微囊藻毒素-LR污染饮水的健康风险及其机制

水体富营养化导致藻类繁殖和水华暴发从而使得藻类释放大量藻毒素,已经演变成为严重的公共卫生问题之一。微囊藻毒素通过饮水严重危害动物和人类的健康安全,最主要的靶器官是肝脏,从而造成肝细胞功能缺陷,比如黄疸和磷酸化活性改变。这些毒性效应主要表现为对磷酸酶的抑制和蛋白磷酸酶活性的调节。综上,微囊藻毒素会造成组织结构损伤、凋亡,即使在低浓度下,也会影响细胞周期,导致肿瘤发生。     

Fe3O4/石墨烯-H2O2预处理对污泥脱水性能的影响及其作用机理

采用共沉淀法制备四氧化三铁/石墨烯（Fe3O4/GE）材料,并对其进行表征,将其与H2O2组成非均相类Fenton体系用来预处理污泥,发现此类Fenton体系能显著降低污泥比阻（SRF）,并深入分析其作用机理。研究了pH、反应时间、反应温度以及Fe3O4/GE-H2O2投加量对污泥胞外聚合物（EPS）破解的影响。结果表明,适宜反应条件为：pH 4.0,反应时间为90 min,反应温度为50 ℃,Fe3O4/GE投加量为1 g·L-1,H2O2与Fe3O4/GE投加量之比控制在8~12之间。在该条件下,污泥上清液中的SCOD、多聚糖和蛋白质浓度分别由56.47、11.48和8.21 mg·L-1增加到498.31、406.72和286.29 mg·L-1。Fe3O4/GE-H2O2非均相类Fenton体系在有效破解EPS的同时,对于污泥的脱水性能也有明显的改善作用,促进了污泥的后续处理。     

高浓度发酵废水生产单细胞蛋白的菌种筛选

为了回收高浓度发酵废水中的有用资源,以近平滑假丝酵母（C. parapsilosis）、热带假丝酵母（C. tropicalis）、产朊假丝酵母（C. utilis）、汉逊德巴利酵母（D. hansenli）、酿酒酵母（S. cerevisiae）、皮状丝孢酵母（T. cutaneum）、白地霉（G. candidum）和黑曲霉（A. niger）8种常见工业菌种为研究对象,通过摇瓶发酵,考察了不同菌种利用高浓度发酵废水生产单细胞蛋白（SCP）的能力,同时比较废水灭菌和不灭菌两种条件对SCP产量的影响。结果表明,在废水COD浓度69 600 mg·L-1、TN浓度4 048 mg·L-1、初始pH 6.5、28℃、150 r·min-1、灭菌条件下发酵40 h,C. parapsilosis的菌体生物量和粗蛋白含量最高,可达7.04 g·L-1和1.87 g·L-1,对废水中COD和TN的去除率分别为33.5%和20.1%;C. parapsilosis和G. candidum可作为废水生产SCP并高效回收氮素和有机质的优势菌种。在不灭菌条件下,各菌种生产SCP的能力明显高于灭菌条件,且不同菌种产量差异不大,生物量和粗蛋白含量平均高达8.0 g·L-1和4.0 g·L-1,废水COD和TN的去除率分别为47%和33%。     

Cell surface-expression of the phosphate-binding protein PstS: System development, characterization, and evaluation for phosphorus removal and recovery

Simultaneous overabundance and scarcity of inorganic phosphate(P_i) is a critical issue driving the development of innovative water/wastewater treatment technologies that not only facilitate Pi removal to prevent eutrophication,but also recover P_i for agricultural reuse.Here,a cell-surface expressed high-affinity phosphate binding protein(PstS) system was developed,and its P_i capture and release potential was evaluated.E.coli was genetically modified to express Ps...     

Phytotoxicity of cadmium on protein, proline and antioxidant enzyme activities in growing Arachis hypogaea L. seedlings

Phytotoxicity of cadmium on growing Arachis hypogaea L. seedlings was studied. Seeds were exposed to 25, 50, and 100 μmol/L CdCl2 concentrations, for a period of 10, 15, 20 and 25 d. The extent of damage to chlorophyll, protein, proline, nitrate and nitrite reductase, antioxidant enzyme activity in leaves and roots were evaluated after 10 d of cadmium stress. The higher concentration of cadmium （100 μmol/L） resulted （leaves and roots） total chlorophyll 91.01%, protein 79.51%, 83.61%, nitrate reductase 79.39%, 80.72% and nitrite reductase 77.07%, 75.88% activity decreased with increase in cadmium concentrations and exposure periods. Cadmium caused significant changes in the activity of antioxidative enzymes. Contrastingly Cd treated plant tissues showed an increase in proline 159.87%, 239.6%, gluthion reductase （GR） 337.72%, 306.14%, superoxide disumutase （SOD） 688.56%, 381.72%, ascorbate peroxidase （APX） 226.47%, 252.14%, peroxidase （POD） 72.19%, 60.29% and catalase （CAT） 228.96%, 214.74% as compared to control. Cadmium stress caused a significant increase in the rate of SOD activity in leaves and roots of plant species. Results show the crop A. hypogaea is highly sensitive even at very low cadmium concentrations.     

