11 Citations (Scopus)

Abstract

Natural antibacterial clays can inhibit growth of human pathogens; therefore, understanding the antibacterial mode of action may lead to new applications for health. The antibacterial modes of action have shown differences based on mineralogical constraints. Here we investigate a natural clay from the Colombian Amazon (AMZ) known to the Uitoto natives as a healing clay. The physical and chemical properties of the AMZ clay were compared to standard reference materials: smectite (SWy-1) and kaolinite (API #5) that represent the major minerals in AMZ. We tested model Gram-negative (Escherichia coli ATCC #25922) and Gram-positive (Bacillus subtilis ATCC #6633) bacteria to assess the clay’s antibacterial effectiveness against different bacterial types. The chemical and physical changes in the microbes were examined using bioimaging and mass spectrometry of clay digests and aqueous leachates. Results indicate that a single dose of AMZ clay (250 mg/mL) induced a 4–6 order of magnitude reduction in cell viability, unlike the reference clays that did not impact bacterial survival. AMZ clay possesses a relatively high specific surface area (51.23 m2/g) and much higher total surface area (278.82 m2/g) than the reference clays. In aqueous suspensions (50 mg clay/mL water), soluble metals are released and the minerals buffer fluid pH between 4.1 and 4.5. We propose that the clay facilitates chemical interactions detrimental to bacteria by absorbing nutrients (e.g., Mg, P) and potentially supplying metals (e.g., Al) toxic to bacteria. This study demonstrates that native traditional knowledge can direct scientific studies.

Original languageEnglish (US)
Pages (from-to)363-379
Number of pages17
JournalEnvironmental Geochemistry and Health
Volume38
Issue number2
DOIs
StatePublished - Apr 1 2016

Fingerprint

Clay
clay
Bacteria
bacterium
Minerals
surface area
Metals
Kaolin
Kaolinite
Poisons
metal
traditional knowledge
Pathogens
Bacilli
mineral
Application programming interfaces (API)
Specific surface area
smectite
Chemical properties
Escherichia coli

Keywords

  • Antibacterial clay
  • Bacillus subtilis
  • Escherichia coli
  • Medical geology

ASJC Scopus subject areas

  • Environmental Engineering
  • Environmental Science(all)
  • Environmental Chemistry
  • Water Science and Technology
  • Geochemistry and Petrology

Cite this

Unraveling the antibacterial mode of action of a clay from the Colombian Amazon. / Londono, Sandra Carolina; Williams, Lynda.

In: Environmental Geochemistry and Health, Vol. 38, No. 2, 01.04.2016, p. 363-379.

Research output: Contribution to journalArticle

@article{31276d0331c84b888e9e0e6107b7f40c,
title = "Unraveling the antibacterial mode of action of a clay from the Colombian Amazon",
abstract = "Natural antibacterial clays can inhibit growth of human pathogens; therefore, understanding the antibacterial mode of action may lead to new applications for health. The antibacterial modes of action have shown differences based on mineralogical constraints. Here we investigate a natural clay from the Colombian Amazon (AMZ) known to the Uitoto natives as a healing clay. The physical and chemical properties of the AMZ clay were compared to standard reference materials: smectite (SWy-1) and kaolinite (API #5) that represent the major minerals in AMZ. We tested model Gram-negative (Escherichia coli ATCC #25922) and Gram-positive (Bacillus subtilis ATCC #6633) bacteria to assess the clay’s antibacterial effectiveness against different bacterial types. The chemical and physical changes in the microbes were examined using bioimaging and mass spectrometry of clay digests and aqueous leachates. Results indicate that a single dose of AMZ clay (250 mg/mL) induced a 4–6 order of magnitude reduction in cell viability, unlike the reference clays that did not impact bacterial survival. AMZ clay possesses a relatively high specific surface area (51.23 m2/g) and much higher total surface area (278.82 m2/g) than the reference clays. In aqueous suspensions (50 mg clay/mL water), soluble metals are released and the minerals buffer fluid pH between 4.1 and 4.5. We propose that the clay facilitates chemical interactions detrimental to bacteria by absorbing nutrients (e.g., Mg, P) and potentially supplying metals (e.g., Al) toxic to bacteria. This study demonstrates that native traditional knowledge can direct scientific studies.",
keywords = "Antibacterial clay, Bacillus subtilis, Escherichia coli, Medical geology",
author = "Londono, {Sandra Carolina} and Lynda Williams",
year = "2016",
month = "4",
day = "1",
doi = "10.1007/s10653-015-9723-y",
language = "English (US)",
volume = "38",
pages = "363--379",
journal = "Environmental Geochemistry and Health",
issn = "0269-4042",
publisher = "Springer Netherlands",
number = "2",

