共查询到20条相似文献,搜索用时 15 毫秒
1.
Steven K. Schmidt Gregory M. Colores Thomas F. Hess Petra M. Radehaus 《Applied biochemistry and biotechnology》1995,54(1-3):259-270
We have developed a substrate-induced growth response (SIGR) method for quantifying activity and population dynamics of microorganisms
involved in bioremediation processes in soil and bioreactors. The biomass of organisms that can mineralize a given chemical
can be estimated based on the concentration of that chemical needed to induce the growth of the standing population. Estimates
of population size are obtained by using nonlinear regression techniques to fit a simple model of microbial population dynamics
to biodegradation curves. Using this approach we obtain estimates of values for parameters such as initial population size
and growth rate of organisms carrying out biodegradative processes. Our approach was validated by comparing model parameter
estimates with independent estimates of the same parameters from the same bioremediation systems. Examples studied include
pentachlorophenol degraders introduced into soil and 2,4-dinitrophenol degrading organisms in a bioreactor. 相似文献
2.
Duncan Kathleen Levetin Estelle Wells Harrington Jennings Eleanor Hettenbach Susan Bailey Scott Lawlor Kevin Sublette Kerry Berton Fisher J. 《Applied biochemistry and biotechnology》1997,(1):879-889
Analysis of samples taken from three experimental soil lysimeters demonstrated marked long-term effects of managed bioremediation
on soil chemistry and on bacterial and fungal communities 3 yr after the application of crude oil or crude oil and fertilizer.
The lysimeters were originally used to evaluate the short-term effectiveness of managed (application of fertilizer and water,
one lysimeter) vs unmanaged bioremediation (one lysimeter) of Michigan Silurian crude oil compared to one uncontaminated control
lysimeter. Three years following the original experiment, five 2-ft-long soil cores were extracted from each lysimeter, each
divided into three sections, and the like sections mixed together to form composited soil samples. All subsequent chemical
and microbiological analyses were performed on these nine composited samples. Substantial variation was found among the lysimeters
for certain soil chemical characteristics (% moisture, pH, total Kjeldahl nitrogen [TKN], ammonia nitrogen [NH4-N], phosphate phosphorous [PO4-P], and sulfate [SO4
−2]). The managed lysimeter had 10% the level of total petroleum hydrocarbons (TPH-IR) found in the unmanaged lysimeter. Assessment
of the microbial community was performed for heterotropic bacteria, fungi, and aromatic hydrocarbon-degrading bacteria (toluene,
naphthalene, and phenanthrene) by dilution onto solid media. There was little difference in the number of heterotrophic bacteria,
in contrast to counts of fungi, which were markedly higher in the contaminated lysimeters. Hydrocarbon-degrading bacteria
were elevated in both oil-contaminated lysimeters. In terms of particular hydrocarbons as substrates, phenanthrene degraders
were greater in number than naphthalene degraders, which outnumbered toluene degraders. Levels of sulfate-reducing bacteria
seem to have been stimulated by hydrocarbon degradation. 相似文献
3.
Arakaki Atsushi Takeyama Haruko Tanaka Tsuyoshi Matsunaga Tadashi 《Applied biochemistry and biotechnology》2002,98(1-9):833-840
Cadmium recovery by a sulfate-reducing magnetotactic bacterium, Desulfovibrio magneticus strain RS-1, was investigated. D. magneticus precipitated >95% of cadmium at an initial concentration of 1.3 ppm in the growth medium. Electron microscopic analysis revealed
that D. magneticus formed electron-dense particles on its surface when cultivated in the presence of cadmium ions (Cd2+). Sulfide was also found in the precipitate, and the composition ratio of sulfide/cadmium was 0.7. Sixty percent of viable
RS-1 cells was recovered by a simple magnetic separation revealing the removal of 58% cadmium from the culture medium. 相似文献
4.
