金属离子对嗜热菌BF80生长及苯酚降解的影响研究

探测了17种金属离子对嗜热菌BF80菌生长和降解苯酚的影响。结果表明：与对照相比, 0.01%的Cu2+、Zn2+、Co2+、Ba2+、Hg2+、Ni2+、Ag+ 和Al3+对嗜热菌BF80有强抑制作用; Cr2+对嗜热菌BF80的苯酚降解特性有强抑制作用, 而其生长量只受到一定的抑制作用; Sn2+、Fe2+、Fe3+和Pn2+ 对嗜热菌BF80的生长和苯酚降解有一定抑制作用, 该作用随金属粒子浓度的增加而增大; 低浓度Mn2+ 和Mo2+可以使其生长量增大且促进苯酚降解, 但超过0.1%的浓度则抑制其生长; Ca2+ 和Mg2+可以加速嗜热菌BF80的生长和降解苯酚的速率, 但对苯酚的最大降解率却几乎没有影响; Mo2+ 和Mn2+的复合作用使嗜热菌BF80的生长量更大, 但是苯酚降解率却比分别单独添加Mo2+ 和Mn2+时低。     

一株嗜热菌的分离鉴定及其苯酚降解特性

从油田地层水中分离到一株嗜热并高效降解苯酚的BF80菌株,其最适生长和降解苯酚的温度为60℃65℃。利用API50CHB/E系统和16SrDNA序列分析对菌株BF80进行了分类鉴定,该菌株的形态和生理生化特性与Geobacillusthermoglucosidasius基本相同,其16SrDNA序列与GeobacillusthermoglucosidasiusBGSCW95A1(=ATCC43742)的相似性为99·22%。在接种量为1%的条件下,该菌在20h内能完全降解3mmol/L的苯酚;在pH值5·59·0范围内能保持对苯酚良好的降解能力,并在12mmol/L苯酚的无机盐培养基中也能生长和降解苯酚,表明该菌能耐受高浓度苯酚并可用于高温含酚废水的生物处理。     

低温高效苯酚降解菌的分离与降解特性

从哈尔滨太平污水厂活性污泥中筛选到7株高效苯酚降解菌,可利用苯酚作为唯一碳源和能源。通过对这7株菌在不同温度、pH值、以及不同苯酚浓度下生长和苯酚降解情况的考察,确定了这7株菌的最适生长温度为10°C,最适pH值为7.5,最大可降解苯酚浓度为3000mg/L。通过对这7株苯酚降解菌降解性能的研究表明:其具有较强的苯酚降解能力,在10°C、pH值为7.5、装液量为50mL、接种量15%、摇床振荡速度160r/min的条件下,反应48h后可使500mg/L的苯酚降解率达90%以上。葡萄糖对菌体的生长及苯酚降解能力均有一定的影响,当葡萄糖浓度是500mg/L时,该菌对苯酚的降解率仍在80%以上。该研究对处理含有其它碳源的含酚废水具有一定的意义。通过DGGE图谱条带的分析表明,其亮度可以说明这些菌在各个系统中均表现为优势菌,且在污水环境中表现出较强的活性,其优势地位能够稳定地存在。其中2、4、24、28条带丰富,表现出它们在污水环境系统中的多样性。     

苯酚降解菌ZJ-1的分离及降解特性研究

目的:筛选苯酚降解菌,用于降解苯酚提高氧化塘处理效率.方法:以苯酚为惟一碳源进行选择性培养.结果:从乌鲁木齐市某炼油厂污水池的活性污泥中分离出一株能以苯酚为惟一碳源培养基上生长的菌株,编号为ZJ-1,该菌株最高可耐受1000mg/L的苯酚.对该苯酚降解菌降解性能研究表明:该菌具有较强的降解能力,在32℃、pH 7左右、接种量1%时,摇床振荡速度120r/min的条件下,该菌株在48h内苯酚降解率可达81%以上.培养液中苯酚浓度在300mg/L、500mg/L时,该菌株的降解率比较明显.当苯酚浓度大于1000mg/L时,则元明显降解效果.结论:ZJ-1菌株对苯酚具有较强的降解能力,具有广阔的应用前景.     

