Effects of Plant Growth-Promoting Bacteria (PGPB) Inoculation on the Growth, Antioxidant Activity, Cu Uptake, and Bacterial Community Structure of Rape (Brassica napus L.) Grown in Cu-Contaminated Agricultural Soil.

Previous analyses of plant growth-promoting bacteria (PGPB) combined with the remediation of heavy metal pollution in soil have largely been performed under potting or greenhouse conditions, and in situ remediation experiments under field conditions have rarely been reported. In this study, the effects of the metal-resistant PGPB Microbacterium oxydans JYC17, Pseudomonas thivervalensis Y1-3-9, and Burkholderia cepacia J62 on soil Cu pollution under rape remediation were studied in the farmland surrounding the Nanjing Jiuhuashan copper mining region in China. Following inoculation treatment for 50 days, the biomasses of the rape inoculated with strains JYC17, Y1-3-9, and J62 increased, and the total amounts of Cu uptake increased by 113.38, 66.26, and 67.91%, respectively, the translocation factor (TF) of rape inoculated with J62 was 0.85, a significant increase of 70.68%, thus improving the Cu remediation efficiency of the rape. Y1-3-9 and J62 affected the bioavailability of Cu in the soil, and the water-soluble Cu contents were increased by 10.13 and 41.77%, respectively, compared with the control. The antioxidant activities in the rape leaves showed that the tested bacteria increased the contents of antioxidant non-enzymatic substances, including ascorbic acid (ASA) and glutathione (GSH), which were increased by 40.24-91.22% and 9.89-17.67%, respectively, thereby reducing the oxidative stress caused by heavy metals and the contents of thiobarbituric acid-reactive substances (TBARS) and peroxidase (POD). PCR-denaturing gradient gel electrophoresis (PCR-DGGE) was used to analyze the effects of the tested bacteria on the cultivation-dependent and cultivation-independent bacterial communities in the root endosphere and rhizosphere soil of the rape. The sequencing results of the DGGE bands indicated that the tested bacteria colonized the endosphere and rhizosphere, and they became an important component of the cultivation-dependent bacteria. The canonical correspondence analysis (CCA) of the DGGE profile and similarity cluster analysis showed that the tested bacteria affected the cultivation-dependent and cultivation-independent bacterial communities in the root endosphere and rhizosphere. In this experiment, the effects and mechanisms of the combined plant-microbe remediation under field conditions were preliminarily studied, and the results are expected to provide a theoretical basis for future combined remediation experiments.

[Temporal and Spatial Changes in Sediment Nutrients and Heavy Metals of the Danjiangkou Reservoir Before and After Water Division of the Mid-route Project].

Reservoir/lake sediments are potential pollutant acceptors and sources of pollution. The Danjiangkou Reservoir, as the largest drinking water source in China, is the source water area for the Mid-route Project of the South-North Water Diversion. To illustrate the temporal and spatial changes in the environmental risks of both nutrients and heavy metals in the surface sediments of Danjiangkou Reservoir, the levels of pH, OM, TP, TN, and six kinds of metal elements during the period 2011-2016 were measured at five ecological sites. Canadian freshwater sediment quality guidelines for aquatic environments (from the CCME) were used to assess the potential ecological risks. The results showed that the contents of OM, TP, and TN in the surface sediments were 25.85, 0.57, and 1.34 g·kg-1, respectively, and those of Cr, Mn, Cu, Zn, Cd, and Pb were 57.96, 521.78, 13.91, 195.74, 0.37, and 12.92 mg·kg-1, respectively. The contents of both Zn and Cd were under the corresponding Ⅱ-level standards of soil environmental quality, but the contents of the other four heavy metals were lower than their corresponding I-level standards. After water diversion of the Mid-route Project, the OM, TN, Mn, and Zn contents increased, and the TP and other heavy metal contents displayed downward trends. Excluding the pH value, the distribution of measured nutrients and heavy metals in the surface sediments of the Danjiangkou Reservoir reached the extremely significant level (P<0.01). OM in the sediments was negatively correlated with TN and Pb, but had positive correlations with the other indicators measured. The results from the potential ecological risk assessment showed that:①Cd, Cu, and Pb had no harmful effects on organisms; ② OM had low ecological risk in most years; ③ the risk of TP was between zero and low ecological risk; and ④Cr, Zn, and TN had low ecological risk in most cases. The K and H sites had higher ecological risk for Cr, Zn, and TN, thus attention should be paid to those cases. These results illustrate the effects of human activities on nutrients and heavy metals in surface sediments.

