Effective Antifouling Using Quorum-Quenching Acylase Stabilized in Magnetically-Separable Mesoporous Silica

Abstract

Highly effective antifouling was achieved by immobilizing and stabilizing an acylase, disrupting bacterial cell-to-cell communication, in the form of cross-linked enzymes in magnetically separable mesoporous silica. This so-called "quorum-quenching" acylase (AC) was adsorbed into spherical mesoporous silica (S-MPS) with magnetic nanoparticles (Mag-S-MPS), and further cross-linked for the preparation of nanoscale enzyme reactors of AC in Mag-S-MPS (NER-AC/Mag-S-MPS). NER-AC effectively stabilized the AC activity under rigorous shaking at 200 rpm for 1 month, while free and adsorbed AC lost more than 90% of their initial activities in the same condition within 1 and 10 days, respectively. When applied to the membrane filtration for advanced water treatment, NER-AC efficiently alleviated the biofilm maturation of Pseudomonas aeruginosa PAO1 on the membrane surface, thereby enhancing the filtration performance by preventing membrane fouling. Highly stable and magnetically separable NER-AC, as an effective and sustainable antifouling material, has a great potential to be used in the membrane filtration for water reclamation.

Immobilization and Stabilization of Acylase on Carboxylated Polyaniline Nanofibers for Highly Effective Antifouling Application via Quorum Quenching

“…In other words, the delayed increase of TMP in the presence of Mag-EPC can be explained by the quorum quenching of Mag-EPC that can inactivate the AHL autoinducers. 28,[41][42] We also found that the recycle of filtrate vividly expedited the membrane fouling even in the presence of Mag-EPC ( Figure S4). This result can be explained by the recycle of autoinducers in the filtrate that can speed up the membrane fouling.…”

“…28 The acylase-immobilized cPANFs were mixed with N-acetyl-L -methionine solution for an initiation of enzyme reaction. Then, 0.2 mL of aliquot was taken from the reaction solution at appropriate time intervals, and added to the 2.8 mL of o- 9 phthalaldehyde solution (0.05 mg/mL) in 50 mM sodium borate buffer (pH 9.5).…”

“…In other words, immobilized and stabilized acylase in the form of Mag-EPC effectively inhibits the biofilm formation potentially via their catalytic hydrolysis of AHL autoinducers. 41,28,42 …”

“…Previous studies have proposed the potential of antifouling using quorum quenching acylases. [26][27][28][29] However, the short lifetime of enzymes themselves is one of the main problems against the successful antifouling application of enzymes under a long-term operation.…”

Microbial population dynamics and profiling of quorum sensing agents in membrane bioreactor

“…However, the widespread application of MBR is severely affected by membrane fouling caused by organic, inorganic or colloidal substances (Amy, 2008;Kim et al, 2012). Among various types of fouling, biofouling caused by formation of biocake (or deposition of microbial flocs) on the membrane surface, has attracted a great deal of attention due to its strong negative effects including, but not limited to, membrane clogging resulting in low treatment efficiency (Lee et al, 2014;Siddiqui et al, 2015).…”