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排序方式: 共有172条查询结果,搜索用时 93 毫秒
1.
畜禽养殖废水有机物水质水量变化大,有机物、氨氮与磷的浓度较高,直接排放会严重危害环境。通过构建厌氧-好氧序批式反应器(SBR)处理预酸化畜禽养殖废水,分析了不同进水负荷条件下反应器对污染物的去除性能和微生物群落结构的变化规律。结果表明:SBR反应器对高负荷进水中TN、PO3-4—P和COD的平均去除率可分别达到64.5%、97.5%和94.5%。反应器出现NH+4—N和NO2—N亚硝酸同时积累的短程硝化现象,这可能与高进水负荷对氨氧化菌和亚硝酸盐氧化菌的活性和种群的影响有关。与乙酸盐相比,以丙酸盐作碳源时污泥的强化生物除磷活性更高。随着进水负荷的增大,聚糖菌(GAOs)的相对丰度明显升高。四联球状菌(Tetrasphaera)为反应器中始终占优势的聚磷菌(PAOs),对反应器除磷性能有重要贡献。在高有机负荷条件下,SBR内PAOs与GAOs之间不存在明显的底物竞争关系,系统脱氮除磷性能未受影响。 相似文献
2.
采用酶解结合醇沉法从新鲜牡蛎中提取制备牡蛎糖原(oyster glycogen,OG),经阴离子交换柱DEAE-52、葡聚糖凝胶柱SephadexG-100分离纯化,得到纯度较高的牡蛎糖原组分OG11.其蛋白质量分数为0.33%,糖质量分数为97.77%.用气相色谱法对OG11进行单糖组成鉴定,结果表明其中只含有葡萄糖... 相似文献
3.
To elucidate the phosphorus removal and metabolism under various COD / P ratio,a sludge highly enriched in PAOs was used to investigate the impacts of COD / P in batch tests under different carbon supply conditions. Acetate,propionate and a mixture of acetate and propionate at a ratio of 3 ∶ 1( COD basis) was used as carbon sources with the COD / P of 20,15,10 and 5. 0 g COD /gP,respectively. The minimum COD / P ratios for complete P removal were found to be 8. 24 g COD /gP for acetate,11. 40 g COD /gP for propionate and9. 10 g COD /gP for the 3 ∶ 1 mixture of acetate and propionate. Converted to a mass basis,all three cases had a very similar ratio of 7. 7 g VFA /gP,which represented a useful guide for operation of EBPR plants to identify possible shortages in VFAs. The trend in PHV accumulation during the anaerobic period along with the decrease of COD / P ratios suggested that,PAOs may use the TCA pathway for anaerobic VFA uptake to maintain the required NADH production with reduced glycogen degradation. During the aerobic phase,the glycogen pool was reduced but remained enough compared to the requirement for anaerobic VFA uptake,and the synthesis and degradation of glycogen was not the inhibition factor of PAOs. 相似文献
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Tatiana B. Eronina Valeriya V. Mikhaylova Natalia A. Chebotareva Kristina V. Tugaeva Boris I. Kurganov 《International journal of molecular sciences》2022,23(7)
Protein–protein interactions (PPIs) play an important role in many biological processes in a living cell. Among them chaperone–client interactions are the most important. In this work PPIs of αB-crystallin and glycogen phosphorylase b (Phb) in the presence of betaine (Bet) and arginine (Arg) at 48 °C and ionic strength of 0.15 M were studied using methods of dynamic light scattering, differential scanning calorimetry, and analytical ultracentrifugation. It was shown that Bet enhanced, while Arg reduced both the stability of αB-crystallin and its adsorption capacity (AC0) to the target protein at the stage of aggregate growth. Thus, the anti-aggregation activity of αB-crystallin increased in the presence of Bet and decreased under the influence of Arg, which resulted in inhibition or acceleration of Phb aggregation, respectively. Our data show that chemical chaperones can influence the tertiary and quaternary structure of both the target protein and the protein chaperone. The presence of the substrate protein also affects the quaternary structure of αB-crystallin, causing its disassembly. This is inextricably linked to the anti-aggregation activity of αB-crystallin, which in turn affects its PPI with the target protein. Thus, our studies contribute to understanding the mechanism of interaction between chaperones and proteins. 相似文献
6.
