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1.
Batch experiments were conducted to assess both the biotransformation potentials of one hydrocarbon (α-pinene) and four alcohol
monoterpenes (arbanol, linalool, plinol, and α-terpineol) under nitrate-reducing conditions at 23 °C, as well as their effects
on the nitrate-reducing process. A mixed, nitrate-reducing culture developed from a forest-soil extract was enriched using
ethanol as the electron donor and used in this study. α-Pinene was not biotransformed under the conditions of this study and
inhibited both ethanol and nitrate utilization. Partial transformation of the alcohol monoterpenes was observed and resulted
in inhibition of the nitrate-reducing process and cessation of further utilization of the added monoterpenes. Accumulation
of biotransformation products – mainly hydrocarbon monoterpenes such as camphene, β-myrcene, and d-limonene – was observed. The hydrocarbon monoterpenes formed may have been responsible for the observed inhibition of the
nitrate-reducing process and lack of complete utilization of the alcohol monoterpenes. These results have significant implications
for the expected rate and extent of biotransformation of monoterpenes under anoxic conditions as well as their effect on the
nitrate-reducing process in both engineered and natural systems.
Received: 8 December 1998 / Received revision: 9 June 1999 / Accepted: 27 June 1999 相似文献
2.
In order to evaluate hydrocarbon inputs to Crater Lake from anthropogenic and natural sources, samples of water, aerosol,
surface slick and sediment were collected and analyzed by gas chromatography-mass spectrometry (GC-MS) for determination of
their aliphatic and aromatic hydrocarbon concentrations and compositions. Results show that hydrocarbons originate from both
natural (terrestrial plant waxes and algae) and anthropogenic (petroleum use) sources and are entering the lake through direct
input and atmospheric transport. The concentrations of petroleum hydrocarbons range from low to undetectable. The distributions
and abundances of n-alkanes, polycyclic aromatic hydrocarbons (PAH) and unresolved complex mixture (UCM) from petroleum are similar for all surface
slick sampling sites. The estimated levels of PAH in surface slicks range from 7–9 ng/m2 which are low. Transport of petroleum-derived hydrocarbons from the lake surface has resulted in their presence in some sediments,
particularly near the boat operations mooring (total petroleum HC = 1440 μg/kg, dry wt. compared to naturally derived n-alkanes, 240 μg/kg, dry wt.). The presence of biomarkers such as the tricyclic terpanes, hopanes and steranes in shallow
sediments further confirms petroleum input from boat traffic. In the deep lake sediments, petroleum hydrocarbon concentrations
were very low (16 μg/kg, dry wt.). Very low concentrations of PAH were detected in shallow sediments (17–40 μg/kg at 5 m depth
near the boat operations) and deep sediments (3–15 μg/kg at 580 m depth). The individual PAH concentrations in sediments (μg/kg
or ppb range) are at least three orders of magnitude less than reported threshold effects levels (mg/kg or ppm range, test
amphipod Hyalella azteca). Therefore, no adverse effects are expected to occur in benthic biota exposed to these sediments. Boating activities are leaving a detectable level of petroleum in surface waters and lake sediments but these concentrations are very low. 相似文献
3.
Utilization of sorbed compounds by microorganisms specifically isolated for that purpose 总被引:10,自引:0,他引:10
A bacterium obtained by enrichment on nonsorbed phenanthrene was unable to degrade phenanthrene sorbed to polyacrylic beads
and had little activity on phenanthrene sorbed to lake-bottom sediment. A bacterium obtained by enrichment on phenanthrene
sorbed to polyacrylic beads readily mineralized the compound sorbed to the beads or the sediment. Degradation by the second
bacterium of phenanthrene sorbed to beads 38–63 μm or 63–150 μm in diameter was more rapid than the rate of desorption of
the hydrocarbon in the absence of the bacterium. Little degradation of sorbed, nonleachable phenanthrene in soil was effected
by another isolate obtained by enrichment with the nonsorbed hydrocarbon, but a mixed culture and the bacterium obtained by
enrichment on the sorbed compound extensively degraded phenanthrene. Because microorganisms specifically obtained for their
capacity to degrade sorbed phenanthrene are more active than species not specialized for use of the bound compound, we suggest
that microorganisms enriched on nonsorbed compounds may not be appropriate for evaluation of biodegradation and bioremediation
of sorbed compounds.
