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1.
A sequential anaerobic–aerobic biodegradation of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) was studied. The results demonstrated
that: (i) a complete degradation of RDX was achieved within 20 days using a consortium of bacteria from a wastewater activated
sludge, (ii) RDX degradation did not occur under aerobic conditions alone, (iii) RDX-degrading bacterial strain that was isolated
from the activated sludge completely degraded RDX within 2 days, and (iv) RDX- induced protein expressions were observed in
the RDX-degrading bacterial strain. Based on fatty acid composition and a confirmation with a 16S rRNA analysis, the RDX-degrading
bacterial strain was identified as a Bacillus pumilus—GC subgroup B. 相似文献
2.
Yeasts isolated from olive mill wastewaters from southern Italy: technological characterization and potential use for phenol removal 总被引:1,自引:0,他引:1
Milena Sinigaglia Nilde Di Benedetto Antonio Bevilacqua Maria Rosaria Corbo Angela Capece Patrizia Romano 《Applied microbiology and biotechnology》2010,87(6):2345-2354
Olive mill wastewater (OMW) samples from two traditional varieties (Peranzana and Ogliarola Garganica) of Apulian region (southern
Italy) and produced through continuous and traditional methods were microbiologically and chemically examined; thus, 104 yeasts
were isolated and selected for further analyses. The strains were identified as Candida boidinii, Pichia holstii, Pichia membranifaciens, and Saccharomyces cerevisiae and analyzed to assess their suitability to metabolize phenols. Based on phenol metabolism, 27 strains were selected and
inoculated into OMW aliquots to determine their ability to reduce phenols in vivo; then, five strains (identified with the
codes 682—C. boidinii and 625, 642, 647, and 941—P. holstii) were used as a cocktail in wastewaters for a final validation step. In this last experiment, the effects of the temperature
(10–30°C) and (NH4)2SO4 (0.0–6.0 g l−1) were studied through a central composite design approach, and the results highlighted that the cocktail was able to reduce
phenols by 40% at 10°C with 6.0 g l−1 of (NH4)2SO4 added. 相似文献
3.
Partial gyrB sequences (>1 kb) were obtained from 34 type strains of the genus Amycolatopsis. Phylogenetic trees were constructed to determine the effectiveness of using this gene to predict taxonomic relationships
within the genus. The use of gyrB sequence analysis as an alternative to DNA–DNA hybridization was also assessed for distinguishing closely related species.
The gyrB based phylogeny mostly confirmed the conventional 16S rRNA gene-based phylogeny and thus provides additional support for
certain of these 16S rRNA gene-based phylogenetic groupings. Although pairwise gyrB sequence similarity cannot be used to predict the DNA relatedness between type strains, the gyrB genetic distance can be used as a means to assess quickly whether an isolate is likely to represent a new species in the
genus Amycolatopsis. In particular a genetic distance of >0.02 between two Amycolatopsis strains (based on a 315 bp variable region of the gyrB gene) is proposed to provide a good indication that they belong to different species (and that polyphasic taxonomic characterization
of the unknown strain is worth undertaking).
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.
The GenBank accession numbers for the gyrB gene sequences obtained in this study are shown in Table 1. 相似文献
4.
Ilmara Varotto Roma Neto Renan Augusto Ribeiro Mariangela Hungria 《World journal of microbiology & biotechnology》2010,26(7):1291-1302
Biodiversity of diazotrophic symbiotic bacteria in the tropics is a valuable but still poorly studied resource. The objective
of this study was to determine if a second housekeeping gene, glnII, in addition to the 16S rRNA, can be employed to improve the knowledge about taxonomy and phylogeny of rhizobia. Twenty-three
elite rhizobial strains, very effective in fixing nitrogen with twenty-one herbal and woody legumes (including species from
fourteen tribes in the three subfamilies of the family Leguminosae) were selected for this study; all strains are used as commercial inoculants in Brazil. Complete sequences of the 16S rRNA
and partial sequences (480 bp) of the glnII gene were obtained. The same primers and amplification conditions were successful for sequencing the glnII genes of bacteria belonging to five different rhizobial genera—Bradyrhizobium, Mesorhizobium, Methylobacterium, Rhizobium, Sinorhizobium)—positioned in distantly related branches. The analysis of the concatenated genes (16S rRNA + glnII) considerably improved information about phylogeny and taxonomy of rhizobia in comparison to the single analysis of the 16S
rRNA. Nine strains might belong to new species. The complementary analysis of the glnII gene was successful with all strains and improved the phylogenetic clustering and clarified the taxonomic position of several
strains. The strategy of including the analysis of glnII, in addition to the 16S rRNA, is cost- and time- effective for the characterization of large rhizobial culture collections
or in surveys of many isolates. 相似文献
5.
