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The potential of Burkholderia cepacia strain RQ1 in the biodegradation of heavy crude oil (Maya) was assessed to develop an active indigenous bacterial consortium for the bioremediation of crude oil-polluted systems in Nigeria. The heavy crude oil (Maya) was utilized as sole source of carbon, attaining maximum cell densities of 10(8) cfu ml(-1) from an initial 10(5) cfu ml(-1) in 15 days. Biomass also increased with oil concentrations up to 0.8% (w/v). Growth rates ranged from 0.028 h(-1) to 0.036 h(-1) and degradation rates decreased with increasing concentrations of oil from 0.009 day(-1) to 0.004 day(-1). The quantity of oil metabolized increased significantly (P < 0.05) with increasing concentrations of oil. However, the growth of the bacterium was inhibited at crude oil concentrations beyond 6% (w/v). The pH of the culture media also dropped significantly (P < 0.05) during the 15-day test period, while the non-asphaltic fractions of the oil were significantly reduced (by about 89%) during the same period. The bacterium harbours a plasmid of about 10 kb that lacks restriction sites for the endonucleases Asp718, BamHI and PstI. 相似文献
23.
PETE SMITH STEPHEN J. CHAPMAN† W. ANDY SCOTT‡ HELAINA I. J. BLACK† MARTIN WATTENBACH RONNIE MILNE§ COLIN D. CAMPBELL† ALLAN LILLY† NICK OSTLE‡ PETER E. LEVY§ DAVID G. LUMSDON† PETER MILLARD† WILLIE TOWERS† SÖNKE ZAEHLE¶ JO U. SMITH 《Global Change Biology》2007,13(12):2605-2609
We present results from modelling studies, which suggest that, at most, only about 10–20% of recently observed soil carbon losses in England and Wales could possibly be attributable to climate warming. Further, we present reasons why the actual losses of SOC from organic soils in England and Wales might be lower than those reported. 相似文献
24.
Mechanisms of action of plant growth promoting bacteria 总被引:1,自引:0,他引:1
Oluwaseyi Samuel Olanrewaju Bernard R. Glick Olubukola Oluranti Babalola 《World journal of microbiology & biotechnology》2017,33(11):197
The idea of eliminating the use of fertilizers which are sometimes environmentally unsafe is slowly becoming a reality because of the emergence of microorganisms that can serve the same purpose or even do better. Depletion of soil nutrients through leaching into the waterways and causing contamination are some of the negative effects of these chemical fertilizers that prompted the need for suitable alternatives. This brings us to the idea of using microbes that can be developed for use as biological fertilizers (biofertilizers). They are environmentally friendly as they are natural living organisms. They increase crop yield and production and, in addition, in developing countries, they are less expensive compared to chemical fertilizers. These biofertilizers are typically called plant growth-promoting bacteria (PGPB). In addition to PGPB, some fungi have also been demonstrated to promote plant growth. Apart from improving crop yields, some biofertilizers also control various plant pathogens. The objective of worldwide sustainable agriculture is much more likely to be achieved through the widespread use of biofertilizers rather than chemically synthesized fertilizers. However, to realize this objective it is essential that the many mechanisms employed by PGPB first be thoroughly understood thereby allowing workers to fully harness the potentials of these microbes. The present state of our knowledge regarding the fundamental mechanisms employed by PGPB is discussed herein. 相似文献
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26.
Douglas G Ward Stephen Nyangoma Howard Joy Emma Hamilton Wenbin Wei Chris Tselepis Neil Steven Michael JO Wakelam Philip J Johnson Tariq Ismail Ashley Martin 《Proteome science》2008,6(1):1-15
Background
Colorectal cancer is the second most common cause of cancer related death in the developed world. To date, no blood or stool biomarkers with both high sensitivity and specificity for potentially curable early stage disease have been validated for clinical use. SELDI and MALDI profiling are being used increasingly to search for biomarkers in both blood and urine. Both techniques provide information predominantly on the low molecular weight proteome (<15 kDa). There have been several reports that colorectal cancer is associated with changes in the serum proteome that are detectable by SELDI and we hypothesised that proteomic changes would also be detectable in urine.Results
We collected urine from 67 patients with colorectal cancer and 72 non-cancer control subjects, diluted to a constant protein concentration and generated MALDI and SELDI spectra. The intensities of 19 peaks differed significantly between cancer and non-cancer patients by both t-tests and after adjusting for confounders using multiple linear regressions. Logistic regression classifiers based on peak intensities identified colorectal cancer with up to 78% sensitivity at 87% specificity. We identified and independently quantified 3 of the discriminatory peaks using synthetic stable isotope peptides (an 1885 Da fragment of fibrinogen and hepcidin-20) or ELISA (β2-microglobulin).Conclusion
Changes in the urine proteome may aid in the early detection of colorectal cancer. 相似文献27.
