Full Paper Isolation, identifi cation and characterization of a glyphosate-degrading bacterium, Bacillus cereus CB4, from soil

Glyphosate (isopropylamine salt of N-phosphonomethyl-glycine) is the active ingredient in Roundup, a herbicide manufactured by Monsanto. It is a broadspectrum postemergent used to control both perennial and annual weeds (Kent-Moor et al., 1983). Glyphosate is a potent inhibitor of the enzyme 3-enol‒pyruvylshikimate-5-phosphate synthase (EPSP synthase, EC 2.5.1.19), which is involved in the biosynthesis of the aromatic amino acids phenylalanine, tyrosine, and tryptophan (Liu et al., 1991). Glyphosate is also a competitive inhibitor of EPSPS with respect to phosphoenolpyruvate and has been shown to block import of the EPSPS preprotein into chloroplast, the subcellular location of the shikimic acid pathway (PenalozaVazquez et al., 1995). China is a big exporter of glyphosate. During the production of glyphosate, the discharge of wastewater can cause serious water pollution problems and environmental damage (Xu et al., 2007). This is because the pollutant in wastewater mainly contains glyphosate, methanol, formaldehyde and so on (Amoros et al., 2007). Microorganism treatment has been widely used in the wastewater treatment process. Two pathways for the breakdown of glyphosate have been documented. One involves cleavage of the C‒N bond by the enzyme known as glyphosate oxidoreductase with J. Gen. Appl. Microbiol., 58, 263‒271 (2012)