An aerobic microorganism with an ability to utilize phenol as sole carbon and energy source was isolated from phenol-contaminated
wastewater samples. The isolate was identified as Bacillus amyloliquefaciens strain WJDB-1 based on morphological, physiological, and biochemical characteristics, and 16S rDNA sequence analysis. Strain
WJDB-1 immobilized in alginate–chitosan–alginate (ACA) microcapsules could degrade 200 mg/l phenol completely within 36 h.
The concentration of phenol was determined using differential pulse voltammetry (DPV) at glassy carbon electrode (GCE) with
a linear relationship between peak current and phenol concentration ranging from 2.0 to 20.0 mg/l. Cells immobilized in ACA
microcapsules were found to be superior to the free suspended ones in terms of improving the tolerance to the environmental
loadings. The optimal conditions to prepare microcapsules for achieving higher phenol degradation rate were investigated by
changing the concentrations of sodium alginate, calcium chloride, and chitosan. Furthermore, the efficiency of phenol degradation
was optimized by adjusting various processing parameters, such as the number of microcapsules, pH value, temperature, and
the initial concentration of phenol. This microorganism has the potential for the efficient treatment of organic pollutants
in wastewater. 相似文献
6.
Tributyl phosphate (TBP) is an organophosphorous compound, used extensively (3000–5000 tonnes/annum) as a solvent for nuclear
fuel processing and as a base stock in the formulation of fire-resistant aircraft hydraulic fluids and other applications.
Because of its wide applications and relative stability in the natural environment TBP poses the problem of pollution and
health hazards. In the present study, fifteen potent bacterial strains capable of using tributyl phosphate (TBP) as sole carbon
and phosphorus source were isolated from enrichment cultures. These isolates were identified on the basis of biochemical and
morphological characteristics and 16S rRNA gene sequence analysis. Phylogenetic analysis of 16S rRNA gene sequences revealed
that two isolates belonged to class Bacilli and thirteen to β and γ-Proteobacteria. All these isolates were found to be members
of genera Alcaligenes, Providencia, Delftia, Ralstonia, and Bacillus. These isolates were able to tolerate and degrade up to 5 mM TBP, the highest concentration reported to date. The GC–MS method
was developed to monitor TBP degradation. Two strains, Providencia sp. BGW4 and Delftia sp. BGW1 showed respectively, 61.0 ± 2.8% and 57.0 ± 2.0% TBP degradation within 4 days. The degradation rate constants,
calculated by first order kinetic model were between 0.0024 and 0.0099 h−1. These bacterial strains are novel for TBP degradation and could be used as an important bioresource for efficient decontamination
of TBP polluted waste streams. 相似文献
7.
