共查询到20条相似文献,搜索用时 15 毫秒
1.
A. E. Filonov W. A. Duetz A. V. Karpov R. R. Gaiazov I. A. Kosheleva A. M. Breure I. F. Filonova J. G. van Andel A. M. Boronin 《Applied microbiology and biotechnology》1997,48(4):493-498
Plasmid-carrying Pseudomonas putida strains degrade naphthalene through different biochemical pathways. The influence of various combinations of host bacteria
and plasmids on growth characteristics and competitiveness of P. putida strains was studied in chemostat culture at a low dilution rate (D=0.05 h−1) with naphthalene as the sole source of carbon and energy. Under naphthalene limitation, the plasmid-bearing strains degrading
naphthalene that use catechol 1,2-dioxygenase for catechol oxidation (ortho pathway), were the most competitive. The strains bearing plasmids that control naphthalene catabolism via catechol 2,3-dioxygenase
(meta pathway), were less competitive. Under these conditions the strain carrying plasmid pBS4, which encodes for naphthalene catabolism
via gentisic acid, was the least competitive.
Received: 24 February 1997 / Received revision: 22 May 1997 / Accepted: 25 May 1997 相似文献
2.
Two plant-growth-promoting bacteria, Azospirillum brasilense Cd and Pseudomonas fluorescens 313, immobilized in 1983 in two types of alginate-bead inoculant (with and without skim-milk supplement) and later dried
and stored at ambient temperature for 14 years, were recovered in 1996. The population in each type of bead had decreased,
yet significant numbers survived (105–106 cfu/g beads). Population numbers depended on the bead type and the three independent bacterial counting methods: the conventional
plate-count method, indirect enzyme-linked immunosorbent assay and the limited-enrichment technique. Both bacterial species
retained several of their original physiological features. When inoculated onto wheat plants, both species colonized and produced
plant-growth effects equal to those of the contemporary strain from a culture collection or to their own 1983 records. This
study showed that bacteria can survive in alginate inoculant over long periods.
Received: 1 May 1998 / Received revision: 24 August 1998 / Accepted: 3 September 1998 相似文献
3.
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
4.
B. E. Whitman J. R. Mihelcic D. R. Lueking 《Applied microbiology and biotechnology》1995,43(3):539-544
A model system was developed for evaluating naphthalene biosorption based on the use of a mutant (strain TG-5 Nah-) derived from a naphthalene-degrading Pseudomonas fluorescens isolate. Cells of strain TG-5 had a sorptive capacity for naphthalene (partition coefficient of 380 cm3/g) significantly higher than a soil with a 5.1% organic carbon content (partition coefficient of 41 cm3/g). However, experimental results and a mass balance model demonstrated that, in soil systems of high organic carbon content,
the mass of naphthalene associated with biological solids is insignificant. In contrast, in a soil system of nonsorptive Ottawa
sand, up to 10% of the initial naphthalene was demonstrated experimentally, and by modeling, to be associated with cells of
strain TG-5.
Received: 6 June 1994/Received revision: 12 September 1994/Accepted: 28 September 1994 相似文献
5.
Bioremediation of atrazine-contaminated soil by repeated applications of atrazine-degrading bacteria 总被引:5,自引:0,他引:5
Bioaugmentation has previously been unreliable for the in situ clean-up of contaminated soils because of problems with poor
survival and the rapid decline in activity of the bacterial inoculum. In an attempt to solve these problems, a 500-l batch
fermenter was investigated for its ability to deliver inoculum repeatedly to contaminated soils via irrigation lines. In a
field experiment, mesocosms were filled with 350 kg soil containing 100 mg kg−1 atrazine, and inoculated one, four or eight times with an atrazine-degrading bacterial consortium that was produced in the
fermenter. After 12 weeks, no significant degradation of atrazine had occurred in soil that was inoculated only once; whereas,
mesocosms inoculated four and eight times mineralized 38% and 72% of the atrazine respectively. Similar results were obtained
in a laboratory experiment using soil contaminated with 100 mg kg−1 [14C]atrazine. After 35 days, soil that was inoculated once with 108 cfu ml−1 of the consortium or with the atrazine-degrading bacterium, Pseudomonas sp. strain ADP, mineralized 17% and 35% of the atrazine respectively. In comparison, microcosms inoculated every 3 days with
the consortium or with Pseudomonas sp. (ADP) mineralized 64% or 90% of the atrazine over this same period. Results of these experiments suggest that repeated
inoculation from an automated fermenter may provide a strategy for bioaugmentation of contaminated soil with xenobiotic-degrading
bacteria.
