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Functionalization of whole-cell bacterial reporters with magnetic nanoparticle.

Zhang D, Fakhrullin RF, Özmen M, Wang H, Wang J, Paunov VN, Li G, Huang WE - Microb Biotechnol (2011)

Bottom Line: The MFBs were all viable and functional as good as the native cells in terms of sensitivity, specificity and quantitative response.More importantly, we demonstrated that salicylate sensing MFBs can be applied to sediments and garden soils, and semiquantitatively detect salicylate in those samples by discriminably recovering MFBs with a permanent magnet.The magnetically functionalized cells are especially useful to complex environments in which the indigenous cells, particles and impurities may interfere with direct measurement of bioreporter cells and conventional filtration is not applicable to distinguish and harvest bioreporters.

View Article: PubMed Central - PubMed

Affiliation: Kroto Research Institute, University of Sheffield, Broad Lane, Sheffield S3 7HQ, UK.

ABSTRACT
We developed a biocompatible and highly efficient approach for functionalization of bacterial cell wall with magnetic nanoparticles (MNPs). Three Acinetobacter baylyi ADP1 chromosomally based bioreporters, which were genetically engineered to express bioluminescence in response to salicylate, toluene/ xylene and alkanes, were functionalized with 18 3 nm iron oxide MNPs to acquire magnetic function. The efficiency of MNPs functionalization of Acinetobacter bioreporters was 99.96 0.01%. The MNPs-functionalized bioreporters (MFBs) can be remotely controlled and collected by an external magnetic field. The MFBs were all viable and functional as good as the native cells in terms of sensitivity, specificity and quantitative response. More importantly, we demonstrated that salicylate sensing MFBs can be applied to sediments and garden soils, and semiquantitatively detect salicylate in those samples by discriminably recovering MFBs with a permanent magnet. The magnetically functionalized cells are especially useful to complex environments in which the indigenous cells, particles and impurities may interfere with direct measurement of bioreporter cells and conventional filtration is not applicable to distinguish and harvest bioreporters. The approach described here provides a powerful tool to remotely control and selectively manipulate MNPs-unctionalized cells in water and soils. It would have a potential in the application of environmental microbiology, such as bioremediation enhancement and environment monitoring and assessment.

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Comparison of dynamic sensing behaviour of MNPs‐functionalized (A) and native Acinetobacter ADPWH_lux (B). Cells are induced by different concentrations of salicylate.
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f2: Comparison of dynamic sensing behaviour of MNPs‐functionalized (A) and native Acinetobacter ADPWH_lux (B). Cells are induced by different concentrations of salicylate.

Mentions: To evaluate the impact of magnetic functionalization on bacterial cellular functionalities, we compared MFBs and native bioreporters for their biosensing performance. In this study, we examined three chromosomally based Acinetobacter bioreporters: ADPWH_lux, ADPWH‐Pu‐lux‐xylR and ADPWH_alk, which are able to sense salicylate, toluene/xylenes and alkanes separately (Huang et al., 2005; 2008; D. Zhang, Y. He, J. Zhao, L. Wu, J. Wang, H. Wang and W.E. Huang, in preparation). To induce native bioreporters, the inducers (salicylate, toluene/xylenes or alkanes) should pass through the cell membranes of the bioreporters, enter into the cytoplasm and interact with regulatory proteins (SalR, XylR or AlkR) which will undergo conformational change and activate the associated promoters to express reporter genes luxCDABE and show bioluminescence (Huang et al., 2005; 2008; D. Zhang, Y. He, J. Zhao, L. Wu, J. Wang, H. Wang and W.E. Huang, in preparation). Because the MNPs functionalization affected cell absorbance property, it would be appropriate to use bioluminescence intensity per cell for the estimation of relative bioluminescence. Therefore, the cell turbidity OD600 was converted to cell population (MFBs and native cells) by using the calibration curves plotted in Fig. S4. The results show that dynamic induction patterns of ADPWH_lux MFBs (Fig. 2A) were similar to that of the native cells (Fig. 2B).


