State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China; Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China.
State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China.
Environ Pollut. 2017 Jun;225:47-54. doi: 10.1016/j.envpol.2017.03.039. Epub 2017 Mar 26.
In the study, the capability of Paecilomyces lilacinus XLA (CCTCC: M2012135) to reduce Cr and its main antagonistic mechanisms to Cr were experimentally evaluated. Activated growing fungus XLA efficiently reduced over 90% Cr in the media with Cr concentration below 100 mg L at pH 6 after 14 days. After 1-day exposure to 100 mg L Cr, nearly 50% of Cr was reduced. Moreover, SO stimulated Cr reduction, whereas other interferential ions inhibited Cr reduction. The interaction mechanisms between XLA and Cr mainly involve biotransformation, biosorption, and bioaccumulation, as detected by electron microscopy and chemical methods. The lower concentrations of Cr (5 and 50 mg L) stimulated the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH) level in XLA, respectively, but the higher concentration of Cr (150 mg L) decreased the enzymatic activities and GSH concentration. The results implied that SOD, CAT and GSH were defensive guards to the oxidant stress produced by Cr. All these extracellular/intracellular defense systems endowed XLA with the ability to resist and detoxify Cr by transforming its valent species. The fungus XLA could efficiently reduce Cr under different environmental conditions (pH, interferential ions, and concentration). Moreover, XLA could endure the high concentration of Cr probably due to its high biotransformation capability of Cr and intracellular antioxidant systems for the detoxification of ROS generated by external Cr. All these results suggested that the fungus XLA can be applied to remediation of Cr-contaminated environments.
在这项研究中，实验评估了拟青霉 XLA（CCTCC：M2012135）降低 Cr 的能力及其对 Cr 的主要拮抗机制。在 pH 值为 6 时，活性生长真菌 XLA 在 14 天内可有效降低浓度低于 100mg/L 的培养基中超过 90%的 Cr。在 1 天接触 100mg/L Cr 后，近 50%的 Cr 被还原。此外，SO 刺激 Cr 的还原，而其他干扰性离子抑制 Cr 的还原。电子显微镜和化学方法检测到，XLA 与 Cr 之间的相互作用机制主要包括生物转化、生物吸附和生物积累。较低浓度的 Cr（5 和 50mg/L）分别刺激了 XLA 中超氧化物歧化酶（SOD）、过氧化氢酶（CAT）和谷胱甘肽（GSH）的活性，但较高浓度的 Cr（150mg/L）降低了酶活性和 GSH 浓度。结果表明，SOD、CAT 和 GSH 是抵御 Cr 产生的氧化应激的防御机制。所有这些细胞外/细胞内防御系统使 XLA 能够通过转化 Cr 的价态来抵抗和解毒 Cr。该真菌 XLA 能够在不同的环境条件（pH 值、干扰性离子和浓度）下有效地还原 Cr。此外，XLA 可能能够耐受高浓度的 Cr，这可能是由于其对 Cr 的高生物转化能力和细胞内抗氧化系统用于解毒由外部 Cr 产生的 ROS。所有这些结果表明，真菌 XLA 可应用于受 Cr 污染环境的修复。
