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1.
自盐渍化地区（黄河三角洲）采集4种不同石油污染程度的土壤样品,从中筛选出高效降解石油烃的4个菌系和8个单菌株。分别以原油、柴油、烷烃和多环芳烃（PAHs）为底物进行培养,测定降解菌的生物量和降解率,研究其对不同底物的耐受浓度和降解潜力。结果表明,获得的石油烃降解菌为轻度嗜盐菌;不同菌株对不同底物的耐受浓度不同,混合菌系对不同底物的降解能力强于单菌株,对单一组分底物的降解优于复杂组分的底物;单菌株I-2、3、5、7能较好地降解PAHs并且对原油的降解能力高于柴油,单菌株I-1、4、6、8能够利用烷烃且对柴油的降解能力要比原油高;降解菌对柴油和原油的最高降解率分别可达78．4％和70．7％,对正十六烷和菲的生物降解率分别高达87．7％和88．1％,表现出较强的降解能力。研究结果表明黄河三角洲盐渍化土壤中土著菌对石油烃污染土壤具有较强的牛物修复潜力。 相似文献
2.
选用假单胞菌Nwu1-mu对陕北地区石油污染土壤进行生物修复。通过检测修复过程中土壤样品的菌体生长数量、脱氢酶活性、表面张力和石油烃及其组分降解率综合考察了菌株对石油烃类物质的降解作用。结果表明,在不添加营养物质的前提下假单胞菌Nwu1-mu在60d内对石油污染土壤中的石油烃类物质降解率达到了86.5%,尤其对石油烃中的C24～C28和〉C28组分有突出的降解效果;菌株产脱氢酶和表面活性剂显示出了良好的性能,在石油烃类物质的降解过程中均起着关键的促进作用。假单胞菌Nwu1-mu显示出的强大的生物修复潜力及其不依赖于外来营养源的特性,为黄土高原的土壤生态环境修复提供了新的解决思路。 相似文献
3.
从长期施用多菌灵农药的土壤中,通过富集筛选,获得1株新的多菌灵高效降解菌株。通过生理生化实验和16SrDNA序列同源性分析鉴定该菌株,应用高效液相色谱法对纯培养条件下菌株的降解特性和粗酶提取液的降解性能进行了分析。结果表明,筛选所获得的菌株与Raoultella菌属的亲缘关系最近,将其命名为Raoultellasp．MBC,该菌株能在以多菌灵为唯-碳源的无机盐培养基中生长;25℃、pH7．0、200r·min。的最适生长条件下避光振荡培养72h,多菌灵的降解率达到100％;在最适培养条件下外加氮源和碳源在培养后期均可以提高多菌灵的降解率,外加氮源对多菌灵的降解效果优于外加碳源;该菌体的粗酶提取液具有降解多菌灵活性,且多菌灵降解酶为诱导酶。研究结果为多菌灵污染土壤的生物修复和酶修复提供了材料和理论依据。 相似文献
4.
采用室内培养方法,从吴江市郊长期被多环芳烃污染的土壤中富集到以菲为唯一碳源和能源的菲降解复合微生物菌群,复合菌群在7d内对无机盐液体中菲（含量100mg·L^-1）的降解率达到99%。从复合菌群中分离纯化获得两株菲高效降解菌B1和L2,经过菌体形态特征、生理生化特征和16SrDNA序列分析,鉴定菌株B1为百日咳博行特氏菌（Bordetella petrii）,菌株L2为墨西哥假黄单胞菌（Pseudoxanthomonas mexicana）。这两株菌在菲含量为100mg·L^-1的无机盐培养液中,7d内对菲（含量100mg·L^-1）的降解率大约为80%,9d内的降解率可达到99%。将复合菌群和菲污染土壤混合,在光照培养箱中进行培养修复。结果表明,修复88d后,接种复合菌群的低污染浓度（8.22mg·kg^-1）处理和高污染浓度（39.65mg·kg^-1）处理的菲去除率分别达到95.74%和98.06%。 相似文献
5.
不同石油污染程度土壤细菌群落多样性及优势菌群分析 总被引：1，自引：0，他引：1
6.
