Electronic Journal of Biotechnology
ISSN: 0717-3458 |
Vol. 7 No. 3, Issue of December 15, 2004 |
© 2004 by Pontificia Universidad Católica
de Valparaíso -- Chile |
Received March 30, 2004 / Accepted July 9, 2004 |
Preliminary
results of using ESR to examine biofilms
Neil Evan Whitehead*#
Department
of Earth and Space Science
Graduate
School of Science
Osaka
University
1-1
Machikaneyama, Toyonaka
Osaka
560-0043, Japan
E-mail:
whiteh@paradise.net.nz
Tani Atushi
Department
of Earth and Space Science
Graduate
School of Science
Osaka
University
1-1
Machikaneyama, Toyonaka
Osaka
560-0043, Japan
Tel: 81
6 6850 5491
E-mail:
atani@ess.sci.osaka-u.ac.jp
Kazue Tazaki
Department
of Earth Sciences
Faculty
of Science
Kanazawa
University
Kakuma-machi,
Kanazawa 920-1192, Japan
Tel:
82 76 264 5736
E-mail:
kazuet@kenroku.kanazawa-u.ac.jp
Motoji Ikeya
Department
of Earth and Space Science
Graduate
School of Science
Osaka
University
1-1
Machikaneyama, Toyonaka
Osaka
560-0043, Japan
Tel: 81
06 6879 8492
E-mail:
ikeya35@sanken.osaka-u.ac.jp
*Corresponding author
Financial
support: Senior Fellowship from the Japanese Society for the Promotion
of Science.
Keywords:
Biofilms, ESR, ferrihydrite, hematite, magnetite.
Present address:
#54 Redvers Drive,
Lower Hutt, New Zealand
6009. Tel: 64 4 5650263.
This preliminary work
shows ESR (Electron Spin Resonance) can be used to detect biofilms,
particularly from Fe-metabolising bacteria. A film was detected by
ESR as early as 1 day, hence possibly more sensitively than by fluorescent
methods. Films can probably be detected as early as one hour. Spectra
contain a very broad peak at g=2.13, probably due to ferrihydrite.
Results of field experiments from streams and ponds in New
Zealand and Japan,
particularly the Minoh River,
showed a general increase of ferrihydrite with time. Loss by exfoliation
was later than 20 days. The rate of accumulation was faster in a nutrient-rich
stagnant pond. Hematite (g=4.3) was often observed, magnetite (g=9)
once, and usually small amounts of a common bacterial decay product.
The latter was detected for at least 18 months film storage. ESR is
a particularly good tool for observing the growth of oxic biofilms
containing Fe-metabolising bacteria, and should be just as sensitive
for observing Mn-metabolising bacteria in reducing conditions.
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