Functionalization of whole-cell bacterial reporters with magnetic nanoparticle.

Zhang D, Fakhrullin RF, Özmen M, Wang H, Wang J, Paunov VN, Li G, Huang WE - Microb Biotechnol (2011)

Comparison of dynamic sensing behaviour of MNPs‐functionalized (A) and native Acinetobacter ADPWH_lux (B). Cells are induced by different concentrations of salicylate.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3815799&req=5

f2: Comparison of dynamic sensing behaviour of MNPs‐functionalized (A) and native Acinetobacter ADPWH_lux (B). Cells are induced by different concentrations of salicylate.
Mentions: To evaluate the impact of magnetic functionalization on bacterial cellular functionalities, we compared MFBs and native bioreporters for their biosensing performance. In this study, we examined three chromosomally based Acinetobacter bioreporters: ADPWH_lux, ADPWH‐Pu‐lux‐xylR and ADPWH_alk, which are able to sense salicylate, toluene/xylenes and alkanes separately (Huang et al., 2005; 2008; D. Zhang, Y. He, J. Zhao, L. Wu, J. Wang, H. Wang and W.E. Huang, in preparation). To induce native bioreporters, the inducers (salicylate, toluene/xylenes or alkanes) should pass through the cell membranes of the bioreporters, enter into the cytoplasm and interact with regulatory proteins (SalR, XylR or AlkR) which will undergo conformational change and activate the associated promoters to express reporter genes luxCDABE and show bioluminescence (Huang et al., 2005; 2008; D. Zhang, Y. He, J. Zhao, L. Wu, J. Wang, H. Wang and W.E. Huang, in preparation). Because the MNPs functionalization affected cell absorbance property, it would be appropriate to use bioluminescence intensity per cell for the estimation of relative bioluminescence. Therefore, the cell turbidity OD600 was converted to cell population (MFBs and native cells) by using the calibration curves plotted in Fig. S4. The results show that dynamic induction patterns of ADPWH_lux MFBs (Fig. 2A) were similar to that of the native cells (Fig. 2B).

Bottom Line: The MFBs were all viable and functional as good as the native cells in terms of sensitivity, specificity and quantitative response.More importantly, we demonstrated that salicylate sensing MFBs can be applied to sediments and garden soils, and semiquantitatively detect salicylate in those samples by discriminably recovering MFBs with a permanent magnet.The magnetically functionalized cells are especially useful to complex environments in which the indigenous cells, particles and impurities may interfere with direct measurement of bioreporter cells and conventional filtration is not applicable to distinguish and harvest bioreporters.

View Article: PubMed Central - PubMed

Affiliation: Kroto Research Institute, University of Sheffield, Broad Lane, Sheffield S3 7HQ, UK.

ABSTRACT
We developed a biocompatible and highly efficient approach for functionalization of bacterial cell wall with magnetic nanoparticles (MNPs). Three Acinetobacter baylyi ADP1 chromosomally based bioreporters, which were genetically engineered to express bioluminescence in response to salicylate, toluene/ xylene and alkanes, were functionalized with 18 3 nm iron oxide MNPs to acquire magnetic function. The efficiency of MNPs functionalization of Acinetobacter bioreporters was 99.96 0.01%. The MNPs-functionalized bioreporters (MFBs) can be remotely controlled and collected by an external magnetic field. The MFBs were all viable and functional as good as the native cells in terms of sensitivity, specificity and quantitative response. More importantly, we demonstrated that salicylate sensing MFBs can be applied to sediments and garden soils, and semiquantitatively detect salicylate in those samples by discriminably recovering MFBs with a permanent magnet. The magnetically functionalized cells are especially useful to complex environments in which the indigenous cells, particles and impurities may interfere with direct measurement of bioreporter cells and conventional filtration is not applicable to distinguish and harvest bioreporters. The approach described here provides a powerful tool to remotely control and selectively manipulate MNPs-unctionalized cells in water and soils. It would have a potential in the application of environmental microbiology, such as bioremediation enhancement and environment monitoring and assessment.

Show MeSH