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821.
Oluwafemi S. Obayori Sunday A. Adebusoye Adams O. Adewale Ganiyu O. Oyetibo Odunola O. Oluyemi Rashid A. Amokun Matthew O. Ilori 《环境科学学报(英文版)》2009,21(2):243-248
Four hydrocarbon degraders isolated from enriched oil- and asphalt-contaminated soils in Lagos, Nigeria, were tested for their
petroleum degradation potentials. All the isolates were identified as species of Pseudomonas. Pseudomonas putida P11 demonstrated a
strong ability to degrade kerosene, gasoline, diesel, engine oil and crude oil while P. aeruginosa BB3 exhibited fair degradative ability
on crude oil, gasoline, engine oil, anthracene and pyrene but weak on kerosene, diesel and dibenzothiophene. Pseudomonas putida
WL2 and P. aeruginosa MVL1 grew on crude oil and all its cuts tested with the latter possessing similar polycyclic aromatic potentials
as P11. All the strains grew logarithmically with 1–2 orders of magnitude and with generation time ranging significantly between 3.07
and 8.55 d at 0.05 level of confidence. Strains WL2 and MVL1 utilized the oil substrate best with more than 70% in 6 d experimental
period, whereas the same feat was achieved by P11 in 12 d period. BB3 on the other hand degraded only 46% within 6 d. Interestingly,
data obtained from gas chromatographic analysis of oil recovered from the culture fluids of MVL1 confirmed near-disappearance of
major peaks (including aliphatics and aromatics) in the hydrocarbon mixture. 相似文献
822.
823.
The investigation of dissolved organic matter (DOM) on urease, catalase and polyphenol oxidase activity in a phenanthrene (Phe)-
contaminated soil was conducted under laboratory incubation conditions. Values of soil enzymatic activity depended mainly on
incubation time. In the initial 16 days, urease activity increased, and was followed by a decrease. In the initial 8 days, catalase activity
decreased and then increased. Variation of polyphenol oxidase activity was just the reverse of catalase activity. After 30 days of
incubation, no pronounced di erence among treatments with Phe, Phe and DOM, and control were detected in urease, catalase and
polyphenol oxidase activity. Phe might inhibit urease and catalase, and stimulate polyphenol oxidase. DOM could improve inhibition
of Phe in soil urease and catalase activity during the initial period of applying DOM. Nevertheless, DOM had no significant e ect on
polyphenol oxidase activity in the Phe contaminated soil. There was a negative correlation between catalase and polyphenol oxidase
(r = –0.761***), and catalase and urease (r = –0.554**). Additionally, a positive correlation between polyphenol oxidase and urease
was also detected (r = 0.701***). It is implied that the formed DOM after application of organic wastes into soils may counteract the
inhibition of polycyclic aromatic hydrocarbons in soil enzyme activities. 相似文献
824.
超声萃取—高效液相色谱法测定土壤中多环芳烃 总被引:2,自引:0,他引:2
多环芳烃(简称PAHs)是一类具有致癌、致畸及致突变的持久性污染物。可靠的PAHs检测方法是研究其环境行为的重要保证。实验采用超声萃取、用固相萃取柱(SPE-C18)进行净化处理土壤样品,用液相色谱-荧光检测技术对美国环保署(USEAP)优先监测的15种多环芳烃污染物进行定量分析。实验结果表明,该方法对15种PAHs的最低检出限为0.231μg/kg-3.846μg/kg,回收率为51.48%-69.84%,相对标准偏差为6.84%-11.92%。 相似文献
825.
Tobias Weil Katharina Hoffmann Johannes Kroiss Erhard Strohm Judith Korb 《Die Naturwissenschaften》2009,96(2):315-319
In social insects, it is assumed that signals of the queen inform nestmates about her reproductive status. Thus, workers forego
their own reproduction if the queen signals high fertility. In hemimetabolous termites, little is known about reproductive
inhibition, but evidence exists for a royal-pair control. Workers of lower termites exhibit a high developmental flexibility
and are potentially able to become reproductives, but the presence of a fertile reproductive restrains them from reaching
sexual maturity. The nature of this control, however, remains unknown. Here, we report on qualitative differences in cuticular
hydrocarbon profiles between queens and workers of the basal drywood termite Cryptotermes secundus. Queens were characterized by a shift to long-chained and branched hydrocarbons. Most remarkably, similar chemical patterns
are regarded as fertility cues of reproductives in social Hymenoptera. This might suggest that both groups of social insects
convergently evolved similar chemical signatures. The present study provides deeper insights into how termites might have
socially exploited these signatures from sexual communication in their cockroach-like ancestor.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
826.
