Synergetic degradation of waste oil by constructed bacterial consortium for rapid in-situ reduction of kitchen waste

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聚芳噁二唑纤维的热降解动力学

采用热失重分析法对聚芳噁二唑(POD)纤维在不同氛围下以不同升温速率升温时发生的热降解行为进行了动力学研究。主要采用Kissinger、Flynn-Wall-Ozawa及Coats-Redfern 3种方法研究得到POD纤维在氮气和空气氛围中的热降解动力学参数。结果表明:采用Flynn-Wall-Ozawa法得到的POD纤维在氮气氛围下的平均活化能为276 k J/mol;而采用Kissinger法得到POD纤维在热降解速率最大时的活化能为277 k J/mol。在空气氛围下,在第1阶段其热降解活化能为257.5 k J/mol,在第2阶段其热分解活化能从195.3 k J/mol逐步降低到79.1 k J/mol;最后,采用Coats-Redfern法并结合Flynn-Wall-Ozawa,得到了POD纤维热降解机制方程的积分形式,其机制均为随机成核和随后生长,仅反应级数有所差异。     

Experimental and mathematical methodology on the optimization of bacterial consortium for the simultaneous degradation of three nitrogen heterocyclic compounds

This study aims to establish a systematic method to optimize the bacterial consortium for the simultaneous biodegradation of multixenobiotics in wastewater. Three nitrogen heterocyclic compounds (NHCs), pyridine, quinoline, and carbazole, were chosen as the target compounds with each about 200 mg/L. Different consortia originated from six bacteria for degrading pyridine (Paracoccus sp. BW001 and Shinella zoogloeoides BC026), quinoline (Pseudomonas sp. BW003 and BW004), and carbazole (Pseudomonas sp. BC039 and BC046) were tested for the capacity of NHCs simultaneous degradation. Mathematical methods including dummy-variable-laden kinetic modeling, cubic spline regression and interpolation, and dimensionality reduction were employed to evaluate the complex impacts of cocontaminants and coexisting bacteria on the simultaneous biodegradation, and the most efficient consortium was determined. The influences of cocontaminants on the bacterial degradation activity were far greater than the interactions among the mixed bacteria. Integrating the experimental results and mathematical analysis, consortium M19 (BC026, BW004, BC039, and BC046 with dose rate of 1:1:0.5:0.5) was the best one, which degraded over 95% of pyridine, quinoline, and carbazole simultaneously in 15.4 h. The research methodology in this study could be applied to the optimization of a bacterial consortium which might be used in the bioaugmentation and bioremediation of multixenobiotics removal.     

PBA/TiO_2复合胶乳整理棉织物的性能

以原位乳液聚合制得的聚丙烯酸丁酯PBA/TiO2复合胶乳为整理剂,通过浸轧对棉织物进行功能整理,并与经TiO2水分散液、PBA胶乳与TiO2分散液共混物、黏合剂VTECO与TiO2分散液共混物等3种不同整理剂整理的棉织物进行功效和服用性能比较。结果发现,在相同的整理工艺下,经自制PBA/TiO2复合胶乳整理的棉织物表面TiO2粒子尺寸较小,分散较好,织物表面附着层较薄、较均匀,纱线内纤维间黏连较少,因而经相应整理的棉织物具有较好的抗紫外线和抗老化性能,且对棉织物原有的白度、手感等服用性能影响较小,这与PBA/TiO2复合胶乳整理本质上实现的是对纱线内单纤维的均匀薄型包覆有关。     

高效液相色谱法测定2-(4-甲氧基苯氧基)丙酸钠的含量

首次建立了测定2-(4-甲氧基苯氧基)丙酸钠的高效液相色谱法.色谱条件为:采用Lichrospher C18(5μm,4.6mm×250mm)为色谱柱;甲醇∶乙腈∶水=50:10:40(pH=3,用磷酸调节)为流动相;检测波长为224nm;柱温为25℃;流速为0.8mL/min.在该色谱条件下,线性相关系数R=0.9999,方法回收率为99.5%100.5%,日内精密度和日间精密度的相对标准偏差分别为0.38%和0.41%.结果显示该方法具有良好的准确度、精密度和重复性,适合2-(4-甲氧基苯氧基)丙酸钠的测定.     

