⁶⁰Co irradiation is an efficient and rapid sterilization method. The aim of this work is to determine the changes in essential-oil composition under different irradiation intensities of ⁶⁰Co and to select an appropriate irradiation dose with GC-IMS. Dosages of 0, 5, and 10 kGy of ⁶⁰Co were used to analyze turmeric (Curcumae Longae Rhizoma) volatile oil after ⁶⁰Co irradiation (named JH-1, JH-2, and JH-3). The odor fingerprints of volatile organic compounds in different turmeric volatile oil samples were constructed by headspace solid-phase microextraction and gas chromatography-ion mobility spectrometry (GC-IMS) after irradiation. The differences in odor fingerprints of volatile organic compounds (VOCs) were compared by principal component analysis (PCA). The results showed that 97 volatile components were detected in the volatile oil of Curcuma longa, and 64 components were identified by database retrieval. With the change in irradiation intensity, the volatile compounds in the three turmeric volatile oil samples were similar, but the peak intensity was significantly different, which was attributed to the change in compound composition and content caused by different irradiation doses. In addition, the principal component analysis showed that JH-2 and JH-3 were relatively correlated, while JH-1 and JH-3 were far from each other. In general, different doses of ⁶⁰Co irradiation can affect the content of volatile substances in turmeric volatile oil. With the increase in irradiation dose, the peak area decreased, and so the irradiation dose of 5 kGy/min was better. It is shown that irradiation technology has good application prospects in the sterilization of foods with volatile components. However, we must pay attention to the changes in radiation dose and chemical composition.

2022-05-01·Environmental Research2区 · 环境科学与生态学

Degradation of dimethachlon by a newly isolated bacterium Paenarthrobacter sp. strain JH-1 relieves its toxicity against Chlorella ellipsoidea

2区 · 环境科学与生态学

Article

作者: Gao, Siyuan ; Qiu, Jiguo ; Hong, Qing ; Ke, Zhijian ; Zhu, Qian ; Zhang, Mingliang ; Jiang, Wankui ; Jiang, Mingli

Dimethachlon, a broad-spectrum dicarboximide fungicide, poses a hazard to the safety of human and ecosystem due to its residue in the environment. A high-efficient dimethachlon degrading bacteria JH-1 belonging to Paenarthrobacter sp. was isolated and characterized. Strain JH-1 can utilize high concentration of dimethachlon as sole carbon source for growth and degrade 98.53% of 300 mg·L^-1 dimethachlon within 72 h. Crude enzyme of strain JH-1 could degrade 99.76% of 100 mg·L^-1 dimethachlon within 2 h. The optimum degradation condition of dimethachlon by strain JH-1 was at 35 °C and pH 7.0. Dimethachlon was degraded in Paenarthrobacter sp. JH-1 as following: it was firstly converted to 4-(3,5-dichloroanilino)-4-oxobutanoic acid and then subjected to the hydrolysis to 3,5-dichloroaniline and succinic acid, the latter was further degraded. Dimethachlon inhibited the growth of Chlorella ellipsoidea, while Paenarthrobacter sp. JH-1 could degrade dimethachlon to relieve its toxicity. This work facilitates our knowledge of the degradation mechanism of dimethachlon and offers potential resource of microbial strains for the bioremediation of dimethachlon-contaminated environments in the future.

2017-10-01·Journal of Hazardous Materials1区 · 环境科学与生态学

Sulfate enhances the dissimilatory arsenate-respiring prokaryotes-mediated mobilization, reduction and release of insoluble arsenic and iron from the arsenic-rich sediments into groundwater

1区 · 环境科学与生态学

Article

作者: Wang, Jianing ; Zeng, Xian-Chun ; Zhu, Xianbin ; Mu, Yao ; Yang, Ye ; Zeng, Xin ; Wang, Yanxin ; Chen, Xiaoming

Dissimilatory arsenate-respiring prokaryotes (DARPs) play key roles in the mobilization and release of arsenic from mineral phase into groundwater; however, little is known about how environmental factors influence these processes. This study aimed to explore the effects of sulfate on the dissolution and release of insoluble arsenic. We collected high-arsenic sediment samples from different depths in Jianghan Plain. Microcosm assays indicated that the microbial communities from the samples significantly catalyzed the dissolution, reduction and release of arsenic and iron from the sediments. Remarkably, when sulfate was added into the microcosms, the microorganisms-mediated release of arsenic and iron was significantly increased. To further explore the mechanism of this finding, we isolated a novel DARP, Citrobacter sp. JH001, from the samples. Arsenic release assays showed that JH001 can catalyze the dissolution, reduction and release of arsenic and iron from the sediments, and the presence of sulfate in the microcosms also caused a significant increase in the JH001-mediated dissolution and release of arsenic and iron. Quantitative PCR analysis for the functional gene abundances showed that sulfate significantly increased the arsenate-respiring reductase gene abundances in the microcosms. Thus, it can be concluded that sulfate significantly enhances the arsenate-respiring bacteria-mediated arsenic contamination in groundwater.

100 项与 JH-001 相关的药物交易

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