Atrazine detoxification by intracellular crude enzyme extracts derived from epiphytic root bacteria associated with emergent hydrophytes

Abstract

The present study demonstrated atrazine detoxification by intracellular crude enzyme extracts of Pseudomonas spp. strains ACB and TLB. Indigenous bacterial protein-based remediation techniques could be an alternative to bioaugmentation which pose multiple challenges when applied to the field. Intracellular enzymes were extracted from strains ACB and TLB and their degradation potential of 10 mg L⁻¹ was determined using Gas Chromatography; further, enzyme extracts were subjected to protein profiling studies. In span of 6 h, enzyme extracts of strain ACB showed maximum degradation at 30 °C and 40 °C (71%) and enzyme extracts of strain TLB showed maximum degradation at 40 °C (48%). Atrazine degradation by enzyme extracts of strain ACB showed maximum degradation at pH 7 (71%) and pH 6 (69%) in 6 h. Similarly, enzyme extracts of strain TLB showed maximal degradation at pH 6 (46%) in 6 h. The present study demonstrated, for the first time, efficient atrazine remediation by intracellular crude enzyme extracts from epiphytic root bacteria at a range of temperature and pH conditions. Protein profiling studies indicated that atrazine induced expression of CoA ester lyase and alkyl hydroperoxide reductase in the strains ACB and TLB respectively. Expressions of these proteins have never been associated with atrazine exposure.

Keywords:

• Atrazine
• bioremediation
• bacterial crude enzyme extract
• Pseudomonas spp.
• peptide mass fingerprinting

Acknowledgement

We are thankful to Dr. Souvik Sen Sharma, Cellular Endocrinology Lab, National Institute of Immunology, for his valuable inputs in data analysis and comments regarding the manuscript. We acknowledge National Fund for Basic, Strategic and Frontier Application Research in Agriculture and Indian Council of Agricultural Research for funding the project Bioremediation of contaminants in polluted sites: Use of weedy plants for which the present study was conducted. Dr. Anina James is thankful to University Grants Commission (UGC) for providing fellowship as JRF/SRF.

Disclosure statement

No potential conflict of interest was reported by the authors.

Data availability statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.