Facilitated Transport of Penicillin G by Bulk Liquid Membrane with TBP as Carrier

Abstract

The facilitated transport of penicillin G from aqueous solutions to the stripping phase through bulk liquid membrane (BLM) containing TBP in 3% iso-octanol and n-butyl acetate was studied. Na(2)CO(3) solution was used as the stripping phase. Experiments were performed as a function of stirring rate, TBP concentration and type of diluent in the liquid membrane phase, pH, and initial penicillin G concentration in the feed phase, Na(2)CO(3) concentration in the stripping phase, etc. The results showed that the BLM process could carry out the simultaneous separation and concentration of penicillin G from dilute aqueous solutions, and arise "up-hill" effect due to the characteristic of non-equilibrium mass transfer. The diffusion of penicillin G complex in the liquid membrane phase played an important role in BLM process. The mass transfer mechanism of BLM for this system was also discussed.

Oriented covalent immobilization of esterase BioH on hydrophilic‐modified Fe3O4 nanoparticles

“…3), which might be attributed to the shielding of enzyme molecules on the carrier surface by each other, in addition to enzyme conformational changes [13]. The superiority of the IMBioH 2 over IMBioH 1 in activity retention may be attributed to the modification of the carrier with the hydrophilic groups (-OH), which could draw the hydrophilic regions opposite to the active center of the enzyme closer to the carriers [6] so that the active site could be more readily exposed to the substrate, as shown in Fig. 4.…”

“…However, there are some limitations in the application of enzymes, such as the nonreusability resulting from the solubility of free enzyme in the aqueous phase, the poor stability under extreme temperature and pH conditions, and the high cost of enzyme production [5]. Enzyme immobilization is a conventional approach to overcome the above-mentioned drawbacks, which can be categorized into adsorption, covalent bonding, entrapment, encapsulation, and cross-linking [6]. Though adsorption of enzyme on carriers is a simple and inexpensive way, it often suffers from severe leakage of enzyme during the reaction and the recycling processes, especially in the aqueous phase.…”

“…According to Francesco Secundo, some enzymes could be immobilized onto the surface of the hydrophilic support with correct orientation [13]. It has been found that a large hydrophilic region of the esterase BioH from Escherichia coli is located at the opposite side of the hemisphere of the active site, which facilitated its successful immobilization on a hydrophilic-modified solid support through oriented adsorption [6]. Meanwhile, the improved hydrophilicity of the carriers was also reported to help in preventing denaturation of enzymes in nonaqueous solutions, increasing the activity retention of the enzyme, and improving the capacity of enzyme loading [4].…”

Internal Architecture and Adsorption Sites of Violet Lander Molecules Assembled on Native and KBr‐Passivated InSb(001) Surfaces

“…A liquid membrane (LM) method integrated extraction and stripping into a continuous process is also very attractive. This method has been studied for selective separation and concentration of alcohol and phenol 12–14, metal ions 15–18, amino acids and their derivation 19–21, synthetic drugs 22, 23, etc . However, the studies on separation and extraction of bioactive components from traditional herbal medicines with the LM method are lacking due to the complexity of the chemical compositions of herbal medicines 24–27.…”

“…There are three basic forms of LM processes: emulsion LM (ELM) 12, 13, supported LM (SLM) 14, 17, 18, 23, and bulk LM (BLM) 15, 16, 19–22. BLM is characterized by its thick and stable LM layer, which corresponds to a high stability but low transport efficiency.…”