正交优化制备污泥水解蛋白质的实验研究

以武汉市污水处理厂剩余活性污泥为原料,在不同加水量、温度和催化条件下水解制备水解蛋白质,并通过正交试验优化了剩余污泥水解的反应条件。结果表明,当时间固定在6h时,以固液比(此为鲜泥与加水量的质量之比)为1∶2,温度1200℃,盐酸催化(pH为1.5)为水解反应的最佳条件。本研究为污泥水解蛋白液的制备及污泥处理的减量化、无害化和资源化提供了理论支持和数值依据。     

神经节苷脂生产废水处理技术研究

针对神经节苷脂生产废水蛋白质含量高的特点,研究了等电点沉淀或混凝沉降预处理、厌氧好氧生物处理、化学沉淀和类Fenton氧化后处理组合工艺处理神经节苷脂生产废水的技术。结果表明,神经节苷脂生产废水的等电点在pH=2.2左右,通过等电点沉淀可去除30%以上的COD,但等电点时蛋白质的沉淀速度非常慢;用聚合硫酸铁对神经节苷脂生产废水进行混凝预处理的最适工艺条件是：pH=7～7.5,聚合硫酸铁用量＝500～750 mg/L。在优化条件下,混凝预处理可以使神经节苷脂生产废水的COD从27 000 mg/L左右降到13 000 mg/L左右。混凝预处理后的神经节苷脂生产废水经48 h厌氧和84 h好氧生物处理,COD值进一步下降到600 mg/L左右。然后向每升生化出水中加入2～3 mmol Fe³⁺,通过化学沉淀作用除去其中的磷酸盐,过量的Fe³⁺作为后续类Fenton氧化的催化剂。当H₂O₂(30％)用量为2～3 mL/L时,最终出水的COD值可以达到国家一级排放标准。     

酸沉降对马尾松菌根共生蛋白及营养关系影响

研究模拟酸雨及不同Ｃａ／Ａｌ比对马尾松（Ｐｉｎｕｓｍ ａｓｓｏｎｉａｎａ Ｌａｍ ｂ．）菌根中真菌与植物共生及营养关系的影响,在分子水平上揭示污染对生物的作用和生物抗性机理．当ｐＨ２０ 的模拟酸雨与铝共同作用时,马尾松菌根中酸性磷酸酶、硝酸还原酶以及海藻糖酶和甘露醇脱氢酶活性明显下降,即ｐＨ２０ 的模拟酸雨及铝离子对马尾松幼苗根的磷、氮吸收以及两共生生物之间的营养物质交换过程产生了影响,且铝离子在ｐＨ值低的情况下毒性作用更强;而钙能有效地缓解铝的毒性⒚在本实验中当Ｃａ／Ａｌ比为１／１ 时,缓解能力最强;在接种外生菌根真菌彩色豆马勃（Ｐｉｓｏｌｉｔｈｕｓｔｉｎｃｔｏｒｉｕｓ）后,马尾松幼苗根部酶活性仍能保持一定水平,植物对模拟酸雨及铝毒的抗性增强．菌根形成初期,经等点聚焦电泳后分离出在植物及真菌纯培养中均不存在的共生蛋白,其等电点为４７０,经ｐＨ２０的模拟酸雨处理后该蛋白仍存在     

Identification and characterization of coagulation inhibitor proteins derived from cyanobacterium Microcystis aeruginosa

The excess growth of cyanobacteria in semi enclosed water areas caused by eutrophication brings about coagulation inhibition in drinking water treatment processes. In this study, coagulation inhibitor proteins produced by Microcystis aeruginosa, a major cyanobacterium in algal bloom, were acquired by a phage display technique, an aluminum-immobilized affinity chromatography and a protein expression technique using Escherichia coli cells. Two cyanobacterial peptides with a high ratio of metallophilic amino acids were recovered, which were a part of homologues of a thiol oxidase enzyme Ero1p and a trans-acting repressor ArsR. It was also shown that the homologue of ArsR exhibited a stronger inhibitory effect on the coagulation of kaolin suspension with polyaluminum chloride than the control proteins. This is the first report to identify a cyanobacterial cell component to inhibit coagulation. The compositions of polar amino acids were critical to explain the strength of coagulation inhibition potential. Polar proteins from cyanobacteria could collectively consume coagulants or stabilize clay particles, which would be plausible explanations for causing coagulation inhibition. Meanwhile, results from the kaolin coagulation tests using the control proteins implied that the neutralization of positive charges of coagulant constituents by simple electrostatic interactions might not be the key mechanism on the protein-induced coagulation inhibition.     

