NMT歷史上的今天丨TiO2提升黃孢原毛平革菌鎘耐受力的生理證據

NMT是基因功能的活體檢測技術，已被103位諾貝爾獎得主所在單位，及北大、清華、中科院使用。

NMT歷史上的今天

2014年12月24日，湖南大學曾光明、陳桂秋、譚瓊用NMT在Chemosphere上發表了標題為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

主題：TiO2提升黃孢原毛平革菌鎘耐受力的生理證據

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

影響因子：4.208

檢測指標：H+、O2、Cd2+流速

作者：湖南大學曾光明、陳桂秋、譚瓊

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（谷歌機翻）

負載有TiO2納米粒子（PTNs）的固定化Phanerochaete chsssporium是用于吸附鎘和降解2,4-二氯苯酚（2,4-DCP）的新型高價值生物修復材料。使用非損傷微測技術（NMT）測量H+和O2通量的實時變化。

加入2,4-DCP后，H+流入量增加，而加入Cd2+后，H+流入量移出。同時添加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）后立即觀察到更大的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）處理后，PTN去除Cd2+的增加比使用0.1 mM暴露溶液（3.49 mg g-1）處理的增加更多。

分析了酶的活性，以審查包含各種濃度的Cd2+的溶液中PTN的抗氧化防御系統。暴露于0.25 mM Cd2+后，輔酶煙酰胺腺嘌呤二核苷酸（NADH）氧化酶和過氧化氫酶（CAT）的活性分別穩定在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+的溶液中逐漸增加，并最終達到最大值（68.86 U g-1 FW）。

這些結果說明了PTN的抗氧化防御系統和生理通量如何響應有毒污染物引起的壓力。

Fig. 2. (A) Real-time Cd2+ ?ux of PTNs exposed to 0.1 mM Cd(NO3)2 and 10 mg L