Competition of a parathion-hydrolyzing Flavobacterium with bacteria from ditch water in carbon-, nitrate- and phosphate-limited continuous cultures

• Published in: FEMS microbiology ecology Vol. 43; no. 1; pp. 45 - 53
• Main Authors: Sprenger, Wander W, Dijkstra, Annereinou, Zwart, Gabriel J.M, van Agterveld, Miranda P, van Noort, Paul C.M, Parsons, John R
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.02.2003
• Subjects: Biodegradation; Chemostat; Competition; Nutrient; Organophosphorus; Pesticide; Organophosphorus; Biodegradation; Competition; Nutrient; Pesticide; Chemostat
• ISSN: 0168-6496; 1574-6941
• DOI: 10.1016/S0168-6496(02)00415-4

The effect of competition for macroelements with bacteria from ditch water on the parathion-hydrolyzing Flavobacterium sp. ATCC 27551 (FB) was investigated within mixed continuous cultures under carbon-, nitrate- or phosphate-limited conditions. The high initial rate of parathion hydrolysis decreased rapidly in all cultures due to the loss of strain FB. Addition of 2-isopropyl-6-methyl-4-pyrimidinol (a selective source of carbon, nitrogen and energy for FB) to one nitrate- and carbon-limited chemostat caused a 20-fold increase in parathion-hydrolyzing activity compared to unamended control cultures and retention of FB. The presence of the parathion hydrolase-encoding gene could be demonstrated by a newly developed PCR detection method in all FB cultures during most of the cultivation period. These results suggest that competition effects cause the pesticide-degrading capacity of microbial communities depending on their frequency of exposure to the pesticide compounds.