Received: 3 June 1997 / Received revision: 2 September 1997 / Accepted: 15 September 1997 相似文献
4.
Enhanced biological phosphorus removal (EBPR) from wastewater can be more-or-less practically achieved but the microbiological
and biochemical components are not completely understood. EBPR involves cycling microbial biomass and influent wastewater
through anaerobic and aerobic zones to achieve a selection of microorganisms with high capacity to accumulate polyphosphate
intracellularly in the aerobic period. Biochemical or metabolic modelling of the process has been used to explain the types
of carbon and phosphorus transformations in sludge biomass. There are essentially two broad-groupings of microorganisms involved
in EBPR. They are polyphosphate accumulating organisms (PAOs) and their supposed carbon-competitors called glycogen accumulating
organisms (GAOs). The morphological appearance of microorganisms in EBPR sludges has attracted attention. For example, GAOs
as tetrad-arranged cocci and clusters of coccobacillus-shaped PAOs have been much commented upon and the use of simple cellular
staining methods has contributed to EBPR knowledge. Acinetobacter and other bacteria were regularly isolated in pure culture from EBPR sludges and were initially thought to be PAOs. However,
when contemporary molecular microbial ecology methods in concert with detailed process performance data and simple intracellular
polymer staining methods were used, a betaproteobacteria called ‘Candidatus Accumulibacter phosphatis’ was confirmed as a PAO and organisms from a novel gammaproteobacteria lineage were GAOs. To preclude making the mistakes of previous researchers, it is recommended that the sludge ‘biography’
be well understood – i.e. details of phenotype (process performance and biochemistry) and microbial community structure should
be linked.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
5.
Gojgic-Cvijovic GD Milic JS Solevic TM Beskoski VP Ilic MV Djokic LS Narancic TM Vrvic MM 《Biodegradation》2012,23(1):1-14
This article presents a study of the efficiency and degradation pattern of samples of petroleum sludge and polluted sandy
soil from an oil refinery. A bacterial consortium, consisting of strains from the genera Pseudomonas, Achromobacter, Bacillus and Micromonospora, was isolated from a petroleum sludge sample and characterized. The addition of nitrogen and phosphorus nutrients and a chemical
surfactant to both the samples and bioaugmentation to the soil sample were applied under laboratory conditions. The extent
of biodegradation was monitored by the gravimetric method and analysis of the residual oil by gas chromatography. Over a 12-week
experiment, the achieved degree of TPH (total petroleum hydrocarbon) degradation amounted to 82–88% in the petroleum sludge
and 86–91% in the polluted soil. Gas chromatography–mass spectrometry was utilized to determine the biodegradability and degradation
rates of n-alkanes, isoprenoids, steranes, diasteranes and terpanes. Complete degradation of the n-alkanes and isoprenoids fractions occurred in both the samples. In addition, the intensities of the peaks corresponding to
tricyclic terpenes and homohopanes were decreased, while significant changes were also observed in the distribution of diasteranes
and steranes. 相似文献
6.
W Wallace S Beshear D Williams S Hospadar M Owens 《Journal of industrial microbiology & biotechnology》1998,20(2):126-131
Wolinella succinogenes HAP-1 is a Gram-negative microaerophile which reduces perchlorate to chloride by the proposed pathway ClO4 to ClO3 to ClO2 to Cl + O2. A cost-effective perchlorate treatment process has been established using a consortium of facultative anaerobic organisms
and W. succinogenes HAP-1. The mixed anaerobic bacterial culture containing W. succinogenes HAP-1 was examined for the ability to form a biofilm capable of perchlorate reduction. An up-flow anaerobic fixed bed reactor
(UAFBR) was packed with diatomaceous earth pellets and operated at residence times of 1.17 and 0.46 h to insure a viable biofilm
had attached to the diatomaceous earth pellets. Reduction rates of perchlorate to chloride in the UAFBR could be maintained
at 1 g of perchlorate reduced h−1 L−1. Studies with the same bacterial consortium in continuously stirred tank reactors (CSTR) generally reduced 0.5–0.7 g of perchlorate
h−1. Viable cell counts were performed periodically on the diatomaceous earth pellets and demonstrated that the W. succinogenes HAP-1 population was maintained at 28–47% of the total microbial population. Scanning electron micrographs demonstrated that
the external and internal surfaces of the diatomaceous pellets were densely colonized with microbial cells of multiple cell
types. This is the first report of an anaerobic mixed culture forming a biofilm capable of perchlorate reduction.