产漆酶真菌筛选及其对PAHs污染土壤修复的初步研究 总被引：1，自引：0，他引：1
真菌漆酶可以高效转化多环芳烃(PAHs),因此,产漆酶真菌在PAHs污染土壤修复中极具应用前景。根据漆酶可将愈创木酚氧化为红色物质的特性,成功从土壤中筛选出一株能够分泌漆酶的真菌菌株F-1,初步鉴定该菌为疣孢漆斑菌(Myrothecium verrucaria)。通过Plackett-Burman试验对菌株F-1的产酶能力进行了分析,发现特定培养条件组合可将其酶活提高近300倍,达5628 U L-1,表明F-1的漆酶活性受到环境条件的显著影响。应用菌株F-1对PAHs污染土壤进行了初步修复研究,结果表明,接种F-1对菲、荧蒽、芘、苯并(a)蒽、屈、苯并(b)荧蒽、苯并(k)荧蒽、苯并(a)芘、二苯并(a,h)蒽、苯并(g,h,i)苝、茚苯(1,2,3-cd)芘等11种PAHs均有不同程度的降解,提示产漆酶真菌在PAHs污染土壤修复中的应用潜力。 相似文献
7.
土壤有机氯污染的生物修复和土壤酶活性的关系 总被引：1，自引：0，他引：1
简述了土壤生物修复的意义以及微生物 -酶 -生物修复之间的关系 ,对有机氯污染土壤的生物修复进行了初步探讨。研究结果表明 ,自然土壤中含有过氧化氢酶 ;加入“六六六”后 ,降低自然土壤中过氧化氢酶活性。此外 ,对产生过氧化氢酶的外源细菌进行初步搜集、筛选 ,并测定了其产生过氧化氢酶能力。结果表明 ,在有机氯污染的土壤中 ,加入外源细菌能增加土壤过氧化氢酶活性 ;有机氯能诱导加入土壤的外源微生物分泌过氧化氢酶的能力 ;细菌 B1是较有希望的能消除有机氯污染的菌株 相似文献
8.
采用淋洗施肥修复方法处理石油污染盐碱土壤,评价该修复方法对石油污染盐碱土壤的修复效果,并且采用最大或然数法和Biolog方法对土壤微生物数量和微生物群落水平生理特性进行研究。结果表明,经过182d的培养,淋洗施肥处理中油和脂的降解率分别比对照处理和施肥处理高（19.7±4.3）%和（13.8±3.4）%,土壤盐分去除率分别比对照处理和施肥处理高（66.5±2.9）%和（41.3±6.2）%,说明该处理是一种修复石油污染盐碱土壤的有效方式。淋洗施肥处理明显提高异养细菌、石油烃降解菌、烷烃降解菌和多环芳烃降解菌数量和土壤微生物活性,促进了微生物对土壤中油和脂的降解。此外,淋洗施肥处理提高了土壤微生物Shannon多样性指数和Simpson指数,促进了微生物种群的稳定,这暗示着土壤微生物种群正在逐渐恢复。 相似文献
9.
热稳定性β-葡聚糖酶菌种选育及产酶特性 总被引：5，自引：0，他引：5
从土壤中筛选到一株热稳定性β－1，3－1，4－葡聚糖产生菌ZJF－1，发酵60h酶活性为64U／mL，经鉴定该菌株为枯草芽孢杆菌（Bacillus subtilis)。紫外线和硫酸二己酯复合诱变，获得的突变株ZJF－1A5发酵60h酶活性达154．7U／mL，是出发菌株酶活性的2．42倍，对B.subtilis ZJF-1A5产酶特性的研究发现：大麦粉，糊精，可溶性淀粉等糖有利于β－1，3－1，4－葡聚糖酶的产生，葡萄糖，麦芽糖等单糖和双糖不利于菌体生长和产酶。B.subtilis ZJF-1A5 β-1,3-1,4-葡聚糖酶的产生与菌体生长部分相关，在细胞进入对数生长后期至稳定期，酶活性显著增加，且β－葡聚糖酶活性与菌体生物量密切相关，B.subtilis ZJF-1A5 α－淀粉酶的产生也与生长部分相关，细胞进入对数生长期，α－淀粉酶开始大量产生，而中性蛋白酶的产生与菌体生长同步。 相似文献
10.