Single-culture aerobic granules with <Emphasis Type="Italic">Acinetobacter calcoaceticus</Emphasis> 总被引:1,自引:0,他引:1
Aerobic granules are cultivated by a single bacterial strain, Acinetobacter calcoaceticus, in a sequencing batch reactor (SBR). This strain presents as a good phenol reducer and an efficient auto coagulator in the
presence of phenol, mediated by heat-sensitive adhesins proteins. Stable 2.3-mm granules were formed in the SBR following
a 7-week cultivation. These granules exhibit excellent settling attributes and degrade phenol efficiently at concentrations
of 250–2,000 mg l−1. The corresponding phenol degradation rate reached 993.6 mg phenol g−1 volatile suspended solids (VSS) day−1 at 250 mg l−1 phenol and 519.3 mg phenol g−1 VSS day−1 at 2,000 mg l−1 phenol concentration. Meanwhile, free A. calcoaceticus cells were fully inhibited at phenol >1,500 mg l−1. Denaturing gradient gel electrophoresis fingerprint profile demonstrated no genetic modification in the strain during aerobic
granulation. The present single-strain granules showed long-term structural stability and performed high phenol degrading
capacity and high phenol tolerance. The confocal laser scanning microscopic test revealed that live A. calcoaceticus cells principally distributed at 200–250 μm beneath the outer surface, with an extracellular polymeric substance layer covering
them to defend phenol toxicity. Autoaggregation assay tests demonstrated the possibly significant role of secreted proteins
on the formation of single-culture A. calcoaceticus granules. 相似文献
8.
Isam A. Mohamed Ahmed Jiro Arima Tsuyoshi Ichiyanagi Emi Sakuno Nobuhiro Mori 《World journal of microbiology & biotechnology》2010,26(8):1455-1464
Soil isolates, identified as Pseudomonas sp. strain A9 and Pseudomonas sp. strain B9b (based on the phenotypic features and phylogenetic analysis) were found to degrade homocholine aerobically.
Morphological characterization using the optical microscope under light and phase contrast conditions showed that cells of
strain A9 formed short rods measuring approximately 0.5–1 × 1.5–2.0 μm in size while those of B9b formed long rods of 0.5–1 × 2.5–3.0 μm
during the early growth phase on both nutrient broth and basal-homocholine (basal-HC) media. Strain A9 was able to grow on
basal-HC medium at a wide range of temperatures (4–41°C) whereas strain B9b was not able to grow at either 4 or 41°C. Comparative
16S rRNA sequencing studies indicated that strain A9 fell into the Pseudomonas putida subclade whereas strain B9b located in Pseudomonas fulva subclade. Washed cells of strains A9 and B9b degraded homocholine completely within 6 h with concomitant formation of several
metabolites. Analysis of the metabolites by capillary electrophoresis, fast atom bombardment–mass spectrometry, and gas chromatography–mass
spectrometry, showed trimethylamine (TMA) as the major metabolite beside β-alanine betaine and trimethylaminopropionaldehyde.
Therefore, the possible degradation pathway of homocholine in the isolated strains is through successive oxidation of the
alcohol group (–OH) to aldehyde (–CHO) and acid (–COOH), and thereafter the cleavage of β-alanine betaine C–N bonds yielding
trimethylamine and an alkyl chain. 相似文献
9.
High lipid concentration contained in wastewater inhibits the activity of microorganisms in biological wastewater treatment
systems such as activated sludge and methane fermentation. To reduce the inhibitory effects, microorganisms capable of efficiently
degrading edible oils were screened from various environmental sources. From Japanese soil, we isolated 2 bacteria strains
with high degradation abilities at an alkaline pH without consumption of biological oxygen demand (BOD) constituents. Acinetobacter sp. strain SS-192 and Pseudomonas aeruginosa strain SS-219 degraded 77.5 ± 0.6% and 89.5 ± 1.5%, respectively, of 3,000 ppm of mixed oil consisting of salad oil/lard/beef
tallow (1/1/1, w/w/w) at 37°C and pH 9.0 in 24 h. Efficient degradation by the two strains occurred at pH 8–9 and 25–40°C.
Strain SS-219 degraded lipids even at pH 3. The degradation rate of 3,000 ppm of salad oil, lard, and beef tallow by strain
SS-192 was 79.9 ± 2.6%, 63.6 ± 1.9%, and 70.1 ± 1.2%, respectively, during a 24-h cultivation. The degradation rate of 3,000 ppm
of salad oil, lard, and beef tallow by strain SS-219 was 82.3 ± 2.1%, 71.9 ± 2.2%, and 71.0 ± 1.1%, respectively, during a
24-h cultivation. After mixed oil degradation by both strains, the BOD value of the cell culture increased from 2,100 ppm
to 3,200–4,000 ppm. The fact that neither strain utilizes BOD ingredients will be beneficial to pretreatment of methane fermentation
systems such as upflow anaerobic sludge blanket reactors. In addition, the growth of usual heterotrophic microorganisms utilizing
soluble BOD can be suppressed under alkaline pH. 相似文献
10.
