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QYM201 is a 4-hydroxyphenylpyruvate dioxygenase (HPPD) inhibiting herbicide recently registered in China for controlling grass and broadleaf weeds in wheat. It is a novel herbicide, and its potential harm to soil ecosystems has not yet been reported. This study investigates the influence of QYM201 on soil enzyme activity and microorganism quantities in two different soils at concentrations of 0.1, 1, and 5 mg kg−1 soil. Results indicate that QYM201 initially inhibited soil protease, urease, and sucrase activity and this effect increased with concentration. During the later stages of incubation, inhibitory effects gradually weakened and by the end of the experiment (45 days), enzyme activity was restored to control levels. Catalase activity was stimulated by QYM201, with significant differences observed between the QYM201-treated groups and the control at the onset of exposure. This stimulation effect decreased during the later stages of the experiment. However, catalase activity was still significantly higher at the end of the experiment compared to the control. The effects of QYM201 on soil microorganisms differed. Initially, bacteria and actinomycetes quantities were decreased by QYM201 (10 days). As the incubation progressed, microorganism quantities in the lower concentration groups (0.1 and 1 mg kg−1 soil) were restored to control levels, while those of the high concentration group (5 mg kg−1 soil) did not fully recover. QYM201 did not significantly impact the quantity of fungi. The half-life and degradation rate constant (k) of QYM201 for the two studied soil types were 23.1 days and 16.1 days, and 0.030 and 0.043 day−1, respectively. [ABSTRACT FROM AUTHOR]

Enzyme activity and microbial population in soils have important roles in keeping soil fertility. ZJ0273 is a novel pyrimidynyloxybenzoic-based herbicide, which was recently developed in China. The effect of ZJ0273 on soil enzyme activity and microbial population in two different soils was investigated in this study for the first time. The protease activity was significantly inhibited by ZJ0273 and this inhibiting effect gradually weakened after 60-day incubation. The results also showed that ZJ0273 had different stimulating effects on the activities of dehydrogenase, urease, and catalase. Dehydrogenase was consistently stimulated by all the applied concentrations of ZJ0273. The stimulating effect on urease weakened after 60-day incubation. Catalase activity was subject to variations during the period of the experiments. The results of microbial population showed that the number of bacteria and actinomycetes increased in ZJ0273-treated soil compared with the control after 20 days of incubation, while fungal number decreased after only 10 days of incubation in soils. DT50 (half-life value) and k (degradation rate constant) of ZJ0273 in S1 (marine-fluvigenic yellow loamy soil) and S2 (Huangshi soil) were found 69.31 and 49.50 days and 0.010 and 0.014 day, respectively. [ABSTRACT FROM AUTHOR]

The impacts of the Pb-Zn mine tailing dam incident on the degree of environmental response from soil properties were investigated in Sidi village, Guangxi Zhuang Autonomous Region, SW China, using statistical analysis, as well as canonical correspondence analysis (CCA). From the descriptive statistical analysis of soil properties in Sidi village, it can be seen that the topsoil pH ranged from 5.53 to 6.57, while the mean value was 5.74, which reflects the acidic and oxidized effect of the tailing sand. The total Pb in topsoil ranged from 569.50 to 6,423 mg kg, while the mean value was 1,852.33 mg kg, and the total Zn in topsoil ranged from 240.70 to 5,513 mg kg, while the mean value was 1,190.42 mg kg, which indicates that this area should not be as farmland anymore according to the environmental quality evaluation standards for farmland of edible agricultural products of China HJ/T332-2006. By analyzing the statistical analysis data and the CCA bioplot, the total Pb and the total Zn have the significant positive correlation coefficients ( r = 0.656, p < 0.01) and the angle between vectors of the total Pb and the total Zn is small, which confirms that the heavy metal contamination is mainly from the Pb-Zn intergrowth ore. Moreover, the soil microorganism and the total Pb-Zn are on the opposite quadrant in the CCA ordination diagram and the sensitivity of the soil microorganism to the total Pb-Zn in topsoil was observed in the order of bacteria < fungi < actinomyces. The soil enzyme was released by the soil microorganisms, therefore, the activities of invertase, urease, and alkaline phosphatase were inhibited into different degrees by the total Pb and the total Zn in topsoil. From the CCA biplot, their complex inwardness between the soil enzyme and the Pb-Zn contamination can be clearly and intuitively depicted. Then, the alkaline phosphatase activities have strongly positive correlation coefficients with the total Zn ( r = 0.451, p < 0.05) and the urease activities ( r = 0.394, p < 0.05). [ABSTRACT FROM AUTHOR]

For the first time in China, a preliminary survey of geochemical characteristics and microbial populations of Neogene brown coal from Zhaotong Basin in Yunnan province, China was conducted to provide a basis for an understanding of the generation of biogenic coal-bed methane in this basin. Coals in this region consist of soft brown coal with lower maturity and good bioactivity, as determined by coal petrologic measurements. Soluble organic matter in coal exhibits the characteristics of unsaturated humic hydrocarbon source rock. Organics in coal were generally associated with higher plants and lower grade aquatic organisms. The bacterial community was dominated by fermentation bacteria, and sulfate-reducing bacteria were relatively rare. [ABSTRACT FROM AUTHOR]