两株苯酚降解茵的分离及降解特性的初步研究

从南昌钢铁公司焦化污水处理厂的活性污泥中分离出64株能降解苯酚的细菌,通过耐受性试验从中筛选出2株降解活性较高的苯酚降解菌,编号为F-38和F-64。研究表明：F-38和F-64都为G-菌,苯酚浓度越高,生长延滞期越长;两株菌降解苯酚基本发生在对数期,其对苯酚降解适宜条件为温度30％,pH值8-9,通气有利于苯酚的降解。     

苯酚降解菌的分离及培养特性研究

对南充市郊炼油厂活性污泥进行富集,驯化筛选得到2株能以苯酚作为唯一碳源和能源生长的菌株,编号为S1,S2,两菌株可耐10,000mg/L左右的苯酚浓度,实验得出其最佳生长条件为pH7-8,温度25℃-30℃,在适宜条件下,对苯酚有较好的降解能力,而且苯对两菌株的生长表现为抑制作用。     

3-苯氧基苯甲酸降解菌Sphingomonas sp. SC-1降解苯酚环境条件及其降解中间产物的研究

【目的】探究高效降解3-苯氧基苯甲酸(3-Phenoxybenzoic acid,3-PBA)的鞘氨醇单胞菌(Sphingomonas sp.) SC-1对苯酚的降解特性。【方法】采用HPLC测定微生物降解体系中苯酚残留量,考察环境条件对菌株SC-1降解苯酚的影响;分析不同培养时间苯酚降解体系混合样品的HPLC谱图,确定其降解中间产物。【结果】菌株SC-1能在基础盐培养基中以苯酚为唯一碳源和能源生长,在初始pH 7.0、30 °C条件下,24 h可完全降解100 mg/L苯酚;Cu2+、Ba2+、Mn2+等对其降解苯酚有不同程度的抑制作用;HPLC谱图分析,初步确定邻苯二酚是菌株SC-1降解苯酚的中间产物,且该菌株可在48 h内完全降解100 mg/L邻苯二酚。【结论】菌株SC-1对苯酚及邻苯二酚均有较强的降解能力,为完善3-PBA的降解途径及污染3-PBA或含酚废水或含酚农药残留的降解提供了数据参考。     

两株苯酚降解菌的分离及降解特性的初步研究

从南昌钢铁公司焦化污水处理厂的活性污泥中分离出64株能降解苯酚的细菌,通过耐受性试验从中筛选出2株降解活性较高的苯酚降解菌,编号为F-38和F-64。研究表明:F-38和F-64都为G—菌,苯酚浓度越高,生长延滞期越长;两株菌降解苯酚基本发生在对数期,其对苯酚降解适宜条件为温度30℃,pH值8-9,通气有利于苯酚的降解。     

一株苯酚降解菌的鉴定及其降解特性

【目的】鉴定从某化工厂附近土样中分离到的一株耐高浓度苯酚的菌株T10,通过优化菌株的培养条件提高菌株对苯酚的降解率。【方法】根据菌株的形态、生理生化鉴定及16S rDNA测序分析确定其种属,以液体摇瓶培养菌株T10对苯酚的降解率为指标,对菌株的生长条件进行优化。【结果】菌株T10属恶臭假单胞菌(Pseudomonas putida)。添加葡萄糖、蛋白胨能有效缩短T10菌的生长周期,并使苯酚的降解率提高1.7倍。在菌体初始接种浓度为10%、温度为30°C、转速为180 r/min条件下,对初始苯酚浓度、pH和装液量的响应面优化结果如下:初始苯酚浓度3 000 mg/L、pH 7.5和装液量80 mL/250 mL,苯酚去除率最高可达到87.56%。【结论】T10菌能够耐受较高浓度的含酚废水,并且对苯酚有较强的降解能力,为下一步利用生物法处理含酚废水提供科学依据。     