蛋壳煅烧合成羟基磷灰石的制备及表征

以蛋壳为原料,磷酸钙为反应剂,采用煅烧合成工艺,可简单快速地制备羟基磷灰石（HA）粉体材料。实验结果表明,煅烧粉体中羟基磷灰石的含量强烈依赖于煅烧工艺的加热速率,当加热速率为6℃/min时,可获得较高羟基磷灰石含量的复合粉体。该工艺提供了环境友好和低成本的羟基磷灰石等生物材料的制备方法,可有效提高蛋壳加工利用技术的附加值。     

热碱水解提取污泥蛋白质的实验研究

为了确定污泥热碱提取微生物蛋白质的操作工艺条件,首先选用1#原泥为原料进行了以pH值、温度T为变量的全面实验,考察了pH值、T随反应时间的延长对蛋白质提取的影响。在1#原泥实验结果的基础上确定了以2#原泥为原料的正交实验因素水平,考察了体系pH值、T、原料含水率W以及水解时间t对污泥蛋白质回收率的影响,结果表明,热碱水解是一种有效的污泥蛋白提取方法,在热碱条件下蛋白质的回收率高达61.37%。水解过程中各因素对蛋白质回收的影响程度为pH>T>W>t,较优的提取工艺条件为：pH=13,T=140,W=91%,t=3 h。     

三烯丙基异氰脲酸酯合成废渣中氯化钠的回收

采用浸取—抽滤分离—减压蒸发—结晶的方法处理三烯丙基异氰脲酸酯(TAIC)合成废渣,回收其中的氯化钠。通过单因素实验和正交实验探讨了液固比、浸取温度、搅拌时间对氯化钠回收率的影响。实验结果表明,在浸取温度为30℃、搅拌时间为30 min、液固比为15的最佳工艺条件下,氯化钠回收率为81.53%。回收氯化钠产品符合GB/T 5462—2003《工业盐》精制工业盐一级标准。采用本工艺每处理1 t TAIC合成废渣可节约费用3 064元,经济效益显著。     

Brief exposure to copper induces apoptosis and alters mediators of olfactory signal transduction in coho salmon

Pacific salmon are particularly susceptible to copper (Cu)-induced olfactory injuries that can ultimately inhibit neurobehaviors critical to survival. However, the molecular mechanisms underlying Cu-mediated olfactory impairment remain poorly understood. In the present study, we conducted a short-term Cu exposure at levels relevant to urban runoff (5, 25 and 50 ppb) , and investigated the roles of impaired olfactory signal transduction and induced apoptosis as underlying mechanisms of olfactory injury. Increased cell death in the olfactory epithelium was evident in coho receiving 4 h exposures to 25 and 50 ppb Cu. Expression of olfactory marker protein (omp), a marker of mature olfactory sensory neurons, also decreased at 50 ppb Cu. Immunohistochemical analysis of coho olfactory epithelium demonstrated a loss of type 3 adenylate cyclase (ACIII) in the apical olfactory epithelium cilia at all levels of Cu exposure, suggesting an inhibitory effect of Cu in olfactory signaling. Accompanying the loss of ACIII in Cu-exposed coho were reduced intracellular cyclic guanosine monophosphate (cGMP) levels in the olfactory rosettes. Collectively, these results support a linkage among the initial steps of olfactory signaling in Cu-induced salmon olfactory injury, and suggesting that monitoring olfactory cGMP levels may aid in the assessment of salmon olfactory injury.     

Metabolism of nC11 fatty acid fed to Trichoderma koningii and Penicillium janthinellum II: Production of intracellular and extracellular lipids

Abstract

Little is known about the fungal metabolism of nC₁₀ and nC₁₁ fatty acids and their conversion into lipids. A mixed batch culture of soil fungi, T. koningii and P. janthinellum, was grown on undecanoic acid (UDA), a mixture of UDA and potato dextrose broth (UDA+PDB), and PDB alone to examine their metabolic conversion during growth. We quantified seven intracellular and extracellular lipid classes using Iatroscan thin-layer chromatography with flame ionization detection (TLC-FID). Gas chromatography with flame ionization detection (GC-FID) was used to quantify 42 individual fatty acids. Per 150 mL culture, the mixed fungal culture grown on UDA+PDB produced the highest amount of intracellular (531 mg) and extracellular (14.7 mg) lipids during the exponential phase. The content of total intracellular lipids represented 25% of the total biomass-carbon, or 10% of the total biomass dry weight produced. Fatty acids made up the largest class of intracellular lipids (457 mg/150 mL culture) and they were synthesized at a rate of 2.4 mg/h during the exponential phase, and decomposed at a rate of 1.8 mg/h during the stationary phase, when UDA+PDB was the carbon source. Palmitic acid (C_16:0), stearic acid (C_18:0), oleic acid (C_18:1), linoleic acid (C_18:2) and vaccenic acid (C_18:1) accounted for >80% of the total intracellular fatty acids. During exponential growth on UDA+PDB, hydrocarbons were the largest pool of all extracellular lipids (6.5 mg), and intracellularly they were synthesized at a rate of 64 μg/h. The mixed fungal species culture of T. koningii and P. janthinellum produced many lipids for potential use as industrial feedstocks or bioproducts in biorefineries.     

水滑石类材料的制备及在水污染治理中的应用

简要介绍了目前国内外水滑石类材料的各种制备方法,包括共沉淀法、焙烧还原法、离子交换法等。同时总结了其作为催化剂和离子交换剂在修复阴离子污染水体、印染废水脱色、重金属去除等方面应用。