Received: 20 November 1998 / Received revision: 8 February 1999 / Accepted: 12 February 1999 相似文献
6.
Bioaugmentation of activated sludge systems with specialised bacterial strains could be a powerful tool to improve several
aspects in wastewater treatment processes, such as improved flocculation and degradation of recalcitrant compounds. This review
focuses on the addition of strains to activated sludge to enhance the biodegradation of recalcitrant compounds, either through
the activity of the inoculated strain or after transfer of degradative plasmids to activated sludge bacteria. Different factors
that improve the aggregation of the sludge flocs and their influence on biodegradation are described. This review further
deals with the role of bacterial plasmids in natural genetic exchange between inoculated and indigenous sludge bacteria, and
in the construction of new genetically modified organisms. The few successful cases of bioaugmentation described in this review,
together with future research, must lead to a better understanding of sludge bioaugmentation.
Received: 5 January 1998 / Received revision: 20 April 1998 / Accepted: 20 April 1998 相似文献
7.
M. Megharaj R.-M. Wittich R. Blasco D. H. Pieper K. N. Timmis 《Applied microbiology and biotechnology》1997,48(1):109-114
The dibenzo-p-dioxin(DD)- and dibenzofuran(DF)-degrading bacterium, Sphingomonas sp. strain RW1, was tagged by insertion of a mini-Tn5 lacZ transposon in order to follow its fate in complex laboratory soil systems. The tagged strain was tested for its ability to
survive in soil and degrade DF and DD applied at a concentration of 1 mg/g. Bacteria pre-adapted to soil conditions were found
to survive better in DF- and DD-amended soil and degrade the substrate more efficiently than bacteria that had not been subjected
to pre-adaptation. The concentration of soil-applied DF and DD, individually and in combination, decreased to less than 2%
of the original concentrations within 3 weeks of addition of the RW1 derivative, accompanied by a short, but significant exponential
increase in RW1 viable cells. During the same period the native bacterial population in soil was stable while viable fungi
declined.
Received: 12 November 1996 / Received revision: 21 February 1997 / Accepted: 22 February 1997 相似文献
8.
Cometabolic biodegradation of methyl t-butyl ether by Pseudomonas aeruginosa grown on pentane 总被引:1,自引:0,他引:1
A bacterial strain identified as Pseudomonas aeruginosa was isolated from a soil consortium able to mineralize pentane. P. aeruginosa could metabolize methyl t-butyl ether (MTBE) in the presence of pentane as the sole carbon and energy source. The carbon balance for this strain, grown
on pentane, was established in order to determine the fate of pentane and the growth yield (0.9 g biomass/g pentane). An inhibition
model for P. aeruginosa grown on pentane was proposed. Pentane had an inhibitory effect on growth of P. aeruginosa, even at a concentration as low as 85 μg/l. This resulted in the calculation of the following kinetic parameters (μmax = 0.19 h−1, K
s = 2.9 μg/l, K
i = 3.5 mg/l). Finally a simple model of MTBE degradation was derived in order to predict the quantity of MTBE able to be degraded
in batch culture in the presence of pentane. This model depends only on two parameters: the concentrations of pentane and
MTBE.
Received: 16 July 1998 / Received revision: 11 November 1998 / Accepted 31 November 1998 相似文献
9.
A Pseudomonas sp. strain NGK 1 (NCIM 5120) was immobilized in various matrices, namely, alginate, agar (1.8 × 1011 cfu g−1 beads) and polyacrylamide (1.6 × 1011 cfu g−1 beads). The degradation of naphthalene was studied, by freely suspended cells (4 × 1010 cfu ml−1) and immobilized cells in batches, with shaken culture and continuous degradation in a packed-bed reactor. Free cells brought
about the complete degradation of 25 mmol naphthalene after 3 days of incubation, whereas, a maximum of 30 mmol naphthalene
was degraded by the bacteria after 3–4 days of incubation with 50 mmol and 75 mmol naphthalene, and no further degradation
was observed even after 15 days of incubation. Alginate-entrapped cells had degraded 25 mmol naphthalene after 3.5 days of
incubation, whereas agar- and polyacrylamide-entrapped cells took 2.5 days; 50 mmol naphthalene was completely degraded by
the immobilized cells after 6–7 days of incubation. Maximum amounts of 55 mmol, 70 mmol and 67 mmol naphthalene were degraded,
from an initial 75 mmol naphthalene, by the alginate-, agar- and polyacrylamide-entrapped cells after 15 days of incubation.
