2,6-Dichlorobenzamide (BAM) herbicide mineralisation by Aminobacter sp. MSH1 during starvation depends on a subpopulation of intact cells maintaining vital membrane functions.

Abstract

Mineralisation capability was studied in the 2,6-dichlorobenzamide (BAM)-degrading Aminobacter sp. MSH1 under growth-arrested conditions. Cells were starved in mineral salts (MS) solution or groundwater before (14)C-labelled BAM (0.1mM) was added. Cell physiology was monitored with a panel of vitality stains combined with flow cytometry to differentiate intact, depolarised and dead cells. Cells starved for up to 3 weeks in MS solution showed immediate growth-linked mineralisation after BAM amendment while a lag-phase was seen after 8 weeks of starvation. In contrast, cells amended with BAM in natural groundwater showed BAM mineralisation but no growth. The cell-specific mineralisation rate was always comparable (10(-16)molCintact cell(-1)day(-1)) independent of media, growth, or starvation period after BAM amendment; lower rates were only observed as BAM concentration decreased. MSH1 seems useful for bioremediation and should be optimised to maintain an intact cell subpopulation as this seems to be the key parameter for successful mineralisation.

• Authors: Ole R Sjøholm, Ole Nybroe, Jens Aamand, Jan Sørensen
• Journal: Environmental pollution (Barking, Essex : 1987) (Environ Pollut) Vol. 158 Issue 12 Pg. 3618-25 (Dec 2010) ISSN: 1873-6424 [Electronic] England
• PMID: 20828902 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2010 Elsevier Ltd. All rights reserved.

Chemical References

• Benzamides
• Culture Media
• Herbicides
• Soil Pollutants
• Water Pollutants, Chemical
• Water
• 2,6-dichlorobenzamide

Topics

• Alphaproteobacteria (metabolism)
• Benzamides (metabolism)
• Biodegradation, Environmental
• Culture Media (chemistry)
• Herbicides (metabolism)
• Soil Microbiology
• Soil Pollutants (metabolism)
• Water (chemistry)
• Water Pollutants, Chemical (metabolism)