[Quantization determination study of micro-Raman spectroscopy of methemoglobin induced by sodium nitrite].

In the present study, Raman spectral characteristics of methemoglobin (MetHb) induced by sodium nitrite (NaNO2) were investigated. Hemoglobin (Hb) was oxidated to MetHb with NaNO2, the Raman spectral specific changes of MetHb was studied by determining the Raman spectral changes of methemoglobin/total hemoglobin of different ratios, and the Raman intensities of methemoglobin/total hemoglobin of different ratios at 1 586, 1 605 and 1 637 cm(-1) were linearly fitted to realize its quantitative detection. The results show that the completely oxidized MetHb can be obtained when the molar ratio of NaNO2 to Hb is 3.5 : 1 whose Raman characteristic peaks are at around 499, 1 340, 1 562 and 1 622 cm(-1), and that the linear fitting correlation coefficients R2 of the Raman intensities of methemoglobin/total hemoglobin of different ratios at 1 586, 1 605 and 1 637 cm(-1) are 0.972 84, 0.997 97 and 0.991 26 respectively, which shows a good linear relationship. This study indicates that the Raman spectrums of MetHb induced by NaNO2 have characteristic differences when compared with normal Hb, that the locations and intensities of Raman characteristic peaks change correspondingly with the alterations of the ratios of methemoglobin/total hemoglobin, and that there are linear correlations between the ratios and their corresponding Raman intensities, which would provide theoretical bases for the clinical Raman spectral detection and quantitative study of methemoglobinemia.

[Colorimetric investigation of normal tongue and lip colors from 516 healthy adults by visible reflection spectrum].

OBJECTIVE: Using the data from normal tongue and lip colors of normal people which were collected by the visible reflection spectrum, we analyzed the colorimetric parameters of tongue and lip colors. METHODS: In this study, 516 healthy students aging from 19 to 26 from the colleges and universities of Guangdong Province of China were taken as research subjects. After collecting the data of tongue and lip colors of the 516 subjects using visible reflectance spectroscopy, CIE XYZ tristimulus values as defined by the International Commission on Illumination in 1964 were calculated, and the colorimetric parameters of the normal tongue and lip colors were obtained, such as the CIE 1964 chromaticity coordinate, brightness, dominant wavelength and excitation purity. RESULTS: The results of CIE 1964 chromaticity diagram calculated on the visible reflection spectrum showed that the normal tongue color chromaticity coordinate x(10) was 0.341 3±0.008 5 and y(10) was 0.332 6±0.005 1, and the normal lip color chromaticity coordinate x(10) was 0.357 7±0.009 2 and y(10) was 0.338 3±0.005 7; the brightness Y values of the normal tongue color and lip colors were 17.96±3.78 and 19.78±3.72, the dominant wavelength values of the normal tongue color and lip color were (626.3±51.6) nm and (600.4±18.2) nm, and the excitation purity values of the normal tongue color and lip color were 0.083±0.031 and 0.144±0.036, respectively. CONCLUSION: Application of the visible reflection spectrum is a standard way to collect colorimetric data for inspection of the complexion. The investigation of chromaticity coordinates, brightness, dominant wavelength and excitation purity of the normal tongue and lip colors may offer the basic reference for diagnosing morbid complexion on the tongue and lip colors in traditional Chinese medicine.

[Application of FRET in fluorescence detection of FQ-PCR].

The theory of fluorescence resonance energy transfer (FRET) and methods of fluorescence detection in fluorescent-quantitative polymerase chain reaction (FQ-PCR) are introduced in this article. Applications of FRET in fluorescence detection of PCR are emphatically discussed, and FRET research progress and future trends are pointed out too.