Evidence map›Paper›PMID 26530383›Full record

ArticlemBio2015

Silica Gel for Enhanced Activity and Hypochlorite Protection of Cyanuric Acid Hydrolase in Recombinant Escherichia coli.

Adi Radian, Kelly G Aukema, Alptekin Aksan, Lawrence P Wackett

Open access · goldAbstract read
PubMed Full text at PMC Publisher
In one paragraph

Article in mBio, 2015. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 5 papers.

0numbers the graph read from it
0cells of the map it votes in
5citing papers in PubMed
1.2field-weighted citation impact, top 21% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

5 citing papers in PubMed, 16 citations in OpenAlex.

  1. Review
  2. Article
  3. Article
  4. Article
  5. Review
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

4 authors at 2 institutions in 1 country.

Adi RadianBioTechnology Institute, University of Minnesota, St. Paul, Minnesota, USA Department of Mechanical Engineering, University of Minnesota, Minneapolis, Minnesota, USA.
Kelly G AukemaBioTechnology Institute, University of Minnesota, St. Paul, Minnesota, USA Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, St. Paul, Minnesota, USA.
Alptekin AksanBioTechnology Institute, University of Minnesota, St. Paul, Minnesota, USA Department of Mechanical Engineering, University of Minnesota, Minneapolis, Minnesota, USA.
Lawrence P WackettBioTechnology Institute, University of Minnesota, St. Paul, Minnesota, USA Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, St. Paul, Minnesota, USA wacke003@umn.edu.
Biotechnology Institute · USUniversity of Minnesota · US

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

unlabelledChlorinated isocyanuric acids are widely used water disinfectants that generate hypochlorite, but with repeated application, they build up cyanuric acid (CYA) that must be removed to maintain disinfection. 3-Aminopropyltriethoxysilane (APTES)-treated Escherichia coli cells expressing cyanuric acid hydrolase (CAH) from Moorella thermoacetica exhibited significantly high CYA degradation rates and provided protection against enzyme inactivation by hypochlorite (chlorine). APTES coating or encapsulation of cells had two benefits: (i) overcoming diffusion limitations imposed by the cell wall and (ii) protecting against hypochlorite inactivation of CAH activity. Cells encapsulated in APTES gels degraded CYA three times faster than nonfunctionalized tetraethoxysilane (TEOS) gels, and cells coated with APTES degraded CYA at a rate of 29 µmol/min per mg of CAH protein, similar to the rate with purified enzyme. UV spectroscopy, fluorescence spectroscopy, and scanning electron microscopy showed that the higher rates were due to APTES increasing membrane permeability and enhancing cyanuric acid diffusion into the cytoplasm to reach the CAH enzyme. Purified CAH enzyme was shown to be rapidly inactivated by hypochlorite. APTES aggregates surrounding cells protected via the amine groups reacting with hypochlorite as shown by pH changes, zeta potential measurements, and infrared spectroscopy. APTES-encapsulated E. coli cells expressing CAH degraded cyanuric acid at high rates in the presence of 1 to 10 ppm hypochlorite, showing effectiveness under swimming pool conditions. In contrast, CAH activity in TEOS gels or free cells was completely inactivated by hypochlorite. These studies show that commercially available silica materials can selectively enhance, protect, and immobilize whole-cell biocatalysts for specialized applications. IMPORTANCE: Hypochlorite is used in vast quantities for water disinfection, killing bacteria on surfaces, and washing and whitening. In pools, spas, and other waters, hypochlorite is frequently delivered as chlorinated isocyanuric acids that release hypochlorite and cyanuric acid. Over time, cyanuric acid accumulates and impairs disinfection and must be removed. The microbial enzyme cyanuric acid hydrolase can potentially remove cyanuric acid to restore disinfection and protect swimmers. Whole bacterial cells expressing cyanuric acid hydrolase were encapsulated in an inert silica matrix containing an amine group. The amine group serves to permeabilize the cell membrane and accelerate cyanuric acid degradation, and it also reacts with hypochlorite to protect against inactivation of cyanuric acid hydrolase. Methods for promoting whole-cell biocatalysis are important in biotechnology, and the present work illustrates approaches to enhance rates and protect against an inhibitory substance.

Indexed as

AminesChlorineDisinfectantsEscherichia coliHydrogen-Ion ConcentrationHydrolasesHypochlorous AcidKineticsPropylaminesSilanesSilica GelSwimming PoolsTriazinesAminesamino-propyl-triethoxysilaneChlorinecyanuric acidDisinfectantsHydrolasesHypochlorous AcidPropylaminesSilanesSilica GeltetraethoxysilaneTriazines

Identifiers

PMID26530383
PMCPMC4631802
OpenAlexW2174210018

What OpenQuestion holds

Textmetadata
LicenceCC BY-NC-SA
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.