Wipa ChungjatupornchaiSirirat Fa-AroonsawatMahidol University2018-07-122018-07-122008-05-28Journal of Microbiology and Biotechnology. Vol.18, No.5 (2008), 946-95117388872101778252-s2.0-50249181034https://repository.li.mahidol.ac.th/handle/20.500.14594/18917The 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 verfied 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 low-cost and low-maintenance biocatalyst that is useful for detoxification of organophosphate pesticides. © The Korean Society for Microbiology and Biotechnology.Mahidol UniversityBiochemistry, Genetics and Molecular BiologyChemical EngineeringImmunology and MicrobiologyArticleSCOPUS