|
KMID : 0545120080180050946
|
|
Journal of Microbiology and Biotechnology
2008 Volume.18 No. 5 p.946 ~ p.951
|
|
|
Biodegradation of Organophosphate Pesticide Using Recombinant Cyanobacteria with Surface- and Intracellular-expressed Organophosphorus Hydrolase
|
|
Chungjatupornchai Wipa
Fa-aroonsawat Sirirat
|
|
|
Abstract
|
|
|
|
The opd gene, encoding organophosphorus hydrolase (OPH) from Flavobacterium sp. capable of degrading a wide range of organophosphate pesticides, was surface- and intracellular-expressed in Synechococcus PCC7942, a prime example of photoautotrophic cyanobacteria. OPH was displayed on the cyanobacterial cell surface using the truncated ice nucleation protein as an anchoring motif. A minor fraction of OPH was displayed onto the outermost surface of cyanobacterial cells, as verified by immunostaining visualized under confocal laser scanning microscopy and OPH activity analysis; however, a substantial fraction of OPH was buried in the cell wall, as demonstrated by proteinase K and lysozyme treatments. The cyanobacterial outer membrane acts as a substrate (paraoxon) diffusion barrier affecting whole-cell biodegradation efficiency. After freeze-thaw treatment, permeabilized whole cells with intracellular-expressed OPH exhibited 14-fold higher bioconversion efficiency (Vmax/Km) than that of cells with surface-expressed OPH. As cyanobacteria have simple growth requirements and are inexpensive to maintain, expression of OPH in cyanobacteria may lead to the development of a lowcost and low-maintenance biocatalyst that is useful for detoxification of organophosphate pesticides.
|
|
|
KEYWORD
|
|
|
Cyanobacteria, surface display, ice nucleation protein, organophosphates, organophosphorus hydrolase, biodegradation
|
|
|
FullTexts / Linksout information
|
|
|
|
|
|
Listed journal information
|
|
  
|