Cellobiose accumulation and the compromised temperature for yeast fermentation are the main limiting factors of enzymatic hydrolysis process during simultaneous saccharification and fermentation (SSF). In this study, genes encoding cellobiose transporter and β-glucosidase were introduced into an industrial Saccharomyces cerevisiae strain, and evolution engineering was carried out to improve the cellobiose utilization of the engineered yeast strain. The evolved strain exhibited significantly higher cellobiose consumption rate (2.8-fold) and ethanol productivity (4.9-fold) compared with its parent strain. Besides, the evolved strain showed a high cellobiose consumption rate of 3.67 g/L/h at 34°C and 3.04 g/L/h at 38°C. Moreover, little cellobiose was accumulated during SSF of Avicel using the evolved strain at 38°C, and the ethanol yield from Avicel increased by 23% from 0.34 to 0.42 g ethanol/g cellulose. Overexpression of the genes encoding cellobiose transporter and β-glucosidase accelerated cellobiose utilization, and the improvement depended on the strain background. The results proved that fast cellobiose utilization enhanced ethanol production by reducing cellobiose accumulation during SSF at high temperature.
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http://dx.doi.org/10.3389/fmicb.2016.00241 | DOI Listing |
J Agric Food Chem
January 2025
Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, China.
Cellulose, as the most abundant and cheap renewable resource in nature, is of great importance for its utilization. An enzymatic cellulose solution, mainly containing cellobiose and glucose, was utilized to produce astragalin instead of cellobiose in the recombinant strains. However, the crystalline structure of cellulose affects the production of cellobiose, resulting in a low astragalin yield.
View Article and Find Full Text PDFJ Basic Microbiol
December 2024
State Key Laboratory of Digital Medical Engineering, Jiangsu Key Laboratory for Biomaterials and Device, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China.
Sugar transporters are of great importance in sensing and transporting varied sugars for cellulase biosynthesis of lignocellulolytic fungi. Nevertheless, the function and the relevant mechanism of sugar transporters in fungal cellulase biosynthesis remain to be explored. Here, putative maltose transporters Mal1, Mal2, Mal3, Mal4, and Mal5 in Trichoderma reesei were investigated.
View Article and Find Full Text PDFInt J Mol Sci
November 2024
The Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Jiangsu Key Lab for the Chemistry & Utilization of Agricultural and Forest Biomass, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, China.
This study explores the effect of carbohydrate-binding module 1 (CBM1) and the linker on the function of auxiliary activity 9 (AA9) lytic polysaccharide monooxygenases (LPMOs), with a particular focus on monooxygenase activity, using different crystallinity celluloses and electron donors. The tested C1/C4-oxidizing AA9 LPMOs exhibited higher oxidase and peroxidase activities compared to those of the C4-oxidizing AA9 LPMOs. While the presence of CBM1 promoted cellulose-binding affinity, it reduced the oxidase activity of modular AA9 LPMOs.
View Article and Find Full Text PDFInt J Biol Macromol
December 2024
Key Laboratory for Molecular Enzymology and Engineering of Ministry of Education, School of Life Sciences, Jilin University, Changchun 130012, China. Electronic address:
Enzymatic glycosylation is an efficient and biocompatible approach to enhance natural product bioavailability. Cellobiose phosphorylase, a novel glycosyltransferase, utilizes 1-phospho-glucose (1-p-Glc) as a glycosyl donor for regioselective glycosylation of various natural substrates. However, the high cost of 1-p-Glc limits the economic feasibility of the process.
View Article and Find Full Text PDFMicrob Cell Fact
November 2024
Laboratory of Enzymology and Molecular Biology of Microorganisms (LEBIMO), Department of Biochemistry and Tissue Biology, Institute of Biology, Universidade Estadual de Campinas (UNICAMP), Campinas, SP, 13083-862, Brazil.
Background: Fermentation of sugars derived from plant biomass feedstock is crucial for sustainability. Hence, utilizing customized enzymatic cocktails to obtain oligosaccharides instead of monomers is an alternative fermentation strategy to produce prebiotics, cosmetics, and biofuels. This study developed an engineered strain of Aspergillus niger producing a tailored cellulolytic cocktail capable of partially degrading sugarcane straw to yield cellooligosaccharides.
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