Development of mechanistically based model for simulating soluble microbial products generation in an aerated/non-aerated SBR

Soluble microbial products (SMPs) are considered as the main organic components in wastewater treatment plant effluent from biological wastewater treatment systems. To investigate and explore SMP metabolism pathway for further treatment and control, two innovative mechanistically based activated sludge models were developed by extension of activated sludge model no.3 (ASM3). One was the model by combining SMP formation and degradation (ASM3-SMP model) processes with ASM3, and the other by combining both SMP and simultaneous substrate storage and growth (SSSG) mechanisms with ASM3 (SSSG-ASM3-SMP model). The detailed schematic modification and process supplements were introduced for comprehensively understanding all the mechanisms involved in the activated sludge process. The evaluations of these two models were demonstrated by a laboratory-scale sequencing batch reactor (SBR) operated under aerated/non-aerated conditions. The simulated and measured results indicated that SMP comprised about 83% of total soluble chemical oxygen demand (SCOD) in which biomass-associated products (BAPs) were predominant compared with utilization-associated products (UAPs). It also elucidated that there should be a minimum SMP value as the reactive time increases continuously and this conclusion could be used to optimize effluent SCOD in activated sludge processes. The comparative results among ASM3, ASM3-SMP and SSSG-ASM3-SMP models and the experimental measurements (SCOD, ammonia and nitrate nitrogen) showed clearly the best agreement with SSSG-ASM3-SMP simulation values (R = 0.993), strongly suggesting that both SMP formation and degradation and SSSG mechanisms are necessary in biologically activated sludge modeling for municipal wastewater treatment.     

Genetic and alkaloid analysis of Menispermum dauricum DC. by RAPD and HPLC

The aim of the present work was to determine whether dauricine could be used as a taxonomic marker for Menispermum dauricum DC., and to explore the correlation among RAPD, ecological markers and chemical markers. To this end, the chemical and genetic differences of 173 individual samples of M. dauricum from nine different sources were studied based on the relevant ecological factors including longitude, latitude, annual precipitation, mean temperature, annual accumulated temperature and mean sea level. The contents of dauricine in the sample rhizomes were assayed by HPLC with photodiode array detection. The leaves from the same sample were assayed using randomly amplified polymorphism DNA (RAPD). The genetic distances were then compared. Hierarchical cluster analysis and multiple linear stepwise regression analysis were used in the statistical analysis. The results indicated that the contents of dauricine were respectively correlated with the genetic distance (r = 1.000), longitude (r = 0.849), latitude (r = 0.861), annual precipitation (r = 0.903), mean temperature(r = 0.912), annual accumulated temperature (r = 0.919) and mean sea level (r = 0.925). It is concluded that the content of dauricine in M. dauricum is significantly correlated with genetic distance and ecological factors, and may be used as the taxonomic marker.     

温度对香蕉花蓟马发育和存活的影响

通过在人工气候箱内饲养香蕉花蓟马,测定了14、18、22、26℃和30℃5个温度下香蕉花蓟马不同虫态的发育历期,分析了温度与香蕉花蓟马发育速率的关系,计算了其发育起点温度、有效积温及存活率。结果表明:香蕉花蓟马各虫态的发育历期随温度的升高而缩短,发育速率和温度之间有很大的相关性;香蕉花蓟马卵、一龄若虫、二龄若虫、预蛹、蛹及世代的发育起点温度分别为8.26、10.56、7.92、9.17、9.53、8.69℃,世代的有效积温为153.81d·℃。26℃下香蕉花蓟马的世代存活率最高,为63.16%;30℃下的存活率最低,为46.34%。     

花香的生物合成、调控及基因工程研究进展

花香能提高观赏植物的审美特性,并且在植物的繁衍中起着重要作用。近年来,随着分子生物学的发展,花香分子水平的研究呈现加速发展的趋势,已成为当前的一大研究热点。该文主要论述了花香的生物合成途径及关键酶基因、分子水平的调控和共调控探索、花香基因工程策略,以期为花香性状改良提供参考。     

γ-谷氨酰转肽酶活性电泳染色新方法

目的：建立一种新的电泳活性染色方法,以快速地对活性电泳中γ-谷氨酰转肽酶（GGT）进行显色,从而准确鉴定和定位该酶,并可用于该酶的电泳法纯化制备。方法：低温下,样品活性电泳结束后立即将浸有γ-L-谷氨酰-α-萘氨和双甘肽混合底物溶液的滤纸贴在胶面上反应5min,然后再用浸有对氨基苯磺酸和亚硝酸钠混合显色液的滤纸覆盖在基质滤纸上显色。结果：在滤纸上很快显示出一条红色条带,经切胶酶促反应检验确定为GGT,经电泳法和高效液相色谱法确定GGT达到了电泳纯。结论：该法快速、灵敏、简单、直观,为GGT的鉴定和纯化提供了一条新思路。     