When the cell concentrations were doubled, 25 mmol and 50 mmol naphthalene were degraded after 2 and 5.5 days of incubation
by the immobilized cells. Complete degradation of 75 mmol naphthalene occurred after 10 days incubation with agar- and polyacrylamide-entrapped␣cells,
whereas only 60 mmol naphthalene was degraded by alginate-entrapped cells after 15 days of␣incubation. Further, with 25 mmol
naphthalene, alginate-, agar- and polyacrylamide-entrapped cells (1.8 × 1011 cfu g−1 beads) could be reused 18, 12 and 23 times respectively. During continuous degradation in a packed-bed reactor, 80 mmol naphthalene
100 ml−1 h−1 was degraded by alginate- and polyacrylamide-entrapped cells whereas 80 mmol naphthalene 125 ml−1␣h−1 was degraded by agar-entrapped cells.
Received: 21 October 1997 / Received revision: 15 January 1998 / Accepted: 18 January 1998 相似文献
10.
Bioremediation of polychlorinated biphenyl-contaminated soil using carvone and surfactant-grown bacteria 总被引:4,自引:0,他引:4
Singer AC Gilbert ES Luepromchai E Crowley DE 《Applied microbiology and biotechnology》2000,54(6):838-843
Partial bioremediation of polychlorinated biphenyl (PCB)-contaminated soil was achieved by repeated applications of PCB-degrading
bacteria and a surfactant applied 34 times over an 18-week period. Two bacterial species, Arthrobacter sp. strain B1B and Ralstonia eutrophus H850, were induced for PCB degradation by carvone and salicylic acid, respectively, and were complementary for the removal
of different PCB congeners. A variety of application strategies was examined utilizing a surfactant, sorbitan trioleate, which
served both as a carbon substrate for the inoculum and as a detergent for the mobilization of PCBs. In soil containing 100 μg
Aroclor 1242 g−1 soil, bioaugmentation resulted in 55–59% PCB removal after 34 applications. However, most PCB removal occurred within the
first 9 weeks. In contrast, repeated addition of surfactant and carvone to non-inoculated soil resulted in 30–36% PCB removal
by the indigenous soil bacteria. The results suggest that bioaugmentation with surfactant-grown, carvone-induced, PCB-degrading
bacteria may provide an effective treatment for partial decontamination of PCB-contaminated soils.
Received: 9 March 2000 / Received revision: 27 June 2000 / Accepted: 16 July 2000 相似文献
11.
M. Wenk T. Baumgartner J. Dobovšek T. Fuchs J. Kucsera J. Zopfi G. Stucki 《Applied microbiology and biotechnology》1998,49(5):624-630
The evaluation of pesticide-mineralising microorganisms to clean-up contaminated soils was studied with the widely applied
and easily detectable compound atrazine, which is rapidly mineralised by several microorganisms including the Pseudomonas sp. strain Yaya 6. The rate of atrazine removal was proportional to the water content of the soil and the amount of bacteria
added to the soil. In soil slurry, 6 mg atrazine kg soil−1 was eliminated within 1 day after application of 0.3 g dry weight inoculant biomass kg soil−1 and within 5 days when 0.003 g kg soil−1 was used. In partially saturated soil (60% of the maximal water-holding capacity) 15 mg atrazine kg soil−1 was eliminated within 2 days by 1 g biomass kg soil−1 and within 25 days when 0.01 g biomass kg soil−1 was used. In unsaturated soil, about 60% [U-ring-14C]atrazine was converted to 14CO2 within 14 days. Atrazine was very efficiently removed by the inoculant biomass, not only in soil that was freshly contaminated
but also in soil aged with atrazine for up to 260 days. The bacteria exposed to atrazine in unsaturated sterile soil were
still active after a starvation period of 240 days: 15 mg newly added atrazine kg soil−1 was eliminated within 5 days.
