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1.
M. Eriksson A. Swartling G. Dalhammar J. Fäldt A.-K. Borg-Karlson 《Applied microbiology and biotechnology》1998,50(1):129-134
Solid-phase micro-extraction (SPME) was used for monitoring degradation of hydrocarbons in diesel-fuel-contaminated (1% v/v)
water and soil. Natural soil bacteria with and without external addition of inoculum were used. Directly after a 10-s exposure
of the sample, the polydimethylsiloxane fibre was injected into the GC-MS. This method strongly reduced the time of analysis
compared to a conventional liquid/liquid extraction. A comparison of SPME and pentane extraction of diesel oil was made and
found to be consistent. The degradation of diesel fuel in water was monitored for 10 weeks using SPME. After 5 weeks all hydrocarbons
were degraded except for the decahydronaphthalenes. These compounds were approximately 3% of the total hydrocarbons in the
diesel oil used and remained undegraded throughout the study although none of the chemical or physical parameters was limiting.
In the soil study the degradation of diesel fuel in normal soil was completed after 3 weeks, when the only remaining substances
were decahydronaphthalenes. All samples were compared to sterile references to make up for evaporation losses. SPME proved
to be a fast and reliable method to monitor changes in concentrations of semi-volatile organic compounds.
Received: 23 December 1997 / Received revision: 5 February 1998 / Accepted: 27 February 1998 相似文献
2.
C. Löser H. Seidel A. Zehnsdorf U. Stottmeister 《Applied microbiology and biotechnology》1998,49(5):631-636
Microbial hydrocarbon degradation in soil was studied during periodical aerobic/anaerobic switching and under purely aerobic
conditions by using a pilot-scale plant with diesel-fuel-contaminated sand. The system worked according to the percolation
principle with controlled circulation of process water and aeration. Periodical switching between 4 h of aerobic and 2 h of
anaerobic conditions was achieved by repeated saturation of the soil with water. Whatever the cultivation mode, less than
50% of the diesel was degraded after 650 h because the hydrocarbons were adsorbed. Contrary to expectations, aerobic/anaerobic
changes neither accelerated the rate of degradation nor reduced the residual hydrocarbon content of the soil. Obviously the
pollutant degradation rate was determined mainly by transport phenomena and less by the efficiency of microbial metabolism.
The total mass of oxygen consumed and carbon dioxide produced was greater under aerobic/anaerobic changing than under aerobic
conditions, although the mass of hydrocarbons degraded was nearly the same. As shown by an overall balance of microbial growth
and by a carbon balance, the growth yield coefficient was smaller during aerobic/anaerobic changes than under aerobic conditions.
Received: 25 November 1997 / Received revision: 15 January 1998 / Accepted: 18 January 1998 相似文献
3.
Bacterial dehalogenation 总被引:16,自引:0,他引:16
S. Fetzner 《Applied microbiology and biotechnology》1998,50(6):633-657
Halogenated organic compounds are produced industrially in large quantities and represent an important class of environmental
pollutants. However, an abundance of haloorganic compounds is also produced naturally. Bacteria have evolved several strategies
for the enzyme-catalyzed dehalogenation and degradation of both haloaliphatic and haloaromatic compounds: (i) Oxidative dehalogenation
is the result of mono- or dioxygenase-catalyzed, co-metabolic or metabolic reactions. (ii) In dehydrohalogenase-catalyzed
dehalogenation, halide elimination leads to the formation of a double bond. (iii) Substitutive dehalogenation in most cases
is a hydrolytic process, catalyzed by halidohydrolases, but there also is a “thiolytic” mechanism with glutathione as cosubstrate.
Dehalogenation by halohydrin hydrogen-halide lyases is the result of an intramolecular substitution reaction. (iv) A distinct
dechlorination mechanism involves methyl transfer from chloromethane onto tetrahydrofolate. (v) Reductive dehalogenations
are co-metabolic processes, or they are specific reactions involved in substrate utilization (carbon metabolism), or reductive
dehalogenation is coupled to energy conservation: some anaerobic bacteria use a specific haloorganic compound as electron
acceptor of a respiratory process. This review discusses the mechanisms of enzyme-catalyzed dehalogenation reactions, describes
some pathways of the bacterial degradation of haloorganic compounds, and indicates some trends in the biological treatment
of organohalogen-polluted air, groundwater, soil, and sediments.