Immobilization of cellulases on the reversibly soluble polymer Eudragit S‐100 for cotton treatment

Cellulases can penetrate into the fiber, causing tensile strength loss of the cellulosic fibers or fabrics. To minimize the tensile strength loss, we have immobilized cellulases on Eudragit S‐100. The characteristics of covalent Eudragit cellulase were evaluated using gel filtration analysis and UV spectra. Gel filtration analysis revealed that the cellulases were covalently bound to the polymer. Covalent Eudragit cellulase was loaded with the enzyme of about 40% and had a relative activity about 80% at a Eudragit S‐100 concentration of 15 g/L. When cellulase is bound to the polymer, the solubility profile becomes similar to the one of Eudragit. In addition, the effects of the enzyme on the cotton yarns and fabric using cellulases have been investigated. Native and immobilized cellulases caused improvements in whiteness and wrinkle recovery angle of the fabric in comparison to the control samples. The bending stiffness results show that native and immobilized cellulase treated cotton fabric has an improved softness than the control samples. It was found that using the immobilized cellulase reduced the weight and tensile strength, because the hydrolytic attack is only limited to the surfaces of cotton fibers.     

番石榴果实蝇与桃实蝇的形态区别

介绍我国口岸截获频率较高的2种形态相似的实蝇---番石榴果实蝇Bactrocera (Bactrocera) correcta(Bezzi) 和桃实蝇Bactrocera zonata Saunders的鉴别特征。两者主要区别在于桃实蝇具1对卵圆形黑色颜斑,中胸背板红褐色。     

增温及隔离降水对杉木幼树细根生物量、形态及养分特征的影响

为揭示全球变暖和降水格局改变对我国中亚热带地区森林生态系统地下生态过程的影响,在福建三明森林生态系统国家野外科学观测研究站内开展杉木(Cunninghamia lanceolata)幼树土壤增温和隔离降水双因子试验,研究增温和隔离降水在夏季对杉木幼树细根生物量、形态及养分特征的影响。结果表明,增温(+5℃,W)、隔离降水(–50%,P)和增温+隔离降水(WP)处理的细根总生物量分别比对照(CT)显著降低35.7%、51.7%和59.1%,P和WP处理的细根总生物量分别比W处理显著降低24.9%和36.4%;W、P和WP处理的0~1 mm细根比根长(specific root length,SRL)比对照均显著增加,而0~1和1~2 mm细根比表面积(specific root area,SRA)均无显著变化;与对照相比,W处理的细根N含量、C/N和δ¹⁵N均无显著变化,P处理的细根N含量和C/N分别显著增加和下降,WP处理的细根N含量和δ¹⁵N显著增加,而C/N显著降低。因此,未来在全球变暖和降水减少的双重环境胁迫下,调整表层细根形态特征可能不是杉木幼树的主要应对策略;而相较于温度升高,降水减少可能是影响杉木幼树细根生物量及表层化学元素分配的主要环境因子。     

Ubiquitin-proteasome pathway modulates mouse oocyte meiotic maturation and fertilization via regulation of MAPK cascade and cyclin B1 degradation

Degradation of proteins mediated by ubiquitin-proteasome pathway (UPP) plays important roles in the regulation of eukaryotic cell cycle. In this study, the functional roles and regulatory mechanisms of UPP in mouse oocyte meiotic maturation, fertilization, and early embryonic cleavage were studied by drug-treatment, Western blot, antibody microinjection, and confocal microscopy. The meiotic resumption of both cumulus-enclosed oocytes and denuded oocytes was stimulated by two potent, reversible, and cell-permeable proteasome inhibitors, ALLN and MG-132. The metaphase I spindle assembly was prevented, and the distribution of ubiquitin, cyclin B1, and polo-like kinase 1 (Plk1) was also distorted. When UPP was inhibited, mitogen-activated protein kinase (MAPK)/p90rsk phosphorylation was not affected, but the cyclin B1 degradation that occurs during normal metaphase-anaphase transition was not observed. During oocyte activation, the emission of second polar body (PB2) and the pronuclear formation were inhibited by ALLN or MG-132. In oocytes microinjected with ubiquitin antibodies, PB2 emission and pronuclear formation were also inhibited after in vitro fertilization. The expression of cyclin B1 and the phosphorylation of MAPK/p90rsk could still be detected in ALLN or MG-132-treated oocytes even at 8 h after parthenogenetic activation or insemination, which may account for the inhibition of PB2 emission and pronuclear formation. We also for the first time investigated the subcellular localization of ubiquitin protein at different stages of oocyte and early embryo development. Ubiquitin protein was accumulated in the germinal vesicle (GV), the region between the separating homologous chromosomes, the midbody, the pronuclei, and the region between the separating sister chromatids. In conclusion, our results suggest that the UPP plays important roles in oocyte meiosis resumption, spindle assembly, polar body emission, and pronuclear formation, probably by regulating cyclin B1 degradation and MAPK/p90rsk phosphorylation.