Water pollution from the release of industrial wastewater is a serious problem for almost every industry. Enzymes from portulaca, Portulaca oleracea cv., have been investigated for their ability to degrade bisphenol A (BPA), one of the well-known estrogenic pollutants. Enzymatic crude extracts from P. oleracea cv. roots were immobilized on aminopropyl-modified glass beads. They maintained BPA metabolic activity over a broad range of pH values and temperatures. The immobilized enzyme was reusable with more than 50 % of its initial activity retained after 12 batch reactions and no loss of activity after storage for 1 month at -30 °C. Thus, the immobilization of extracts from P. oleracea cv. roots is a useful method for removing BPA from industrial wastewater.

Portulaca (Portulaca oleracea cv.), a garden plant, e ciently removes endocrine-disrupting chemicals (EDCs) including bisphenol A (BPA) from hydroponic solution. We hypothesized that polyphenol oxidase (PPO) was involved in the initial steps of detoxifying EDCs in portulaca roots. In order to elucidate the molecular basis of portulaca's ability to metabolize EDCs, we rst isolated ve PPO genes (PoPPO1-5) that were expressed mainly in portulaca roots. Among these genes, PoPPO2, PoPPO4 and PoPPO5 were introduced into cultured tobacco cells and expressed as active forms. We found that crude extracts from the cells expressing PoPPO2, PoPPO5, and to a lesser extent PoPPO4, could metabolize BPA. In addition, we found that the BPA metabolites from crude extracts of cells expressing PoPPO2, PoPPO4 and PoPPO5 were identical to those of portulaca. Moreover, PoPPO2 and PoPPO5 also caused hydroxylation of octylphenol, nonylphenol and 17β-estradiol. erefore, these results strongly suggest that PoPPOs signi cantly contribute to the superior ability of portulaca to metabolize EDCs.