Received: 24 June 1998 / Received revision: 1 September 1998 / Accepted: 3 September 1998 相似文献
4.
J. Benitez J. Beltran-Heredia J. Torregrosa J. L. Acero V. Cercas 《Applied microbiology and biotechnology》1997,47(2):185-188
The degradation of olive mill wastewater by aerobic microorganisms has been investigated in a batch reactor, by conducting
experiments where the initial concentration of organic matter, quantified by the chemical oxygen demand, and the initial biomass
were varied. The evolution of the chemical oxygen demand, biomass and the total contents of phenolic and aromatic compounds
were followed through each experiment. According to the Contois model, a kinetic expression for the substrate utilization
rate is derived, and its biokinetic constants are evaluated. This final predicted equation agrees well with all the experimental
data.
Received: 12 June 1996 / Received revision: 11 September 1996 / Accepted: 13 September 1996 相似文献
5.
Bioremediation of soil contaminated by organic compounds can remove the contaminants to a large extent, but residual contamination
levels may remain which are not or only slowly biodegraded. Residual levels often exceed existing clean-up guidelines and
thereby limit the use of bioremediation in site clean-up. A method for estimating the expected residual levels would be a
useful tool in the assessment of the feasability of bioremediation. In this study, three soil types from a creosote-contaminated
field site, which had been subjected to 6 months of bioremediation in laboratory column studies, were used to characterize
the residual contamination levels and assess their availability for biodegradation. The soils covered a wide range of organic
carbon levels and particle size distributions. Results from the biodegradation studies were compared with desorption rate
measurements and selective extractability using butanol. Residual levels of polycyclic aromatic hydrocarbons after bioremediation
were found to be strongly dependent on soil type. The presence of both soil organic matter and asphaltic compounds in the
soil was found to be associated with higher residual levels. Good agreement was found between the biodegradable fraction and
the rapidly desorbable fraction in two of the three soils studied. Butanol extraction was found to be a useful method for
roughly estimating the biodegradable fraction in the soil samples. The results indicate that both desorption and selective
extraction measurements could aid the assessment of the feasability for bioremediation and identifying acceptable end-points.
Received: 15 September 1999 / Received revision: 7 February 2000 / Accepted: 13 February 2000 相似文献
6.
Biodegradation of EDTA 总被引:8,自引:0,他引:8
B. Nörtemann 《Applied microbiology and biotechnology》1999,51(6):751-759
The chelating agent ethylenediaminetetraacetate (EDTA) is not degraded by conventional biological and physicochemical methods
for the treatment of wastewater and the purification of drinking water. Of the measurable organic compounds it is the one
present at the highest concentration in many surface and drinking waters. In recent years, however, studies have demonstrated
that EDTA can be degraded by specially enriched bacterial cultures and in wastewater treatment plants receiving EDTA-containing
effluents. The amounts of EDTA released into the aquatic environment could thus be reduced by establishing appropriate biological
wastewater treatment plants. This article describes the degradation of EDTA and its metal chelates by different bacterial
cultures, catabolic steps in EDTA degradation, and biological methods for the removal of this chelating agent from wastewaters.
Received: 14 September 1998 / Received revision: 9 December 1998 / Accepted: 11 December 1998 相似文献
7.
Initiation of [36Cl]hexachlorobenzene dechlorination in three different soils under artificially induced anaerobic conditions 总被引:1,自引:0,他引:1
P. Rosenbrock R. Martens F. Buscot J. C. Munch 《Applied microbiology and biotechnology》1997,48(1):115-120
The potential for reductive dechlorination of hexachlorobenzene was investigated in samples of three different, naturally
oxic soils held under conditions of high oxygen deficiency. The soils were water-saturated and the influence on dechlorination
of adding different electron donors, a surfactant and an anaerobic microbial consortium was tested. The influence of supplied
electron donors seems to depend on the organic matter content of the soils. Dechlorination in the organic-matter-rich soil
from Maulach was not affected by amendment with organic electron donors. A release of about 40% chloride within 140 days was
observed for this soil in all biotic-treated assays. By contrast, the organic-matter-poor soil of Eppingen showed no dechlorination
in unamended assays. However, when it was supplemented with organic electron donors dechlorination of 2%–37% occurred within
140 days, depending on the type of electron donor. Complex substrate (wheat strawdust), from which carbon is slowly liberated,
gave the best results. These two soils had an indigenous dechlorinating anaerobic microflora, whereas the third soil (Rastatt)
required inoculation with an anaerobic consortium for dechlorination. The addition of electron donors alone did not cause
dechlorination in this sandy soil. The addition of a surfactant (Tween 80) to increase the bioavailability of hexachlorobenzene
did not enhance dechlorination. This process was not inhibited by inherent alternative electron acceptors in soil (NO3−, SO4
2−, Fe3+). The dechlorination did not require methanogenic conditions.
