氢气代谢及其环境生物修复功能研究进展

分子氢是多种微生物代谢之间相互作用的关键中介物,环境中产氢微生物和耗氢微生物的活动决定了全球氢气循环,对其他重要元素生物地球化学循环具有潜在的驱动作用。环境功能微生物在维持环境生态系统平衡、消除次生环境污染等领域中扮演着不容忽视的重要作用。因此,理解环境中氢气代谢（氢气的产生和消耗）微生物对生态环境的影响及其在环境生物修复中的作用与功能,对认识氢气的生态环境效应并将该生物能源应用于生物修复具有重要的科学意义和实践价值。系统分析了氢气代谢过程及氢化酶的分类和功能,总结了微生物产生和消耗氢气的多种途径及其对土壤生态环境效应和生物修复作用的影响,指出了目前氢气代谢过程及氢化酶应用于环境生物修复领域存在的关键科学技术问题,提出了未来的研究思路与重点方向,以推动氢气这种生物能源成就一种有前景的环境污染修复策略。     

Effects of hydrogen peroxide on sodium current in acutely isolated rat hippocampal CA1 neurons

AIM and METHODS: The effects of hydrogen peroxide on Na⁺ currents were studied in freshly dissociated rat hippocampal CA1 neurons using the whole-cell patch-clamp techinique. RESULTS: ①H₂O₂ caused a dose-dependent and voltage-dependent increase in the voltage-activated Na⁺ currents. The amplitudes of Na⁺ currents were increased (48.0±4.2)% and (88. 2±5. 1)% (n=10) by H₂O₂ at 10 μmol/L and 100 μmol/L, respectively. ②H₂O₂ (10 μmol/L) did not affect the activation process, but changed the inactivation process significantly. Before and after application of 10 μmol/L of H₂O₂, the half-inactivation voltage was (-64.58±1.22)mV and (-53.55±0.94)mV (n=10, P<0.01), but the slope factor was not changed. CONCLUSION: As a product of oxidation metabolism, H₂O₂ is related to some diseases in the central nervous system.     

Growing season and hydrogen peroxide effects on root induction and development in Olea europaea L. (cvs ‘Frantoio’ and ‘Gentile di Larino’) cuttings

Semi-hardwood cuttings of ‘Frantoio’ (high rooting ability) and ‘Gentile di Larino’ (low rooting ability) cultivars were obtained from 1-year-old olive shoots sampled in mid-August during the 2000 and 2001 growing season. Semi-hardwood cuttings were dipped in IBA 4000 ppm and H₂O₂ (0%-control or 3.5% w/v) solutions before rooting in greenhouse equipped with an automatic mist system. At 57 and 88 days after the beginning of rooting treatments cuttings were scored for the presence of callus, roots and roots number. In both cultivars and years, the IBA 4000+H₂O₂ treatment significantly modified rooting of cuttings at 57 days in comparison with IBA 4000 treatment. The positive effects of H₂O₂ on rooting were gradually smoothed after 88 days. At the end of the propagation cycle (88th days), cuttings treated with IBA 4000+H₂O₂ had significantly higher root number in comparison with those treated with IBA 4000 alone.     

微粒子感染对家蚕过氧化氢代谢的影响

本文探讨了100万N.b/(mm)~3感染五龄起蚕对家蚕过氧化氢代谢的影响,结果表明:①N.b感染后H_2O_2:水平后期显著增加,SOD活性差异不显著,CAT活性显著升高;②硒处理组添食N.b后H_2O_2水平与单纯添食N.b相似,SOD活性在第5、第7天显著升高,CAT活性第2、4、5天显著增加;③磁处理组添食N.b后与单纯添食N.b相比,H_2O_2含量初期显著升高,但从第5天开始显著降低而与对照接近,SOD活性初期显著降低,中后期与单纯N.b处理接近,CAT活性第6、7、9三天显著下降.N.b感染对家蚕H_2O_22代谢的最显著影响是CAT活性上升.     

硫氢化钠对大蒜衰老与生理特性的影响

以大蒜(Allium stativum L.)为试验材料,研究外源H2S处理对大蒜衰老与生理特性的影响.结果表明:用浓度为0、100、500、1 000、1 500 μmol/L的H2S供体NaHS浇灌处理大蒜,与对照相比,一定浓度H2S处理下,大蒜保持较高的叶绿素含量和根系活力；尤其是T2 (500 μmol/L)处理,与对照相比,显著提高了大蒜叶片抗氧化酶SOD、POD、CAT及APX活性；较高的抗氧化酶活性有利于清除大蒜叶片内活性氧,从而减轻了其对细胞膜的破坏,表现在大蒜叶片电解质渗漏率和MDA含量降低；并且大蒜叶片保持较高自由水含量,延缓大蒜的衰老.高浓度的H2S处理,不但没有延缓大蒜的衰老,反而加剧其衰老.     