Received: 31 October 1997 / Received revision: 16 January 1998 / Accepted: 18 January 1998 相似文献
12.
Manipulation of the DNA coding for the desulphurizing activity in a new isolate of Arthrobacter sp. 总被引:3,自引:0,他引:3
A new bacterial strain able to cleave CS bonds from organosulphur heterocyclic compounds through the 4-S pathway and tentatively
classified as Arthrobacter sp. was recently isolated. In the present short article we describe the cloning and the characterization of the DNA encoding
the enzymes responsible for desulphurization in this microorganism, referred to as Arthrobacter sp. DS7. The desulphurization operon was found to be located in a large plasmid that also bears the genes conferring cadmium
and arsenic resistance. By shortening this plasmid, a new cloning vector was prepared and used to obtain a recombinant derivative
strain that desulphurizes dibenzothiophene despite of the presence of inorganic sulphur in the growth medium.
Received: 25 May 1998 / Received revision: 4 September 1998 / Accepted: 13 September 1998 相似文献
13.
H. Mulder A. M. Breure D. van Honschooten J. T. C. Grotenhuis J. G. van Andel W. H. Rulkens 《Applied microbiology and biotechnology》1998,50(2):277-283
The effect of biofilm formation by Pseudomonas 8909N (DSM no. 11634) on the dissolution and biodegradation rates of solid naphthalene was quantified. Biofilms were cultivated
on solid naphthalene as a model polycyclic aromatic hydrocarbon in continuous cultures. After different periods of incubation,
the dissolution rate of naphthalene was determined by batch dissolution tests with active or inactivated biofilms and without
biofilms. Results show that the naphthalene dissolution rate to the bulk liquid phase was reduced by over 90% after 7 days
of biofilm formation. The degradation of naphthalene in the biofilm proved to be insignificant compared to the decrease in
the bulk liquid conversion of naphthalene, and the overall biodegradation rate of the solid naphthalene decreased.
Received: 26 January 1998 / Received revision: 16 April 1998 / Accepted: 19 April 1998 相似文献
14.
Isolation and characterization of a 2-methylphenanthrene utilizing bacterium: identification of ring cleavage metabolites 总被引:1,自引:0,他引:1
J. Sabaté M. Grifoll M. Viñas A. M. Solanas 《Applied microbiology and biotechnology》1999,52(5):704-712
A bacterial strain capable of utilizing 2-methylphenanthrene (2-MP) as its sole source of carbon and energy for growth was
isolated from creosote contaminated soil. The isolate was identified as a strain of Sphingomonas sp. and was designated strain JS5. Utilization of 2-MP by strain JS5 was demonstrated by an increase in bacterial biomass
concomitant with a decrease of 2-MP in liquid mineral medium with this compound as sole source of carbon and energy. Growth
yield indicated a 23% assimilation of 2-MP carbon. Washed-cell suspensions of strain JS5 incubated with 2-MP accumulated a
major metabolite identified as 1-hydroxy-6-methyl-2-naphtoic acid, according to its UV, mass and NMR spectra, and a minor
compound with HPLC R
t
and UV spectrum indistinguishable from 5-methylsalicylate. The identification of those metabolites, and the demonstration
of 2,3-catechol dioxygenase activity in 2-MP induced cells show that the biodegradation of 2-MP by strain JS5 is initiated
via dioxygenation and meta-cleavage of the non-methylated aromatic ring, and then proceeds by reactions similar to those reported for phenanthrene.
Incubation of the strain with a MP-containing mixture from a pyrolytic fuel oil demonstrates that strain JS5 also acts on
other methylated phenanthrenes.
Received: 28 December 1998 / Received revision: 21 June 1999 / Accepted: 27 June 1999 相似文献
15.