Mejdi Snoussi Hafedh Hajlaoui Emira Noumi Donatella Usai Leonardo Antonio Sechi Stefania Zanetti Amina Bakhrouf 《World journal of microbiology & biotechnology》2008,24(12):3071-3076
The chemical composition of five aromatic plants (Mentha longifolia, M. pulegium, Eugenia caryophyllata, Thymus vulgaris and Rosmarinus officinalis) frequently used in food preparation in Tunisia was analysed by GC-MS. The antimicrobial effect of the essential oils obtained
from these plants was tested against Vibrio alginolyticus, Vibrio parahaemolyticus, Vibrio vulnificus and Vibrio fluvialis strains. Thyme oil exhibited a high level of antimicrobial activities against Vibrio spp. strains. The diameter of the zones of growth inhibition for V. parahaemolyticus species was interestingly high (ranging from 14.66 to 28 mm). The MIC and MBC values were interestingly low for thyme oil
(MIC 0.078–0.156 mg/ml) and (MBC >0.31–1.25 mg/ml). These results showed that these plants especially thyme and clove, can
be to be used for seafood preparation to protect against contamination by Vibrio spp. strains.
An erratum to this article can be found at 相似文献
11.
Duc Danh Ha 《Biodegradation》2018,29(5):499-510
Thauera sp. strain DKT isolated from sediment utilized 2,4-dichlorophenoxyacetic acid (2,4D) and its relative compounds as sole carbon and energy sources under anaerobic conditions and used nitrate as an electron acceptor. The determination of 2,4D utilization at different concentrations showed that the utilization curve fitted well with the Edward model with the maximum degradation rate as 0.017?±?0.002 mM/day. The supplementation of cosubstrates (glucose, acetate, sucrose, humate and succinate) increased the degradation rates of all tested chemical substrates in both liquid and sediment slurry media. Thauera sp. strain DKT transformed 2,4D to 2,4-dichlorophenol (2,4DCP) through reductive side-chain removal then dechlorinated 2,4DCP to 2-chlorophenol (2CP), 4-chlorophenol (4CP) and phenol before complete degradation. The relative degradation rates by the isolate in liquid media were: phenol?>?2,4DCP?>?2CP?>?4CP?>?2,4D?≈?3CP. DKT augmentation in sediment slurry enhanced the degradation rates of 2,4D and chlorophenols. The anaerobic degradation rates in the slurry were significantly slower compared to the rates in liquid media. 相似文献
12.
Covalent immobilization of Aspergillus awamori NRRL 3112 was conducted onto modified polyacrylonitrile membrane with glutaraldehyde as a coupling agent. The polymer carrier
was preliminarily modified in an aqueous solution of NaOH and 1,2-diaminoethane. The content of amino groups was determined
to be 0.58 mgeq g−1. Two ways of immobilization were used—in the presence of 0.2 g l−1 phenol and without phenol. The capability of two immobilized system to degrade phenol (concentration—0.5 g l−1) as a sole carbon and energy source was investigated in batch experiments. Seven cycles of phenol biodegradation were conducted.
Better results were obtained with the immobilized system prepared in the presence of phenol, regarding degradation time and
phenol biodegradation rate. Scanning electron micrographs of the polyacrylonitrile membrane/immobilized Aspergillus awamori NRRL at the beginning of repeated batch cultivation and after the 7th cycle were compared. After the 7th cycle of cultivation
the observations showed large groups of cells. The results from the batch experiments with immobilized system were compared
to the results produced by the free strain. Phenol biodegradation experiments were carried out also in a bioreactor with spirally
wound membrane with bound Aspergillus awamori NRRL 3112 in a regime of recirculation. 10 cycles of 0.5 g l−1 phenol biodegradation were run consecutively to determine the degradation time and rate for each cycle. The design of the
bioreactor appeared to be quite effective, providing large membrane surface to bind the strain. 相似文献
13.
