CLEAN-Soil Air Water
·
2015
·Vol. 44
·期 1
·72-77
·
IF 1.945
Qun He,Ruijuan Qu,Xinghao Wang,Zhongbo Wei,Ping Sun,Zunyao Wang
Although it has been widely known that arsenic poses great threat to organisms and arsenic species account for the toxic effect of the metalloid, relatively little attention has been given to the arsenic toxicity to different organisms at different pH values. Three kinds of aquatic organisms including Photobacterium phosphoreum , Daphnia magna , and Danio rerio were used to study the effects of pH on the toxicity of arsenic. Toxicity test results were analyzed by calculating EC 50 values and for arsenic species at five different pH values (5.0, 6.0, 7.0, 8.0, and 9.0). As a result, As(III) is more toxic to the tested organisms than As(V), and P. phosphoreum was more sensitive to the toxicity of arsenic than D. magna and D. rerio . The toxicity of As(III) species is different for different organisms: dihydrogen arsenite, H 2 AsO 3 – , is more toxic to P. phosphoreum and D. rerio than arsenous acid, H 3 AsO 3 , while H 3 AsO 3 is more toxic to D. magna . As for As(V), arsenate, HAsO 4 2− , is the most toxic to P. phosphoreum , whereas dihydrogen arsenate, H 2 AsO 4 – , may be responsible for the toxicity to D. magna and D. rerio . As(III) and As(V) are more toxic to P. phosphoreum in an alkaline environment, while for D. magna in an acidic environment and As(III) is more toxic to D. rerio in an alkaline environment and As(V) in an acidic environment.
研究领域:
环境生物学
·
毒理学
✓ 已验证
产品关联
DOI
高影响因子
Food Science & Nutrition
·
2022
·Vol. 10
·期 6
·1841-1853
·
IF 3.553
Jun Yang,Shulin Hu,Anqi Liao,Yetian Weng,Shuli Liang,Ying Lin
Current chemical analysis approaches for contaminants have failed to reveal their biotoxicity. Moreover, conventional bioassays are time consuming and exhibit poor repeatability. In this study, we performed the acute toxicity detection of various contaminants (chromium (Cr), cadmium (Cd), lead (Pb), arsenic (As), mercury (Hg), tin (Sn), nickel (Ni), and bisphenol A (BPA)) with four bioluminescent bacteria ( Vibrio qinghaiensis Q67, V. fischeri , Photobacterium phosphoreum T3, and P. phosphoreum 502) using a rapid, flexible, and low-cost bioassay. We found that the temperature affected the bacterial luminescence, and freeze-dried cells exhibited sensitive toxic responses to contaminants. Indeed, the optimized protectants containing 12% (w/v) trehalose, 4% sucrose, and 2% sorbitol displayed better luminescence and toxic sensitivity. Furthermore, freeze-dried powders of these strains were prepared and subjected to acute toxicity detection. The results showed that all contaminants exhibited acute toxicity toward Q67, but the other strains did not show obvious response to nickel and tin. The relative half-maximal effective concentration (EC 50 ) values of BPA, Cr, Cd, Pb, As, Hg, Ni, and Sn to Q67 were 0.674, 1.313, 11.137, 5.921, 4.674, 0.911, 5.941, and 54.077 mg/L, respectively. In addition, the EC 50 values of contaminants toward different strains were suggested to be statistically significant. Freeze-dried Q67 exhibited toxic responses to more contaminants than the other bioluminescent strains; therefore, Q67 was selected to be more suitable than the other strains for single and mixture toxicity detection tests. Compared with other strains, Q67 was more appropriate for the rapid screening of the mixture toxicity of contaminants in samples as a nonspecific screening sensor before the use of standard analysis approaches.
研究领域:
环境科学
·
毒理学
·
生物技术
·
化学分析
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产品关联
DOI
PubMed
高影响因子
CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
·
2024
·Vol. 40
·期 2
·287-292
·
IF 3.1
Li Yaohua,Wang Wei
Intracellular pH (pH i ) is a fundamental indicator of cellular physiological state, regulating cellular state and function, and has important research values. Although various probes for measuring intracellular pH were available, it is challenging to reflect pH i in real-time and reversible manners. Herein, we developed a whole-cell bioluminescent (BL) probe based on wild type BL bacteria, photobacterium phosphoreum ( P. phosphoreum ), to determine and image pH i . The dependence of BL intensity of P. phosphoreum on pH values of culture solutions was established. It was found that BL intensity could respond to the change of pH values rapidly and reversibly. We further revealed that P. phosphoreum maintained pH homeostasis in the extracellular pH (pH e ) within the range of 5.0–7.0, while intracellular pH homeostasis was destroyed at the alkaline pH e . This method opens up the enormous potential of BL bacteria as an alternative to fluorescence for monitoring and imaging pH i .