Received 22 May 1997/ Accepted in revised form 07 January 1998 相似文献
7.
The present work attempts to ascertain the efficacy of low cost technology (in our case, composting) as a bioremediation technique
for reducing the hydrocarbon content of oil refinery sludge with a large total hydrocarbon content (250–300 g kg−1), in semiarid conditions. The oil sludge was produced in a refinery sited in SE Spain The composting system designed, which
involved open air piles turned periodically over a period of 3 months, proved to be inexpensive and reliable. The influence
on hydrocarbon biodegradation of adding a bulking agent (wood shavings) and inoculation of the composting piles with pig slurry
(a liquid organic fertiliser which adds nutrients and microbial biomass to the pile) was also studied. The most difficult
part during the composting process was maintaining a suitable level of humidity in the piles. The most effective treatment
was the one in which the bulking agent was added, where the initial hydrocarbon content was reduced by 60% in 3 months, compared
with the 32% reduction achieved without the bulking agent. The introduction of the organic fertiliser did not significantly
improve the degree of hydrocarbon degradation (56% hydrocarbon degraded). The composting process undoubtedly led to the biodegradation
of toxic compounds, as was demonstrated by ecotoxicity tests using luminescent bacteria and tests on plants in Petri dishes. 相似文献
8.
Estuaries are often considered sinks for contaminants and the cleanup of salt marshes, sensitive ecosystems with a major ecological
role, should be carried out by means of least intrusive approaches, such as bioremediation. This study was designed to evaluate
the influence of plant–microorganisms associations on petroleum hydrocarbons fate in salt marshes of a temperate estuary (Lima
River, NW Portugal). Sediments un-colonized and colonized (rhizosediments) by different plants (Juncus maritimus, Phragmites australis, Triglochin striata and Spartina patens) were sampled in four sites of the lower and middle estuary for hydrocarbon degrading microorganisms (HD), total cell counts
(TCC) and total petroleum hydrocarbons (TPHs) assessment. In general, TPHs, HD and TCC were significantly higher (P < 0.05) in rhizosediments than in un-colonized sediments. Also recorded were differences on the abundance of hydrocarbon
degraders among the rhizosediment of the different plants collected at the same site (J. maritimus < P. australis < T. striata), with statistically significant differences (P < 0.05) between J. maritimus and T. striata. Moreover, strong positive correlations—0.81 and 0.84 (P < 0.05), between biotic (HD) and abiotic (organic matter content) parameters and TPHs concentrations were also found. Our
data clearly suggest that salt marsh plants can influence the microbial community, by fostering the development of hydrocarbon-degrading
microbial populations in its rhizosphere, an effect observed for all plants. This effect, combined with the plant capability
to retain hydrocarbons around the roots, points out that salt marsh plant–microorganisms associations may actively contribute
to hydrocarbon removal and degradation in estuarine environments. 相似文献
9.
A mixed bacterial culture capable of biodegrading of jet fuel was isolated from a heavily polluted site in Tapa, Estonia.