Pseudomonas fluorescence KNU417 was able to degrade up to 700 mg/L of phenol in 65 h but could not degrade 1,000 mg/L of phenol. Phenol degradation
rate was noticeably enhanced by pre-adaptation. In addition, the cell was able to degrade up to 1,300 mg/L of phenol by pre-adapting
to 700 mg/L of phenol. Repeated adaptations to the same concentration of phenol showed negligible increase in degradation
rate. Also, relatively low concentration of phenol (100–700 mg/L) required only one pre-adaptation while high concentration
(1,000 mg/L) did two consecutive stepwise pre-adaptations for rapid degradation. Optimal adaptation routes were suggested
for the fast phenol degradation. For example, 1,000 mg/L of phenol was degraded as fast as in 48 h when the cell was pre-adapted
to 100 and 300 mg/L of phenol sequentially. The mechanism of adaptation was explained in terms of catechol 1,2-dioxygenase
induction, related to aromatic ring cleavage. 相似文献
14.
Djokic L Narancic T Nikodinovic-Runic J Savic M Vasiljevic B 《Applied microbiology and biotechnology》2011,91(4):1227-1238
Four new Gram-positive, phenol-degrading strains were isolated from the rhizospheres of endemorelict plants Ramonda serbica and Ramonda nathaliae known to exude high amounts of phenolics in the soil. Isolates were designated Bacillus sp. PS1, Bacillus sp. PS11, Streptomyces sp. PS12, and Streptomyces sp. PN1 based on 16S rDNA sequence and biochemical analysis. In addition to their ability to tolerate and utilize high amounts
of phenol of either up to 800 or up to 1,400 mg l−1 without apparent inhibition in growth, all four strains were also able to degrade a broad range of aromatic substrates including
benzene, toluene, ethylbenzene, xylenes, styrene, halogenated benzenes, and naphthalene. Isolates were able to grow in pure
culture and in defined mixed culture on phenol and on the mixture of BTEX (benzene, toluene, ethylbenzene, and xylenes) compounds
as a sole source of carbon and energy. Pure culture of Bacillus sp. PS11 yielded 1.5-fold higher biomass amounts in comparison to mixed culture, under all conditions. Strains successfully
degraded phenol in the soil model system (2 g kg−1) within 6 days. Activities of phenol hydroxylase, catechol 1,2-dioxygenase, and catechol 2,3-dioxygenase were detected and
analyzed from the crude cell extract of the isolates. While all four strains use ortho degradation pathway, enzyme indicative of meta degradation pathway (catechol 2,3-dioxygenase) was also detected in Bacillus sp. PS11 and Streptomyces sp. PN1. Phenol degradation activities were induced 2 h after supplementation by phenol, but not by catechol. Catechol slightly
inhibited activity of catechol 2,3-dioxygenase in strains PS11 and PN1. 相似文献
15.
In this work, the variability of spo0A gene in the genus Geobacillus and applicability of this gene for the taxonomy within this genus were evaluated. The protein Spo0A is the master regulator
of the endospore-forming process in the all endospore-forming bacteria. Geobacillus genus-specific primers GEOSPO were designed based on the sequences of Geobacillus
spo0A gene available through the public databases. Inter and intraspecific variability of Geobacillus spo0A gene was determined after sequencing of the GEOSPO-PCR products. Geobacillus
spo0A sequence analysis showed that three species—Geobacillus thermodenitrificans, G. stearothermophilus, and G. jurassicus—could be easily identified. Similarity between the sequences of these species and the other species were in the range of 83.3%–92.0%.