研究领域:
生物化学
·
细胞生物学
·
生物物理学
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微生物学
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生物医学工程
✓ 已验证
DOI
高影响因子
ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
·
2013
·
IF 2.203
R.-J. Qu,X.-H. Wang,M.-B. Feng,Y. Li,H.-X. Liu,L.-S. Wang,Z.-Y. Wang
This study investigated the effect of pH on cadmium toxicity to three aquatic organisms: Photobacterium phosphoreum , Daphnia magna and Carassius auratus . The acute toxicity of Cd 2+ to P. phosphoreum and D. magna at five pH values (5.0, 6.0, 7.0, 8.0, and 9.0) was assessed by calculating EC 50 values. We determined that Cd 2+ was least toxic under acidic conditions, and D. magna was more sensitive to the toxicity of Cd than P. phosphoreum . To evaluate Cd 2+ -induced hepatic oxidative stress in C. auratus at three pH levels (5.0, 7.25, 9.0), the activity of antioxidant enzymes (superoxide dismutase, catalase and glutathione peroxidase), the level of glutathione and the malondialdehyde content in the liver were measured. Oxidative damage was observed after 7 d Cd exposure at pH 9.0. An important finding of the current research was that Cd 2+ was generally more toxic to the three test organisms in alkaline environments than in acidic environments.
研究领域:
环境科学
·
水生毒理学
·
生态毒理学
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产品关联
DOI
PubMed
高影响因子
CRYOLETTERS
·
2023
·Vol. 44
·期 5
·280-290
·
IF 1
Wu Jiawei,Liu Yeyu,Zhang Jinping,Wang Xiaohui
BACKGROUND: Chitin is the second largest carbon source on the earth, and chitosan oligosaccharides produced by its degradation have good application prospects in medicine, cosmetics, and agricultural production. OBJECTIVE: The discovery of a chitinase with high efficiency,
high stability and clear degradation mechanism is of great help to promote the research of chitin derivatives and the development of the industrial chain. MATERIALS AND METHODS: In this experiment, a lowtemperature chitinase-producing strain Photobacterium sp. LG-29 was isolated
from deep-sea mud in the Bohai Sea, and studied by means of molecular biology, biochemistry and bioinformatics. RESULTS: Purification of chitinase yielded an enzyme solution with a concentration of 0.918 mg/mL and a specific activity of 21.036 U/mg. The optimum action temperature is
35°C, and it is still active at 4°C, showing low-temperature enzymatic activity, and also has certain thermal stability. The optimum pH is 8.0, and it maintains more than 70% of the enzyme activity at pH 11, which is very stable in an alkaline environment. Mn2+, Ca2+,
and Mg2+ are the main activators of enzymes, while Fe2+, Zn2+, etc. have extremely significant inhibitory effects on enzymes. The Km and Kcat of chitinase were determined to be 269.05 μ mol/L and 0.49 min-1, respectively. Chitinase PbCHI5 has
both endonuclease and exonuclease activity. The theoretical pI of the enzyme is 4.16, which is a stable hydrophilic protein. CONCLUSION: This experiment laid a theoretical foundation for the development and utilization of new low-temperature chitinases.
研究领域:
分子生物学
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生物化学
·
生物信息学
·
酶学
·
海洋微生物学
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DOI
PubMed
高影响因子
MICROCHEMICAL JOURNAL
·
2020
·
IF 3.594
Yisheng Chen,Caihong Huang,Zhengyu Jin,Xueming Xu,Yina Cai,Yuxiang Bai
Ginkgo biloba was a popular phytomedicine as the essential ingredient of many food supplement. In this work, a bio-inspired HPTLC method was proposed for the visualized screening of nifedipine adulteration in food supplement based on Gingko biloba . To customize the visualization of the analyte by inhibiting bacterium ( Photobacterium phosphoreum ) bioluminescence, the silica gel plate that gives the highest detectability was selected as the stationary phase of separation. Thereafter, the HPTLC procedure (toluene and ethyl acetate 8/2, v/v, as the mobile phase, to a distance of 60 mm) was optimized and standardized as a sample cleanup tool to exclude noises caused by bioactive co-extracts. Then, the separation result fixed on the plate layer was selectively visualized as dark bands against the white background, only after 6 min exposure. To achieve quantitation of the obtained HPTLC images, an enhanced quantitative analysis was optimized via software (ImageJ) facilitated pixel scanning, offered remarkable sensitivity (LOD=24.0 μg/g), linearity ( R 2 =0.9985 within 50–300 ng/band) and precision (RSD<7.2%). Further, the developed method was validated with real samples (recovery rates within 81.0–92.8%). In conjunction with image quantitation, in-situ surface enhance Raman spectroscopy was incorporated into the analysis, using silver nanoparticles as the active substrate and He:Ne 633 nm lamp the incident laser source. The obtained SERS spectra displayed highly characteristic fingerprint patterns, enabling unambiguous confirmation of effect-directed results.
研究领域:
药物分析
·
分析化学
·
食品科学
·
植物化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）