Residual concentrations of pollutants in the chemostat culture were determined. The total residual concentrations of dissolved
jet fuel in culture medium were 0.42 and 2.1 μg l-1 at the dilution rates 0.1 and 0.17 h-1respectively. Benzene, toluene, ethylbenzene, and xylenes were completely degraded and thus not detected in culture broth
(detection limit 0.1 μg l-1)at the dilution rates 0.1 and 0.17 h-1. The values of apparent substrate saturation constant(KSapp) in multisubstrate growth conditions were estimated from the experimental data. The residual concentrations satisfy the regulations
in the Republic of Estonia for petroleum hydrocarbons (0.00 mg l-1 – ‘very good’). Results obtained indicate that use of the biodegradation could be sufficient for the treatment of polluted
with kerosene-type jet fuel groundwater up to the acceptable quality.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
10.
快速筛选复杂有机物降解微生物混合菌系,在污染物治理过程中具有重要的实践意义.本研究首次尝试利用MicroRespTM技术分析微生物酶液活性的方法,快速标定高效降解菌及混合菌系的石油烃降解能力,并采用传统的摇瓶培养检测法予以验证.通过微生物胞内、胞外及混合酶液的活性分析,考察了不同酶系(胞外、胞内及混合酶液)、菌系对石油烃分子的降解情况.结果表明: 结合MicroRespTM技术的酶液活性测定法能够快速检测石油烃代谢酶系的降解能力,其灵敏度好、通量高,与传统的菌株摇瓶培养方法的检测结果基本一致.其中,7株菌株的120种全组合菌系活性测定试验在12 h周期内1次完成.筛选周期由传统摇瓶培养所需的7 d缩短10倍以上.以酶活性测定结果为指导设计的复配菌系具有较高的降解效率,最高石油烃降解率达(56.1±1.6)%.表明本筛选方法精度高、通量高,可用于石油烃降解功能菌系的构建. 相似文献
11.
Cultures able to dechlorinate cis-1,2-dichloroethene (cDCE) were selected with ethene (3–20%, v/v) as the sole source of carbon and energy. One mixed culture (K20) could degrade
cDCE (400 μmol l–1) or vinyl chloride (100 μmol l–1) in the presence of ethene (≤ 80 μmol l–1 and ≤ 210 μmol l–1, respectively). This culture consists of at least five bacterial strains. All five strains were able to degrade cDCE cometabolically in pure culture. The mixed culture K20 was highly tolerant against cDCE (up to 6 mmol l–1 in the liquid phase). Degradation of cDCE (200 μmol l–1) was not affected by the presence of trichloroethene (100 μmol l–1) or tetrachloroethene (100 μmol l–1). Transformation yields (Ty, defined as unit mass of chloroethene degraded per unit mass of ethene consumed) of the mixed culture K20 were relatively
high (0.51 and 0.61 for cDCE and vinyl chloride, respectively). The yield for cDCE with ethene as auxiliary substrate was ninefold higher than any values reported with methane or methane/formate as auxiliary
substrate. The viability of the cells of the mixed culture K20 (0.3 mg of cells ml–1) was unaffected by the transformation of ≤ 200 μmol l–1
cDCE in 300 min.
Received: 9 March 1999 / Accepted: 21 July 1999 相似文献
12.
Volatile hydrocarbon biodegradation by a mixed-bacterial culture during growth on Bow River crude oil was investigated using
solid phase microextraction (SPME). Inoculum treatments were examined in relation to C5–C11 hydrocarbon degradation. Up to 1600 mg/l biomass (dry weight) was tested without achieving significant volatile hydrocarbon
partitioning and affecting analysis. Inoculum age rather than concentration had the most profound impact on biodegradation.
When late log phase crude oil-grown inocula were used, C5–C11 biodegradation reached 55–60%; methylcyclohexane and other branched compounds eluting before n-C8 were recalcitrant. Increasing the late log inoculum concentration from 0.63 to 63 mg/l resulted in a twofold increase in
degradation rate without improving the substrate range. Methylcyclohexane recalcitrance was correlated with reduced levels
of hydrocarbon-degrading bacteria and volatile hydrocarbon evaporation from the inoculum flasks. A decreased lag phase prior
to degradation was observed when using early stationary phase cultures as inocula and most compounds up to C11, including methylcyclohexane, were biodegraded. Journal of Industrial Microbiology & Biotechnology (2001) 26, 356–362.
