Specific Immobilization of Escherichia coli Expressing Recombinant Glycerol Dehydrogenase on Mannose-Functionalized Magnetic Nanoparticles

Abstract

Mannose-functionalized magnetic nanoparticles were prepared for the immobilization of Escherichia coli cells harboring the recombinant glycerol dehydrogenase gene. Immobilization of whole E. coli cells on the carrier was carried out through specific binding between mannose on the nanoparticles and the FimH lectin on the E. coli cell surface via hydrogen bonds and hydrophobic interactions. The effects of various factors including cell concentration, pH, temperature, and buffer concentration were investigated. High degrees of immobilization (84%) and recovery of activity (82%) were obtained under the following conditions: cell/support 1.3 mg/mL, immobilization time 2 h, pH 8.0, temperature 4°C, and buffer concentration 50 mM. Compared with the free cells, the thermostability of the immobilized cells was improved 2.56-fold at 37 °C. More than 50% of the initial activity of the immobilized cells remained after 10 cycles. The immobilized cells were evaluated functionally by monitoring the catalytic conversion of glycerol to 1,3-dihydroxyacetone (DHA). After a 12 h reaction, the DHA produced by the immobilized cells was two-fold higher than that produced by the free cells. These results indicate that mannose-functionalized magnetic nanoparticles can be used for the specific recognition of gram-negative bacteria, which gives them great potential in applications such as the preparation of biocatalysts and biosensors and clinical diagnosis.

Evaluation of MxOy/fucoidan hybrid system and their application in lipase immobilization process

“…The protons bind to the lone pair electrons on the amino N atom under acidic conditions. Whereas under pH 8, the hydrogen bonds on support will be broken in alkalinity conditions 4 , 5 . Based on the information, the optimal pH for immobilization was determined to be 7.0.…”

“…It is highly preferable that the carrier matrix that binds the enzyme can be produced reproducibly and does not disrupt the enzyme activity, because it has a great importance for technological performance and commercial success 1 – 3 . However, those materials also have some disadvantages (low mechanical strength and limited thermal stability) which can be improved using appropriate modification process 4 , 5 .…”

Synthesis of Ribose-Coated Copper-Based Metal–Organic Framework for Enhanced Antibacterial Potential of Chloramphenicol against Multi-Drug Resistant Bacteria

“…The results of the study revealed that the bactericidal potential of CHL increased significantly upon encapsulation in ribose-coated Cu-MOFs. This is because of the interaction of ribose with lectins present on the bacterial cell surface for enhancing the antibacterial activity of CHL [ 51 ].…”

Recent Advances on Biocatalysis and Metabolic Engineering for Biomanufacturing

“…Several investigations in this issue focused on the development of immobilization methods for better biocatalytic performance. By using mannose-functionalized magnetic nanoparticles, Li et al successfully immobilized E. coli cells harboring recombinant glycerol dehydrogenase gene, which showed two-fold higher production of 1,3-dihydroxyacetone from glycerol, compared to the free cells [7]. An optimized procedure of fluorescein diacetate hydrolysis for quantifying total enzymatic activity in the whole biofilm on the carrier without disturbing immobilization was reported by Dzionek et al, which can serve as a promising method to evaluate the physiological state of immobilized bacterial cells [8].…”