Jennings David A. Petersen James N. Skeen Rodney S. Hooker Brian S. Peyton Brent M. Johnstone Donald L. Yonge David R. 《Applied biochemistry and biotechnology》1995,(1):727-734
The high nutrient concentrations that would exist near the nutrient injection well during the application of cometabolicin situ bioremediation may lead to the development of significant quantities of biomass at this point in the subsurface. This biomass
can decrease the porosity of the soil to such an extent that nutrient injection is no longer possible. In this work, experiments
were conducted using a porous media biofilm reactor, operated under constant substrate loading conditions, such that the pressure
drop across the reactor was allowed to increase to maintain a constant volumetric flow rate through the reactor. Results suggest
that biomass production, and hence biofilm thickness, near the injection feed port is highly sensitive to substrate loading.
In addition, these variations in biofilm thickness produce dramatic differences in the pressure drop that is attained across
the reactor. Use of the Kozeny-Carman equation can be used to predict that once a critical depth has been exceeded, the pressure
drop across the bed will increase exponentially within biofilm depth. This result means that pressure is not a reliable indicator
of the onset of pore plugging. 相似文献
5.
Th. Spanos V. Simeonov S. Tsakovski D. Thiokas 《Central European Journal of Chemistry》2004,2(2):402-416
The present paper deals with chemometric interpretation of soil analysis data collected from 31 sampling sites in the region
of Kavala and Drama, Northern Greece. The determination of 16 different chemical and physicochemical characteristics is principally
needed for prognosis of the land treatment and fertilizing. The study carried out indicates that the application of multivariate
statistical approaches could reveal new and specific information about sampling sites. It has been found that they could be
divided into four general patterns: pattern 1 contains dominantly inorganic and alkaline soil samples from semi-mountainous
regions in close proximity to the seacoast; pattern 2 indicates the same soil sample type and regional location as pattern
1 but is far from the coastal line; pattern 3 includes samples from sites from the plains with organic and alkaline soils
with close proximity to the coast; pattern 4 resembles pattern 3 as soil type but involves samples from sites far from the
shore. Further, six latent factors were identified, conditionally named “structural”, “acidic”, “nutritional”, “salt”, “microcomponents”
and “organic”. Finally, an apportioning procedure was carried out to find the source contributions in the measured analytical
values. In this way the routine estimation of the soil quality could be improved. 相似文献
6.
Electroanalytical and chromatographic determination of pentachlorophenol and related molecules in a contaminated soil: a real case example 总被引:1,自引:0,他引:1
L. Codognoto V. G. Zuin D. de Souza J. H. Yariwake S. A. S. Machado L. A. Avaca 《Microchemical Journal》2004,77(2):177-184
Electroanalytical and chromatographic methodologies have been applied for the determination of pentachlorophenol (PCP) and some of its derivatives in real soil samples contaminated by industrial discharge. The analytes were extracted with hexane from soil samples collected at different points of the site and mixed to produce a representative sample. Square wave voltammetry (SWV) experiments were carried out on either a boron-doped diamond (BDD) electrode or a gold ultramicroelectrode (Au-UME) in an analyte composed by the Britton-Robinson (B-R) buffer at pH 5.5 with the direct addition of proper amounts of the extract. The voltammetric responses revealed an irreversible anodic peak at approximately 0.80 V vs. Ag/AgCl with a peak current showing a linear dependence on PCP concentration. This linear relationship yielded a detection limit (DL) of 2×10−8 mol l−1 (or 5.5 μg l−1) for the BDD electrode and 6.9×10−8 mol l−1 (18.4 μg l−1) for the Au-UME, while the independently measured HPLC detection limit was 1.1×10−8 mol l−1 (3.0 μg l−1). The application of electroanalytical and chromatographic methodologies in the analysis of soil extracts revealed, besides the PCP responses, signals for some related molecules such as o-tetrachlorobenzoquinone (o-chloranil), hexachlorobenzene and tetrachlorophenol. Recovering experiments for PCP showed a concentration of 27.5 mg kg−1 for the electroanalytical determinations and 26.8 mg kg−1 for the HPLC analysis, values exceedingly high if considering that the maximum residue limit established for natural waters by the Brazilian Environmental Agency is 10 μg l−1. 相似文献
7.
