gal was found to be stable when an amphiphilic 1,2-dimethoxyethane (DME) was used as a co-solvent; the transgalactosylation efficiency and octyl-gal conversion were optimal at 50% (v/v) DME. In addition, the product was maximally obtained from 100mM lactose in a phosphate buffer/n-octanol/DME (25/25/50, v/v) mixture. By increasing the agitation speed and the amount of spores displaying β-Gal, a yield of 33.7 mM octyl-gal was obtained over 24h in a batch mode, which is much higher than in other octyl-gal bioconversion processes, such as those involving lipid-coating, reverse micelles, or whole cells. On the other hand, intermittent addition of spore-displayed β-Gal and/or lactose in the reaction medium had no effect on the octyl-gal yield. The synthesized octyl-gal was hydrolyzed by the spore-displayed β-Gal, and a high concentration of octyl-gal competitively inhibited the enzymes (K(i) value of 10.8mM). In summary, we demonstrate that octyl-gal synthesis by spore-displayed β-Gal in non-aqueous medium can be significantly improved with the use of DME as a co-solvent. |
| Databáze: | OpenAIRE |
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