百菌清是一种广谱非内源性农药，在土壤中难以降解，已经成为农业环境污染的主要污染源之一。因此，其对环境的污染和被污染土壤的修复技术越来越受到关注。土壤环境中原位降解细菌的多样性对于评价环境毒理学、生物降解性、自净化能力和污染物的修复潜力具有重要价值。该研究从长期被百菌清污染的土壤中收集大量样本，分离到了14种能够明显降解百菌清的细菌。根据菌株形态和rDNA同源性分析，将它们分为假单胞菌属（Pseudomonas sp.）、无色杆菌属（Achromobacter sp.）、苍白杆菌属（Ochrobactrum sp.）、青枯菌属（Ralstonia sp.）和溶杆菌属（Lysobacter sp.）。其中溶杆菌属是该研究中新发现的具有百菌清降解能力的功能菌属，该发现扩大了已知的百菌清降解菌的菌属范围。通过进一步鉴定及生理生化分析，确定了该降解菌的分类地位及理化特征。此外，该研究通过基因文库法克隆到了发挥关键降解作用的水解酶基因，并发现该基因与转座子原件IS-Olup相连，二者组成代谢转座子，具有水平转移的分子基础。通过揭示降解基因在细菌间的漂移机制，为修复百菌清污染土壤的生物技术奠定了理论基础。 相似文献
11.
低氮和干旱胁迫对富士和秦冠生长及氮素利用的影响 总被引：2，自引：2，他引：0
【目的】以富士（Fuji）、 秦冠（Qinguan）嫁接在平邑甜茶（Malus hupehensis Rehd.）上的当年生盆栽苗为试验材料,采用砂培方法,研究了缺氮胁迫和干旱对富士和秦冠生长情况、 光合参数、 植株各部位氮磷钾含量及氮素利用效率的影响,分析比较了低氮干旱条件下富士和秦冠生长及氮素利用的差异,以期为果树生产高效肥水利用提供理论指导。【方法】试验共设四个处理: 正常氮正常水（ZZ）、 低氮正常水（DZ）、 正常氮干旱（ZG）、 低氮干旱（DG）。氮素和水分均设置两个水平,分别为正常氮（6 mmol/L NO-3-N）、 低氮（0.3 mmol/LNO-3-N）、 正常供水（保持盆中砂子相对含水量为饱和含水量的80%~85%）、 干旱处理（保持盆中砂子相对含水量为饱和含水量的60%~65%）。【结果】富士和秦冠的生物量（茎和叶）、 株高茎粗等生长指标以及光合速率、 气孔导度、 蒸腾速率均为正常氮正常水（ZZ）＞低氮正常水（DZ）＞正常氮干旱（ZG）＞低氮干旱（DG）,并且相对应处理下秦冠的以上指标均高于富士;正常供水下,缺氮处理使富士、 秦冠的根冠比比正常氮处理均有所增加,富士提高了2.05%,秦冠提高了22.40%。富士和秦冠的氮、 磷、 钾含量均表现出正常氮正常水（ZZ）＞低氮正常水（DZ）＞正常氮干旱（ZG）＞低氮干旱（DG）; 氮、 钾元素含量在植株各部位的分布顺序依次是叶＞根＞茎,磷元素则是根＞叶＞茎;光合氮素利用效率（PNUE）和氮素利用效率表现为秦冠处理之间差异极显著,富士处理之间差异不显著;秦冠的PNUE和NUE明显高于富士,在低氮正常水（DZ）处理下,秦冠氮肥利用率比富士高42.07%,在低氮干旱（DG）处理下高64.14%;低氮胁迫下富士和秦冠的NUE显著提高,并且秦冠提高的幅度高于富士。【结论】施用氮肥能够显著提高富士与秦冠的干物质量,同等水肥条件下,秦冠生长优于富士;水分亏缺会减少叶片对氮的吸收,干旱条件下适度增施氮肥,可提高果树的抗旱能力;低氮干旱胁迫下秦冠的生长指标、 光合指标及氮素利用效率指标均优于富士,表现出较强的抗低氮干旱胁迫的能力。 相似文献
12.
