Studies on metabolic extract of Altemaria alternata and toxicity

Altemaria alternata were isolated from wheat seeds collected from villages in Tianshui area of Gansu Province where Kaschin-Beck disease is prevalent. TLC, IR and UV analyses of metabolic extract of A. alternata show that A. alternata produce main secondary metabolites, including alternariol, alternariol methyl ether, and tenuazonic acid.There was a significant decrease in Se-GSH-Px and SOD activities, and an acceleration in lipid peroxidation in rats fed with a diet containing metabolites produced by A. alternata.     

尿液中多环芳烃羟基代谢产物分析方法研究

通过实验建立了"酶水解-固相萃取-HPLC 荧光检测"尿液中多环芳烃羟基代谢产物1-羟基芘,9-羟基苯并[a]芘和3-羟基苯并[a]芘的分析方法,研究了3种代谢产物在不同保存温度下的稳定性,并通过对200个实际尿液的测定初步验证了该方法的可行性。该方法回收率为70%～85%,最低检出限为0 02～0 05μg L。-20℃保存的尿液样品及尿液提取液中3种化合物在1个月内降解了10%～36%,提取液比尿液的稳定性稍好,保存温度越高稳定性越差。      

污水地下渗滤系统微生物代谢组学分析

应用超高效液相色谱-质谱技术（UPLC-MS）,基于代谢组学方法,筛选不同进水有机负荷下地下渗滤系统潜在生物标志物.采用偏最小二乘法（PLS-DA）和主成分分析（PCA）模式识别方法对样品进行分型处理,根据模型的变量重要性因子（VIP值）筛选潜在生物标志物,分析代谢产物蕴含的生物学信息,研究代谢通路,通过RDA分析探索代谢产物与环境因子之间的相关性.PLS-DA模型结果表明,当进水有机负荷为250mg/L、400mg/L、500mg/L时,同一高度层代谢产物间存在显著性差异,共筛选出VIP值大于1.5的230种差异代谢物,以有机酸为主;同时也存在一些醇类、酚类等微生物代谢中间产物.此外,微生物代谢产物与模拟土柱高度有显著对应性.在水力负荷为0.14m³/（m²·d）,COD污染负荷为400mg/L条件下,3个高度层H2（500mm）、H4（1000mm）、H6（1500mm）筛选出53种VIP值大于1.5的差异代谢物,以酸类、酮类物质为主.RDA分析表明,随着有机负荷波动和剖面高度的变化,代谢产物受到氧化还原环境（ORP）与硝态氮（NO₃^-）的影响较大,呈负相关.     

Identification of naphthalene metabolism by white rot fungus Armillaria sp. F022

Armillaria sp. F022, a white rot fungus isolated from tropical rain forest (Samarinda, Indonesia) was used to biodegrade naphthalene in cultured medium. Transformation of naphthalene by Armillaria sp. F022 which is able to use naphthalene, a two ring-polycyclic aromatic hydrocarbon (PAH) as a source of carbon and energy was investigated. The metabolic pathway was elucidated by identifying metabolites, biotransformation studies and monitoring enzyme activities in cell-free extracts. The identification of metabolites suggests that Armillaria sp. F022 initiates its attack on naphthalene by dioxygenation at its C-1 and C-4 positions to give 1,4-naphthoquinone. The intermediate 2-hydroxybenzaldehyde and salicylic acid, and the characteristic of the meta-cleavage of the resulting diol were identified in the long-term incubation. A part from typical metabolites of naphthalene degradation known from mesophiles, benzoic acid was identified as the next intermediate for the naphthalene pathway of this Armillaria sp. F022. Neither phthalic acid, catechol and cis,cis-muconic acid metabolites were detected in culture extracts. Several enzymes (manganese peroxidase, lignin peroxidase, laccase, 1,2-dioxygenase and 2,3-dioxygenase) produced by Armillaria sp. F022 were detected during the incubation.     