Received 16 November 2000/ Accepted in revised form 17 March 2001 相似文献
13.
P. Olguín-Lora S. Le Borgne G. Castorena-Cortés T. Roldán-Carrillo I. Zapata-Peñasco J. Reyes-Avila S. Alcántara-Pérez 《Biodegradation》2011,22(1):83-93
Haloalkaliphilic sulfur-oxidizing mixed cultures for the treatment of alkaline–saline effluents containing sulfide were characterized
and evaluated. The mixed cultures (IMP-PB, IMP-XO and IMP-TL) were obtained from Mexican alkaline soils collected in Puebla
(PB), Xochimilco (XO) and Tlahuac (TL), respectively. The Ribosomal Intergenic Spacer Analysis (RISA) revealed bacteria related
to Thioalkalibacterium and Thioalkalivibrio in IMP-XO and IMP-PB mixed cultures. Halomonas strains were detected in IMP-XO and IMP-TL. In addition, an uncultured Bacteroides bacterium was present in IMP-TL. Mixed cultures were evaluated at different pH and NaCl concentrations at 30°C. IMP-PB and
IMP-TL expressed thiosulfate-oxidizing activity in the 7.5–10.5 pH range, whereas IMP-XO presented its maximal activity with
19.0 mg O2 gprotein−1 min−1, at pH 10.6; it was not affected by NaCl concentrations up to 1.7 M. In continuous culture, IMP-XO showed a growth rate of
15 day−1, productivity of 433.4 mgprotein l−1 day−1 and haloalkaliphilic sulfur-oxidizing activity was also detected up to 170 mM by means of N-methyl-diethanolamine (MDEA). Saline–alkaline soil samples are potential sources of haloalkaliphilic sulfur-oxidizing bacteria
and the mixed cultures could be applied in the treatment of inorganic sulfur compounds in petroleum industry effluents under
alkaline–saline conditions. 相似文献
14.
Postsynaptic currents and action potentials recorded from neurons in a mixed culture of rat dorsal root ganglion and spinal
cord cells are described. The existence of mutual synaptic connections between the above two types of neurons is demonstrated.
Neirofiziologiya/Neurophysiology, Vol. 38, No. 4, pp. 358–360, July–August, 2006. 相似文献
15.
Acid, alkaline and enzymatic hydrolysis of agricultural crop wastes were compared for yields of total reducing sugars with
the hydrolysates being evaluated for ethanol production using a mixed culture of Zymomonas mobilis and Candida tropicalis. Acid hydrolysis of fruit and vegetable residues gave 49–84 g reducing sugars l−1 and 29–32 g ethanol l−1 was then obtained. Alkaline hydrolysis did not give significant amount of reducing sugars. Enzymatic hydrolysis of fruit
and vegetable residues yielded 36–123 g reducing sugars l−1 and 11–54 g ethanol l−1. 相似文献
16.
A high-yielding serum-free, suspension cell culture process to manufacture recombinant adenoviral vectors for gene therapy 总被引:3,自引:0,他引:3
G. Schoofs T. J. Monica J. Ayala J. Horwitz T. Montgomery G. Roth F. J. Castillo 《Cytotechnology》1998,28(1-3):81-89
We have developed an efficient, reproducible, and scaleable cell culture process for a recombinant adenoviral vector expressing
therapeutic transgenes for clinical trials. HEK 293 cells – which support the propagation of E1 deficient adenovirus – were
first adapted to serum free media and suspension growth. Subsequent studies focused on the infection, virus production and
harvest from suspension culture bioreactors. Future studies are planned to address the kinetics of adenovirus production in
HEK 293 as well as in other cell lines.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
17.