生物可降解聚己二酸-对苯二甲酸丁二醇酯纤维的制备及其环境降解性能

为研究生物可降解聚己二酸-对苯二甲酸丁二醇酯(PBAT)的可纺性及纤维降解性能,采用熔融纺丝-牵伸二步法制得生物可降解PBAT纤维,研究了纺丝温度、牵伸倍数对PBAT纤维结晶度、回潮率、力学性能的影响,对比分析了PBAT纤维在不同环境下的降解性能.结果 表明:PBAT的最佳纺丝温度为260℃,且随着牵伸倍数的增加,PB...     

分光光度法测定酸奶中L（-）-羟脯氨酸含量的不确定度评定

对分光光度法测定酸奶中L（-）-羟脯氨酸的含量进行不确定度评定,为评价该方法的准确性和可靠性提供依据。根据《化学分析中不确定度的评估指南》、《化学分析测量不确定度评定》提供的不确定度分析思路,用改进后的L（-）-羟脯氨酸检测方法对市售某酸奶进行重复性检测,分析影响测量结果的各个因素,并对不确定度进行评定和表述。本方法的标准不确定度为0.0015g/100g,扩展不确定度为0.0030g/100g。改进后的L（-）-羟脯氨酸检测方法操作简单、有效可行;最终结果的不确定度主要由样品溶液中L（-）-羟脯氨酸含量和样品处理过程产生。      

细菌纤维素气凝胶接枝甲基丙烯酸二甲氨乙酯的制备

为制备新型细菌纤维素（BC）气凝胶可控接枝聚合物,采用电子转移活化再生催化剂原子转移自由基聚合(ARGET ATRP)法,以含溴的细菌纤维素为引发剂、维生素C（Vc）为还原剂、N,N,N',N,'N'-五甲基二亚乙基三胺（PMDETA）/溴化铜（CuBr2）为催化剂,制备了含聚甲基丙烯酸二甲氨乙酯（PDMAEMA）的细菌纤维素气凝胶规整接枝共聚物。采用能谱分析仪对大分子引发剂元素含量进行测定。通过凝胶渗透色谱、红外光谱、X射线衍射、扫描电镜、热失重分析表征了接枝物结构和性能。结果表明：以细菌纤维素气凝胶为原料,采用ARGET ATRP聚合法成功制备了BC-g-PDMAEMA聚合物,分子量分布指数为1.27,接枝率为875.76%,接枝后纤维直径增大且在纤维表面形成覆盖层,热稳定性由205℃升高到230℃。     

Thermal kinetic degradation of anthocyanins in a roselle (Hibiscus sabdariffa L. cv. 'Criollo') infusion

The degradation kinetics of anthocyanins in a Roselle infusion (Hibiscus sabdariffa L.), as assessed by visible absorption spectroscopy (absorbance at 520 nm), was verified (60–100 °C). The rate constants for absorbance retention were obtained from first-order reaction kinetic plots. Based on an Arrhenius-type model, the experimental data showed an energy of activation of 15.83 kcal mol⁻¹ (66.22 kJ mol⁻¹) and a Q₁₀ value of 1.01. The obtained pattern allows to predict the retention of these antioxidant compounds as a function of temperature and time of thermal treatment.     

Production of menaquinone (vitamin K2)-7 by Bacillus subtilis

Menaquinone-7 (MK-7) is a highly bioactive homologue of vitamin K. We obtained a diphenylamine-resistant mutant strain D200-41 from Bacillus subtilis strain MH-1 which was isolated from fermented soybeans, natto. The mutant strain exhibited decreased production of MK-6. Using strain D200-41, efficient production of MK-7 was achieved. We found that, compared with an agitated and aerated culture, production of MK-7 was increased by static culture. The sporulation of the cells progressed more slowly in a static culture than in an agitated culture. The maximum concentration of MK reached about 60 mg/l in a medium containing 10% soybean extract, 5% glycerol, 0.5% yeast extract and 0.05% K2HPO4 (pH 7.3) when D200-41 cells as well as MH-1 cells were statically cultured at 45 degrees C for 5 d after being cultured with shaking at 37 degrees C for 1 d.     