食物贸易视角下的全球食物供需平衡及其演化分析

用食物供给量与生产量分别表示食物的可及性与自给率,其差值可表示食物贸易量,以人均每天卡路里为单位进行的折算可以更好地反映膳食营养的变化。从食物贸易视角分析了28年来食物供需平衡状况,结果表明:(1)1986—2013年,全球食物贸易量增加1.5倍;食物总产量增加0.75倍,贸易量在总产量中的比例增加约8个百分点,相当于7.9×10⁸t食物进入国际市场,这成为改善膳食结构的重要因素。(2)28年来,食物可及性与自给率呈上升趋势,全球绝大部分人口已经达到最低2200 kal的营养标准。(3)食物可及性、自给率、贸易量均存在地域差异,非洲及南亚的部分国家是低值地区。(4)总体来看,全球人均每天热量与蛋白质供给量增加。低收入国家增速最快,中等收入国家增速次之,高收入国家增速最慢。但非洲、东南亚等地的一些欠发达国家仍未达到最低的营养标准,全球仍有一部分人处于营养不良状态。     

酸热絮凝法提取甘薯淀粉分离汁水中的蛋白质

甘薯淀粉加工过程产生大量的淀粉分离汁水,其中含有丰富的蛋白质。采用酸热絮凝法从甘薯淀粉分离汁水中提取蛋白质,通过单因素试验,选择pH、温度、离心时间和离心转速为变量,利用正交试验分析影响甘薯淀粉分离汁水蛋白质提取效果的因素主次和较佳工艺,采用集成装置进行工艺模拟试验,检验甘薯淀粉分离汁水蛋白质提取的效果,并分析技术和经济可行性。结果表明：在温度为100 ℃、pH为4.0、离心转速3 500 r/min和离心时间10 min条件下,甘薯淀粉分离汁水的TN和COD_Cr去除率分别达到76.79%和40.66%;集成装置的蛋白质回收率达到48.86%,回收的粗蛋白质粉的蛋白质含量（以干基计）为73.22%,满足动物饲料原料要求。此外,对于1个大中型甘薯淀粉企业,1 m³甘薯淀粉分离汁水通过回收蛋白质可以创造毛利润20.51元。

     

活性污泥胞外聚合物中蛋白质的探针分析方法

应用微相吸附-光谱修正技术(Microsurface adsorption-spectral correction,简称MSASC),利用刚果红(Congo Red,简称CR)探针测定了活性污泥胞外聚合物(Extracellular polymeric substances,简称EPS)中蛋白质(Protein)的含量,与常用的Folin酚法比较,结果一致,蛋白加标回收率为94.5%～107.1%,相对标准偏差(RSD)＜4.5%.对反应机理的分析和产物结合常数的计算结果表明,在pH 2.21时CR-Protein作用符合Langmuir单分子层吸附理论,产物的结合比79∶1,结合常数K=2.17×106,聚集形式为Protein·CR79,摩尔吸收系数ε664r=8.50×105L·mol-1·cm-1.     

The malaria parasite Plasmodium relictum in the endemic avifauna of eastern Cuba

Island populations are vulnerable to introduced pathogens, as evidenced by extinction or population decline of several endemic Hawaiian birds caused by the malaria parasite, Plasmodium relictum (order Haemosporida). We analyzed blood samples from 363 birds caught near Guantánamo Bay, Cuba, for the presence of haemosporidian infections. We characterized parasite lineages by determining nucleotide variation of the parasite's mitochondrial cyt b gene. Fifty‐nine individuals were infected, and we identified 7 lineages of haemosporidian parasites. Fifty individuals were infected by 6 Haemoproteus sp. lineages, including a newly characterized lineage of Haem. (Parahaemoproteus) sp. CUH01. Nine individuals carried the P. relictum lineage GRW4, including 5 endemic Cuban Grassquits (Tiaris canorus) and 1 migratory Cape May Warbler (Setophaga tigrina). A sequence of the merozoite surface protein gene from one Cuban Grassquit infected with GRW4 matched that of the Hawaiian haplotype Pr9. Our results indicate that resident and migratory Cuban birds are infected with a malaria lineage that has severely affected populations of several endemic Hawaiian birds. We suggest GRW4 may be associated with the lack of several bird species on Cuba that are ubiquitous elsewhere in the West Indies. From the standpoint of avian conservation in the Caribbean Basin, it will be important to determine the distribution of haemosporidian parasites, especially P. relictum GRW4, in Cuba as well as the pathogenicity of this lineage in species that occur and are absent from Cuba.     

You are What You Eat: Meat, Novel Protein Foods, and Consumptive Freedom

Animal husbandry has been accused ofmaltreating animals, polluting the environment, and soon. These accusations were thought to be answered whenthe Dutch research program ``Sustainable TechnologicalDevelopment' (STD) suggested a government-initiatedconversion from meat to novel protein foods (NPFs).STD reasoned that if consumers converted from meat toNPFs, non-sustainable animal husbandry would no longerbe needed. Whereas STD only worried about how toconstruct NPFs with a meat bite, this paper drawsattention to the presumed, but problematic, role forthe government in the execution of the STDsuggestions. Although vegetarians take the credo ``YouAre What You Eat' literally and accuse non-vegetariansof being beasts, a different interpretation is morepromising: eating meat has become a leading thread inmany lifestyles and narratives of self-identity. Sincethe freedom to follow your own lifestyle orconsumptive preferences is a core value incontemporary affluent societies, governmentintervention in the formation and satisfaction ofconsumer preferences for meat dishes is a precariousissue. Hence, NPFs might be interesting for a smallfraction of society, but we had better not expect toomuch from a government-initiated conversion from meatto NPFs as the answer to animal husbandry'sproblems.