Nitro-PAH exposures of occupationally-exposed traffic workers and associated urinary 1-nitropyrene metabolite concentrations

The assessment of occupational exposure to diesel exhaust(DE) is important from an epidemiological perspective. Urinary biomarkers of exposure have been proposed as a novel approach for measuring exposure to DE. In this study, we measured the concentrations of two urinary metabolites of 1-nitropyrene(1NP), a nitrated polycyclic aromatic hydrocarbon that has been suggested as a molecular marker of diesel particulate matter. These two metabolites, 6-hydroxy-1-nitropyrene and 8-hydroxy-1-nitropyrene, were determined in urine samples(10 m L) from a small group of workers who were occupationally-exposed to vehicle exhaust in Trujillo, Peru, before and after their workshifts. Workshift exposures to1 NP, as well as PM_(2.5), 2-nitropyrene and 2-nitrofluoranthene, were also measured.Exposures to 1NP were similar in all studied workers, averaging 105 ± 57.9 pg/m~3(±standard deviation). Median urinary concentrations of the average of the pre- and post-exposure samples for 6-hydroxy-1-nitropyrene and 8-hydroxy-1-nitropyrene, were found to be 3.9 and 2.3 pg metabolite/mg creatinine, respectively in the group of occupationally-exposed subjects(n = 17) studied. A direct relationship between workshift exposure to 1NP and urinary 1NP metabolites concentrations was not observed. However,the 1NP exposures and the creatinine-corrected urinary concentrations of the hydroxynitropyrene metabolites in these Peruvian traffic workers were similar to occupationally-exposed taxi drivers in Shenyang, China, and were higher than biomarker levels in office workers from Trujillo without occupational exposure to vehicle exhaust.This study provides further evidence that urinary metabolites of 1NP are associated with exposure to DE and may serve as a useful exposure biomarker.     

亚致死剂量氯吡嘧磺隆胁迫对斑马鱼典型肝脏代谢物的影响

为获知水环境中亚致死剂量的氯吡嘧磺隆对斑马鱼肝脏的影响,将斑马鱼暴露在亚致死剂量的氯吡嘧磺隆药液中8 d,采用超高效液相色谱与四级杆-轨道离子阱质谱串联对斑马鱼的肝脏代谢物进行分析,采用SIEVE软件将图谱信息转换为含有保留时间、质荷比和相对峰面积的二维数据阵.同时,结合mz Cloud、Human Metabolome Database(HMDB)数据库共鉴定出33种代谢物,包括氨基酸、糖、有机酸等物质.最后,采用SIMCA软件对正离子和负离子模式下的检测结果进行主成分、偏最小二乘法和正交校正的偏最小二乘法分析.主成分和偏最小二乘法结果表明,对照组与处理组在2种检测模式下均存在差异代谢物.为了寻找造成对照组与处理组之间差异的代谢物,对代谢物进行S-Plot分析,结果表明,肌酸酐、牛磺酸、多巴胺和5b-胆甾醇硫酸酯组间差异最大(p0.01).4种代谢产物可作为斑马鱼在氯吡嘧磺隆亚致死剂量胁迫下肝脏代谢异常的潜在标记物.     

NPnEO在中国北方四城市污水处理厂的污染研究

测定了中国北方4个城市污水处理厂进、出水中壬基酚聚氧乙烯醚(NPnEO,n为聚合度)及其代谢产物的浓度及分布,同时测定了其中2个污水处理厂污泥中上述物质的浓度和分布,初步探讨了NPnEO在城市污水处理过程中的迁移转化行为.结果表明:在4个城市污水处理厂的进、出水及其中2个厂的污泥中均检测到了浓度不等的NPnEO及其代谢产物;NPnEO在各城市污水处理厂都得到了一定程度的降解去除,去除率为23.38%～77.11%,平均为52.86%;NPnEO大分子组分降解成了小分子组分,但并未完全矿化;出水中以壬基酚(NP)、壬基酚一乙氧基醚(NP1EO)和壬基酚二乙氧基醚(NP2EO)小分子组分的浓度高.这些小分子产物都具有比母体化合物更高的毒性,并具有环境内分泌干扰性质,因此污水处理过程不但没有降低反而增加了生态风险,是环境中小分子NPnEO的主要来源;污泥对NPnEO,特别是小分子代谢产物有良好的吸附性能,其在污泥中的浓度水平较高,合理处置污泥避免二次污染值得进一步研究探讨.      

