New molecular method to detect denitrifying anaerobic methane oxidation bacteria from different environmental niches

The denitrifying anaerobic methane oxidation is an ecologically important process for reducing the potential methane emission into the atmosphere. The responsible bacterium for this process was Candidatus Methylomirabilis oxyfera belonging to the bacterial phylum of NC10. In this study, a new pair of primers targeting all the five groups of NC10 bacteria was designed to amplify NC10 bacteria from different environmental niches. The results showed that the group A was the dominant NC10 phylum bacteria from the sludges and food waste digestate while in paddy soil samples, group A and group B had nearly the same proportion. Our results also indicated that NC10 bacteria could exist in a high pH environment (pH 9.24) from the food waste treatment facility. The Pearson relationship analysis showed that the pH had a significant positive relationship with the NC10 bacterial diversity (p < 0.05). The redundancy analysis further revealed that the pH, volatile solid and nitrite nitrogen were the most important factors in shaping the NC10 bacterial structure (p = 0.01) based on the variation inflation factors selection and Monte Carlo test (999 times). Results of this study extended the existing molecular tools for studying the NC10 bacterial community structures and provided new information on the ecological distributions of NC10 bacteria.     

Extra-pair paternity, offspring mortality and offspring sex ratio in the socially monogamous coal tit (Parus ater)

Females of many socially monogamous bird species commonly engage in extra-pair copulations. Assuming that extra-pair males are more attractive than the females’ social partners and that attractiveness has a heritable component, sex allocation theory predicts facultative overproduction of sons among extra-pair offspring (EPO) as sons benefit more than daughters from inheriting their father’s attractiveness traits. Here, we present a large-scale, three-year study on sex ratio variation in a passerine bird, the coal tit (Parus ater). Molecular sexing in combination with paternity analysis revealed no evidence for a male-bias in EPO sex ratios compared to their within-pair maternal half-siblings. Our main conclusion, therefore, is that facultative sex allocation to EPO is absent in the coal tit, in accordance with findings in several other species. Either there is no net selection for a deviation from random sex ratio variation (e.g. because extra-pair mating may serve goals different from striving for ‘attractiveness genes’) or evolutionary constraints preclude the evolution of precise maternal sex ratio adjustment. It is interesting to note that, however, we found broods without EPO as well as broods without mortality to be relatively female-biased compared to broods with EPO and mortality, respectively. We were unable to identify any environmental or parental variable to co-vary with brood sex ratios. There was no significant repeatability of sex ratios in consecutive broods of individual females that would hint at some idiosyncratic maternal sex ratio adjustment. Further research is needed to resolve the biological significance of the correlation between brood sex ratios and extra-pair paternity and mortality incidence, respectively.     

Surface measurements of global warming causing atmospheric constituents in Korea

The expansion of the industrial economy and the increase of population in Northeast Asian countries have caused much interestin climate monitoring related to global warming. However, new techniques and better platforms for the measurement of globalwarming and regional databases are still old-fashioned and arenot being developed sufficiently. With respect to this agenda,since 1993, at the request of the World Meteorological Organization (WMO), to monitor functions of global warming, theKorea Meteorological Administration (KMA) has set up a Global Atmospheric Watch (GAW) Station on the western coast of Korea(Anmyun-do) and has been actively monitoring global warming overNortheast Asia. In addition, atmospheric carbon dioxide (CO₂) has been measured for a similar KMA global warmingprogram at Kosan, Cheju Island since 1990. Aerosol and radiationhave also been measured at both sites as well as in Seoul. Theobservations have been analyzed using diagnostics of climate change in Northeast Asia and also have been internationally compared. Results indicate that greenhouse gases are in good statistic agreement with the NOAA/Climate Monitoring and Diagnostics Laboratory (CMDL) long-term trends of monthly meanconcentrations and seasonal cycles. Atmospheric particulatematter has also been analyzed for particular Asian types interms of optical depth, number concentration and size distribution.     

抗锶放线菌的分子鉴定及对Sr~(2+)的吸附效果和初步吸附机理分析

从大亚湾核电站附近水体中分离筛选出一株抗锶放线菌(编号YF-64),研究了该菌株在不同环境参数条件下对锶的吸附效果和初步机理,通过形态和16S rDNA序列相结合的方法对菌株进行了分类鉴定,采用红外光谱(FT-IR)分析技术对菌株吸附前后进行表征,探讨其吸附机制。结果表明,抗锶菌株隶属于天蓝黄链霉菌(基因序列登录号:JF901702),菌株对Sr~(2+)具有较强的吸附效果,根据数据显示,当接触时间为50 min,pH值为6,Sr~(2+)初始浓度为50 mg/L,摇床转速为120 r/min时,该菌株的吸附效果达到最佳为44.29 mg/g;FT-IR结果显示,JF901702菌株对Sr~(2+)的吸附主要是由细胞壁上的羟基,次甲基,羰基起主要吸附作用。由此可知,JF901702菌株可作为经济、高效、环境友好的生物吸附材料进行废水重金属处理。     