Abstract: Successful site remediation is critically based on a comprehensive understanding of distribution of contaminants, soil physico-chemical and microbial properties in oil contaminated sites. One hundred and ten topsoils were sampled from seven typical oil fields in different geoclimate regions across north to south China to investigate the spatial variances of oil contaminations and soil parameters. Oil concentrations and compositions, soil geochemical properties and microbial populations were analyzed and statistic analysis methods were used to analyze the spatial pattern of soil variables. The results indicated that oil contaminations were serious in most oil exploring areas in China, especially with high levels of polycyclic aromatic hydrocarbons (PAHs) from petrogenic origin. Ordination analyses indicated a relatively distinct spatial pattern that all soil samples grouped mainly by geographic locations, instead of distributing along contamination or other geochemical variable gradient. Microbial populations were found to be statistically positively correlated with soil nitrogen, phosphorus and water content, and negatively correlated with salt pH and soluble salts (P <0.05). This study provided insights into the spatial variability of soil variables in hydrocarbon-contaminated fields across large spatial scales, which is important for the environmental protection and further remediation in oil contaminated sites according to local conditions. [Copyright &y& Elsevier]

Methane (CH 4 ) and nitrous oxide (N 2 O) emissions from an irrigated rice field under continuous flooding and intermittent irrigation water management practices in northern China were measured in situ by the static chamber technique during May to October in 2000. The intermittent irrigation reduced total growing‐season CH 4 emission by 24.22% but increased N 2 O emission by 23.72%, when compared with the continuous flooding. Soil Eh and four related bacterial groups were also measured to clarify their effects on gaseous emissions. Three ranges of soil redox potential were related to gas emissions: below -100 mV with vigorous CH 4 emission, above +100 mV with significant N 2 O emission, and +100 to -100 mV with little CH 4 and N 2 O emissions. Intermittently draining the field increased soil oxidation, with a decrease in CH 4 emission and an increase in N 2 O emission. In general the mid‐season drainage slightly increased the populations of methanotrophs, nitrifiers, and denitrifiers but decreased that of methanogens. [ABSTRACT FROM AUTHOR]

The characteristics of bioaerosol emissions from wastewater treatment plants (WWTPs) have attracted extensive attention. The anaerobic-anoxic-oxic (A 2 O) process, which uses the activated sludge approach to wastewater treatment, is the most widely used process in WWTPs. Concentration, size distribution, population, and exposure risk from bacteria and fungi in bioaerosols of WWTPs using the A 2 O process were studied in this work. The results showed that the maximum concentration of airborne bacteria (1.00 × 10 4 Colony Forming Units per cubic meter (CFU m -3 )) and fungi (1.44 ×10 4 CFU m -3 ) occurred from the facility's aerobic tank, in summer. As one of the main factors affecting bioaerosol exposure risk, particle size distribution was related to season. The study found that particles larger than 3.3 µm in diameter were detected mainly in spring and summer, while particles less than 3.3 µm were detected mainly in autumn and winter, whether bacterial aerosol or fungal aerosol. In addition, pathogenic bacteria were observed in bioaerosols from WWTPs, with 18 of the 65 species of bacteria detected found to be potentially or opportunistically pathogenic, such as Chryseobacterium, Stenotrophomonas, Alcaligenes, Micrococcus, Pantoea, Enterobacter and Escherichia-Shigella. The presence of these pathogens further increased the exposure risk from bioaerosols. The results of an inhalation risk assessment for airborne bacteria and fungi indicated that potential adverse health risks for adults mainly occurred in spring, summer, and autumn. On this basis, it was concluded that WWTP operators should set up effective bioaerosol controls as soon as possible to protect the health of workers, and of residents near the plant., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Microbial populations in probiotic supplements in China were investigated using the plate count method and PCR- DGGE technique. Our results indicated that total viable cells in most probiotic products could meet the minimum requirement of the Chinese National Standards (106 CFU/ mL); however, total viable cell counts of the species detected in the probiotic products did not correspond with the cell number given in the label. [ABSTRACT FROM AUTHOR]

In iron and manganese-containing groundwater treatment for drinking water production, biological filter is an effective process to remove such pollutants. Until now the exact microbial mechanism of iron and manganese removal, especially coupled with other pollutants, such as ammonia, has not been clearly understood. To assess this issue, the performance of a full-scale biofilter located in Harbin, China was monitored over four months. Microbial populations in the biofilter were investigated using T-RFLP and clone library technique. Results suggested that Gallionella, Leptothrix, Nitrospira, Hyphomicrobium and Pseudomonas are dominant in the biofilter and play major roles in the removal of iron, manganese and ammonia. The spatial distribution of microbial populations along the depth of the biofilter demonstrated the stratification of the removal of iron, manganese and ammonia. Additionally, the absence of ammonia-oxidizing bacteria in the biofilter implicated that ammonia-oxidizing archaea might be responsible for the oxidation of ammonia to nitrite., (Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.)