Effects of Cu2+ and humic acids on degradation and fate of TBBPA in pure culture of Pseudomonas sp. strain CDT

Soil contamination with tetrabromobisphenol A(TBBPA) has caused great concerns;however, the presence of heavy metals and soil organic matter on the biodegradation of TBBPA is still unclear. We isolated Pseudomonas sp. strain CDT, a TBBPA-degrading bacterium, from activated sludge and incubated it with ~(14)C-labeled TBBPA for 87 days in the absence and presence of Cu~(2+)and humic acids(HA). TBBPA was degraded to organic-solvent extractable(59.4% ± 2.2%) and non-extractable(25.1% ± 1.3%) metabolites,mineralized to CO_2(4.8% ± 0.8%), and assimilated into cells(10.6% ± 0.9%) at the end of incubation. When Cu~(2+)was present, the transformation of extractable metabolites into non-extractable metabolites and mineralization were inhibited, possibly due to the toxicity of Cu~(2+)to cells. HA significantly inhibited both dissipation and mineralization of TBBPA and altered the fate of TBBPA in the culture by formation of HA-bound residues that amounted to 22.1% ± 3.7% of the transformed TBBPA. The inhibition from HA was attributed to adsorption of TBBPA and formation of bound residues with HA via reaction of reactive metabolites with HA molecules, which decreased bioavailability of TBBPA and metabolites in the culture. When Cu~(2+)and HA were both present, Cu~(2+)significantly promoted the HA inhibition on TBBPA dissipation but not on metabolite degradation. The results provide insights into individual and interactive effects of Cu~(2+)and soil organic matter on the biotransformation of TBBPA and indicate that soil organic matter plays an essential role in determining the fate of organic pollutants in soil and mitigating heavy metal toxicity.     

Relation of hepatic EROD activity and cytochrome P4501A level in Sebastiscus marmoratus exposed to benzo[a]pyrene

This study was designed to investigate the in vivo effects of benzo[a]pyrene （BaP） on hepatic ethoxyresorufin-O-deethylase （EROD） activity and its correlation with cytochrome P4501A （CYP1A） protein levels in Sebastiscus marmoratus, which were exposed through a water column to BaP （10, 100, 1000 ng/L, respectively） or were treated with intraperitoneal injections of BaP （0.5, 1, 5, 10 mg/kg, respectively） every 7 d. The results showed that after 25 d of waterborne exposure to 1000 ng/L BaP, fish hepatic CYP1A levels and EROD activity were significantly induced. In contrast, EROD activity was not altered 7 d after second intraperitoneal injections, whereas, CYP1A protein levels were increased. Dose-dependent increase of biliary BaP metabolites demonstrated that the catalytic activity of CYP1A was induced by treatment with BaP. The lowest observable effect concentration with regard to biliary BaP metabolites （100 ng/L） was much lower than that with reference to EROD activity （1000 ng/L）. The results suggest that biliary polycyclic aromatic hydrocarbon （PAH） metabolites were shown to better reflect the contamination gradients of PAHs than EROD activity. It appeared to be necessary to measure CYP1A protein levels to complement the EROD activity in relevant toxicological assessments.     

Relation of hepatic EROD activity and CYP1A level in Sebastiscus marmoratus exposed to benzo[a]pyrene

This study was designed to investigate the in vivo effects of benzo[a]pyrene (BaP) on hepatic ethoxyresorufin-O-deethylase (EROD) activity and its correlation with cytochrome P450 1A (CYP1A) protein levels in Sebastiscus marmoratus, which were exposed through a water column to BaP (10, 100, 1000 ng/L, respectively) or were treated with intraperitoneal injections of BaP (0.5, 1, 5, 10 mg/kg, respectively) every 7 d. The results showed that after 25 d of waterborne exposure to 1000 ng/L BaP, fish hepatic CYP1A levels and EROD activity were significantly induced. In contrast, EROD activity was not altered 7 d after second ip injections, whereas, CYP1A protein levels were increased. Dose-dependent increase of biliary BaP metabolites demonstrated that the catalytic activity of CYP1A was induced by treatment with BaP. The lowest observable effect concentration with regard to biliary BaP metabolites (100 ng/L) was much lower than that with reference to EROD activity (1000 ng/L). The results suggest that biliary polycyclic aromatic hydrocarbon (PAH) metabolites were shown to better reflect the contamination gradients of PAHs than EROD activity. It appeared to be necessary to measure CYP1A protein levels to complement the EROD activity in relevant toxicological assessments.     