Kyle Devey Michael Mucalo Gordon Rajendram Joseph Lane 《Communications in Soil Science and Plant Analysis》2015,46(4):72-80
Laser-induced breakdown spectroscopy (LIBS) is a new technique for the analysis of plant material. This study investigates the application of LIBS to pasture-based plant samples. The LIBS measurements were obtained from pelletized pasture samples (100 samples) that had been also analyzed by inductively coupled plasma–optical emission spectroscopy (ICP-OES) following microwave digestion for calibration and comparison purposes. Comparisons for elements sodium (Na), potassium (K), magnesium (Mg), calcium (Ca), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), boron (B), phosphorus (P), and sulfur (S) showed that LIBS could be used for almost all the standard profile total elements with concentrations down to low mg/kg levels (observed error of Na: 0.024 percent, K: 0.18 percent, Mg: 0.016 percent, Ca: 0.073 percent, P: 0.017 percent, Mn: 31 mg/kg, Fe: 150 mg/kg, Zn: 6.6 mg/kg, and B: 1.1 mg/kg). Elemental analysis at less than mg/kg levels was not possible using LIBS. The elements S and Cu were particularly difficult to analyze with reliability using LIBS at the concentration levels found in the plant samples. Replacing microwave digestion and subsequent ICP analysis with a direct analysis of dried plant samples using LIBS has the potential to improve the productivity and reduce the cost of testing. 相似文献
13.
《中国生态农业学报》2014,(8)
正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications from individuals who have expertise and a record of accomplishment in research areas related to ecology,agro-hydrology, 相似文献
14.
M.A. Callaham Jr. J.M. BlairT.C. Todd D.J. KitchenM.R. Whiles 《Soil biology & biochemistry》2003,35(8):1079-1093
The responses of tallgrass prairie plant communities and ecosystem processes to fire and grazing are well characterized. However, responses of invertebrate consumer groups, and particularly soil-dwelling organisms, to these disturbances are not well known. At Konza Prairie Biological Station, we sampled soil macroinvertebrates in 1994 and 1999 as part of a long-term experiment designed to examine the effects and interactions of annual fire, mowing, and fertilization (N and P) on prairie soil communities and processes. For nearly all taxa, in both years, responses were characterized by significant treatment interactions, but some general patterns were evident. Introduced European earthworms (Aporrectodea spp. and Octolasion spp.) were most abundant in plots where fire was excluded, and the proportion of the total earthworm community consisting of introduced earthworms was greater in unburned, unmowed, and fertilized plots. Nymphs of two Cicada genera were collected (Cicadetta spp. and Tibicen spp.). Cicadetta nymphs were more abundant in burned plots, but mowing reduced their abundance. Tibicen nymphs were collected almost exclusively from unburned plots. Treatment effects on herbivorous beetle larvae (Scarabaeidae, Elateridae, and Curculionidae) were variable, but nutrient additions (N or P) usually resulted in greater densities, whereas mowing usually resulted in lower densities. Our results suggest that departures from historical disturbance regimes (i.e. frequent fire and grazing) may render soils more susceptible to increased numbers of European earthworms, and that interactions between fire, aboveground biomass removal, and vegetation responses affect the structure and composition of invertebrate communities in tallgrass prairie soils. 相似文献
15.
I.L. Boyd 《Biological conservation》2010,143(7):1664-1674
“Wicked” problems are those that are complex and that change when solutions are applied. Many conflicts in conservation fall into this category. The study approached the problem of how to constrain the apparent wickedness of a problem in the conservation management of a species by using simple empirical indicators to carry out iterative assessment of the risk to a population and to document how this risk evolves in relation to the addition of new data and the implementation of management actions. Effects of high levels of uncertainty within data and also concerning population structure were examined through stochastic simulation and by exploration of scenarios. Historical trends in the example used, the Steller sea lion, showed rapid declines in abundance in some regions during the 1980s. The current total population is 130,000-150,000 Steller sea lions through Alaska and British Columbia and this number has been stable since about 1990 in spite of regional differences in population dynamics. Regional differences in the sequence of changes in the number of pups and non-pups, suggested that an internal re-distribution of juveniles could have happened between 1980 and 1990. Current productivity also appears close to the long-term mean. Stochastic population projection using various scenarios showed that, based upon this history, the risk of extinction for the population has declined and is below reasonable thresholds for considering the population to be endangered. The trends in risk suggest that management actions taken since 1990 have probably been effective. Consequently, the conservation management objectives for the Steller sea lion are probably being met. The approach provides a mechanism, based upon experience and scenario analysis, for exploring future policy options and may help to constrain the debate amongst stakeholders about the cost-benefit trade-offs associated with different options. 相似文献
16.