高氟对动物生殖功能影响的研究概况

研究表明,摄入过量氟能使动物生殖器官的结构、超微结构等受到损伤,致使生精功能、精子生存的内环境等发生改变;还使生殖内分泌功能紊乱,性激素活性改变,进而影响生殖功能。文章概述了氟对啮齿类动物、反刍动物以及禽类的生殖功能的影响,以期了解氟对动物生殖功能的影响研究现状,为深入探讨氟的生殖毒性奠定基础。     

氟化物对酸性土壤溶液组成的影响

Atmospheric emissions of fluoride from an aluminium smelter-alumina refinery located on the northern coast of Galicia, NW Spain, increase the content of fluorine in soils and vegetation in the vicinity of the complex. The effects of the addition of fluoride solutions on the chemical properties of soil samples from the area surrounding the complex were investigated in laboratory experiments. Addition of fluoride to soils resulted in increases in pH and concentrations of Fe, Al, and organic matter in the equilibrium solutions and decreases in concentrations of Ca, Mg, and K. No consistent effects were observed on the Cu, Mn, or Zn concentrations. Most of the Al in solution was bound to organic matter. Within the fraction “labile aluminium,” the concentration of Al-OH complexes decreased and the Al-F complexes increased, especially AlF3 and AlF4-, which are less toxic than Al3+ and Al-OH species.     

外源H_2O_2对盐胁迫下黄瓜幼苗氧化胁迫及抗氧化系统的影响

为阐明外源H_2O_2缓解盐胁迫的生理机制,以水培法培养的黄瓜‘春夏秋王’幼苗为试材,采用0、1、5、10μmol·L~(-1) H_2O_2处理200 mmol·L~(-1)NaCl胁迫的黄瓜幼苗。通过测定黄瓜幼苗的叶面积、株高、根长、叶鲜质量、根鲜质量及根干质量等指标,结果显示外源H_2O_2缓解了NaCl胁迫对植株生长的抑制,其中5μmol·L~(-1)H_2O_2对盐胁迫下黄瓜幼苗的缓解效应最有效。H_2O_2不仅降低盐胁迫下黄瓜幼苗叶片和根系O■、H_2O_2和丙二醛质量摩尔浓度及相对电导率,也提高了还原型谷胱甘肽质量分数、抗坏血酸质量摩尔浓度和过氧化物酶、谷胱甘肽还原酶活性。此外,不同浓度H_2O_2处理引起盐胁迫下黄瓜叶片甲基转移酶PMT5和铁氧还原蛋白的谷氨酸合成酶上调-下调-上调的变化模式,而在根中网格蛋白重链1表现出逐渐下调和热休克蛋白70样蛋白15逐渐上调的模式。以上结果表明,外源H_2O_2通过增强黄瓜的抗氧化系统来降低盐胁迫引起的氧化胁迫,同时调控相关蛋白质的表达,从而缓解NaCl胁迫造成的伤害。     

粗制蜂蜡脱色过程研究

[目的]研究粗制蜂蜡的脱色过程,以期为蜂蜡生产提供理论指导。[方法]以过氧化氢为脱色剂对粗制蜂蜡进行脱色,研究了不同试剂用量、脱色温度、脱色时间与搅拌速度对蜂蜡色泽及酸价的影响。[结果]蜂蜡色泽随过氧化氢用量增加而降低,过氧化氢用量为0.3 ml/g时色泽达到1级;脱色时间对蜂蜡脱色效果的影响与过氧化氢用量有关与蜂蜡酸价无关;而脱色温度对蜂蜡色泽的影响与脱色时间有关,随脱色温度升高蜂蜡胶价低。脱色时,随着搅拌速度的提高,蜂蜡色泽变浅;但转速太高会造成蜂蜡色泽回升。[结论]在该试验条件下,过氧化氢用量0.3 ml/g,脱色时间60 min,脱色温度80℃,搅拌速度700 r/min,脱色效果达到1级。蜂蜡脱色过程受多种因素影响,并且伴随有回色现象发生,需结合具体情况确定最为经济高效的脱色条件。     

pH与氟对莱茵衣藻和蛋白核小球藻胞外碳酸酐酶活性及光合效率的影响

本文研究了不同pH(5.0、7.0和9.0)和F-浓度(0.1、1、10、50、100、200mmol·L-1)对莱茵衣藻和蛋白核小球藻的胞外碳酸酐酶活性、PSⅡ实际光合效率ΦPSⅡ和叶绿素a合成量的共同影响。结果表明:在低于1mmol·L-1的F-作用下,两种微藻的生理和生长指标主要受pH影响;酸性条件下,两种微藻胞外碳酸酐酶活性显著低于中性和碱性条件时,ΦPSⅡ随pH升高而增大,叶绿素a合成量随pH升高而增加。在高于1mmol·L-1的F-作用下,两种微藻的生理及生长指标受F-和pH共同影响,且F-的作用大于pH的作用,胞外碳酸酐酶活性随着F-浓度升高先增加后降低,同时随着pH下降而降低;ΦPSⅡ和叶绿素a合成量则随着F-浓度升高和pH下降而迅速下降。胞外碳酸酐酶活性、ΦPSⅡ和叶绿素a合成量都能够作为指示微藻受氟胁迫的指标,以微藻为材料除去自然界氟超标水体中的超标F-,理论上是可行的。