Synthesis of lsopropyl-1-thio-Β-D-glucopyranoside (IPTGlc), an inducer ofaspergillus niger b1 Β-glucosidase production

Production of Β-glucosidase inAspergillus niger Bl is subjected to catabolic repression by glucose.Aspergillus niger Bl grown on bran as a carbon source secreted Β-glucosidase. The maximum level of the enzyme was reached after 7 d of fermentation. Addition of 1% glucose to the medium suppressed Β-glucosidase production to undetectable levels. In this study, the organic synthesis of a potential inducer of Β-glucosidase production by A.niger Bl’s reported. Isopropyl-1-thio-Β-D-glucopyranoside (IPTGlc) was synthesized using a two-step organic synthesis protocol. The H-NMR data agreed with those reported previously for the galactoside analog. When IPTGlc was added 24 h after inoculation at a final concentration of 0.4 mM, similar levels of Β-glucosidase were reached 3 to 4 d earlier as compared to fermentation without IPTGlc induction. In practice, this may translate to a more efficient method of producing Β-glucosidase from this fungus.