Previous Article | Next Article ![]()
Appl. Environ. Microbiol., Oct 1997, 3837-3843, Vol 63, No. 10
F Caccavo Jr, PC Schamberger, K Keiding and PH Nielsen
The mechanisms by which the dissimilatory Fe(III)-reducing bacterium
Shewanella alga adheres to amorphous Fe(III) oxide were examined through
comparative analysis of S. alga BrY and an adhesion-deficient strain of
this species, S. alga RAD20. Approximately 100% of S. alga BrY cells
typically adhered to amorphous Fe(III) oxide, while less than 50% of S.
alga RAD20 cells adhered. Bulk chemical analysis, isoelectric point
analysis, and cell surface analysis by time-of-flight secondary-ion mass
spectrometry and electron spectroscopy for chemical analysis demonstrated
that the surfaces of S. alga BrY cells were predominantly protein but that
the surfaces of S. alga RAD20 cells were predominantly exopolysaccharide.
Physicochemical analyses and hydrophobic interaction assays demonstrated
that S. alga BrY cells were more hydrophobic than S. alga RAD20 cells. This
study represents the first quantitative analysis of the adhesion of a
dissimilatory Fe(III)-reducing bacterium to amorphous Fe(III) oxide, and
the results collectively suggest that hydrophobic interactions are a factor
in controlling the adhesion of this bacterium to amorphous Fe(III) oxide.
Despite having a reduced ability to adhere, S. alga RAD20 reduced Fe(III)
oxide at a rate identical to that of S. alga BrY. This result contrasts
with results of previous studies by demonstrating that irreversible cell
adhesion is not requisite for microbial reduction of amorphous Fe(III)
oxide. These results suggest that the interaction between dissimilatory
Fe(III)-reducing bacteria and amorphous Fe(III) oxide is more complex than
previously believed.
Copyright © 1997, American Society for Microbiology
Role of Hydrophobicity in Adhesion of the Dissimilatory Fe(III)-Reducing Bacterium Shewanella alga to Amorphous Fe(III) Oxide
Department of Microbiology, University of New Hampshire, Durham, New Hampshire; Center for Biofilm Engineering, Montana State University, Bozeman, Montana; and Environmental Engineering Laboratory, Aalborg University, Aalborg, Denmark
This article has been cited by other articles:
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»