In contrast, intraspecific similarity of G. thermodenitrificans and G. stearothermophilus was high—above 99.0%. Similarity of spo0A sequences of G. subterraneus–G. uzenensis species cluster also matched this interval. Intercluster similarity between G. lituanicus–G. thermoleovorans–G. kaustophilus–G. vulcani and G. thermocatenulatus–G. gargensis–G. caldoxylosilyticus–G. toebii–G. thermoglucosidasius species clusters, as well as interspecific similarity within these two clusters was in the range of the intraspecific similarity
determined for G. thermodenitrificans and G. stearothermophilus. It was also determined that spo0A cannot be used as the phylogenetic marker for the genus Geobacillus. 相似文献
16.
– | — Use of a 2-dimensional spectrophotometer allows the detection and analysis of spatiotemporal patterns in biological samples |
– | — the “in vitro” system—yeast extract—behaves as an excitable medium. Oscillatory degradation of trehalose yields NADH-oscillations which, after running out, convert to spatiotemporal waves |
– | — the observation of excitability coupled to oscillatory processes in biological systems might provide new insights into the meaning of oscillations for metabolism |
– | — with an “in vitro” system at hand, it should be possible to perform defined experimental manipulations in order to detect the mechanism for excitability in biological systems. |
17.
Halophilic archaeal strains R26T and R22 were isolated from the brown alga Laminaria produced at Dalian, Liaoning Province, China. Cells from the two strains were pleomorphic rods and Gram negative, and colonies
were red pigmented. Strains R26T and R22 were able to grow at 20–50°C (optimum 37°C) in 1.4–5.1 M NaCl (optimum 3.1–4.3 M) at pH 5.5–9.5 (optimum pH 8.0–8.5)
and neither strain required Mg2+ for growth. Cells lyse in distilled water and the minimum NaCl concentration required to prevent cell lysis was 8% (w/v)
for strain R26T and 12% (w/v) for strain R22. The major polar lipids of the two strains were phosphatidylglycerol, phosphatidylglycerol phosphate
methyl ester and minor phosphatidylglycerol sulfate; glycolipids were not detected. Phylogenetic analyses based on 16S rRNA
genes and rpoB′ genes revealed that strains R26T and R22 formed a distinct clade with the closest relative, Natronoarchaeum mannanilyticum. The DNA G+C content of strains R26T and R22 was 65.8 and 66.4 mol%, respectively. The DNA–DNA hybridization value between strains R26T and R22 was 89%. The phenotypic, chemotaxonomic and phylogenetic properties suggest that the strains R26T and R22 represent a novel species in a new genus within the family Halobacteriaceae, for which the name Salinarchaeum laminariae gen. nov., sp. nov. is proposed. The type strain is R26T (type strain R26T = CGMCC 1.10590T = JCM 17267T, reference strain R22 = CGMCC 1.10589). 相似文献
18.
Chen C Shi R Liu BB Zhang YJ Sun HZ Li CT Tang SK Zhang LL Li WJ 《Antonie van Leeuwenhoek》2011,100(3):365-373
Two moderately halophilic, Gram-negative, rod-shaped bacteria, designated YIM 93003T and YIM 94343T, were isolated from a salt lake in Xinjiang province, north-west China. The two strains YIM 93003T and YIM 94343T grew at 20–40°C, pH 6–9, 0.5–24% (w/v) NaCl and at 20–40°C, pH 6–9, 0.5–23% (w/v) NaCl, respectively. No growth occurred
in absence of NaCl. Phylogenetic analyses based on 16S rRNA gene sequences showed that strains YIM 93003T and YIM 94343T were phylogenetically affiliated to the genus Halomonas and exhibited sequence similarity of 97.5% and 97.4% to the type strain Halomonas anticariensis DSM 16096T, respectively. The strains possessed chemotaxonomic markers that were consistent with their classification in the genus Halomonas (Q-9 as predominant respiratory quinine; C18:1ω7c, C16:0 and C16:1 ω7c/iso-C15:02-OH as the major fatty acids). The DNA–DNA hybridization values for strains YIM 93003T and YIM 94343T, YIM 93003T and DSM 16096T, YIM 94343T and DSM 16096T were 38.1 ± 3.0, 18.3 ± 4.7, and 20.8 ± 4.6%, respectively. The G+C contents of the strains YIM 93003T and YIM 94343T were 63.4 and 64.0 mol%, respectively. Based on comparative analysis of physiological, biochemical and chemotaxonomic data,
including low DNA–DNA hybridization results, two novel species, Halomonas qijiaojingensis sp. nov., and Halomonas
flava sp. nov., are proposed. The type strains are YIM 93003T (=CCTCC AB 208133T =KCTC 22228T) and YIM 94343T (=CCTCC AB 2010382T =KCTC 23356T), respectively. 相似文献
19.