Carbon monoxide (CO) can be metabolized by a number of microorganisms along with water to produce hydrogen (H2) and carbon dioxide. National Renewable Energy Laboratory researchers have isolated a number of bacteria that perform this
so-called water-gas shift reaction at ambient temperatures. We performed experiments to measure the rate of CO conversion
and H2 production in a trickle-bed reactor (TBR). The liquid recirculation rate and the reactor support material both affected the
mass transfer coefficient, which controls the overall performance of the reactor. A simple reactor model taken from the literature
was used to quantitatively compare the performance of the TBR geometry at two different size scales. Good agreement between
the two reactor scales was obtained. 相似文献
8.
Digrazia Philip M. Blackburn James W. Bienkowski Paul R. Hilton Barry Reed Gregory D. King J. M. Henry Sayler Gary S. 《Applied biochemistry and biotechnology》1990,(1):237-252
An experimental and mathematical method is developed for the microbial systems analysis of polyaromatic hydrocarbon (PAH)-degrading
mixed cultures in PAH-contaminated “town gas” soil systems. Frequency response is the primary experimental and data analysis
tool used to probe the structure of these complicated systems. The objective is to provide a fundamental protocol for evaluating
the performance of specific mixed microbial cultures on specific soil systems by elucidating the salient system variables
and their interactions. Two well-described reactor systems, a constant volume stirred tank reactor (CSTR) and a plug flow
differential volume reactor, are used in order to remove performance effects that are related to reactor type as opposed to
system structure. These two reactor systems are well-defined systems that can be described mathematically and represent the
two extremes of one potentially important system variable, macroscopic mass transfer. The experimental and mathematical structure
of the protocol is described, experimental data is presented, and data analysis is demonstrated for the stripping, sorption,
and biodegradation of napththalene. 相似文献
9.
Liquid state, high resolution 13C NMR spectroscopy and mass spectrometry were used to study the composition and structure of soil organic matter (SOM) using
soil extracts from two long-term experiments at the Rothamsted Experimental Station. Both one- and two-dimensional NMR techniques
were applied. 13C NMR sub-spectra of the CH
n
(n=0...3) groups, obtained by the Distortionless Enhancement by Polarisation Transfer (DEPT) technique, were used for the
elucidation of the qualitative and quantitative composition of humic and fulvic acids in the soils. The chemical structure
of SOM was further analysed at the molecular level through Fast Atom Bombardment Mass Spectrometry (FABMS) and Gas Chromatography-Mass
Spectrometry (GC/MS). Humic and fulvic extract results were not only compared to each other, but also to the solid state 13C NMR results for the complete soil sample. 相似文献
10.
Similarities and differences between the retention characteristics of octadecylsilica wettable with water used in TLC and RP-18 used in HPLC have been elucidated by use of the linear relationships between log k and RM. The stationary phases compared were investigated with the same mobile phases—binary mixtures of methanol and water, acetonitrile and water, and tetrahydrofuran and water. For these adsorbents of the same type but differing in specific surface area the correlation line was shifted by log (systemI/systemII). High values of the correlation coefficients obtained over the whole range of mobile phase organic modifier concentration examined indicated that the TLC systems could be used to predict HPLC conditions for flavonoid separation. 相似文献
11.
An alternative to traditional hydrocarbon bioremediation is to pump air through unsaturated soils to create aerobic conditions
and induce biodegradation. This study examines the effects of moisture and nutrient augmentation on biodegradation of petroleum
hydrocarbons in aerated soils. Findings indicate that forced aeration, coupled with additions of nutrients and moisture, stimulate
hydrocarbon-degrading microorganisms and present a feasible approach to bioremediation management. 相似文献
12.
Toyama Hideo Yamagishi Naotsugu Toyama Nobuo 《Applied biochemistry and biotechnology》2002,98(1-9):257-263
We have attempted to develop an active selection system for strains that have a higher potential for Avicel degradation using
haploidized conidia from colchicine-treated Trichoderma reesei Rut C-30 as a model strain. Avicel, absorbent cotton, and wood powder were used as substrates for selection. It appeared
that the strains that degrade Avicel actively could be effectively selected when the solid medium containing the selection
substrate and the liquid medium containing Avicel were used. 相似文献
13.