Antibacterial properties of polypropylene textiles modified by poly(2-(N,N-dimethyloamino ethyl) methacrylate)

Polypropylene nonwoven fabrics samples were modified using poly(2-(N,N-dimethyloamino ethyl) methacrylate) (PDAMA) and silver-containing layers. The structure of the material after modification was confirmed using scanning electron mocroscope, energy-dispersive X-ray spectroscopy, Fourier Transfer Infrared Spectroscopy (FTIR), and electro-kinetic measurements. It was found that samples with external PDAMA layers have excellent activity against Staphylococcus aureus under dynamic contact conditions. In contrast, samples finished with deposited silver showed little antimicrobial effect. Antibacterial tests conducted under static conditions showed no antibacterial activity irrespective of the deposited layers.     

Development of a Nile tilapia (Oreochromis niloticus) gut microbiota-derived bacterial consortium with antibacterial activity against fish pathogens

Multistrain potential probiotic mixtures were assembled from isolates from Nile tilapia (O. niloticus) gut microbiota. Lactococcus lactis A12, Priestia megaterium M4, and Priestia sp. M10 demonstrating antibacterial activity against two fish pathogens, Streptococcus agalactiae and Aeromonas hydrophila, were proportion optimized using mixture design software. Two potential probiotic mixtures were chosen and compared for storage viability: one containing 61% of strain A12, 16% of M4, and 23% of M10; the other containing 28% of M4 and 72% of M10. The mixtures were combined with maltodextrin or fish feed, freeze-dried, and bacterial counts were monitored over 28 days while stored at 4 °C or 25 °C. At 4 °C storage, the multistrain potential probiotics were stable in maltodextrin and fish feed. In conclusion, a mixture design may be used to define a multistrain potential probiotic, and freeze-drying while combined with maltodextrin or fish feed followed by refrigeration could be employed to stabilize these tilapia-derived potential probiotics.     

退浆废水中PVA对环境的影响及其降解性能

讨论了PVA的几种主要处理方法，并对其生物降解机理作了进一步分析；在物理和化学方法中，γ-射线辐射降解和光助Fenton氧化的效果比较好．     

β-Casomorphin-7的酶联免疫吸附分析(ELISA)方法的建立

β－酪啡肽－7（β－Casomorphin-7)是一个有代表性的乳源外啡肽，有调节动物消化道运动和采食、内分泌、免疫等多种生物学功能。本研究以β－Casomorphin-7与人血清白蛋白（HSA）经戊二醛交联的复合物作为包被抗原；一抗为鸡抗β－Casomorphin-7与牛血清白蛋白（BSA）交联复合物的抗血清；酶标二抗为兔抗鸡IgG经戊二醛与辣根过氧化物酶（HRP）交换的复合物。包被抗原和一抗的稀释度经方阵稀释实验确定。本实验所建立的竞争ELISA方法的孔间差异为3．3％，板间差异为8．6％，检测灵敏度20ng/ml，检测范围20－320ng/ml，在实验浓度范围内。β－Casomorphin-7的抗血清与β－内啡肽、脑啡肽、强啡肽、精氨酸降压素和神经降压素等活性肽未显示免疫交叉反应。表明所建立的方法有较高的特异性，可用于酪啡肽的体内功能研究。     

L.helveticus L7生物转化的共轭亚油酸异构体结构分析

利用HPLC分离出L.helveticusL7生物转化的2种CLA异构体单体,通过紫外光谱、傅立叶变换红外光谱、气相色谱-质谱联用分析,确定了L.helveticusL7生物转化形成的两种CLA异构体是t9t11-CLA和c/t-911-CLA。     

