NMT历史上的今天丨TiO2提升黄孢原毛平革菌镉耐受力的生理证据

2014年12月24日，湖南大学曾光明、陈桂秋、谭琼用NMT在Chemosphere上发表了标题为Physiological  fluxes and antioxidative enzymes activities of immobilized  Phanerochaete chrysosporium loaded with TiO2 nanoparticles after  exposure to toxic pollutants in solution的研究成果。

期刊：Chemosphere

主题：TiO2提升黄孢原毛平革菌镉耐受力的生理证据

标题：Physiological fluxes and antioxidative enzymes  activities of immobilized Phanerochaete chrysosporium loaded with  TiO2 nanoparticles after exposure to toxic pollutants in solution

影响因子：4.208

检测指标：H+、O2、Cd2+流速

作者：湖南大学曾光明、陈桂秋、谭琼

英文摘要

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 Cd2+. The O2 flux decreased after the addition of both  2,4-DCP and Cd2+. A larger Cd2+ flux was immediately observed after  exposure to 0.5 mM Cd2+ (−351.25 pmol cm−2 s−1) than to 0.1 mM Cd2+  (−107.47 pmol cm−2 s−1). The removal of Cd2+ 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 Cd2+. 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 Cd2+. The  activity of superoxide dismutase (SOD) increased gradually in solutions  containing 0.1–0.6 mM Cd2+, 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.

中文摘要（谷歌机翻）

负载有TiO2纳米粒子（PTNs）的固定化Phanerochaete chsssporium是用于吸附镉和降解2,4-二氯苯酚（2,4-DCP）的新型高价值生物修复材料。使用非损伤微测技术（NMT）测量H+和O2通量的实时变化。

加入2,4-DCP后，H+流入量增加，而加入Cd2+后，H+流入量移出。同时添加2,4-DCP和Cd2+后，O2通量下降。暴露于0.5  mM Cd2+（-351.25 pmol cm-2 s-1）后立即观察到更大的Cd2+通量，而不是暴露于0.1 mM Cd2+（-107.47  pmol cm-2 2 s-1）。用0.5 mM暴露溶液（27.6 mg g-1）处理后，PTN去除Cd2+的增加比使用0.1  mM暴露溶液（3.49 mg g-1）处理的增加更多。

分析了酶的活性，以审查包含各种浓度的Cd2+的溶液中PTN的抗氧化防御系统。暴露于0.25  mM Cd2+后，辅酶烟酰胺腺嘌呤二核苷酸（NADH）氧化酶和过氧化氢酶（CAT）的活性分别稳定在6.5 U g-1 FW和9.7 U g-1  FW上。超氧化物歧化酶（SOD）的活性在含0.1–0.6 mM Cd2+的溶液中逐渐增加，并最终达到最大值（68.86 U g-1 FW）。

这些结果说明了PTN的抗氧化防御系统和生理通量如何响应有毒污染物引起的压力。

Fig. 2. (A) Real-time Cd2+ flux of PTNs exposed to 0.1 mM Cd(NO3)2 and 10 mg L􀀁1 2,4-DCP.