金属离子和醇类对混合菌产聚乙烯醇降解酶的影响

混合菌能完全降解PVA,并产生胞外PVA降解酶.本研究通过摇瓶发酵,考察了不同金属离子对混合菌生长和产酶的影响.研究表明:Mg2 和Fe2 对混合菌的生长和产酶影响是非常显著的,酶活分别比没有添加前提高了449.0 %和1766.3 %;Cu2 和Z n2 对混合菌有明显的抑制作用,酶活比没有添加前分别降低了71.5 %和20.1 % ;Mn 2 和Ca2 的影响是微弱的.通过正交实验确定了Mg2 、Fe2 、Mn 2 和Ca2 浓度的最佳组合为100、50、25、20 mg/L.醇类的添加对混合菌的生长和产酶不利.     

金属离子对地衣芽孢杆菌合成多聚γ-谷氨酸的影响

多聚γ 谷氨酸 [γ Ｐｏｌｙ(ｇｌｕｔａｍｉｃａｃｉｄ) ,γ ＰＧＡ]是由某些杆菌 (Ｂａｃｉｌｌｕｓ)合成的一种细胞外水溶性高分子氨基酸聚合物 ,是由Ｌ 谷氨酸、Ｄ 谷氨酸两种构型的单体通过γ 酰胺键聚合形成的[1 ] 。γ ＰＧＡ具有极佳的成膜性、成纤维性 ,阻氧性、可塑性、粘结性、保湿性和可生物降解等许多独特的理化和生物学特性[2 ,3] 。因此 ,γ ＰＧＡ可以被广泛用于医药制造 ,食品加工 ,蔬菜、水果、海产品防冻、保鲜 ,化妆品工业 ,烟草、皮革制造工业和植物种子保护等许多领域 ,是一种有极大开发价值和前景的多功能新型生物制…     

Biosorption of chromium, copper, manganese and zinc by Pseudomonas aeruginosa AT18 isolated from a site contaminated with petroleum

The study describes the sorption of Cr, Cu, Mn and Zn by Pseudomonas aeruginosa AT18 isolated from a site contaminated with petroleum and heavy metals. The concentrations studied were 50, 49, 60 and 70 (mg L(-1)) for Cr, Cu, Mn and Zn, respectively. The solution pH and ionic strength were very important factors in the metal biosorption performance and the biosorption capacity of P. aeruginosa AT18 for Cr3+,Cu2+, Mn2+ and Zn2+. In aqueous solution, the biosorption increased with increasing pH in the range 5.46-7.72. The results obtained in the experimental assays show that P. aeruginosa AT18 has the capacity for biosorption of the metallic ions Cr3+, Cu2+ and Zn2+ in solutions, although its capacity for the sorption of manganese is low (22.39 mg Mn2+/g of biomass) in comparison to the Cr3+, Cu2+ and Zn2+ ions, as shown by the individual analyses. However, 20% of the manganese was removed from an initial concentration of 49.0 mg L(-1), with a Qm value similar to that obtained in solutions containing mixtures of Cr3+, Cu2+, Mn2+and Zn2+. The chromium level sorbed by P. aeruginosa AT18 biomass was higher than that for Cu, Mn and Zn, with 100% removal in the pH range 7.00-7.72 and a Qm of 121.90-200.00 mg of Cr3+/g of biomass. The removal of Cr, Cu and Zn is also a result of precipitation processes.     

Characteristics of the ionic composition and ultrastructure of Bordetella pertussis in controlled regulation of the mineral element content in a growth medium

The content of trace elements necessary for the normal growth of bacteria was found to have no effect on the intracellular concentration of Ca2+ and Al3+. The content of Cu2+, Fe3+, Mn2+, Mg2+ was considerably reduced. The addition of Mg2+ at different concentrations to this culture medium stimulated the capacity of cells for accumulating not only Mg2+, but also some other ions. Their maximum intracellular concentration was observed when the concentration of Mg2+ in the culture medium was 41 mM. The growth of microbial cells in the standard culture medium containing Mg2+ at a concentration of 4 mM was accompanied by the increased consumption of elements actively participating in redox reactions (Cu2+, Fe3+, Mn2+). Shifts in the ionic composition of microbial cells were manifested by the morphological features of B. pertussis, linked with the increased synthesis of crystalloid structures. The influence of Mn2+, Al3+, Zn2+ at different concentrations on the ionic composition and morphology of B. pertussis was studied.     