Received: 12 December 1996 / Received revision: 14 March 1997 / Accepted: 15 March 1997 相似文献
8.
Repeated application of carvone-induced bacteria to enhance biodegradation of polychlorinated biphenyls in soil 总被引:4,自引:0,他引:4
Carvone, the principal component of spearmint oil, induces biodegradation of polychlorinated biphenyls (PCB) by Arthrobacter sp. strain B1B. This study investigated the effectiveness of the repeated application of carvone-induced bacteria for bioremediation
of Aroclor-1242-contaminated soil. Control treatments compared a single inoculation of carvone-induced cells, repeated applications
of noninduced cells, and repeated applications of cell-free carvone/fructose medium. The results showed that repeated application
of carvone-induced bacteria was the most effective treatment for mineralizing PCB, resulting in 27 ± 6% degradation of Aroclor
1242 after 9 weeks; whereas a single application of cells resulted in no significant degradation. Addition of cell-free, carvone/fructose
medium resulted in 10% degradation of PCB, which suggests that this treatment stimulated biodegradation of PCB by the indigenous
microflora. The di- and trichlorobiphenyls were the most readily degraded congeners. More highly chlorinated congeners, which
had been previously shown to be degraded in liquid culture, were not substantially degraded in soil, indicating that low bioavailability
may have limited their degradation. With the development of new technology, which permits automated in situ fermentation and
delivery of degrader microorganisms, the repeated application of carvone-induced bacteria may facilitate bioremediation of
PCB-contaminated soils.
Received: 7 January 1998 / Received revision: 18 June 1998 / Accepted: 27 June 1998 相似文献
9.
Bioremediation of two diesel-oil-contaminated alpine subsoils, differing in soil type and bedrock, was investigated in laboratory
experiments at 10 °C after supplementation with an inorganic fertilizer. Initial diesel oil contamination of 4000 mg kg−1 soil dry matter (dm) was reduced to 380–400 mg kg−1 dm after 155 days of incubation. In both soils, about 30 % of the diesel oil contamination (1200 mg kg−1 dm) was eliminated by abiotic processes. The residual decontamination (60 %–65 %) could be attributed to microbial degradation
activities. In both soils, the addition of a cold-adapted diesel-oil-degrading inoculum enhanced biodegradation rates only
slightly and temporarily. From C/N and N/P ratios (determined by measuring the contents of total hydrocarbons, NH4
+ N, NO3
− N and PO4
3− P) of soils␣it could be deduced that there was no nutrient deficiency during the whole incubation period. Soil biological
activities (basal respiration and dehydrogenase activity) corresponded to the course of biodegradation activities in the soils.
Received: 9 September 1996 / Accepted: 7 December 1996 相似文献
10.
Bacterial catabolic transposons 总被引:14,自引:0,他引:14
Tan HM 《Applied microbiology and biotechnology》1999,51(1):1-12
The introduction of foreign organic hydrocarbons into the environment in recent years, as in the widespread use of antibiotics,
has resulted in the evolution of novel adaptive mechanisms by bacteria for the biodegradation of the organic pollutants. Plasmids
have been implicated in the catabolism of many of these complex xenobiotics. The catabolic genes are prone to undergo genetic
rearrangement and this is due to their presence on transposons or their association with transposable elements. Most of the
catabolic transposons have structural features of the class I (composite) elements. These include transposons for chlorobenzoate
(Tn5271), chlorobenzene (Tn5280), the newly discovered benzene catabolic transposon (Tn5542), and transposons encoding halogenated alkanoates and nylon-oligomer-degradative genes. Transposons for the catabolism of
toluene (Tn4651, Tn4653, Tn4656) and naphthalene (Tn4655) belong to class II (Tn3 family) elements. Many catabolic genes have been associated with insertion sequences, which suggests that these gene clusters
could be rapidly disseminated among the bacterial populations. This greatly expands the substrate range of the microorganisms
in the environment and aids the evolution of new and novel degradative pathways. This enhanced metabolic versatility can be
exploited for and is believed to play a major part in the bioremediation of polluted environments.
