Components from wheat roots modify the bioactivity of ZnO and CuO nanoparticles in a soil bacterium.
ZnO and CuO nanoparticles (NPs) have widespread commercial uses and their impact on agricultural systems is unresolved. This study examined whether the metabolites washed from wheat (Triticum aestivum L.) roots modulated the metabolic response to the NPs of a biosensor generated in the root colonizer, Pseudomonas putida KT2440. The root wash components boosted light output of the biosensor consistent with their catabolism. Dose-dependent and rapid inhibition of cell metabolism occurred with both ZnO and CuO NPs in water suspensions but high light output was maintained in root wash. Root wash also protected biosensor output in challenges with Zn ions. However the root wash components did not protect culturability or biosensor light output upon exposure to Cu ions. Imaging by atomic force microscopy suggested that root wash materials coated the NPs. We deduced that the response of a microbe to these metal oxide NPs could be negated by components released from roots.
Department of Biology, Utah State University, Logan, UT 84322-5305, USA.
Nicole
N
Martineau
Utah Water Research Laboratory, Utah State University, Logan, UT 84322-5305, USA.
Joan E
JE
McLean
Department of Biology, Utah State University, Logan, UT 84322-5305, USA.
Christian O
CO
Dimkpa
Department of Biological Engineering, Utah State University, Logan, UT 84322-5305, USA.
David W
DW
Britt
Department of Biology, Utah State University, Logan, UT 84322-5305, USA. Electronic address: anne.anderson@usu.edu.
Anne J
AJ
Anderson
D001673:Biodegradation, Environmental; D003300:Copper / Q000378:metabolism*; D053768:Metal Nanoparticles / Q000032:analysis; D053758:Nanoparticles / Q000378:metabolism*; D018517:Plant Roots / Q000378:metabolism; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology; D014908:Triticum / Q000502:physiology*; D015034:Zinc Oxide / Q000378:metabolism*
D012987:Soil; D003300:Copper; D015034:Zinc Oxide; C030973:cupric oxide
Biosensor; Metal speciation nanoparticles; Pseudomonad; Wheat