Degradation of di(2-ethyl hexyl) phthalate by Fusarium culmorum: Kinetics, enzymatic activities and biodegradation pathway based on quantum chemical modelingpathway based on quantum chemical modeling.
Di(2-ethylhexyl) phthalate (DEHP) is a plasticizer widely used in the manufacture of plastics, and it is an environmental contaminant. The specific growth rate (μ), maximum biomass (Xmax), biodegradation constant of DEHP (k), half-life (t1/2) of DEHP biodegradation and removal efficiency of DEHP, esterase and laccase specific activities, and enzymatic yield parameters were evaluated for Fusarium culmorum grown on media containing glucose and different concentrations of DEHP (0, 500 and 1000mg/L). The greatest μ and the largest Xmax occurred in media supplemented with 1000mg of DEHP/L. F. culmorum degraded 95% of the highest amount of DEHP tested (1000mg/L) within 60h of growth. The k and t1/2 were 0.024h(-1) and 28h, respectively, for both DEHP concentrations. The removal efficiency of DEHP was 99.8% and 99.9% for 1000 and 500mg/L, respectively. Much higher specific esterase activity than specific laccase activity was observed in all media tested. The compounds of biodegradation of DEHP were identified by GC-MS. A DEHP biodegradation pathway by F. culmorum was proposed on the basis of the intermolecular flow of electrons of the identified intermediate compounds using quantum chemical modeling. DEHP was fully metabolized by F. culmorum with butanediol as the final product. This fungus offers great potential in bioremediation of environments polluted with DEHP.
Doctorado en Biología Experimental, Universidad Autónoma Metropolitana-Iztapalapa (UAM-I), Mexico; Facultad de Agrobiología, Universidad Autónoma de Tlaxcala, Ixtacuixtla, Tlaxcala, Mexico.
Miriam
M
Ahuactzin-Pérez
Universidad Politécnica de Tlaxcala, San Pedro Xalcatzinco, Tepeyanco, Tlaxcala CP 90180, Mexico.
Saúl
S
Tlecuitl-Beristain
Universidad Politécnica de Tlaxcala, San Pedro Xalcatzinco, Tepeyanco, Tlaxcala CP 90180, Mexico.
Jorge
J
García-Dávila
Universidad Popular Autónoma del Estado de Puebla, Puebla CP 72410, Mexico.
Manuel
M
González-Pérez
Departamento de Ciencias de la Salud, Universidad Autónoma Metropolitana-Iztapalapa, D.F, Mexico.
María Concepción
MC
Gutiérrez-Ruíz
Laboratory of Biotechnology, Research Centre for Biological Sciences, Universidad Autónoma de Tlaxcala, Ixtacuixtla, Tlaxcala CP. 90062, Mexico. Electronic address: sanher6@hotmail.com.
Carmen
C
Sánchez
D001673:Biodegradation, Environmental; D004051:Diethylhexyl Phthalate / Q000378:metabolism*; D005670:Fusarium / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism*; D007700:Kinetics; D008956:Models, Chemical; D012989:Soil Pollutants / Q000378:metabolism*
D012989:Soil Pollutants; D004051:Diethylhexyl Phthalate
Biodegradation constant; Di(2-ethylhexyl) phthalate; Esterase; Fusarium culmorum; Laccase; Quantum chemical modeling