Soil-profile distribution of primary and secondary plant-available nutrients under conventional and no tillage 总被引：1，自引：0，他引：1
Nutrient distributions under no tillage (NT) compared with conventional disk-and-bed tillage (CT) management in the warm, humid region of the southeastern USA need to be assessed so that future placement, quantity, and type of fertilizers can be altered, if necessary, to efficiently match crop demands. We determined soil-profile distributions of pH, N, P, S, K, Ca, Mg, Na, Zn, Fe, Mn, and Cu to a depth of 0.9 m at the end of 8.5 years of continuous CT and NT management on a Weswood silty clay loam (fine, mixed, thermic Fluventic Ustochrept) in southcentral Texas. Most dramatic changes occurred within the 0–0.05 m depth, where soil under NT had lower pH, Fe, and Cu than under CT, but greater P, K, Zn, and Mn. Greater P and K under NT than under CT also occurred below the till-zone (0.15–0.3 m). At a depth of 0–0.3 m, soil under NT contained greater amounts of extractable P, K, Zn, Fe, Mn, and Cu than under CT. Nitrogen fertilization had little effect on nutrient distributions, except resulting in greater extractable K at 0–0.05 m and greater nitrate at 0–0.15 m. Few changes in soil-profile distributions were observed for extractable S, Ca, Mg, and Na. Long-term continuous use of NT on this fine-textured, high-fertility (except for N) soil had no apparent adverse effects on nutrient distributions relative to CT, but enhanced conservation and availability of P, K, Zn, Fe, Mn, and Cu near the soil surface where crop roots proliferate. 相似文献
17.
Grete Skrede Berit Karoline Martinsen Anne-Berit Wold Stein-Erik Birkeland Kjersti Aaby 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2013,63(3):193-208
Abstract A 3-year study was carried out to investigate quality parameters in 14 tree fruit and berry species grown in southern Norway. The species were blueberry, apple, aronia, sour cherry, sweet cherry, red raspberry, strawberry, blackcurrant, gooseberry, red currant and elderberry, harvested along with wild bilberry, cloudberry and lingonberry. Significant differences between species were identified for all quality parameters. The coefficient of variation between species was lowest for pH (12.5%), dry matter (18.9%) and soluble solids (25.3%), followed by titratable acids (59.3%), total phenolics (83.8%), antioxidant capacity FRAP (85.7%) and antiradical power by the DPPH-assay (97.8%), total monomeric anthocyanins (132%) and ascorbic acid (137%). Average coefficient of variation within species were lower and ranged from 4 (pH) to 62% (ascorbic acid). Only the FRAP values were significantly affected by harvesting year with lower levels in 2004 than in 2005 and 2006. There were significant interactions between species and harvesting year for dry matter, soluble solids, pH, ascorbic acid and FRAP. The results indicate generic ranges in composition within species independent upon growing location and climate, and the composition of the tree fruits and berries is not likely to deviate from these ranges. It is concluded that desirable composition of tree fruits and berries and their products should primarily be achieved by selection among species rather than searching fors broadened variation within individual species. 相似文献
18.