Debrominated and methoxylated polybrominated diphenyl ether metabolites in rainbow trout (Oncorhynchus mykiss) after exposure to decabromodiphenyl ether

Decabromodiphenyl ether (BDE209) is the primary component in a commonly used flame retardant. Previous studies had proved that BDE209 itself was not toxic, while its metabolites including debrominated diphenyl ethers (De-BDEs) and methoxylated brominated diphenyl ethers (MeO-BDEs) posed a potential threat to organisms. Many studies had indicated that BDE209 could metabolize quickly in mammals, but lacking in the basic data about the metabolism of BDE209 in fish. In the present study, two replicate treatment groups of rainbow trout (Oncorhynchus mykiss) were exposed to BDE209 via a single intraperitoneal injection approximately 100 and 500 ng/g, respectively. Muscle, liver and blood samples were collected to analyze the specific metabolites on day 1 and day 28 post injection. The highest concentration of BDE209 was detected in muscle tissues, from 796.1 ng/g wet weight (day 1) to 687.1 ng/g wet weight (day 28) in high dose group, suggesting that BDE209 could accumulate slightly in muscle tissues. However, BDE209 was not detected in the blood for all treatments. Most congeners of De-BDEs were found in muscle and liver tissues, with the highest concentration in the liver. The main De-BDEs were nona-, octa-, hepta- and penta-De-BDEs. A total of seven MeO-BDE metabolites were observed among di erent fish tissues. Blood had the highest contribution of the MeO-BDE metabolites. Each MeO-BDE congener increased over the 28 days. These results in contrast to other studies suggested possible species-specific di erences in metabolic abilities.     

全国23个城市水源水中邻苯二甲酸酯代谢物浓度调查

采用UPLC-MS/MS方法对中国23个城市的90个自来水厂141个水源水样中5种常用PAEs的8种代谢产物进行检测.结果发现,所有自来水水源水中均检出了MPAEs,邻苯二甲酸单正丁酯（MnBP）检出浓度最高,为74.7ng/L.水源水中邻苯二甲酸单乙酯（MEP）,邻苯二甲酸单异丁酯（MiBP）和MnBP浓度与邻苯二甲酸二乙酯（DEP）,邻苯二甲酸二异丁酯（DiBP）和邻苯二甲酸二正丁酯（DnBP）浓度分别呈显著相关,表明两者可能是同源.邻苯二甲酸二（2-乙基己基）酯（DEHP）二级代谢产物所占DEHP一级、二级代谢产物浓度和（∑DEHP）为4.0%±5.6%,和天然水体中DEHP的微生物降解结果类似,水源水中的MPAEs可能来自PAEs在自然水体中的微生物降解.     

壬基酚初级生物降解产物的辨认

为分析污水生物处理过程中壬基酚的去除机制,采用混合基质加标对照培养活性污泥、单一基质培养优势菌群2种生物降解实验,结合气相色谱-质谱谱图解析,从分子水平分析了壬基酚初级代谢产物和代谢途径.研究结果表明,活性污泥降解壬基酚的初级代谢产物主要为C4-C6烷基取代苯酚,烷基链的结构差异与其母体壬基的异构方式有关,烷基上的支链主要为甲基;优势降解菌群代谢壬基酚的初级产物除烷基苯酚外,还有苯乙酸等.污水生物处理过程中壬基酚可能的初级生物代谢途径是壬基上的长支链断裂为短的甲基链,生成一系列带有不同分支结构的短链烷基酚类代谢产物,进一步的代谢产物有苯乙酸.根据烷基酚类物质的内分泌干扰特性,短链烷基酚仍然具有雌激素活性,因此在壬基酚污染防治过程中应给与足够的重视.     

