Fungal β-glucosidase expression in Saccharomyces cerevisiae

• Published in: Journal of industrial microbiology & biotechnology 2012-10, Vol.39 (10), p.1445-1452
• Main Authors: Njokweni, A. P, Rose, S. H, van Zyl, W. H
• Format: Article
• Language: English
• Subjects: anaerobic conditions; Anaerobiosis; beta-glucosidase; beta-Glucosidase - biosynthesis; beta-Glucosidase - genetics; beta-Glucosidase - metabolism; Biochemistry; Bioenergy/Biofuels/Biochemicals; Bioinformatics; Biological and medical sciences; Biomedical and Life Sciences; Biotechnology; cellobiose; Cellobiose - metabolism; Cellulose - metabolism; Chromatography, High Pressure Liquid; ethanol; Ethanol - metabolism; Ethanol - supply & distribution; Fermentation; Fundamental and applied biological sciences. Psychology; fungi; Genetic Engineering; Inorganic Chemistry; Kluyveromyces - enzymology; Kluyveromyces - genetics; Kluyveromyces lactis; Kluyveromyces marxianus var. lactis; lactose; Life Sciences; Membrane Transport Proteins - genetics; Membrane Transport Proteins - metabolism; Microbiology; Phanerochaete - enzymology; Phanerochaete - genetics; Phanerochaete chrysosporium; Recombinant Proteins - biosynthesis; Recombinant Proteins - genetics; Recombinant Proteins - metabolism; Saccharomyces cerevisiae; Saccharomyces cerevisiae - genetics; Saccharomyces cerevisiae - growth & development; Saccharomyces cerevisiae - metabolism; temperature; Thermoascus - enzymology; Thermoascus - genetics; Thermoascus aurantiacus
• ISSN: 1367-5435; 1476-5535
• DOI: 10.1007/s10295-012-1150-9

Recombinant Saccharomyces cerevisiae strains expressing β-glucosidases from Thermoascus aurantiacus (Tabgl1) and Phanerochaete chrysosporium (PcbglB and Pccbgl1) were constructed and compared to S. cerevisiae Y294[SFI], previously identified as the best β-glucosidase-producing strain. The PcbglB was also intracellularly expressed in combination with the lac12 lactose permease of Kluyveromyces lactis in S. cerevisiae Y294[PcbglB + Lac12]. The recombinant extracellular β-glucosidases indicated maximum activity in the pH range 4–5 and temperature optima varying from 50 to 75 °C. The S. cerevisiae Y294[Pccbgl1] strain performed best under aerobic and anaerobic conditions, producing 2.6 times more β-glucosidase activity than S. cerevisiae Y294[SFI] and an ethanol concentration of 4.8 g l−1 after 24 h of cultivation on cellobiose as sole carbohydrate source. S. cerevisiae Y294[Tabgl1] was unable to grow on cellobiose (liquid medium), whereas S. cerevisiae Y294[PcbglB + Lac12] exhibited limited growth.