Qu Yuanyuan Zhang Ruijie Ma Fang Zhou Jiti Yan Bin 《World journal of microbiology & biotechnology》2011,27(8):1919-1926
A novel alkali-tolerant strain JY-2, which could utilize phenol as sole source of carbon and energy, was isolated from activated
sludge. It was identified as Pseudomonas sp. by 16S rDNA sequencing analysis. The appropriate conditions for strain growth and phenol biodegradation were as follows:
pH 8.0–10.0 and temperature 23–30°C. With initial phenol concentrations of 225, 400, 550 and 750 mg/l, the degradation efficiencies
were 94.9, 93.3, 89.3 and 48.2% within 40 h at pH 10.0 and 30°C, respectively. The alkaline phenol-containing wastewater treatment
augmented with strain JY-2 in sequencing batch reactor (SBR) system was investigated, which suggested that the bioaugmented
(BA) system exhibited the better performance for adjusting high pH to neutral value than the non-bioaugmented (non-BA) one.
Also, the BA system showed strong abilities for phenol degradation and maintaining good sedimentation coefficient (SV30). The microbial community dynamics of both sequencing batch reactor (SBR) systems were analyzed by Denaturing Gradient Gel
Electrophoresis (DGGE) technique, which showed substantial changes between the two systems. This study suggests that it is
feasible to treat alkaline phenol-containing wastewater augmented with strain JY-2. 相似文献
20.
Paavo Ahvenniemi Matthias Wolf Mari J. Lehtonen Paula Wilson Malgorzata German-Kinnari Jari P. T. Valkonen 《Journal of molecular evolution》2009,69(2):150-163
The rRNA cistron (18S–ITS1–5.8S–ITS2–28S) is used widely for phylogenetic analyses. Recent studies show that compensatory
base changes (CBC) in the secondary structure of ITS2 correlate with genetic incompatibility between organisms. Rhizoctonia solani consists of genetically incompatible strain groups (anastomosis groups, AG) distinguished by lack of anastomosis between
hyphae of strains. Phylogenetic analysis of internal transcribed spacer (ITS) sequences shows a strong correlation with AG
determination. In this study, ITS sequences were reannotated according to the flanking 5.8S and 28S regions which interact
during ribogenesis. One or two CBCs were detected between the ITS2 secondary structure of AG-3 potato strains as compared
to AG-3 tobacco strains, and between these two strains and all other AGs. When a binucleate Rhizoctonia species related to Ceratobasidiaceae was compared to the AGs of R. solani, which were multinucleate (3–21 nuclei per cell), 1–3 CBCs were detected. The CBCs in potato strains of AG-3 distinguish
them from AG-3 tobacco strains and other AGs yielding further evidence that the potato strains of AG-3 originally described
as R. solani are a species distinct from other AGs. The ITS1–5.8S–ITS2 sequences were analyzed by direct sequencing of PCR products from
497 strains of AG-3 isolated from potato. The same 10 and 4 positions in ITS1 and ITS2, respectively, contained variability
in 425 strains (86%). Nine different unambiguous ITS sequences (haplotypes) could be detected in a single strain by sequencing
cloned PCR products indicating that concerted evolution had not homogenized the rRNA cistrons in many AG-3 strains. Importantly,
the sequence variability did not affect the secondary structure of ITS2 and CBCs in AG-3.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献