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131.
T. Al-Surrayai A. Yateem R. Al-Kandari T. Al-Sharrah A. Bin-Haji 《Soil & Sediment Contamination》2009,18(3):354-368
The role of the Conocarpus lancifolius tree in remediaitng oil-contaminated soil, which was bioremediated using conventional methods, was investigated. The selected tree was used to phytoremediate bioremediated oil-contaminated soil for three successive growing seasons. At the end of the phytoremediation experiment, 85.7% of measurable total petroleum hydrocarbon (TPH) was degraded in Conocarpus lancifolius rhizosphere, and the detectable concentrations of some poly aromatic hydrocarbons (PAHs) were less than 0.02 ppm. A number of hydrocarbon degrading microorganisms (HDMs) were isolated at 35°C under aerobic conditions, and were identified using 16S rRNA gene sequencing and fatty acid methyl ester (FAME) analysis. The efficiency of the isolated HDMs in degrading a mixture of hydrocarbon compounds (HC) was assessed. Among the bacterial isolates, Rhodococcus equi was distinguished from the other isolates because of its efficient degradation of some compounds in the HC mixture.
Samples were also collected from Conocarpus lancifolius vegetative parts and were analyzed for heavy metal and mineral accumulation. The results demonstrated that the Conocarpus lancifolius tree was able to uptake high levels of chromium (Cr), vanadium (V), and nickel (Ni) and accumulate them in the tree's roots. Additionally, Conocarpus trees tolerated high concentration and accumulated several metals in all plant tissues. These metals included aluminum (Al), calcium (Ca) and iron (Fe). 相似文献
132.
Allelic genes encoding water-borne signal proteins (pheromones) were amplified and sequenced from the somatic (macronuclear) sub-chromosomic genome of Antarctic and Arctic strains of the marine ciliate, Euplotes nobilii. Their open reading frames appeared to be specific for polypeptide sequences of 83 to 94 amino acids identifiable with cytoplasmic pheromone precursors (pre-pro-pheromones), requiring two proteolytic steps to remove the pre- and pro-segments and secrete the mature pheromones. Differently from most of the macronuclear genes that have so far been characterized from Euplotes and other hypotrich ciliates, the 5′ and 3′ non-coding regions of all the seven E. nobilii pheromone genes are much longer than the coding regions (621 to 700 versus 214 to 285 nucleotides), and the 5′ regions in particular show nearly identical sequences across the whole set of pheromone genes. These structural peculiarities of the non-coding regions are likely due to the presence of intron sequences and provide presumptive evidence that they are site of basic, conserved activities in the mechanism that regulates the expression of the E. nobilii pheromone genes. 相似文献
133.
Chelliah Edward Raja Kolandaswamy Anbazhagan Govindan Sadasivam Selvam 《World journal of microbiology & biotechnology》2006,22(6):577-585
Summary The use of microorganisms to remove heavy metals from industrial effluent is an area of extensive research and development.
Attempts have been made to isolate and characterize metal-resistant microorganisms from treated oil mill industry effluent
wastewater samples. The metal-resistant organisms that showed values of minimum inhibitory concentration towards metals (Cd,
Cr, Ni and Pb) ranging from 100 to 800 ppm level were screened. A potent metal-resistant organism, isolate BC15 from the wastewater
samples was tentatively identified as Pseudomonas sp. Detailed analysis of morphological, biochemical and 16S rDNA sequence of the isolate revealed that it is closely related
to Pseudomonas aeruginosa (94%). Pseudomonas BC15 was capable of absorbing 93% Ni, 65% Pb, 50% Cd and 30% Cr within 48 h from the medium containing 100 mg of each heavy
metal per liter. The multiple metal tolerance of this strain was also associated with resistance to antibiotics such as ampicillin,
tetracycline, chloramphenicol, erythromycin, kanamycin and streptomycin. 相似文献
134.
Aims
One of the outstanding challenges facing humankind is increasing crop production under various types of severe environmental conditions. Many measures have been taken to adopt molecular and biotechnological approaches that lead to the development of transgenic plants able to deal with such harsh and polluted environments. However, such solutions could be very expensive and require considerable efforts and time to achieve these objectives. The main objective of this review is to discuss the new biological solutions that have emerged in the last decade, as environmentally friendly approaches, perhaps to support and/or replace the present efforts. These solutions based on plant–microbe interactions could be a lifeline and promising alternative strategy to create plants with a high resistance to the extreme environments. 相似文献
135.
136.
137.