为了确定反硝化聚糖菌(DGAOs)的脱氮性能及N2O释放特性,采用序批式生物反应器,分别以乙酸钠和葡萄糖为碳源(反应器分别记作SBRAc和SBRGl),考察其脱氮过程中的碳源变化以及N2O释放特性。结果表明,SBRAc和SBRGl的总氮去除率分别为(80.2±2.8)%和(63.4±3.5)%,N2O产率分别为(7.16±1.43)%和(13.35±2.46)%。以乙酸钠为碳源时,聚糖菌厌氧阶段吸收的有机物主要以胞内聚-β-羟基烷酸(PHA)形式储存;以葡萄糖为碳源时,部分有机物用于胞内糖原(Gly)的积累,PHA合成量减少。聚糖菌内源反硝化过程中,依次利用胞内PHA和Gly作为内碳源,且PHA提供电子的速率远大于Gly,导致SBRGl内NO2-大量积累、N2O释放量增加。NO2-对氧化亚氮还原酶活性的抑制效应是导致聚糖菌内源反硝化过程释放N2O的主要因素。与葡萄糖相比,乙酸钠更易被反硝化聚糖菌吸收为易利用的内碳源PHA,并降低反硝化过程中N2O的释放量。 相似文献
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Romina Giacometti Florencia Kronberg Ricardo M. Biondi Susana Passeron 《Yeast (Chichester, England)》2009,26(5):273-285
Candida albicans cAMP‐dependent protein kinase (PKA) is coded by two catalytic subunits (TPK1 and TPK2) and one regulatory subunit (BCY1). In this organism the cAMP/PKA signalling pathway mediates basic cellular processes, such as the yeast‐to‐hyphae transition and cell cycle regulation. In the present study, we investigated the role of C. albicans PKA in response to saline, heat and oxidative stresses as well as in glycogen storage. To fine‐tune the analysis, we performed the studies on several C. albicans PKA mutants having heterozygous or homozygous deletions of TPK1 and/or TPK2 in a different BCY1 genetic background. We observed that tpk1Δ/tpk1Δ strains developed a lower tolerance to saline exposure, heat shock and oxidative stress, while wild‐type and tpk2Δ/tpk2Δ mutants were resistant to these stresses, indicating that both isoforms play different roles in the stress response pathway. We also found that regardless of the TPK background, heterozygous and homozygous BCY1 mutants were highly sensitive to heat treatment. Surprisingly, we observed that those strains devoid of one or both TPK1 alleles were defective in glycogen storage, while strains lacking Tpk2 accumulated higher levels of the polysaccharide, indicating that Tpk1 and Tpk2 have opposite roles in carbohydrate metabolism. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
9.
目的:探讨绿茶饮料浓缩物缓解小鼠体力疲劳的作用。方法:240只清洁级雄性昆明小白鼠随机分为4组,分别以经口灌胃方式给予蒸馏水(对照组)、不同剂量绿茶饮料浓缩物[133mg/(kg·bw),665mg/(kg·bw),1995mg/(kg·bw)],每日1次,连续45d,进行负重游泳实验,测定血乳酸、血清尿素及肝糖原含量。结果:与对照组比,低、中剂量能够增加小鼠负重游泳时间(P<0.01);低剂量组可降低游泳后即刻的血乳酸水平(P<0.05),各剂量组均能降低游泳后20min的血乳酸水平(P<0.05);中剂量组能够增加小鼠肝糖原储备(P<0.05);各剂量组血清尿素水平没有明显变化(P>0.05)。结论:绿茶饮料浓缩物具有缓解小鼠体力疲劳的作用,以中剂量作用最强。 相似文献
10.
Anu Harju 《Journal of chemical ecology》1996,22(4):709-717
The effect of protein and birch bark powder (BBP) content of forage on food consumption and growth of root voles (Microtus oeconomus) was studied by feeding young voles with eight different diets for two weeks. Voles ate more when the protein content of forage was moderate (6%) or low (3%), and when BBP was added to the diets, as compared to a high (12%) protein diet without BBP addition. On high and moderate protein diets voles gained weight, whereas on low protein diets they lost weight. Addition of BBP caused reduced growth or weight loss. Consuming a diet with moderate (6%) protein and high BBP (20%) resulted in high mortality (9 of 10 died). These results show that root voles need at least 6% protein for growth and that the effect of birch bark depends on the protein content of the forage. 相似文献