The effect of calcium ion on the biodegradation of octylphenol polyethoxylates, and the antiandrogenic activity of their biodegradates

Abstract

Because limes have been used as important fertilizers to neutralize acidified farmland in Japan, our interest in this study was focused on the effect of calcium ion on the biodegradation of octylphenol polyethoxylates (OPEOn) by a pure culture of Pseudomonas putida S5 isolated from a rice paddy field in Japan. In the presence of calcium ion, P. putida S5 accelerated the formation of octylphenol oligoethoxy carboxylates (OPECn) rather than that of octylphenol oligoethoxylates under an aerobic condition, indicating that more soluble biodegradates with terminal carboxyl group may liquate out easily to surface and ground water rather than more hydrophobic biodegradates with shorter ethylene oxide residues. Therefore, the androgen receptor (AR) activity of their degradation products was characterized using an in vitro reporter gene assay. As ethylene oxide chain length decreased, the biodegradates, OPEOn (n < 3), increased their AR antagonist activity. However, OPECn (n < 3) were unable to determine their AR activity because of their cytotoxicity in our reporter gene assay system.

Diversity of octylphenol polyethoxylate-degrading bacteria in river sediments and enrichment cultures, was revealed by 16S rRNA and adh1-gene molecular analysis

“…Because this compound is characterized with an average of 9.5 ethoxy segments per molecule, we calculated its molecular weight to be 624.32. Surfactants with shorter ethylene oxide chains and the carboxylic acid derivatives used as standards were synthesized and purified by the method described by Shibata et al 21) …”

“…[17][18][19][20] Moreover, the biodegradation of APEO n is significantly dependent on environmental conditions. 21,22) Consequently, the well-characterized microbial degradation of APEO n highlights the importance of understanding and predicting microbial behavior for bioremediation or prevention of APEO n pollution. 17,20,21) Although it is difficult to confirm changes in microbial diversity caused by human activity without supporting data, we notice these changes whenever we are faced with their adverse effects.…”

Application of matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry for the identification of alkylphenol polyethoxylate-degrading bacteria in the environment

“…3,11) Moreover, this study revealed that APEO n was biodegraded into many type of degradation patterns by diverse bacteria in the environment, suggesting that a rapid and reliable bacterial identication method will be necessary to characterize the biodegradation mechanism of man-made chemicals, especially when resultant biodegradation compounds may have an environmental impact. e MALDI-TOF MS is currently used for the rapid and reliable identi cation of bacteria at the species level especially in clinical diagnostic microbiology.…”

“…9,10) Moreover, environmental elements, such as Mg 2+ , Ca 2+ , and Fe 3+ , signi cantly in uence the nal degradation metabolites. 3,11) In a previous study, we demonstrated that bacteria that can degrade OPEO n to estrogenic and antiandrogenic metabolites are ubiquitous in paddy elds in Japan. 12,13) Furthermore, the study of the dynamic relationship between the microbial diversity and biodegradation capacity of OPEO n using enrichment cultures of various sediments from Iwata River in Japan revealed that OPEO n -degrading bacteria are widely distributed at the sites of di erent types of human activity along Iwata River.…”

“…In particular, accumulated OP, OPEO 1 , and OPEO 2 , with their relatively high hydrophobicity in the environment, act as estrogen agonists and androgen antagonists. [1][2][3] Accumulated knowledge of APEO n biodegradation has revealed that there are two biodegradation mechanisms: 1) exo-type shortening of the EO chain accompanied by either oxidation of the EO moiety (oxidative biodegradation) [4][5][6][7][8] ; or 2) nonoxidative hydroxy shift. 9,10) Moreover, environmental elements, such as Mg 2+ , Ca 2+ , and Fe 3+ , signi cantly in uence the nal degradation metabolites.…”