The Degradation of Dimethoate and the Mineral Immobilizing Function for Cd2+ by Pseudomonas putida

• Published in: Geomicrobiology journal Vol. 34; no. 4; pp. 346 - 354
• Main Authors: Li, Xiaoxiao, Yin, Xingjia, Lian, Bin
• Format: Journal Article
• Language: English
• Published: New York Taylor & Francis 21.04.2017; Taylor & Francis Ltd
• Subjects: Atomic absorption analysis; Atomic absorption spectrophotometry; Biodegradation; Biomineralization; Cadmium; Calcium; Calcium carbonate; Calcium carbonates; Calcium phosphates; Carbonates; Chemical composition; Culture; Degradation; Dimethoate; Electron microscopy; Gas chromatography; heavy metal removal; Heavy metals; Immobilization; Metals; Microorganisms; mineral immobilizing function; organophosphorus degradation; Peptones; Pesticides; pH effects; Phosphates; Pollution; Precipitates; Precipitation; Pseudomonas putida; Removal; Scanning electron microscopy; Spectral analysis; Spectrophotometry; Transmission electron microscopy; Wastewater; Wastewater treatment; X-ray diffraction
• ISSN: 0149-0451; 1521-0529
• DOI: 10.1080/01490451.2016.1193571

Organophosphorus pollution and heavy metal pollution are prominent in China and have caused increasingly severe environmental pollution. This research used Pseudomonas putida to degrade dimethoate so as to induce the formation of calcium carbonate (CaCO 3 ) and calcium phosphate (Ca 3 (PO 4 ) 2 ) in beef extract peptone medium. In addition, the mineral immobilizing function of the generated Ca 3 (PO 4 ) 2 and CaCO 3 for Cd 2+ was studied by adding different concentrations of Cd 2+ to the culture solution. Meanwhile, transmission electron microscopy (TEM), scanning electronic microscopy (SEM), X-ray diffraction, gas chromatography and atomic absorption spectrophotometry were used to investigate the biodegradation of dimethoate, the concentration variation of Ca 2+ and Cd 2+ , the mineral and chemical compositions of the precipitates. The results showed that the growth of P. Putida could increase the pH value of the culture solution and effectively degrade the organophosphorus pesticide dimethoate. Besides, the concentration of Ca 2+ in the culture solution decreased significantly in the first four days and then tended to be stable. Moreover, the TEM and SEM results presented that there were large amounts of biogenic sedimentary CaCO 3 and a little Ca 3 (PO 4 ) 2 in the precipitates. Furthermore, in the employed culture system, the removal rates of Cd 2+ , when added at two different concentrations (6 ppm and 15 ppm), reached 100%. Therefore, this study provided a new idea for treating wastewater polluted with organophosphorus pesticide and heavy metals by using microorganisms.