Site-Specific and High-Loading Immobilization of Proteins by Using Cohesin–Dockerin and CBM–Cellulose Interactions

Immobilization of enzymes enhances their properties for application in industrial processes as reusable and robust biocatalysts. Here, we developed a new immobilization method by mimicking the natural cellulosome system. A group of cohesin and carbohydrate-binding module (CBM)-containing scaffoldins were genetically engineered, and their length was controlled by cohesin number. To use green fluorescent protein (GFP) as an immobilization model, its C-terminus was fused with a dockerin domain. GFP was able to specifically bind to scaffoldin via cohesin–dockerin interaction, while the scaffoldin could attach to cellulose by CBM–cellulose interaction. Our results showed that this mild and convenient approach was able to achieve site-specific immobilization, and the maximum GFP loading capacity reached ∼0.508 μmol/g cellulose

Co-fermentation of Cellulose and Sucrose/Xylose by Engineered Yeasts for Bioethanol Production

Consolidated bioprocessing (CBP) of cellulose mixed with fermentable sugar(s) is considered as a promising alternative to the use of cellulose as sole substrate for bioethanol production. Our research metabolically engineered Saccharomyces cerevisiae to allow for the co-conversion of cellulose and either sucrose or xylose to bioethanol. Constitutive promoter substitution and xylose metabolic pathway integration were carried out in a strain previously modified to express both bifunctional minicellulosomes by galactose induction and a cellodextrin pathway. Strain EBY101-CC, engineered for the co-fermentation of cellulose and sucrose, produced 4.3 g/L ethanol from 10 g/L carboxymethyl cellulose (CMC) and batch-fed sucrose with an ethanol yield of 0.43 g/g of total sugars. Strains modified for co-fermentation of xylose and cellulose, EBY101-X5CC and EBY101-X5CP were able to produce 2.9 g/L cellulosic ethanol from 8.0 g/L CMC and 1.2 g/L from 3.2 g/L phosphoric acid-swollen cellulose (PASC), respectively, when xylose was depleted

Additional file 1: Figure S1. of The prescriptions from Shenghui soup enhanced neurite growth and GAP-43 expression level in PC12 cells

The TQSS and EPSI drugs suppressed the viability of PC12 cells. (A) The viability of PC12 cells was measured with MTT after incubated for 48 h with TQSS derived from Shenghui soup at different concentrations (10, 20, 50, 100, 200, 500 and 2000 mg/L). (B) The relative viability of PC12 cells treated with different concentrations (5, 10, 20, 50, 100, 200 and 500 mg/L) of EPSI derived from Shenghui soup for 48 h. Data are expressed as mean ± SD, n = 3, **p < 0.01, ***p < 0.001 versus control without drugs. Figure S2. Little apoptosis of PC12 cells treated with TQSS and EPSI occurred. (A) The representative TUNEL pictures of PC12 cells detected by flow cytometry. The normal group and control group represent the cells cultured with 15 % serum DMEM and 1.5 % serum DMEM, respectively. The TQSS and EPSI groups stand for the apoptosis rates of PC12 cells treated with 1000 mg/L TQSS and 500 mg/L EPSI in 1.5 % serum DMEM, respectively. (B) The statistical analysis for control group, normal group TQSS and EPSI groups Data are expressed as mean ± SD, n = 3, ***p < 0.001 versus normal. (PDF 152 kb