title: Physiological fluxes and antioxidative enzymes activities of immobilized Phanerochaete chrysosporium loaded with TiO2 nanoparticles after exposure to toxic pollutants in solution.
abstract: Immobilized Phanerochaete chrysosporium loaded with TiO2 nanoparticles (PTNs) are novel high-value bioremediation materials for adsorbing cadmium and for degrading 2,4-dichlorophenol (2,4-DCP). The real-time changes in H(+) and O2 fluxes were measured using the noninvasive microtest technique (NMT). The H(+) influx increased after the addition of 2,4-DCP, and shifted to efflux following the addition of Cd(2+). The O2 flux decreased after the addition of both 2,4-DCP and Cd(2+). A larger Cd(2+) flux was immediately observed after exposure to 0.5mM Cd(2+) (-351.25 pmol cm(-2) s(-1)) than to 0.1 mM Cd(2+) (-107.47 pmol cm(-2) s(-1)). The removal of Cd(2+) by the PTNs increased more after treatment with the 0.5 mM exposure solution (27.6 mg g(-1)) than with the 0.1 mM exposure solution (3.49 mg g(-1)). The enzyme activities were analyzed to review the antioxidative defense system of PTNs in a solution containing various concentrations of Cd(2+). The activities of the coenzyme nicotinamide adenine dinucleotide (NADH) oxidase as well as the enzyme catalase (CAT) plateaued at 6.5 U g(-1) FW and 9.7 U g(-1) FW, respectively, after exposure to 0.25 mM Cd(2+). The activity of superoxide dismutase (SOD) increased gradually in solutions containing 0.1-0.6 mM Cd(2+), and eventually reached a maximum (68.86 U g(-1) FW). These results illustrate how the antioxidative defense system and the physiological fluxes of PTNs respond to the stress caused by toxic pollutants.
authors: College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China.
authors: Qiong
authors: Q
authors: Tan
authors: College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China. Electronic address: gqchen@hnu.edu.cn.
authors: Guiqiu
authors: G
authors: Chen
authors: College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China. Electronic address: zgming@hnu.edu.cn.
authors: Guangming
authors: G
authors: Zeng
authors: College of Resources and Environment, Hunan Agricultural University, Changsha 410128, PR China.
authors: Anwei
authors: A
authors: Chen
authors: College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China.
authors: Song
authors: S
authors: Guan
authors: College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China.
authors: Zhongwu
authors: Z
authors: Li
authors: College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China.
authors: Yanan
authors: Y
authors: Zuo
authors: College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China.
authors: Zhenzhen
authors: Z
authors: Huang
authors: College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China.
authors: Zhi
authors: Z
authors: Guo
mesh_terms: D000975:Antioxidants / Q000494:pharmacology*; D001673:Biodegradation, Environmental; D002104:Cadmium / Q000633:toxicity; D002733:Chlorophenols / Q000633:toxicity; D052918:Environmental Restoration and Remediation / Q000295:instrumentation; D053768:Metal Nanoparticles / Q000032:analysis; D010100:Oxygen / Q000009:adverse effects; D020075:Phanerochaete / Q000187:drug effects* / Q000201:enzymology; D011522:Protons / Q000009:adverse effects; D014025:Titanium / Q000494:pharmacology*; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D000975:Antioxidants; D002733:Chlorophenols; D011522:Protons; D014874:Water Pollutants, Chemical; D002104:Cadmium; C009495:titanium dioxide; D014025:Titanium; C004762:2,4-dichlorophenol; D010100:Oxygen
keywords: 2,4-Dichlorophenol; Cadmium; Enzymes; Microbe; Physiological fluxes