Chemotaxis and degradation of organophosphate compound by a novel moderately thermo-halo tolerantPseudomonassp. strain BUR11: evidence for possible existence of two pathways for degradation

Abstract

An organophosphate (OP) degrading chemotactic bacterial strain BUR11 isolated from an agricultural field was identified as a member of Pseudomonas genus on the basis of its 16S rRNA gene sequence. The strain could utilize parathion, chlorpyrifos and their major hydrolytic intermediates as sole source of carbon for its growth and exhibited positive chemotactic response towards most of them. Optimum concentration of parathion for its growth was recorded to be 200 ppm and 62% of which was degraded within 96 h at 37 °C. Growth studies indicated the strain to be moderately thermo-halo tolerant in nature. Investigation based on identification of intermediates of parathion degradation by thin layer chromatography (TLC), high performance liquid chromatography (HPLC), gas chromatography (GC) and liquid chromatography mass spectrometry (LC-MS/MS) provided evidence for possible existence of two pathways. The first pathway proceeds via 4-nitrophenol (4-NP) while the second proceeds through formation of 4-aminoparathion (4-APar), 4-aminophenol (4-AP) and parabenzoquinone (PBQ). This is the first report of chemotaxis towards organophosphate compound by a thermo-halo tolerant bacterium.

Evaluation of Sulfadiazine Degradation in Three Newly Isolated Pure Bacterial Cultures

“…Similarly, metabolism independent chemotaxis has been also reported for different bacterial strains towards various toxic chemicals [ 41 , 44 , 45 ]. However, we are not sure whether this chemotaxis behavior is metabolically independent and/or dependent [ 40 , 42 ], although results presented in this study demonstrated that all three bacteria had the ability to degrade both SDZ and 2-aminopyrimidine. More experiments related to chemotaxis behavior of these bacteria for those substrates which these strains were not able to metabolize and/or transform will be needed to clarify the chemotactic mechanism.…”

“…There are reports on various bacteria having the ability of chemotactic response towards various toxic pollutants such as nitroaromatics, organophosphate, chloroaromatics and aminobenzoates etc. [ 27 , 40 , 41 ]. In this study, SDZ-degrading bacteria such as Paracoccus sp.…”

“…The chemotactic response (capillary method) results in this study were similar to the results observed in Pseudomonas sp. strain BUR11 (chemotaxis towards organophosphate compound) [ 40 ]. However, it is necessary to investigate at genomic level for better understanding of this chemotactic activity in all of these three pure bacterial cultures, since this feature is a novel and characteristic to our SDZ-degrading bacteria.…”

Advances in Chemotactic and Non-chemotactic Bioremediation of Water: A Comprehensive Review

“…Pailan and Saha (2015) reported a novel Pseudomonas sp. strain BUR11, moderately thermo-halo tolerant, was chemotactic to parathion and chlorpyrifos as well as degraded both pesticides [101]. Metabolism independent chemotaxis was observed for parathion by Pseudomonas sp.…”