Interference of heavy metals on the photosynthetic response from a Cr(VI)-resistant Dictyosphaerium chlorelloides strain
The successful selection of a particular type of bioelement and its association to the appropriate transducer determines the specificity of a biosensor. Therefore, from a strain of chloroficea Dictyosphaerium chlorelloides, modified in laboratory to tolerate high Cr(VI) concentrations, the possible interferences of other heavy metals on photosynthetic activity were studied. After exposing wild type and Cr(VI)-resistant cells to increasing Ag+1, Co+2, Hg+2, Cr+3, Cu+2, Zn+2, Fe+3 and Cd+2 concentrations, both photosynthetic quantum yields was compared. Photosynthetic electron transport rates were measured with a TOXY-PAM chlorophyll fluorometer, non-linear regression analysis of each of the toxicity tests was done, and means of both groups were compared using unpaired t test. The results show no significant differences between both cell types when they were exposed to Ag+1, Co+2, Hg+2, Cr+3, Cu+2, Fe+3 and Cd+2 metal ions, and extremely significant differences (p < 0.0001) to Zn+2 exposures. These results demonstrate the suitability of this Cr(VI)-resistant type D. chlorelloides strain as a suitable bioelement to be coupled to a biosensor based on dual-head microalgae strategy to detect and quantify Cr(VI) in water courses and waste water treatment plants. However, some disturbance may be expected, especially when certain analyte species such as zinc are present in water samples tested. The analysis of binary mixtures between Zn+2 and other heavy metals showed a slight antagonistic phenomenon in all cases, which should not alter the potential Zn+2 interference in the Cr+6 detection process.
KeywordsDyctiosphaerium chlorelloides Photosynthetic quantum yield Selective bioelement Cr(VI)-resistant strain Heavy metals interference
This study has been supported by Spanish Government (CGL 2008-00652/BOS), the Madrid Community Government (S-505/AMB/0374), and the Mexican UMSNH University (PI 26.8). The technical support of Juan José Garcia and Lara de Miguel is kindly acknowledged.
Conflict of interest
The authors declare that they have no conflict of interest.
- Abdel Hameed MS (2002) Effect of immobilization on growth and photosynthesis of the green alga Chlorella vulgaris and its efficiency in heavy metals removal. Bull Fac Sci Assiut Univ 31:233–240Google Scholar
- Altamirano M, Garcia-Villada L, Agrelo M, Sanchez-Martin L, Martin-Otero L, Flores-Moya A, Rico M, Lopez-Rodas V, Costas E (2004) A novel approach to improve specificity of algal biosensors using wild-type and resistant mutants: an application to detect TNT. Biosens Bioelectron 19:1319–1323CrossRefGoogle Scholar
- Bijnsdorp IV, Giovannetti E, Peters GJ (2011) Analysis of drug interactions. Methods Mol Biol 731:21–34Google Scholar
- Boobis A, Budinsky R, Collie S, Crofton K, Embry M, Felter S, Hertzberg R, Kopp D, Mihlan G, Mumtaz M, Price P, Solomon K, Teuschler L, Yang R, Zaleski R (2011) Critical analysis of literature on low-dose synergy for use in screening chemical mixtures for risk assessment. Crit Rev Toxicol 41:369–383CrossRefGoogle Scholar
- García-Villada L, Rico M, Altamirano M, Sánchez-Martín L, Lopez-Rodas V, Costas E (2004) Occurrence of copper-resistant mutants in the toxic cyanobacterium Microcystis aeruginosa: characterization and future implications in the use of copper sulfate as an algaecide. Water Res 38:2207–2213CrossRefGoogle Scholar
- Giardi MT, Piletska EV (eds) (2010) Biotechnological applications of photosynthetic proteins: biochips, biosensors and biodevices. Springer, GeorgetownGoogle Scholar
- International Organization for Standardization (1982) Water quality-algal growth inhibition test. ISO/DIN 8692, GenevaGoogle Scholar
- Kortenkamp A, Faust M, Backhaus T (2009) State of the art report on mixture toxicology. Report commisioned by the European Commision, DG Environment. 070307/2007/485103/ETU/D.1Google Scholar
- Marks RS, Lowe CR, Cullen DC, Weetall HH, Karube I (eds) (2007a) Handbook of biosensors and biochips, vol 1. Wiley, New YorkGoogle Scholar
- Marks RS, Lowe CR, Cullen DC, Weetall HH, Karube I (eds) (2007b) Handbook of biosensors and biochips, vol 2. Wiley, New YorkGoogle Scholar