Differential effects of monovalent, divalent and trivalent metal ions on rat brain hexokinase

The effects of monovalent (Li+, Cs+) divalent (Cu2+, Ca2+, Sr2+, Ba2+, Zn2+, Cd2+, Hg2+, Pb2+, Mn2+, Fe2+, Co2+, Ni2+) and trivalent (Cr3+, Fe3+, Al3+) metals ions on hexokinase activity in rat brain cytosol were compared at 500 microM. The rank order of their potency as inhibitors of brain hexokinase was: Cr3+ (IC50 = 1.3 microM) greater than Hg2+ = Al3+ greater than Cu2+ greater than Pb2+ (IC50 = 80 microM) greater than Fe3+ (IC50 = 250 microM) greater than Cd2+ (IC50 = 540 microM) greater than Zn2+ (IC50 = 560 microM). However, at 500 microM Co2+ slightly stimulated brain hexokinase whereas the other metal ions were without effect. That inhibition of brain glucose metabolism may be an important mechanism in the neurotoxicity of metals is suggested.     

Analysis of the metal requirement of 3-deoxy-D-arabino-heptulosonate-7-phosphate synthase from Escherichia coli.

The three isozymes of 3-deoxy-D-arabino-heptulosonate-7-phosphate synthase from Escherichia coli were overproduced, purified, and characterized with respect to their requirement for metal cofactor. The isolated isozymes contained 0.2-0.3 mol of iron/mol of enzyme monomer, variable amounts of zinc, and traces of copper. Enzymatic activity of the native enzymes was stimulated 3-4-fold by the addition of Fe2+ ions to the reaction mixture and was eliminated by treatment of the enzymes with EDTA. The chelated enzymes were reactivated by a variety of divalent metal ions, including Ca2+, Cd2+, Co2+, Cu2+, Fe2+, Mn2+, Ni2+, and Zn2+. The specific activities of the reactivated enzymes varied widely with the different metals as follows: Mn2+ greater than Cd2+, Fe2+ greater than Co2+ greater than Ni2+, Cu2+, Zn2+ much greater than Ca2+. Steady state kinetic analysis of the Mn2+, Fe2+, Co2+, and Zn2+ forms of the phenylalanine-sensitive isozyme (DAHPS(Phe)) revealed that metal variation significantly affected the apparent affinity for the substrate, erythrose 4-phosphate, but not for the second substrate, phosphoenolpyruvate, or for the feedback inhibitor, L-phenylalanine. The tetrameric DAHPS(Phe) exhibited positive homotropic cooperativity with respect to erythrose 4-phosphate, phophoenolpyruvate, and phenylalanine in the presence of all metals tested.     

Role of the capsule produced by Bacillus megaterium ATCC 19213 in the accumulation of metallic cations

A study was undertaken to determine if the capsule produced by Bacillus megaterium ATCC 19213 was capable of binding metallic ions. For non-toxic metallic ions, this was accomplished by determining the relative concentrations of Fe2+, Ca2+, Zn2+, Mg2+, and Mn2+ removed from a chemically defined medium by the normally capsulated parent strain and two mutants with much smaller capsules. For toxic metals, the rates of respiration of the parent strain and a small capsule mutant in the presence of Cu2+, Hg2+, and Ag1+ were compared. It was found that the parent strain accumulated more Ca2+, Mg2+, and Mn2+. Accumulation of Fe2+ and Zn2+ was similar for the parent strain and the small capsule mutants. Respiration of the parent strain was less inhibited by Cu2+, Hg2+, and Ag1+, indicating that these metals are also bound to the capsule.     