Aerobic bacteria degrading o-nitrobenzaldehyde (ONBA) were isolated from activated sludges. One of the isolates, ONBA-17, was identified as Pseudomonas sp. The isolate could grow on ONBA as its sole source of carbon and nitrogen. Further studies demonstrated that the strain
was a moderately halophilic bacterium and capable of degrading benzoic acid, 2-nitrophenol, 2-aminophenol, 4-hydroxybenzoic
acid, and 4-dimetylaminobenzaldehyde. It could completely degrade 100 mg L−1 ONBA at a range of pH 6–8 in 48 h at 30°C, and up to 400 mg L−1 after 288 h. The strain showed potential to be a good candidate for biotreatment of industrial wastewaters containing ONBA
due to its salt-tolerance ability, multiresistance to some heavy metals and antibiotics, and the abilities of degradation
of aromatic compounds. These findings may help in developing a process for ONBA-containing industrial wastewater treatment. 相似文献
18.
The biodegradation of Bonny light crude petroleum by bacteria in batch culture was enhanced by the addition to culture media, of 0.2 mg of urea and soya bean lecithin per 100 ml of crude oil, sediment and water mixture. Biodegradation was found to be purely an aerobic process. There was a direct relationship between hydrocarbon content and proportion (%) of total heterotrophic count that was capable of growing on crude petroleum as sole carbon and energy source. 相似文献
19.
During cassava starch production, large amounts of cyanoglycosides were released and hydrolysed by plant-borne enzymes, leading
to cyanide concentrations in the wastewater as high as 200 mg/l. For anaerobic degradation of the cyanide during pre-acidification
or single-step methane fermentation, anaerobic cultures were enriched from soil residues of cassava roots and sewage sludge.
In a pre-acidification reactor this culture was able to remove up to 4 g potassium cyanide/l of wastewater at a hydraulic
retention time (t
HR) of 4 days, equivalent to a maximal cyanide space loading of 400 mg CN− l−1 day−1. The residual cyanide concentration was 0.2–0.5 mg/l. Concentrated cell suspensions of the mixed culture formed ammonia and
formate in almost equimolar amounts from cyanide. Little formamide was generated by chemical decay. A concentration of up
to 100 mmol ammonia/l had no inhibitory effect on cyanide degradation. The optimal pH for cyanide degradation was 6–7.5, the
optimal temperature 25–37 °C. At a pH of 5 or lower, cyanide accumulated in the reactor and pre-acidification failed. The
minimal t
HR for continuous cyanide removal was 1.5 days. The enriched mixed culture was also able to degrade cyanide in purely mineralic
wastewater from metal deburring, either in a pre-acidification reactor with a two-step process or in a one-step methanogenic
reactor. It was necessary to supplement the wastewater with a carbon source (e.g. starch) to keep the population active enough
to cope with any possible inhibiting effect of cyanide.
Received: 29 April 1998 / Received revision: 8 June 1998 / Accepted: 14 June 1998 相似文献
20.
Manoj Kumar Vladimir León Angela De Sisto Materano Olaf A. Ilzins Luis Luis 《World journal of microbiology & biotechnology》2008,24(7):1047-1057
A hydrocarbon degrading and biosurfactant producing, strain DHT2, was isolated from oil-contaminated soil. The organism grew
and produced biosurfactant when cultured in variety of substrates at salinities up to 6 g l−1 and temperatures up to 45°C. It was capable of utilizing crude oil, fuels, alkanes and PAHs as carbon source across the wide
range of temperature (30–45°C) and salinity (0–6%). Over the range evaluated, the salinity and temperature did not influence
the degradation of hydrocarbon and biosurfactant productions. Isolate DHT2 was identified as Pseudomonas aeruginosa by analysis of 16S rRNA sequences (100% homology) and biochemical analysis. PCR and DNA hybridization studies revealed that
enzymes involved in PAH metabolism were related to the naphthalene dioxygenase pathway. Observation of both tensio-active
and emulsifying activities indicated that biosurfactants were produced by DHT2 during growth on both, water miscible and immiscible
substrates, including PAH. The biosurfactants lowered the surface tension of medium from 54.9 to 30.2 dN/cm and formed a stable
emulsion. The biosurfactant produced by the organism emulsified a range of hydrocarbons with hexadecane as best substrate
and toluene was the poorest. These findings further indicate that the isolate could be useful for bioremediation and bio-refining
application in petroleum industry. 相似文献