A bacterial complementation assay has been developed for the rapid screening of a large number of compounds to identify those
that inhibit an enzyme target for structure-based inhibitor design. The target enzyme is the hypoxanthine phosphoribosyltransferase
(HPRT). This enzyme has been proposed as a potential target for inhibitors that may be developed into drugs for the treatment
of diseases caused by several parasites. The screening assay utilizes genetically deficient bacteria complemented by active,
recombinant enzyme grown in selective medium in microtiter plates. By comparing absorbance measurements of bacteria grown
in the presence and absence of test compounds, the effect of the compounds on bacterial growth can be rapidly assayed. IC50 values for inhibition of bacterial growth are a reflection of the ability of the compounds to bind and/or inhibit the recombinant
enzyme. We have tested this bacterial complementation screening assay using recombinant HPRT from the parasites Plasmodium falciparum and Trypanosoma cruzi, as well as the human enzyme. The results of these studies demonstrate that a screening assay using bacterial complement
selection can be used to identify compounds that target enzymes and can become an important part of structure-based drug design
efforts.
Received: 4 December 1997 / Received revision: 17 March 1998 / Accepted: 26 March 1998 相似文献
16.
D. Stassi D. Post M. Satter M. Jackson G. Maine 《Applied microbiology and biotechnology》1998,49(6):725-731
The erythromycin producer, Saccharopolyspora erythraea ER720, was genetically engineered to produce 6,12-dideoxyerythromycin A, a novel erythromycin derivative, as the major macrolide
in the fermentation broth. Inspection of the biosynthetic pathway for erythromycin would suggest that production of this compound
could be achieved simply through the disruption of two genes, that encoding the erythromycin C-6 hydroxylase (eryF ) and that encoding the erythromycin C-12 hydroxylase (eryK ). The double mutant, however, was found to produce a mixture of 6,12-dideoxyerythromycin A and the precursor, 6-deoxyerythromycin
D. Complete conversion to the desired product (to the limit of detection by TLC) was achieved by inserting an additional copy
of the eryG gene, encoding the erythromycin 3′′-O-methyltransferase and driven by the ermE* promoter, into the S. erythraea chromosome.
Received: 6 October 1997 / Received revision: 27 January 1998 / Accepted: 24 February 1998 相似文献
17.
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
18.
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
19.
T. Potrawfke T.-H. Löhnert K. N. Timmis R.-M. Wittich 《Applied microbiology and biotechnology》1998,50(4):440-446
The biphenyl-mineralizing bacterium Burkholderia sp. strain LB400 also utilized 3-chloro-, 4-chloro-, 2,3′-dichloro- and 2,4′-dichlorobiphenyl for growth. By the attack of the initial enzyme a chlorine was eliminated dioxygenolytically
from position 2 of one of the aromatic rings when hydrogens of both were substituted by chlorine. The strain mineralized 3-chloro-
and 2,3′-dichlorobiphenyl via the central intermediate 3-chlorobenzoate through its chlorocatechol pathway enzymes, but excreted
stoichiometric amounts of 4-chlorobenzoate from 4-chloro- and 2,4′-dichlorobiphenyl. These two compounds were mineralized by a co-culture of strain LB400 and a derivative of the (methyl-)
benzoate-degrading strain Pseudomonas putida mt-2 (TOL). The complete degradation was achieved upon transfer of a cluster of at least five genes, encoding the regulated
chlorocatechol pathway operon, from strain LB400 to strain mt-2. This transfer was demonstrated by the polymerase chain reaction.
Received: 15 April 1998 / Received revision: 12 June 1998 / Accepted: 19 June 1998 相似文献
20.
Antimould activity of sourdough lactic acid bacteria: identification of a mixture of organic acids produced by Lactobacillus sanfrancisco CB1 总被引:1,自引:0,他引:1
A. Corsetti M. Gobbetti J. Rossi P. Damiani 《Applied microbiology and biotechnology》1998,50(2):253-256
Sourdough lactic acid bacteria, cultivated in wheat flour hydrolysate, produced antimould compounds. The antimould activity
varied greatly among the strains and was mainly detected within obligately heterofermentative Lactobacillus spp. Among these, Lb. sanfrancisco CB1 had the largest spectrum. It inhibited moulds related to bread spoilage such as Fusarium, Penicillium, Aspergillus and Monilia. A mixture of acetic, caproic, formic, propionic, butyric and n-valeric acids, acting in a synergistic way, was responsible for the antimould activity. Caproic acid played a key role in
inhibiting mould growth.
Received: 20 January 1998 / Received revision: 17 April 1998 / Accepted: 27 April 1998 相似文献