多环芳烃的分布特征及其与有机碳和黑碳的相关性研究——以汕头国际湿地示范区三种红树林湿地表层沉积物为例 总被引:9,自引:0,他引:9
野外采集了汕头国际湿地示范区内3种红树林湿地(苏埃湾天然次生桐花树林湿地、外砂河口人工种植海桑与无瓣海桑混交林湿地、义丰溪口人工无瓣海桑林湿地)的表层沉积物样品,在实验室内分析了沉积物的多环芳烃、有机碳和黑碳含量.研究了多环芳烃在3种不同红树林湿地沉积物中的分布特征,以及沉积物有机碳、黑碳与多环芳烃的相关性.结果表明:多环芳烃在天然次生红树林湿地沉积物中的累积量显著高于人工恢复红树林湿地沉积物的累积量;不同红树林湿地沉积物对多环芳烃的吸附和累积具有共同的特征,即多环芳烃的组成成分相似,主要组分为菲、荧蒽、芘和苯并(b)荧蒽;除义丰溪口红树林湿地外,多环芳烃在另外2个红树林湿地沉积物中吸附和累积都具有林内含量高于林边缘,林边缘含量高于低潮光滩的特征;有机碳和黑碳对低环多环芳烃的影响不显著,但对高环多环芳烃影响显著,黑碳较之有机碳对高环多环芳烃具有更强的吸附能力. 相似文献
827.
Atmospheric particulate and polycyclic aromatic hydrocarbons (PAHs) size distribution were measured at Jhu-Shan (a rural site)
and Sin-Gang (a town site) in central Taiwan during the rice straw burning and non-burning periods. The concentrations of total PAHs
accounting for a roughly 58% (34%) increment in the concentrations of total PAHs due to rice-straw burning. Combustion-related
PAHs during burning periods were 1.54–2.57 times higher than those during non-burning periods. The mass median diameter (MMD)
of 0.88–1.21 m in the particulate phase suggested that rice-straw burning generated the increase in coarse particle number. Chemical
mass balance (CMB) receptor model analyses showed that the primary pollution sources at the two sites were similar. However, ricestraw
burning emission was specifically identified as a significant source of PAH during burning periods at the two sites. Open burning
of rice straws was estimated to contribute approximately 6.3%–24.6% to total atmospheric PAHs at the two sites. 相似文献
828.
829.
江苏省城市污泥中多环芳烃的含量及其主要影响因素分析 总被引:2,自引:0,他引:2
采用高效液相色谱,对江苏省21家代表性城市污水处理厂污水污泥中多环芳烃含量进行了分析.结果发现,污泥中含有7-16种PAH化合物,都是以2(或3)个苯环的化合物为主,而难降解4-6个苯环的化合物所占质量分数均较低.但污水来源及其处理方式、污泥处理方法等均影响着污泥中PAHs的含量及组成,消化可明显降低污泥中PAHs的含量.污泥中∑PAHs总量在11.68-169.91 mg·kg-1,各污泥间含量差异显著;具有致癌性的PAHs含量在1.17-41.03 mg·kg-1,平均值为6.59mg·kg-1;被列入中国环境"优先污染物"的PAHs含量在4.07-59.06 mg-kg-1之间.其中萘是江苏城市污泥中均含有的PAHs化合物,而对于强致癌性化合物苯并(a)芘,其含量相对较低,在污泥中含量一般在0-2.20 mg·kg-1,平均含量为0.15mg·kg-1,远低于我国农用污泥控制标准的3.0 mg·kg-1. 相似文献
830.