The relation between chemical structure and mutagenic activity of some polycyclic aromatic sulfur heterocycles (s‐pah)

Results of Hückel Molecular Orbital (HMO) calculations strongly suggest identical metabolic activation routes for the mutagen benzo[2,3]phenanthro[4,5‐bcd]thiophene and its homocyclic parent, benzo[a]pyrene.     

Insights on the solubilization products after combined alkaline and ultrasonic pre-treatment of sewage sludge

This work provides insights on the solubilization products after a simultaneous combination of alkaline and ultrasonic (ALK + ULS) pre-treatment of sewage sludge. Soluble chemical oxygen demand (SCOD) increased from 1200 to 11,000 mg/L after such treatment. Organics with molecular weight around 5.6 kDa were solubilized because of the synergistic effect of ultrasound and alkali. Organics with molecular weight larger than 300 kDa increased from 7.8% to 60%, 16% and 42.3% after ULS, ALK and ALK + ULS treatment, respectively. Excitation emission matrix fluorescence spectroscopy analysis identified soluble microbial product-like and humic acid-like matters as the main solubilization products. Sludge anaerobic biodegradability was significantly enhanced with the simultaneous application of ALK + ULS pre-treatment. ALK + ULS pre-treatment resulted in 37.8% biodegradability increase compared to the untreated sludge. This value was higher compared to the biodegradability increase induced by individual ALK pre-treatment (5.7%) or individual ULS pre-treatment (20.7%) under the same conditions applied.     

Bayesian spatial prediction

This paper presents a complete Bayesian methodology for analyzing spatial data, one which employs proper priors and features diagnostic methods in the Bayesian spatial setting. The spatial covariance structure is modeled using a rich class of covariance functions for Gaussian random fields. A general class of priors for trend, scale, and structural covariance parameters is considered. In particular, we obtain analytic results that allow easy computation of the predictive distribution for an arbitrary prior on the parameters of the covariance function using importance sampling. The computations, as well as model diagnostics and sensitivity analysis, are illustrated with a set of precipitation data.     

纳米金修饰分子印迹聚合膜电极检测双酚A

以纳米金修饰玻碳电极为基础电极,以双酚A为模板分子,以邻氨基苯硫酚为聚合单体,采用循环伏安法电聚合制备分子印迹聚合膜,利用循环伏安和交流阻抗法研究电极的电化学特性。结果表明,双酚A在修饰电极表面的反应是一个受吸附控制的等电子、质子转移的不可逆反应。采用差分脉冲伏安法检测双酚A,线性范围为5. 0×10~(-6)mol/L～4. 0×10~(-4)mol/L,检出限为2. 3×10~(-7)mol/L。将该电极用于自来水和牛奶样品的测定,结果均为未检出,加标回收率分别为93. 5%和95. 4%,3次测定结果的RSD分别为4. 0%和5. 7%。     

废水生物处理出水中溶解性微生物产物的形成机制与特征

废水生物处理出水中的溶解性微生物产物(SMP)主要产生于基质降解和微生物的内源呼吸过程,它的存在是影响生物处理出水水质和有机物去除率的一个重要因素,已引起人们的普遍关注.简单阐述了SMP的定义,详细探讨了废水生物处理出水中溶解性微生物产物的形成机制与特征.     

Separation of dissolved iron from the aqueous system with excess ligand

A new technique for the separation and pre-concentration of dissolved Fe(III) from the ligand-rich aqueous system is proposed. A solid phase extraction (SPE) system with an immobilized macrocyclic material, commonly known as molecular recognition technology (MRT) gel and available commercially, was used. Synthetic Fe(III) solution in aqueous matrices spiked with a 100-fold concentration of EDTA was used. Dissolved iron that was ‘captured’ by the MRT gel was eluted using hydrochloric acid and subsequently determined by graphite furnace atomic absorption spectrometry. The effect of different variables, such as pH, reagent concentration, flow rate and interfering ions, on the recovery of analyte was investigated. Quantitative maximum separation (∼100%) of the dissolved Fe(III) from synthetic aqueous solutions at a natural pH range was observed at a flow rate of 0.2 mL min^-1. The extraction efficiency of the MRT gel is largely unaltered by the coexisting ions commonly found in natural water. When compared with different SPE materials, the separation performance of MRT gel is also much higher.