Development of a generalist predator,Podisus maculiventris,on glucosinolate sequestering and nonsequestering prey

Insect herbivores exhibit various strategies to counter the toxic effects of plant chemical defenses. These strategies include the detoxification, excretion, and sequestration of plant secondary metabolites. The latter strategy is often considered to provide an additional benefit in that it provides herbivores with protection against natural enemies such as predators. Profiles of sequestered chemicals are influenced by the food plants from which these chemicals are derived. We compared the effects of sequestration and nonsequestration of plant secondary metabolites in two specialist herbivores on the development of a generalist predator, Podisus maculiventris. Profiles of glucosinolates, secondary metabolites characteristic for the Brassicaceae, are known to differ considerably both inter- and intraspecifically. Throughout their immature (=nymphal) development, the predator was fed on larval stages of either sequestering (turnip sawfly, Athalia rosae) or nonsequestering (small cabbage white butterfly, Pieris rapae) prey that in turn had been feeding on plants originating from three wild cabbage (Brassica oleracea) populations that have previously been shown to differ in their glucosinolate profiles. We compared survival, development time, and adult body mass as parameters for bug performance. Our results show that sequestration of glucosinolates by A. rosae only marginally affected the development of P. maculiventris. The effects of plant population on predator performance were variable. We suggest that sequestration of glucosinolates by A. rosae functions not only as a defensive mechanism against some predators, but may also be an alternative way of harmlessly dealing with plant allelochemicals.     

Effects of nitrate concentration on biological hydrogen production by mixed cultures

The effects of nitrate on fermentative hydrogen production and soluble metabolites from mixed cultures were investigated by varying nitrate concentrations from 0 to 10 g N/L at 35°C with an initial pH of 7.0. The results showed that the substrate degradation rate, hydrogen production potential, hydrogen yield, and average hydrogen production rate initially increased with increasing nitrate concentrations from 0 to 0.1 g N/L, while they decreased with increasing nitrate concentrations from 0.1 to 10 g N/L. The maximum hydrogen production potential of 305.0 mL, maximum hydrogen yield of 313.1 mL/g glucose, and maximum average hydrogen production rate of 13.3 mL/h were obtained at a nitrate concentration of 0.1 g N/L. The soluble metabolites produced by the mixed cultures contained only ethanol and acetic acid (HAc) without propionic acid (HPr) and butyric acid (HBu). This study used the Modified Logistic model to describe the progress of cumulative hydrogen production in batch tests. A concise model was proposed to describe the effects of nitrate concentration on average hydrogen production rate.     

溶藻细菌L7(Algicidal Bacteria Strain L7)与中肋骨条藻(Skeletonema costatum)的相互作用

将6组不同初始种群密度的溶藻细菌L7(Bacillus cereus)菌悬液和添加了溶藻细菌L7胞内、外代谢产物的2216E培养液加入到中肋骨条藻(Skeletonema costatum)悬浮液中,将5组不同初始种群密度的中肋骨条藻悬浮液和添加了中肋骨条藻胞内外代谢产物的f/2-Si培养液加入到溶藻细菌L7悬浮液中,探讨溶藻细菌L7和中肋骨条藻的相互作用。在第7天时,L7胞外代谢产物使中肋骨条藻细胞数量下降95.42%,表现为间接溶藻,胞内代谢产物使藻细胞数量增长361.47%,表现为加快藻增长。L7初始种群密度为3.89×106 cfu/mL和3.89×107 cfu/mL时,在第7天藻细胞数量均下降80%以上;初始种群密度为3.89×102~3.89×104 cfu/mL时,在第7天L7促进藻生长。中肋骨条藻种群密度为3.89×103 cells/L、3.89×104 cells/L及3.89×106 cells/L时,最迟于第7天,L7种群密度开始低于对照组,即中肋骨条藻能够在一段时间后抑制L7生长。从第4天开始,中肋骨条藻胞外代谢产物使L7种群密度低于对照组,即中肋骨条藻对L7产生抑制作用;胞内代谢产物对L7生长的影响不明显。     