}

TY - JOUR

T1 - Unraveling the antibacterial mode of action of a clay from the Colombian Amazon

AU - Londono, Sandra Carolina

AU - Williams, Lynda

PY - 2016/4/1

Y1 - 2016/4/1

N2 - Natural antibacterial clays can inhibit growth of human pathogens; therefore, understanding the antibacterial mode of action may lead to new applications for health. The antibacterial modes of action have shown differences based on mineralogical constraints. Here we investigate a natural clay from the Colombian Amazon (AMZ) known to the Uitoto natives as a healing clay. The physical and chemical properties of the AMZ clay were compared to standard reference materials: smectite (SWy-1) and kaolinite (API #5) that represent the major minerals in AMZ. We tested model Gram-negative (Escherichia coli ATCC #25922) and Gram-positive (Bacillus subtilis ATCC #6633) bacteria to assess the clay’s antibacterial effectiveness against different bacterial types. The chemical and physical changes in the microbes were examined using bioimaging and mass spectrometry of clay digests and aqueous leachates. Results indicate that a single dose of AMZ clay (250 mg/mL) induced a 4–6 order of magnitude reduction in cell viability, unlike the reference clays that did not impact bacterial survival. AMZ clay possesses a relatively high specific surface area (51.23 m2/g) and much higher total surface area (278.82 m2/g) than the reference clays. In aqueous suspensions (50 mg clay/mL water), soluble metals are released and the minerals buffer fluid pH between 4.1 and 4.5. We propose that the clay facilitates chemical interactions detrimental to bacteria by absorbing nutrients (e.g., Mg, P) and potentially supplying metals (e.g., Al) toxic to bacteria. This study demonstrates that native traditional knowledge can direct scientific studies.

AB - Natural antibacterial clays can inhibit growth of human pathogens; therefore, understanding the antibacterial mode of action may lead to new applications for health. The antibacterial modes of action have shown differences based on mineralogical constraints. Here we investigate a natural clay from the Colombian Amazon (AMZ) known to the Uitoto natives as a healing clay. The physical and chemical properties of the AMZ clay were compared to standard reference materials: smectite (SWy-1) and kaolinite (API #5) that represent the major minerals in AMZ. We tested model Gram-negative (Escherichia coli ATCC #25922) and Gram-positive (Bacillus subtilis ATCC #6633) bacteria to assess the clay’s antibacterial effectiveness against different bacterial types. The chemical and physical changes in the microbes were examined using bioimaging and mass spectrometry of clay digests and aqueous leachates. Results indicate that a single dose of AMZ clay (250 mg/mL) induced a 4–6 order of magnitude reduction in cell viability, unlike the reference clays that did not impact bacterial survival. AMZ clay possesses a relatively high specific surface area (51.23 m2/g) and much higher total surface area (278.82 m2/g) than the reference clays. In aqueous suspensions (50 mg clay/mL water), soluble metals are released and the minerals buffer fluid pH between 4.1 and 4.5. We propose that the clay facilitates chemical interactions detrimental to bacteria by absorbing nutrients (e.g., Mg, P) and potentially supplying metals (e.g., Al) toxic to bacteria. This study demonstrates that native traditional knowledge can direct scientific studies.

KW - Antibacterial clay

KW - Bacillus subtilis

KW - Escherichia coli

KW - Medical geology

UR - http://www.scopus.com/inward/record.url?scp=84961195084&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84961195084&partnerID=8YFLogxK

U2 - 10.1007/s10653-015-9723-y

DO - 10.1007/s10653-015-9723-y

M3 - Article

C2 - 26055454

AN - SCOPUS:84961195084

VL - 38

SP - 363

EP - 379

JO - Environmental Geochemistry and Health

JF - Environmental Geochemistry and Health

SN - 0269-4042

IS - 2

ER -