瑞士乳杆菌L7生物转化共轭亚油酸的研究

建立了瑞士乳杆菌L7(Lactobacillus helveticusL7)分批发酵生物转化c9,t11-CLA的优化条件:MRS培养基、30℃发酵、静置培养、LA浓度为1.000 mg/mL、发酵时间36h。5L发酵罐分批发酵时,c9,t11-CLA的产量高达0.572 mg/mL。     

Oxidative effects of Tartrazine (CAS No. 1934-21-0) and New Coccin (CAS No. 2611-82-7) azo dyes on CHO cells

Color is an indispensible characteristic of food because it makes foods easily recognizable and attractive in our modern society. Numerous food colors have been removed from the national and international lists of ??accepted food colors?? due to their mutagenic and carcinogenic activities based on a number of toxicity studies that have been conducted since food colors were first identified as carcinogenic by researchers. This study investigated the changes in oxidative stress parameters such as glutathione (GSH), malondialdehyde (MDA), glutathione peroxidase (GPx) activity, and catalase (CAT) activity that occurred when Chinese hamster ovary (CHO) cells were exposed to Tartrazine (CAS No. 1934-21-0) and New Coccin (CAS No. 2611-82-7), commonly-used azo dyes in the food industry. It was found that intracellular GSH significantly decreased, MDA levels increased, and GPx and CAT levels remained the same, (as compared to the control), when CHO cells were exposed to these food colors. Based on our results, Tartrazine and New Coccin food colors can be regarded as toxic. Considering the possible oxidative damage induced by these food colors, due to the depletion of GSH (a cell??s major antioxidant), and a significant increase in MDA levels, we strongly believe that the use of these potentially toxic colors in food needs to be reconsidered.     

高糖食品中2-（4-甲氧基苯氧基）丙酸钠的风险评估

为探讨化学合成的芳氧羧酸类化合物2-（4-甲氧基苯氧基）丙酸钠在食品生产中作为食品添加剂的安全性,本文采用动物实验对化学合成的2-（4-甲氧基苯氧基）丙酸钠进行毒理学评价,采用高效液相色谱法对食品中2-（4-甲氧基苯氧基）丙酸钠的使用率进行研究。毒理学实验结果表明,化学合成的2-（4-甲氧基苯氧基）丙酸钠的半数致死量LD₅₀为6577 mg/kg bw,哺乳动物微粒体酶实验及小鼠精子畸形实验分别显示其未见明显的致突变性及遗传毒性。色谱检测结果表明,月饼、糖果及糕点等3类高糖食品的2-（4-甲氧基苯氧基）丙酸钠使用率较高,其中平均使用量分别为149.48±1.26、52.30±1.87、71.31±1.39 mg/kg;中位值使用量分别为118.05±2.11、72.58±0.94、（65.77±1.02）mg/kg;95%位值使用量分别为439.97±2.06、340.77±1.45、137.63±1.62 mg/kg。综合毒理学评价结果及2-（4-甲氧基苯氧基）丙酸钠的使用情况进行风险评估,结果表明添加量为95%位值使用量时,化学合成的2-（4-甲氧基苯氧基）丙酸钠暴露量已超出其ADI值,可能会对高糖食品的安全性造成影响。      

Kinetics of tocols degradation during the storage of einkorn (Triticum monococcum L. ssp. monococcum) and breadwheat (Triticum aestivum L. ssp. aestivum) flours

The kinetics of tocols degradation in wholemeal and white flours from einkorn cv Monlis and bread wheat cv Serio were studied during storage at five different temperatures (−20, 5, 20, 30 and 38 °C) up to 242 days. Tocols decreased as a function of time and temperature, following first-order kinetics. Degradation rates and their dependence upon temperature were similar for the two Triticum species studied. Tocols decrease was quicker in white flour than in wholemeal flour (on average for total tocols at 38 °C, k = 7.79 × 10⁻³ days⁻¹ vs 3.15 × 10⁻³ days⁻¹, respectively). The temperature-dependent degradation was similar for all homologues (Ea = 34.3–49.4 kJ/mol) except for α-T, less thermostable in white flours (Ea = 61.2 kJ/mol in einkorn and Ea = 54.7 kJ/mol in bread wheat).