两种N源对石油烃降解菌群降解柴油能力的影响

分别以酵母膏作为有机N源,(NH4)2SO4作为无机N源,在含N量相同(70 mmol/L)的条件下,按接种量2%,柴油1%,25℃,150 r/min摇床恒温培养,对海洋石油烃降解菌群进行了为期30 d 的液体摇瓶降解实验,通过GC-MS测定和分析,对柴油中正烷烃的降解情况进行了对比研究.结果表明,对柴油含量为1%的培养液,应用这两种不同N源,降解菌群对正烷烃的最终降解效果相同,均能完全降解,但有机N源只需3 d 时间就能完全降解正烷烃,比无机N源的降解时间短10倍多.因此,酵母膏对柴油的微生物降解具有极大的促进作用.     

4-壬基酚臭氧氧化中雌激素活性变化的影响因素

采用有效的重组基因酵母检测方法,研究了不同影响因素下水中典型内分泌干扰物4-壬基酚(4-NP)在臭氧氧化过程中雌激素活性的变化规律.结果表明,臭氧能迅速氧化4-NP,并有效地去除其雌激素活性;臭氧氧化过程中,水中高臭氧浓度、低pH值、低悬浮物含量、低·OH抑制剂浓度以及适量的腐殖酸浓度均有利于降低4-NP的雌激素活性.     

啤酒废酵母的综合利用

啤酒废酵母含有丰富的营养物质，许多啤酒厂并没有充分利用，而是作为废弃物排入啤酒废水，增加了啤酒废水的处理负荷和难度。针对这种情况，我们利用本厂啤酒废酵母进行了生产酵母抽提物及营养酱油的研究，取得了满意的效果。不仅获得了优质产品，而且大大降低了啤酒酵母的污染负荷。     

利用复合酵母菌系统处理含油污泥

利用筛选得到的10株酵母菌组成复合酵母菌系统，并将该复合菌系统接种到泥浆反应器中对模拟油泥样品进行了处理。在对反应器进行优化的基础上，比较了复合酵母菌体系和经驯化的活性污泥体系对模拟风化油泥的处理效果，发现复合酵母菌在反应速度和油去除率上都优于活性污泥。利用GC—MS对复合酵母菌处理体亲中主要脂肪烃组分的变化进行了分析，结果表明原油组分中脂肪烃部分在处理8d后基本被完全降解。     

不同pH条件下酵母菌处理高含油废水的研究

在使用混合酵母菌菌株处理高浓度含油废水中，研究了序批式反应器（SBR）内酵母菌在不同起始pH条件下对废水的处理效果。通过与pH中性或碱性条件比较发现，pH4～5的条件在酵母菌的发泡抑制、菌体生长以及COD／油去除等方面均显示出更好的效果，pH5是系统运行的最佳条件。长达100d的SBR连续运行试验表明，系统可以在pH=5条件下长期、稳定运行。     

酵母菌处理皂素生产废水的研究

通过小型批量试验 ,对酵母菌处理皂素生产废水的技术条件进行了研究。结果表明 :在pH为 5 .0 ,温度 30℃ ,处理时间 4 8h ,接种量 10 %的条件下 ,废水CODCr去除率可达 70 %。该技术操作简单 ,可作为预处理应用于实际工程中 ,并可回收一定的酵母蛋白 ,具有一定的经济效益     

Analysis of estrogenic activity in coastal surface waters of the Baltic Sea using the yeast estrogen screen

In the present study, the yeast estrogen screen (YES) has been used to assess the estrogenic activity in surface waters of a coastal region in the German Baltic Sea. Solid-phase extraction using the copolymer Oasis HLB followed by a clean-up on silica was carried out on approximately 50-l water samples. From the final 400 μl extract volume, 100 μl aliquots were used for the measurement of estrogenic activity and for chemical analysis, which was performed by liquid chromatography coupled to tandem mass spectrometry (LC–MS/MS). From 29 samples taken during two campaigns (2003 and 2004) at five different stations 27 samples showed an estrogenic response higher than 10%. The response in the YES was expressed as measured estradiol equivalents (EEQs), which were in the range of 0.01 (Darss Peninsula) to 0.82 ng/l (Inner Wismar Bay). Samples from stations located in inner coastal waters showed higher estrogenic activities than those from outer located stations. A comparison of measured estrogenicity (YES) and calculated estrogenicity (chemical analysis) showed significant differences, probably due to the presence of anti-estrogenic compounds and/or the estrogenic activity of unknown, not identified contaminants. The main contributors to the overall estrogenic activity were synthetic and natural hormones.     

废啤酒酵母泥吸附活性黑31的机理研究

探讨了废啤酒酵母泥吸附水中活性黑31的平衡、动力学规律,利用傅里叶红外光谱技术分析了废啤酒酵母泥及活性黑31的吸附官能团间的相互作用.结果表明,废啤酒酵母泥对活性黑31的吸附容易进行;20min前吸附速度都较快,2h后吸附都达到平衡;吸附动力学符合准二级动力学模型.废啤酒酵母泥对活性黑31的吸附等温曲线符合Freund...     

Xenobiotics: Substrates and inhibitors of the plant cytochrome P450

The ability of a plant cytochrome P450 to bind and metabolise plant endogenous molecules and xenobiotics was investigated. The work was performed on the yeast-expressed CYP73A1, a cinnamate 4-hydroxylase isolated fromHelianthus tuberosus. CYP73 controls the general phenylpropanoid pathway and is likely to be one of the most abundant sources of P450 in the biosphere. The enzyme shows a high selectivity toward plant secondary metabolites. Nevertheless, it oxygenates several small and planar xenobiotics with low efficiency, including an herbicide (chlorotoluron). One xenobiotic molecule, 2naphthoic acid, is hydroxylated with an efficiency comparable to that of the physiological substrate. This reaction was used to devise a fluorimetric test for the rapid measurement of enzyme activity. A series of herbicidal molecules (hydroxybenzonitriles) are shown to bind the active site without being metabolised. These molecules behave as strong competitive inhibitors of CYP73 with a K_i in the same micromolar range as the K_m for the physiological substrate. It is proposed that their inhibition of the phenylpropanoid pathway reinforces their other phytotoxic effects at the level of the chloroplasts. All our results indicate a strong reciprocal interaction between plant P450s and xenobiotics.     

Aryl hydrocarbon receptor activities of hydroxylated polycyclic aromatic hydrocarbons in recombinant yeast cells

Hydroxylated polycyclic aromatic hydrocarbons (OH-PAH) with less than four rings are frequently found in the environment, whereas the toxicities associated with these compounds remain unclear. In this study, aryl hydrocarbon receptor (AhR)–ligand binding activities of OH-PAH were investigated by using a recombinant yeast assay system. The majority of the OH-PAH tested showed AhR–ligand binding activities, especially, when the hydroxylated derivatives of naphthalene were incubated with recombinant yeast. The structure–activity relationship between AhR activity and molecular weight or the octanol–water partition coefficient value of OH-PAH displayed significant correlations. These findings indicate that the site and number of hydroxy-groups substituted on PAH skeleton apparently influenced the AhR – ligand binding activity in the recombinant yeast assay.