Received: 13 July 1998 / Received revision: 22 September 1998 / Accepted: 26 September 1998 相似文献
11.
M. Eriksson G. Dalhammar A.-K. Borg-Karlson 《Applied microbiology and biotechnology》1999,51(4):532-535
A hydrocarbon mixture containing p-xylene, naphthalene, Br-naphthalene and straight aliphatic hydrocarbons (C14 to C17) was aerobically degraded without lag phase by a natural uncontaminated potting soil at 20 °C and 6 °C. Starting concentrations
were approximately 46 ppm for the aromatic and 13 ppm for the aliphatic compounds. All aliphatic hydrocarbons were degraded
within 5 days at 20 °C, to levels below detection (ppb levels) but only down to 10% of initial concentration at 6 °C. Naphthalene
was degraded within 12 days at 20 °C and unaffected at 6 °C. At 20 °C p-xylene was degraded within 20 days, but no degradation occurred at 6 °C. Br-naphthalene was only removed down to 30% of initial
concentration at 20 °C, with no significant effect at 6 °C. The biodegradation was monitored with head space solid-phase microextraction
and gas chromatography–mass spectrometry.
Received: 5 October 1998 / Received revision: 4 December 1998 / Accepted: 5 December 1998 相似文献
12.
When grown on vegetable oils and their derivatives, the smut fungus Ustilago maydis (DSM 4500 and ATCC 14826) produces several glycolipids under nitrogen-limiting conditions. With 45 g l−1 sunflower oil fatty acids (technical grade) a yield of 30 g l−1 glycolipid was achieved. The resulting mixture contained predominantly mannosylerythritol lipids together with smaller amounts
of cellobiose lipids. The production of the more polar cellobiose lipids was enhanced when glucose was used as carbon source.
The molecular structure of the main components of the glycolipid mixture were elucidated by a combination of NMR spectroscopic
and mass-spectrometric techniques.
Received: 22 June 1998 / Received revision: 11 September 1998 / Accepted: 13 September 1998 相似文献
13.
Solano-Serena F Marchal R Huet T Lebeault JM Vandecasteele JP 《Applied microbiology and biotechnology》2000,54(1):121-125
The biodegradability under aerobic conditions of volatile hydrocarbons (4–6 carbons) contained in gasoline and consisting
of n-alkanes, iso-alkanes, cycloalkanes and alkenes, was investigated. Activated sludge was used as the reference microflora. The biodegradation
test involved the degradation of the volatile fraction of gasoline in closed flasks under optimal conditions. The kinetics
of biodegradation was monitored by CO2 production. Final degradation was determined by gas chromatographic analysis of all measurable hydrocarbons (12 compounds)
in the mixture after sampling the headspace of the flasks. The degradation of individual hydrocarbons was also studied with
the same methodology. When incubated individually, all hydrocarbons used as carbon sources, except 2,2-dimethylbutane and
2,3-dimethylbutane, were completely consumed in 30 days or less with different velocities and initial lag periods. When incubated
together as constituents of the light gasoline fraction, all hydrocarbons were metabolised, often with higher velocities than
for individual compounds. Cometabolism was involved in the degradation of dimethyl isoalkanes.
Received: 19 October 1999 / Received revision: 21 January 2000 / Accepted: 23 January 2000 相似文献
14.
J. H. de Best A. Hage H. J. Doddema D. B. Janssen W. Harder 《Applied microbiology and biotechnology》1999,51(2):277-283
A methanogenic mixed population in a packed-bed reactor completely transformed 1,1,1-trichloroethane (10 μM) to chloroethane
by a cometabolic process. Chloroethane was not further transformed. Acetate and methanol served as electron donors. Complete
transformation of 1,1,1-trichloroethane to chloroethane only occurred when sufficient electron donor was fed into the reactor.
