Isomerization of glucose to fructose. 1. The stability of a whole cell immobilized glucose isomerase catalyst

1983 ◽  
Vol 22 (3) ◽  
pp. 349-356 ◽  
Author(s):  
Johannes Straatsma ◽  
Klaas Vellenga ◽  
Henk G. J. De Wilt ◽  
Geert E. H. Joosten
Keyword(s):  
Glucose Isomerase ◽  
Whole Cell ◽  
The Stability ◽  
Immobilized Glucose Isomerase

Development of reactor model for glucose isomerization catalyzed by whole-cell immobilized glucose isomerase

1991 ◽  
Vol 7 (4) ◽  
pp. 183-187 ◽  
Author(s):  
D. Vasić-Rački ◽  
N. Pavlović ◽  
S. Čižmek ◽  
M. Dražić ◽  
B. Husadžić
Keyword(s):  
Glucose Isomerase ◽  
Reactor Model ◽  
Whole Cell ◽  
Immobilized Glucose Isomerase ◽  
Glucose Isomerization

scholarly journals Development and Characterization of Two Types of Surface Displayed Levansucrases for Levan Biosynthesis

Catalysts ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 757
Author(s):  
Huiyi Shang ◽  
Danni Yang ◽  
Dairong Qiao ◽  
Hui Xu ◽  
Yi Cao
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Molecular Weight ◽  
Large Scale ◽  
Surface Display ◽  
Yeast Surface Display ◽  
Fusion Partner ◽  
Whole Cell ◽  
Food Industries ◽  
Yeast Surface ◽  
The Stability

Levan has wide applications in chemical, cosmetic, pharmaceutical and food industries. The free levansucrase is usually used in the biosynthesis of levan, but the poor reusability and low stability of free levansucrase have limited its large-scale use. To address this problem, the surface-displayed levansucrase in Saccharomyces cerevisiae were generated and evaluated in this study. The levansucrase from Zymomonas mobilis was displayed on the cell surface of Saccharomyces cerevisiae EBY100 using a various yeast surface display platform. The N-terminal fusion partner is based on a-agglutinin, and the C-terminal one is Flo1p. The yield of levan produced by these two whole-cell biocatalysts reaches 26 g/L and 34 g/L in 24 h, respectively. Meanwhile, the stability of the surface-displayed levansucrases is significantly enhanced. After six reuses, these two biocatalysts retained over 50% and 60% of their initial activities, respectively. Furthermore, the molecular weight and polydispersity test of the products suggested that the whole-cell biocatalyst of levansucrase displayed by Flo1p has more potentials in the production of levan with low molecular weight which is critical in certain applications. In conclusion, our method not only enable the possibility to reuse the enzyme, but also improves the stability of the enzyme.

scholarly journals Smartphone-Based Whole-Cell Biosensor Platform Utilizing an Immobilization Approach on a Filter Membrane Disk for the Monitoring of Water Toxicants

Sensors ◽  
2020 ◽  
Vol 20 (19) ◽  
pp. 5486
Author(s):  
Junning Ma ◽  
Dorin Harpaz ◽  
Yang Liu ◽  
Evgeni Eltzov
Keyword(s):  
Low Cost ◽  
Environmental Water ◽  
Medical Diagnostics ◽  
Whole Cell ◽  
Filter Membrane ◽  
Sensing Applications ◽  
Bacterial Immobilization ◽  
The Stability ◽  
Whole Cell Biosensor ◽  
Membrane Disk

Bioluminescent bacteria whole-cell biosensors (WCBs) have been widely used in a range of sensing applications in environmental monitoring and medical diagnostics. However, most of them use planktonic bacteria cells that require complicated signal measurement processes and therefore limit the portability of the biosensor device. In this study, a simple and low-cost immobilization method was examined. The bioluminescent bioreporter bacteria was absorbed on a filter membrane disk. Further optimization of the immobilization process was conducted by comparing different surface materials (polyester and parafilm) or by adding glucose and ampicillin. The filter membrane disks with immobilized bacteria cells were stored at −20 °C for three weeks without a compromise in the stability of its biosensing functionality for water toxicants monitoring. Also, the bacterial immobilized disks were integrated with smartphones-based signal detection. Then, they were exposed to water samples with ethanol, chloroform, and H2O2, as common toxicants. The sensitivity of the smartphone-based WCB for the detection of ethanol, chloroform, and H2O2 was 1% (v/v), 0.02% (v/v), and 0.0006% (v/v), respectively. To conclude, this bacterial immobilization approach demonstrated higher sensitivity, portability, and improved storability than the planktonic counterpart. The developed smartphone-based WCB establishes a model for future applications in the detection of environmental water toxicants.

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