Wheat germ phosphoglycerate mutase: evidence for a metalloenzyme

Wheat germ phosphoglycerate mutase, exposed to 3.4 M guanidinium chloride at 22 degrees C and pH 7.8, slowly undergoes time-dependent inactivation which can be fully reversed by adding excess Co2+ or Mn2+ to a 50-fold dilution of the denaturing medium. Titration of the denatured enzyme with either Co2+ or Mn2+ shows that wheat germ mutase preferentially binds Co2+. Assuming 1:1 complexation between metal atom and protein, the apparent dissociation constants (Kd) for E Co2+ and E Mn2+ at 22 degrees C and pH 8.7 are approximately 1.06 and 1.84, respectively. Other metal atoms (e.g., Cr2+, Cu2+, Fe2+, Fe3+, Mg2+, and Ni2+) have no effect in restoring the apoenzyme's catalytic activity. At low concentrations (0.11-0.23 mM) Zn2+ partially restores activity, but promotes protein precipitation at elevated concentrations. Evidence suggests that all bisphosphoglycerate-independent phosphoglycerate mutases require either an intra- or an extramolecular metal atom in order to function. Attempts to characterize wheat germ mutase as a glycoprotein have yielded negative results.     

金属离子对粪产碱杆菌C16的脱氮和亚硝酸盐积累的影响

【目的】研究不同金属离子对异养氨氧化细菌C16的生长和脱氮性能影响,探讨适于C16生长和脱氮的金属离子及其浓度。【方法】实验选用Mg2+、Mn2+、Fe2+、Cu2+、Zn2+5种金属离子,对C16的生长﹑脱氮性能﹑亚硝酸盐氮积累以及相关酶活性进行研究。【结果】Mg2+明显促进C16的生长和NH4+-N氧化速率;较高浓度Mn2+使得C16无法生长;原培养基中缺少Fe2+会抑制C16的生长和NH4+-N氧化速率;在原培养基中加入0.1 mmol/L的Cu2+对C16的生长和脱氮具有一定的促进作用,Cu2+使得培养基中基本无NO2--N和NH2OH的积累;不同浓度的Zn2+对C16的生长和氨氮去除有抑制作用。酶活实验结果显示,0.1 mmol/L Mg2+促进了羟胺氧化还原酶(HAO)的活性;0.1 mmol/L Cu2+促进了硝酸盐还原酶(Nar)和亚硝酸盐还原酶(Nir)的活性。【结论】Mg2+是C16生长和脱氮过程中的一种重要金属离子;加入Cu2+可避免过量亚硝酸盐积累。     

The role of divalent cations in structure and function of murine adenosine deaminase.

For murine adenosine deaminase, we have determined that a single zinc or cobalt cofactor bound in a high affinity site is required for catalytic function while metal ions bound at an additional site(s) inhibit the enzyme. A catalytically inactive apoenzyme of murine adenosine deaminase was produced by dialysis in the presence of specific zinc chelators in an acidic buffer. This represents the first production of the apoenzyme and demonstrates a rigorous method for removing the occult cofactor. Restoration to the holoenzyme is achieved with stoichiometric amounts of either Zn2+ or Co2+ yielding at least 95% of initial activity. Far UV CD and fluorescence spectra are the same for both the apo- and holoenzyme, providing evidence that removal of the cofactor does not alter secondary or tertiary structure. The substrate binding site remains functional as determined by similar quenching measured by tryptophan fluorescence of apo- or holoenzyme upon mixing with the transition state analog, deoxycoformycin. Excess levels of adenosine or N6- methyladenosine incubated with the apoenzyme prior to the addition of metal prevent restoration, suggesting that the cofactor adds through the substrate binding cleft. The cations Ca2+, Cd2+, Cr2+, Cu+, Cu2+, Mn2+, Fe2+, Fe3+, Pb2+, or Mg2+ did not restore adenosine deaminase activity to the apoenzyme. Mn2+, Cu2+, and Zn2+ were found to be competitive inhibitors of the holoenzyme with respect to substrate and Cd2+ and Co2+ were noncompetitive inhibitors. Weak inhibition (Ki > or = 1000 microM) was noted for Ca2+, Fe2+, and Fe3+.