Otherwise, besides chloroethane, 1,1-dichloroethane was also found as a product. The products of 1,1,1-trichloroethane transformation
also depended on the type of electron donor present. With acetate, the degree of dechlorination was higher, i.e. more 1,1,1-trichloroethane
was transformed to chloroethane than with methanol. In an enrichment culture obtained from the reactor contents, 1,1,1-trichloroethane
was only transformed to 1,1-dichloroethane and was not further metabolized. Methanol, acetate, formate, ethanol, 2-propanol,
trimethylamine and H2, but not dimethylamine and methylamine, served as electron donors for 1,1,1-trichloroethane transformation by this enrichment
culture. Both nitrate and nitrite inhibited 1,1,1-trichloroethane transformation; while nitrate completely inhibited 1,1,1-trichloroethane
dechlorination, some conversion did occur in the presence of nitrite. The product(s) of this conversion remain unknown, since
no chlorinated hydrocarbons were detected.
Received: 19 June 1998 / Received revision: 14 September 1998 / Accepted: 17 September 1998 相似文献
15.
Containment of a genetically engineered microorganism during a field bioremediation application 总被引:6,自引:0,他引:6
A field release of a genetically engineered microorganism was performed at the Field Lysimeter Site on the Oak Ridge Reservation.
Six large lysimeters were filled with soil that had been contaminated with a mixture of naphthalene, phenanthrene, and anthracene.
A genetically engineered bacterial strain, Pseudomonas fluorescens HK44, was sprayed onto the surface of the soil during soil loading. This strain contains a fusion between the lux genes of Vibrio fischeri and the promoter for the lower pathway of naphthalene degradation, enabling the strain to become bioluminescent when it is
degrading naphthalene. Release of the bacteria outside the lysimeters was monitored, using selective agar plates and one-stage
Anderson air samplers. Although approximately 1014 bacteria were sprayed during the loading process, escape was only detected sporadically; the highest incidence of bacterial
escape was found when the relative humidity and wind speed were low.
Received: 6 March 1998 /thinsp;Received revision: 16 September 1998 / Accepted: 16 October 1998 相似文献
16.
R. Beaudet M.-J. Lévesque R. Villemur M. Lanthier M. Chénier F. Lépine J.-G. Bisaillon 《Applied microbiology and biotechnology》1998,50(1):135-141
Anaerobic biodegradation of pentachlorophenol (PCP) in a contaminated soil from a wood-treating industrial site was studied
in soil slurry microcosms inoculated with a PCP-degrading methanogenic consortium. When the microcosms containing 10%–40%
(w/v) soil were inoculated with the consortium, more than 90% of the PCP was removed in less than 30 days at 29 °C. Less-chlorinated
phenols, mainly 3-chlorophenol were slowly degraded and accumulated in the cultures. Addition of glucose and sodium formate
to the microcosms was not necessary, suggesting that the organic compounds in the soil can sustain the dechlorinating activity.
Inoculation of Desulfitobacterium frappieri strain PCP-1 along with a 3-chlorophenol-degrading consortium in the microcosms also resulted in the rapid dechlorination
of PCP and the slow degradation of 3-chlorophenol. Competitive polymerase chain reaction experiments showed that PCP-1 was
present at the same level throughout the 21-day biotreatment. D. frappieri, strain PCP-1, inoculated into the soil microcosms, was able to remove PCP from soil containing up to 200 mg PCP/kg soil.
However, reinoculation of the strain was necessary to achieve more than 95% PCP removal with a concentration of 300 mg and
500 mg PCP/kg soil. These results demonstrate that D. frappieri strain PCP-1 can be used effectively to dechlorinate PCP to 3-chlorophenol in contaminated soils.
Received: 14 November 1997 / Received revision: 29 January 1998 / Accepted: 24 February 1998 相似文献
17.
N. Christiansen S. R. Christensen E. Arvin B. K. Ahring 《Applied microbiology and biotechnology》1997,47(1):91-94
Reductive dechlorination of tetrachloroethene was studied in a mesophilic upflow anaerobic sludge blanket reactor. Operating
the reactor in batch mode the dynamic transformation of tetrachloroethene, trichloroethene and dichloroethene (DCE) was monitored.