Molecular characterization of microbial communities in bioaerosols of a coal mine by 454 pyrosequencing and real-time PCR

Microbial diversity and abundance in bioaerosols of a coal mine were analyzed based on 454 pyrosequencing and real-time polymerase chain reaction(PCR). A total of 37,191 high quality sequences were obtained and could be classified into 531, 1730 and 448 operational taxonomic units respectively for archaea, bacteria and fungi at 97% sequence similarity. The Shannon diversity index for archaea, bacteria and fungi was respectively 4.71, 6.29 and 3.86, indicating a high diversity in coal mine bioaerosols. Crenarchaeota, Proteobacteria and Ascomycota were the dominant phyla for archaea, bacteria and fungi, respectively. The concentrations of total archaea, bacteria and fungi were 1.44 × 108, 1.02 × 108 and 9.60 × 104cells/m3, respectively.Methanotrophs observed in bioaerosols suggested possible methane oxidation in the coal mine. The identified potential pathogens to coal miners, such as Acinetobacter schindleri,Aeromonas cavernicola, Alternaria alternata, Aspergillus penicillioides, Cladosporium cladosporioides,and Penicillium brevicompactum were also observed. This was the first investigation of microbial diversity and abundance in coal mine bioaerosols. The investigation of microbial communities would be favorable in promoting the progress of methane control based on microbial technique and concern on coal miners’ health.     

溶藻细菌L7代谢物对水华鱼腥藻的溶藻效应

从等体积不同密度的溶藻细菌L7菌液中提取胞内、胞外代谢物,分别加入等体积等密度的水华鱼腥藻中连续培养7d,研究L7代谢物对水华鱼腥藻的溶藻效应。2.78×105~2.78×10 7cfu/mL的L7胞内代谢物能显著促进藻生长和异形胞分化,到培养结束藻密度为对照组的1.7~1.98倍;异形胞数最大可为对照组的2.31倍。2.78×10 8、2.78×10 9cfu/mL的L7胞内代谢物能抑制藻生长,藻密度最低为对照组的58%;能极显著抑制异形胞分化,可不形成异形胞。2.78×10 5~2.78×109 cfu/mL的L7胞外代谢物能极显著抑制藻生长和异形胞分化,藻密度最低为对照组的0.63%,不形成异形胞;藻丝的藻细胞间隔变模糊,藻细胞变大变形,并有大量的单个球形藻体散落。L7主要通过分泌胞外代谢物溶藻,菌胞内代谢物对藻生长有"低促高抑"的作用。     

基于H4IIE细胞株测试间接雌激素效应物质的代谢活化方法

利用鼠肝癌细胞(H4IIE)代谢活化环境样品中间接雌激素效应物质的方法,以标准化合物双酚A和北方某污水处理厂各工艺过程的水样以及南方某水厂自来水样的有机提取物为对象,比较了代谢活化作用对雌激素效应检测结果的影响.研究结果表明,双酚A代谢活化产物的雌激素活性明显高于双酚A;环境样品中存在大量的间接雌激素效应物质,通过细胞代谢活化的方法能够检出其活性.因此,推荐将鼠肝癌细胞代谢活化与重组基因酵母检测的方法相结合,用于环境样品中直接和间接雌激素效应物质的检测.     

基于可疑筛查技术研究有机磷阻燃剂V6转化规律

运用Orbitrap高分辨质谱仪,评估了人体肝微粒体(HLM)代谢V6的转化规律.除5种已被报道过的O-脱烷基、氧化性去磷酸化和氧化脱氯产物外,首次发现了6种新型产物.基于其MS/MS质谱图,该6种代谢产物被鉴定为醛基和羧基产物.其中,5种代谢物生成量随孵育时间呈线性增加趋势,具有累积性.此外,推导的代谢途径表明,脱烷基化和羟基化代谢物进一步转化为次级代谢物,即醛和羧基代谢物.