Open AccessImpact of fluorochrome stains used to study bacterial transport in shallow aquifers on motility and chemotaxis of P seudomonas species
Author(s) -
Toepfer J. Amanda,
Ford Roseanne M.,
Metge David,
Harvey Ronald W.
Publication year - 2012
Publication title -
fems microbiology ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.377
H-Index - 155
eISSN - 1574-6941
pISSN - 0168-6496
DOI - 10.1111/j.1574-6941.2012.01355.x
Subject(s) - pseudomonas stutzeri , chemotaxis , dapi , pseudomonas putida , biology , bacteria , pseudomonas , motility , staining , microbiology and biotechnology , biophysics , biochemistry , genetics , receptor
One of the most common methods of tracking movement of bacteria in groundwater environments involves a priori fluorescent staining. A major concern in using these stains to label bacteria in subsurface injection‐and‐recovery studies is the effect they may have on the bacterium's transport properties. Previous studies investigated the impact of fluorophores on bacterial surface properties (e.g. zeta potential). However, no previous study has looked at the impact of fluorescent staining on swimming speed and chemotaxis. It was found that DAPI lowered the mean population swimming speed of P seudomonas putida F 1 by 46% and P seudomonas stutzeri by 55%. DAPI also inhibited the chemotaxis in both strains. The swimming speeds of P . putida F 1 and P . stutzeri were diminished slightly by CFDA / SE , but not to a statistically significant extent. CFDA / SE had no effect on chemotaxis of either strain to acetate. SYBR ® Gold had no effect on swimming speed or the chemotactic response to acetate for either strain. This research indicates that although DAPI may not affect sorption to grain surfaces, it adversely affects other potentially important transport properties such as swimming and chemotaxis. Consequently, bacterial transport studies conducted using DAPI are biased to nonchemotactic conditions and do not appear to be suitable for monitoring the effect of chemotaxis on bacterial transport in shallow aquifers.