Arelí Durón-Castellanos Vanesa Zazueta-Novoa Hortencia Silva-Jiménez Yolanda Alvarado-Caudillo Eduardo Peña Cabrera Roberto Zazueta-Sandoval 《Applied biochemistry and biotechnology》2005,121(1-3):279-288
Different soluble NAD+-dependent alcohol dehydrogenase (ADH) isozymes were detected in cell-free homogenates from aerobically grown mycelia of YR-1
strain of Mucor circinelloides isolated from petroleumcontaminated soil samples. Depending on the carbon source present in the growth media, multiple NAD+-dependent ADHs were detected when hexadecane or decane was used as the sole carbon source in the culture media. ADH activities
from aerobically or anaerobically grown mycelium or yeast cells, respectively, were detected when growth medium with glucose
added was the sole carbon source; the enzyme activity exhibited optimum pH for the oxidation of different alcohols (methanol,
ethanol, and hexadecanol) similar to that of the corresponding aldehyde (≈7.0). Zymogram analysis conducted with partially
purified fractions of extracts from aerobic mycelium or anaerobic yeast cells of the YR-1 strain grown in glucose as the sole
carbon source indicated the presence of a single NAD+-dependent ADH enzyme in each case, and the activity level was higher in the yeast cells. ADH enzyme from mycelium grown in
different carbon sources showed high activity using ethanol as substrate, although higher activity was displayed when the
cells were grown in hexadecane as the sole carbon source. Zymogram analysis with these extracts showed that this particular
strain of M. circinelloides has four different isozymes with ADH activity and, interestingly, one of them, ADH4, was identified also as phenanthrene-diol-dehydrogenase,
an enzyme that possibly participates in the aromatic hydrocarbon biodegradation pathway. 相似文献
14.
硫丹在土壤中的降解特性与污染修复模拟研究 总被引:1,自引:0,他引:1
硫丹是具有很高毒性的有机氯农药,历史上我国硫丹产量较大,因此急需硫丹污染场地的修复技术.在实验室条件研究了硫丹在土壤中的降解行为,使用模拟生物堆降解研究了硫丹污染土壤的生物堆修复和化学修复条件.结果表明:在土壤介质中,α-硫丹可部分转化为β-硫丹:硫丹为微生物好氧降解;添加秸秆和绿肥及适当的通气可促进硫丹的降解;添加EM菌或葡萄糖和硝酸铵或复合肥均会抑制硫丹降解.碱性条件有利于硫丹快速降解,因而向污染土壤中添加石灰是一种高效的化学修复方法. 相似文献
15.
Wee Young-Jung Yun Jong-Sun Kang Kui-Hyun Ryu Hwa-Won 《Applied biochemistry and biotechnology》2002,98(1-9):1093-1104
Enterococcus faecalis RKY1, a fumarate-reducing bacterium, was immobilized in an asymmetric hollow-fiber bioreactor (HFBR) for the continuous production
of succinic acid. The cells were inoculated into the shell side of the HFBR, which was operated in transverse mode. Since
the pH values in the HFBR declined during continuous operation to about 5.7, it was necessary to change the feed pH from 7.0
to 8.0 after 24 h of operation in order to enhance production of succinic acid. During continuous operation with a medium
containing fumarate and glycerol, the productivity of succinate was 3.0–10.9 g/(L·h) with an initial concentration of 30 g/L
of fumarate, 4.9–14.9 g/(L·h) with 50 g/L of fumarate, and 7.2–17.1 g/(L·h) with 80 g/L of fumarate for dilution rates between
0.1 and 0.4 h−1. The maximum productivity of succinate obtained by the HFBR (17.1 g of succinate /[L·h]) was 1.7 times higher than that of
the batch bioconversions (9.9 g of succinate /[L·h]) with 80 g/L of fumarate. Furthermore, the long-term stability of the
HFBR was demonstrated with a continuously efficient production of succinate for more than 15 d (360 h). 相似文献
16.