Srůtková D Spanova A Spano M Dráb V Schwarzer M Kozaková H Rittich B 《Journal of microbiological methods》2011,87(1):10-16
Bifidobacterium longum is considered to play an important role in health maintenance of the human gastrointestinal tract. Probiotic properties of bifidobacterial isolates are strictly strain-dependent and reliable methods for the identification and discrimination of this species at both subspecies and strain levels are thus required. Differentiation between B. longum ssp. longum and B. longum ssp. infantis is difficult due to high genomic similarities. In this study, four molecular-biological methods (species- and subspecies-specific PCRs, random amplified polymorphic DNA (RAPD) method using 5 primers, repetitive sequence-based (rep)-PCR with BOXA1R and (GTG)5 primers and amplified ribosomal DNA restriction analysis (ARDRA)) and biochemical analysis, were compared for the classification of 30 B. longum strains (28 isolates and 2 collection strains) on subspecies level. Strains originally isolated from the faeces of breast-fed healthy infants (25) and healthy adults (3) showed a high degree of genetic homogeneity by PCR with subspecies-specific primers and rep-PCR. When analysed by RAPD, the strains formed many separate clusters without any potential for subspecies discrimination. These methods together with arabionose/melezitose fermentation analysis clearly differentiated only the collection strains into B. longum ssp. longum and B. longum ssp. infantis at the subspecies level. On the other hand, ARDRA analysis differentiated the strains into the B. longum/infantis subspecies using the cleavage analysis of genus-specific amplicon with just one enzyme, Sau3AI. According to our results the majority of the strains belong to the B. longum ssp. infantis (75%). Therefore we suggest ARDRA using Sau3AI restriction enzyme as the first method of choice for distinguishing between B. longum ssp. longum and B. longum ssp. infantis. 相似文献
138.
S. Krause P. M. van Bodegom W. K. Cornwell P. L. E. Bodelier 《Journal of evolutionary biology》2014,27(6):1240-1247
The presence of phylogenetic signal is assumed to be ubiquitous. However, for microorganisms, this may not be true given that they display high physiological flexibility and have fast regeneration. This may result in fundamentally different patterns of resemblance, that is, in variable strength of phylogenetic signal. However, in microbiological inferences, trait similarities and therewith microbial interactions with its environment are mostly assumed to follow evolutionary relatedness. Here, we tested whether indeed a straightforward relationship between relatedness and physiological traits exists for aerobic methane‐oxidizing bacteria (MOB). We generated a comprehensive data set that included 30 MOB strains with quantitative physiological trait information. Phylogenetic trees were built from the 16S rRNA gene, a common phylogenetic marker, and the pmoA gene which encodes a subunit of the key enzyme involved in the first step of methane oxidation. We used a Blomberg's K from comparative biology to quantify the strength of phylogenetic signal of physiological traits. Phylogenetic signal was strongest for physiological traits associated with optimal growth pH and temperature indicating that adaptations to habitat are very strongly conserved in MOB. However, those physiological traits that are associated with kinetics of methane oxidation had only weak phylogenetic signals and were more pronounced with the pmoA than with the 16S rRNA gene phylogeny. In conclusion, our results give evidence that approaches based solely on taxonomical information will not yield further advancement on microbial eco‐evolutionary interactions with its environment. This is a novel insight on the connection between function and phylogeny within microbes and adds new understanding on the evolution of physiological traits across microbes, plants and animals. 相似文献
139.
盐、碱胁迫下小冰麦体内的pH及离子平衡 总被引:13,自引:0,他引:13
通过混合两种中性盐(NaCl和Na2SO4)和两种碱性盐(NaHCO3和Na2CO3)分别模拟出不同强度的盐、碱胁迫条件,对小冰麦苗进行12 d胁迫处理,测定茎叶组织液的pH值及Na+、K+、Ca2+、Cl-、SO42-、NO3-、H2PO4-和有机酸等溶质的浓度,以探讨盐、碱两种胁迫下小冰麦体内的pH及离子平衡特点.结果表明:盐、碱胁迫下小冰麦茎叶内的pH值均稳定不变;随胁迫强度的增加,盐胁迫下小冰麦茎叶内有机酸浓度没有明显变化,Cl-浓度大幅度增加,而碱胁迫下有机酸浓度大幅度增加,Cl-浓度没有明显变化.盐、碱胁迫下小冰麦茎叶中的阳离子均以Na+和K+为主,但阴离子的来源明显不同.盐胁迫下无机阴离子对负电荷的贡献起主导作用,其贡献率达61.3%~66.7%;而碱胁迫下,随胁迫强度的增大,有机酸对负离子的贡献率从38.35%上升到61.60%,逐渐成为主导成分.实验结果表明,有机酸积累是小冰麦在碱胁迫下保持体内离子平衡和pH稳定的关键生理响应. 相似文献
140.
土壤微生物多样性影响因素及研究方法的现状与展望 总被引:37,自引:0,他引:37
土壤微生物是土壤生态系统的重要组成部分, 在土壤有机物质分解和养分释放、能量转移等生物地化循环中起着重要作用。随着人们对生物多样性重要性认识的不断深入及研究方法的不断改进, 土壤微生物多样性, 尤其是功能多样性的研究工作逐渐受到生态学家的重视。本文从土壤微生物多样性的影响因素以及研究方法等方面阐述了目前国内外土壤微生物多样性的研究现状, 并对其未来研究方向进行了展望。 相似文献