Tetrachloroethene was reductively dechlorinated to trichloroethene, which again was dechlorinated at the same rate as DCE
was produced. DCE showed a lag period of 40 h before transformation was observed. During normal reactor operation trans-1,2-DCE was the major DCE isomer, followed by cis-1,2-DCE. Small amounts of 1,1-DCE but no vinyl chloride were detected. When the influent tetrachloroethene concentration
was increased from 4.6 μM to 27 μM, the transformation rate increased, indicating that the system was not saturated with tetrachloroethene.
The main organic component in the effluent was acetate, indicating that the aceticlastic methane-producing bacteria were inhibited
by the chlorinated ethenes.
Received: 29 July 1996 / Received revision: 13 September 1996 / Accepted: 13 September 1996 相似文献
18.
The majority of lignin-degrading basidiomycetes are able to depolymerize humic acids. In this presentation the relationship
and possible similarities between enzymes involved in lignin degradation and humic acid depolymerization were examined on
the genetic level. We have cloned fragments of the gene encoding the extracellular ligninolytic enzyme laccase from Clitocybula dusenii, Nematoloma frowardii and a fungal strain designated i63-2, and compared the three sequences with those of several other published laccase genes.
The sequenced fragments displayed a high homology both on the DNA (97%–77%) and amino acid (100%–85%) level. Furthermore,
the expression of this gene in the above-mentioned fungi was demonstrated by a nested polymerase chain reaction with cDNA
as template.
Received: 3 February 1998 / Received revision: 31 August 1998 / Accepted: 3 September 1998 相似文献
19.
Guieysse B Bernhoft I Andersson BE Henrysson T Olsson S Mattiasson B 《Applied microbiology and biotechnology》2000,54(6):826-831
Biofilm reactors are particularly suitable for the treatment of large amounts of diluted effluent, such as groundwater contaminated
with scarcely soluble pollutants. A packed-bed column reactor was tested for the degradation of acenaphthene, phenanthrene
and pyrene provided at their aqueous solubility concentrations. Acenapthene and phenanthrene were removed to more than 99%
efficiency from this reactor whilst pyrene was removed to 90%. Pollutant disappearance was also recorded in the control reactor
and was probably caused by the adsorption of pollutants into the reactor. The measurement of oxygen consumption in both reactors
confirmed that microbial degradation of the pollutants was indeed occurring in the inoculated reactor. Physical adsorption
is not however unwanted, as it could help with the formation of a biofilm at an early stage of the treatment.
Received: 29 February 2000 / Received revision: 30 May 2000 / Accepted: 3 June 2000 相似文献
20.
The possibility of enhancing the ex situ bioremediation of a chronically polychlorinated biphenyl (PCB)-contaminated soil
by using Triton X-100 or Quillaya Saponin, a synthetic and a biogenic surfactant, respectively, was studied. The soil, which
contained about 350 mg/kg of PCBs and indigenous aerobic bacteria capable of growing on biphenyl or on monochlorobenzoic acids,
was amended with inorganic nutrients and biphenyl, saturated with water and treated in aerobic batch slurry- and fixed-phase
reactors. Triton X-100 and Quillaya Saponin were added to the reactors at a final concentration of 10 g/l at the 42nd day
of treatment, and at the 43rd and 100th day, respectively. Triton X-100 was not metabolised by the soil microflora and it
exerted inhibitory effects on the indigenous bacteria. Quillaya Saponin, on the contrary, was readily metabolised by the soil
microflora. Under slurry-phase conditions, Triton X-100 negatively influenced the soil bioremediation process by affecting
the availability of the chlorobenzoic acid degrading indigenous bacteria, whereas Quillaya Saponin slightly enhanced the biological
degradation and dechlorination of the soil PCBs. In the fixed-phase reactors, where both the surfactant availability and the
mixing of the soil were lower, Triton X-100 did not exert inhibitory effects on the soil biomass and enhanced significantly
the soil PCB depletion, whereas Quillaya Saponin did not influence the bioremediation process.
Received: 28 April 1998 / Received last revision: 15 July 1998 / Accepted: 29 July 1998 相似文献