MARK BOLTON ANDREA L. SMITH ELENA GÓMEZ‐DÍAZ VICKI L. FRIESEN RENATA MEDEIROS JOËL BRIED JOSE L. ROSCALES ROBERT W. FURNESS 《Ibis》2008,150(4):717-727
The existence of two seasonally distinct breeding populations of Oceanodroma storm‐petrels in the Azores islands was first documented in 1996. The discovery of morphological differences between the populations led to the suggestion that they may represent cryptic sibling species. Recent mtDNA and microsatellite analysis from storm‐petrel populations has considerably advanced our understanding of their taxonomic relationships. Here we present new information on the timing of breeding and moult of the two Azores populations, the extent of exchange of individuals between seasons, and diet from feather isotopes. We conclude that the hot‐season Azores population should be considered a new species for which we propose the name Oceanodroma monteiroi, Monteiro's Storm‐petrel. The species is both genetically distinct and genetically isolated from the sympatric cool‐season population of Madeiran Storm‐petrel Oceanodroma castro, and from all other populations of Oceanodroma castro in the Atlantic and Pacific Oceans examined to date. Differences in the vocalizations permit species recognition, and the extent of primary feather wear and stage of moult aids separation of the two species in the Azores, which is especially valuable during August when both attend the breeding colonies in large numbers. Feather carbon and nitrogen isotopes reveal that the diet of Monteiro's Storm‐petrel differs from that of the sympatric Madeiran Storm‐petrel during both breeding and non‐breeding seasons, and unlike the Madeiran Storm‐petrel, Monteiro's Storm‐petrel appears to maintain the same foraging environment during the summer and winter months, though it shows a dietary shift to higher trophic levels during the non‐breeding season. Monteiro's Storm‐petrel is thought to be confined to the Azores archipelago, where it is currently known to nest on just two small neighbouring islets. The total population size was estimated at 250–300 pairs in 1999. 相似文献
28.
ANA C. NORTE PEDRO M. ARAÚJO HUGO L. SAMPAIO JOSÉ P. SOUSA & JAIME A. RAMOS 《Ibis》2009,151(4):677-688
Blood parasites may act as modulators of their hosts' ecology, life histories and fitness. We studied the prevalence of Plasmodium sp., Haemoproteus sp. and Leucocytozoon sp. and their effects on morphological, biochemical and haematological variables and on breeding effort of Great Tits Parus major . Total prevalence (percentage of individuals infected by any parasite) ranged from 7.7% to 61.1%. There was an overall positive association in prevalence between the three haematozoan parasites. No effect of sex or age on infection status was observed. Negative impacts of infection on physiological condition depended largely on year and/or season and included effects on body condition index, plasma protein and haemoglobin index. There were also indications that parasite infection increased immune response and stress levels and activated antioxidant defence mechanisms. Males with higher fledging success had a higher probability of Haemoproteus infection, and females laying heavier eggs had a higher probability of Plasmodium infection. However, clutch size was negatively associated with the probability of infection by Leucocytozoon and Haemoproteus . Surprisingly, males raising second broods had a lower prevalence of both Haemoproteus and Leucocytozoon . Only 5.7% of first-brood nestlings were infected, but those in infected nestboxes had a lower heterophil/lymphocyte ratio. This study confirms the pathogenicity of blood parasites to the host by demonstrating negative effects of infection on both physiology and breeding performance. 相似文献
29.
Olubukola O. Babalola Bronwyn M. Kirby Marilize Le Roes-Hill rew E. Cook S. Craig Cary Stephanie G. Burton Don A. Cowan 《Environmental microbiology》2009,11(3):566-576
Despite the apparent severity of the environmental conditions in the McMurdo Dry Valleys, Eastern Antarctica, recent phylogenetic studies conducted on mineral soil samples have revealed the presence of a wide diversity of microorganisms, with actinobacteria representing one of the largest phylotypic groups. Previous metagenomic studies have shown that the majority of Antarctic actinobacterial populations are classified as 'uncultured'. In this study, we assessed the diversity of actinobacteria in Antarctic cold desert soils by complementing traditional culture-based techniques with a metagenomic study. Phylogenetic analysis of clones generated with actinobacterium- and streptomycete-specific PCR primers revealed that the majority of the phylotypes were most closely related to uncultured Pseudonocardia and Nocardioides species. Phylotypes most closely related to a number of rarer actinobacteria genera, including Geodermatophilus , Modestobacter and Sporichthya , were also identified. While complementary culture-dependent studies isolated a number of Nocardia and Pseudonocardia species, the majority of the cultured isolates (> 80%) were S treptomyces species – although phylotypes affiliated to the genus Streptomyces were detected at a low frequency in the metagenomic study. This study confirms that Antarctic Dry Valley desert soil harbours highly diverse actinobacterial communities and suggests that many of the phylotypes identified may represent novel, uncultured species. 相似文献
30.
Chidi Obasi Allison Agwu Wale Akinpelu Roger Hammons Clyde Clark Ralph Etienne-cummings Peter Hill Richard Rothman Stella Babalola Tracy Ross Karen Carroll Bolanle Asiyanbola 《Annals of surgical innovation and research》2009,3(1):1-9