《Communications in Soil Science and Plant Analysis》2012,43(7):865-877
Potassium (K) fixation and release in soil are important factors in the long-term sustainability of a cropping system. Changes in K concentration and characteristics of K fixation and release in rhizosphere and nonrhizosphere soils in the rapeseed (Brassica napus L.)–rice (Oryza sativa L.) rotation were investigated using a rhizobox system. The concentrations of different forms of K in both rhizosphere and nonrhizosphere soils decreased with plants compared to without plants, regardless of K fertilizer application. Potassium uptake by crops mainly came from the rhizosphere soil. In the treatment without K fertilizer (–K), the main form of K supplied by the soil to the crops was 1.0 mol L?1 nitric acid (HNO3) nonextractable K, followed by nonexchangeable K, and then exchangeable K. In the treatment with K fertilizer (+K), the main K forms supplied by the soil to the crops were exchangeable K and nonexchangeable K. The amount and rate of K fixation after one cycle of the rapeseed–rice rotation was greater in rhizosphere soil than in nonrhizosphere soil. The amount and rate of K fixation of soil in the +K treatment were significantly less than in the –K treatment. The cumulative amounts of K released with 1.0 mol L?1 ammonium acetate (NH4OAc) and 1.0 mol L?1 HNO3 extraction increased with the increasing numbers of extractions, but the K-releasing power of soil by successive extraction decreased gradually and finally became almost constant. The release of K was less in rhizosphere soil than in nonrhizosphere soil. The release of K in the +K treatment was similar to that in the –K treatment in rhizosphere soil, but the K release in nonrhizosphere soil was greater with the +K than the –K treatment. Overall, the information obtained in this study will be helpful in formulating more precise K fertilizer recommendations for certain soils. 相似文献
19.
Electron donor and pH relationships for biologically enhanced dissolution of chlorinated solvent DNAPL in groundwater 总被引：3，自引：0，他引：3
Biologically enhanced dissolution offers a method to speed removal of chlorinated solvent dense non-aqueous-phase liquid (DNAPL) sources such as tetrachloroethene (PCE) and trichoroethene (TCE) from aquifers. Bioremediation is accomplished by adding an electron donor to the source zone where fermentation to intermediates leading to acetic acid and hydrogen results. The hydrogen and possibly acetic acid are used by dehalogenating bacteria to convert PCE and TCE to ethene and hydrochloric acid. Reductive dehalogenation is thus an acid forming process, and sufficient alkalinity must be present to maintain a near neutral pH. The bicarbonate alkalinity required to maintain pH above 6.5 is a function of the electron donor: 800 mg/L of bicarbonate alkalinity is sufficient to achieve about 1.2 mM TCE dechlorination with glucose, 1.7 mM with lactate, and a much higher 3.3 mM with formate. Laboratory studies indicate that in mixed culture, formate can be used as an electron donor for complete conversion to ethene, contrary to pure cultures studies indicating it cannot. Various strategies can be used to add electron donor to an aquifer for DNAPL dehalogenation while minimizing pH problems and excessive electron donor usage, including use of injection-extraction wells, dual recirculation wells, and nested injection-extraction wells. 相似文献
20.
Yoav Bashan Bernardo Salazar Ma. Esther Puente Macario Bacilio Robert Linderman 《Biology and Fertility of Soils》2009,45(6):585-594
To evaluate the feasibility of long-term desert reforestation technology of mixed vegetation, cardon cactus (Pachycereus pringlei) seedlings from indoor and outdoor nurseries were planted in the field adjacent to one seedling of potential legume nurse
trees: mesquite amargo (Prosopis articulata), yellow palo verde (Parkinsonia microphylla), and blue palo verde (Parkinsonia florida). Some of the planting holes were also supplemented with common dairy compost. Additionally, the combinations of legume tree–cactus
were inoculated with either a consortium of desert arbuscular mycorrhizal (AM) fungi, plant growth promoting bacteria (PGPB;
the diazotroph Azospirillum brasilense Cd, and the phosphate solubilizer Paenibacillus sp.), or a mixture of all. The field experiments were evaluated periodically during 30 months for survival and growth. Cardons
reared in an outdoor screen house survived better in the field than those reared in a controlled growth chamber and hardened
later outdoors. Association with any legume nurse tree increased survival and enhanced growth of untreated cardons. For cardons
growing alone, application of either compost, AM fungi, and all the treatments combined increased survival. For these plants,
no treatment affected plant growth during the first 3 months after transplanting. Later, all treatments, except for AM fungi,
enhanced plant growth. However, only 2 years after transplanting the enhanced growth effect of AM fungi was also significant.
In the presence of the legume nurse trees, transient positive effects on cardon growth were recorded. General evaluation after
30 months of cultivation showed that the treatments positively affected cardon growth when growing alone or in combination
only with mesquite amargo but not with the other two legume trees. This study proposes that young legume trees have the capacity
to enhance survival and growth of cardon cactus, depending on the legume cactus combination. Additional treatments such as
compost or PGPB can either amplify the effect or else attenuate it. 相似文献