Isolation of strains degrading poly(Vinyl alcohol) at high temperatures and their biodegradation ability 总被引:2,自引:0,他引:2
Thermophilic strains were isolated for the first time using activated sludge retrieved from waste water treatment plant of a poly(vinyl alcohol) (PVA) producing factory for biodegradation of PVA at relatively high temperatures. The isolated strains were identified to be Geobacillus tepidamans, Brevibacillus brevis and Brevibacillus limnophilus. The former strain degraded PVA for itself, while the latter 2 strains digested PVA symbiotically. PVA degradation activity of the isolated strains was assessed at first by the halo zone size formed around the colonies and finally by the modified Sturm test. The biodegradation rate of PVA was explored also in the presence of different dyes, because most of the waste water from PVA-consuming factories contains waste dyes. 相似文献
17.
Jin-Nam Kim Jong-Sok Choo Young-Jung Wee Jong-Sun Yun Hwa-Won Ryu 《Applied biochemistry and biotechnology》2005,123(1-3):861-869
A new acetic acid-producing microorganism, Acetobacter sp. RKY4, was isolated from Korean traditional persimmon vinegar, and we optimized the culture medium for acetic acid production
from ethanol using the newly isolated Acetobacter sp. RKY4. The optimized culture medium for acetic acid production using this microorganism was found to be 40 g/L ethanol,
10 g/L glycerol, 10 g/L corn steep liquor, 0.5 g/L MgSO4·7H2O, and 1.0 g/L (NH4H2PO4. Acetobacter sp. RKY4 produced 47.1 g/L of acetic acid after 48 h of fermentation in a 250 mL Erlenmeyer flask containing 50 mL of the
optimized medium. 相似文献
18.
Pavel Tlustoš Jiřina Száková Alena Stárková Daniela Pavlíková 《Central European Journal of Chemistry》2005,3(4):830-851
Twelve soil samples differing in physicochemical properties and total element contents were extracted by three sequential
extraction procedures to determine As, Cd, Pb, and Zn bound to individual soil fractions and are defined by individual operational
procedures. In the case of arsenic, two additional sequential extraction schemes were designed entirely for fractionation
of soil containing arsenic were tested. The results confirmed that determination of element proportions bound to individual
soil fractions is strongly dependent on the extracting agent and/or procedure applied within individual extracting schemes.
As expected, absolute values of the elements released among the individual extracting procedures are weakly comparable. More
reliable results were determined for the more mobile soil elements i.e. cadmium and zinc, in the fractions characterizing
the most mobile proportions of investigated elements where significant correlations with basic soil characteristics were observed.
In contrast, ambiguous results were observed for As and Pb, for both the individual extraction procedures and the effect of
the soil characteristics. Regardless of the studied element, the poorest results were determined for reducible and oxidizable
soil fractions. The application of at least two independent procedures or modification of the extraction scheme according
to element investigated and/or particular soil characteristics can also be helpful in definition of element pattern in soils
in further research. 相似文献
19.
A novel process is described to efficiently photoconvert low-grade organic materials such as waste biomass into natural biological
plastics. When heterogeneous forms of dry biomass are thermally gasified, relatively homogeneous synthesis gas mixtures composed
primarily of carbon monoxide and hydrogen are produced. Unique strains of photosynthetic bacteria were isolated that nearly
quantitatively photoassimilate the carbon monoxide and hydrogen components of synthesis gas into new cell mass. Under unbalanced
culture conditions when cellular growth is limited by shortages of nitrogen, calcium, magnesium, iron, or essential vitamins,
up to 28% of the new cell mass is found as granules of poly-3-hydroxyalkanoate (PHA), a highmolecular-weight thermoplastic
that can be solvent-extracted. The dominant monomeric unit of PHAs is 3-hydroxybutyrate (3HB), which is polymerized into the
homopolymeric poly-3-hydroxybutyrate (PHB). PHB is marketed as a biodegradable plastic with physical properties similar to
polystyrene. When a green alga was cocultured with the photosynthetic bacterium in light-dark (day-night) cycles, the bacteria
synthesized a polymer of poly-3-hydroxybutyrate-3-hydroxyvalerate (PHB-V) with a composition of 70% 3HB and 30% 3-hydroxyvalerate
(3HV) to an extent of 18% of the new cell mass. PHB-V is commercially marketed as Biopol and has physical properties similar
to polypropylene or polyethylene. Our results demonstrate that a strain of photosynthetic bacteria capable of photoassimilating
synthesis gas or producer gas is a potential candidate for large-scale production of biological polyesters. 相似文献