Quantifying bacterial attachment and detachment using leaching solutions of various ionic strengths after bacterial pulse


In this study, we quantified the attachment and detachment of bacteria during transport in order to elucidate the contributions of reversible attachment on bacterial breakthrough curves. The first set of breakthrough experiment was performed for a laboratory sand column using leaching solutions of deionized water and mineral salt medium (MSM) of 200mM with reference to KCl solution by employing Pseudomonas putida as a model bacterium.

In the second set of experiment, the ionic strengths of leaching solutions immediately after bacterial pulse were lowered to tenfold and 100-fold diluted system (2 and 20mM MSM) to focus on the influence of physicochemical factor. Results have shown that bacterial retention occurred in the sand column due to the physical deposition and physicochemical attachment.

The physicochemical attachment was attributed to the high ionic strength (200mM MSM) of leaching solution and the formation of primary energy minimum. Replacing the 200mM leaching solution with the lower ionic strengths after pulse resulted in the increased tailing of breakthrough curve due to the detachment from the attached bacteria.

The detachment could be well explained by DLVO theory, which showed the formation of energy barrier and disappearance of the secondary minimum as the ionic strength gradually decreased. Analysis of mass recovery revealed that 1220% of the attachment was due to physical and physicochemical attachment, respectively, where the latter consisted of 2575% of irreversible and reversible attachment respectively.



Published on: 2017-02-14

Made available by EUPB via SpringerOpen / BioMedCentral. Please make sure to read our disclaimer prior to contacting 7thSpace Interactive. To contact our editors, visit our online helpdesk. To submit your press release click here. The full research and author details are available at http://www.amb-express.com/content/7/1/38

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