共查询到20条相似文献,搜索用时 435 毫秒
1.
Chunyu Yang Yang Li Kun Zhang Xia Wang Cuiqing Ma Hongzhi Tang Ping Xu 《Biodegradation》2010,21(1):97-105
A simple consortium consisted of two members of Klebsiella sp. A1 and Comamonas sp. A2 was isolated from the sewage of a pesticide mill in China. One member of Klebsiella sp. A1 is a novel strain that could use atrazine as the sole carbon and nitrogen source. The consortium showed high atrazine-mineralizing
efficiency and about 83.3% of 5 g l−1 atrazine could be mineralized after 24 h degradation. Contrary to many other reported microorganisms, the consortium was
insensitive to some nitrogenous fertilizers commonly used, not only in presence of 200 mg l−1 atrazine but also in 5 g l−1 atrazine mediums. After 24 h incubation, 200 mg l−1 atrazine was completely mineralized despite of the presence of urea, (NH4)2CO3 and (NH4)2HPO4 in the medium. Very minor influence was observed when NH4Cl was added as additional nitrogen source. Advantages of the simple consortium, high mineralizing efficiency and insensitivity
to most of exogenous nitrogen sources, all suggested application potential of the consortium for the bioremediation of atrazine-contaminated
soils and waters. 相似文献
2.
A dioxane-degrading consortium was enriched from soil obtained from a contaminated groundwater plume. The enriched consortium
did not use dioxane as the sole source of carbon and energy but co-metabolized dioxane in the presence of tetrahydrofuran
(THF). THF and dioxane concentrations up to 1000 ppm were degraded by the enriched consortium in about 2 weeks with a longer
lag phase observable at 1000 ppm. Three colonies from the enriched consortium were then obtained on agar plates containing
basal salts and glucose as the carbon source. Only one of the three colonies was capable of dioxane degradation. Further enrichment
of this colony in liquid media led to a pure culture that grew on glucose and co-metabolically degraded dioxane after THF
degradation. The rate and extent of dioxane degradation of this isolate increased with increasing THF concentration. This
isolate was subsequently identified as a Flavobacterium by 16S rDNA sequencing. Using polymerase chain reaction (PCR) and denaturing gradient gel electrophoresis (DGGE) analysis
of microbial populations, Flavobacterium was determined to be the dominant species in the enriched consortium and was distinct from the two other colonies that did
not degrade dioxane. This is the first report of a dioxane-degrading Flavobacterium which is phylogenetically distinct from any previously identified dioxane degrader. 相似文献
3.
Nehme N Mathieu F Taillandier P 《Journal of industrial microbiology & biotechnology》2008,35(7):685-693
This study examines the interactions that occur between Saccharomyces cerevisiae and Oenococcus oeni strains during the process of winemaking. Various yeast/bacteria pairs were studied by applying a sequential fermentation strategy which simulated the natural winemaking process. First, four yeast strains were tested in the presence of one bacterial strain leading to the inhibition of the bacterial component. The extent of inhibition varied widely from one pair to another and closely depended on the specific yeast strain chosen. Inhibition was correlated to weak bacterial growth rather than a reduction in the bacterial malolactic activity. Three of the four yeast strains were then grown with another bacteria strain. Contrary to the first results, this led to the bacterial stimulation, thus highlighting the importance of the bacteria strain. The biochemical profile of the four yeast fermented media exhibited slight variations in ethanol, SO(2) and fatty acids produced as well as assimilable consumed nitrogen. These parameters were not the only factors responsible for the malolactic fermentation inhibition observed with the first bacteria strain. The stimulation of the second has not been reported before in such conditions and remains unexplained. 相似文献
4.
Fernanda Laroza Paganelli Eliana Gertrudes de Macedo Lemos Lúcia Maria Carareto Alves 《World journal of microbiology & biotechnology》2011,27(4):773-778
Polyhydroxyalkanoates (PHAs) are hydroxyalkanoate polymers that are produced and accumulate by many kinds of bacteria. These
polymers act as an energy store for bacteria. Polyhydroxybutyrate (PHB) is the most studied polymer in the PHA family. These
polymers have awakened interest in the environmental and industrial research areas because they are biodegradable and have
thermoplastic qualities, like polypropylene. In this work, we analyzed the PHB production in Bradyrhizobium sp., Rhizobium leguminosarum bv. phaseoli, and Rhizobium huautlense cultured with two different carbon sources. We did biochemical quantification of PHB production during the three phases of
growth. Moreover, these samples were used for RNA extraction and phbC gene expression analysis via real-time PCR. The bacteria showed different manner of growth, PHB accumulation and phbC gene expression when different quantity and quality of carbon sources were used. These results showed that under different
growth media conditions, the growth and metabolism of different species of bacteria were influenced. These differences reflect
the increase or decrease in PHB accumulation. 相似文献
5.
Leticia Montoya Victor M. Bandala Antero Ramos Edith Garay-Serrano 《Symbiosis (Philadelphia, Pa.)》2017,72(2):135-142
Gut bacterium Pantoea sp. is one of the predominant bacterial species in the larval gut of the diamondback moth, Plutella xylostella. The phenotypic characters of Pantoea sp. were investigated with BIOLOG phenotype MicroArray (PM) in this study. Totally 950 different metabolic phenotypes were tested using the PM plates 1–10. Results exhibited that Pantoea sp. was able to metabolize 37.37 % of the tested carbon sources, 91.32 % of nitrogen sources, 100 % of sulfur sources, and 98.31 % of phosphorus sources. Most informative utilization patterns for carbon sources of Pantoea sp. were organic acids and carbohydrates, and for nitrogen were various amino acids. The bacterium had 94 different biosynthetic pathways. It had a wide range of adaptabilities, and could still metabolize in osmolytes with up to 9 % sodium chloride, 6 % potassium chloride, 5 % sodium sulfate, 20 % ethylene glycol, 4 % sodium formate, 4 % urea, 5 % sodium lactate, 200 mmol/L sodium phosphate (pH 7.0), 100 mmol/L ammonium sulfate (pH 8.0), 100 mmol/L sodium nitrate, and 100 mmol/L sodium nitrite, respectively. It also exhibited active metabolism under pH values between 4.5 and 10. Pantoea sp. showed active decarboxylase activities while poor deaminase activities in the presence of various amino acids. The phenotypic characterization of Pantoea sp. increased our knowledge of the bacterium, in particular its interactions with insect hosts and the adaptability in gut environments, and showed us some possible approaches to controlling diamondback moth through decreasing Pantoea sp. density. 相似文献
6.
7.
Twenty six Rhizobium strains isolated from root nodules of Sesbania sesban were studied for chitinase activity on chitin agar plates. Among them, only 12 strains showed chitinase activity. The strain
showing the highest chitinase activity was selected based on maximum clear zone/colony size ratio on chitin agar plates and
chitinase activity in culture filtrate. The strain was identified as Rhizobium sp. which showed a high degree of similarity with Rhizobium radiobacter (= Agrobacterium radiobacter). The cultural and nutritional conditions were optimized for maximum chitinase activity. The Rhizobium sp. exhibited maximum chitinase activity after 36 h of incubation, at neutral pH. Among the different nutritional sources,
arabinose and yeast extract were found to be good inducers for chitinase activity. Rhizobium sp. could degrade and utilize dead mycelia of Aspergillus flavus, Aspergillus niger, Curvularia lunata, Fusarium oxysporum and Fusarium udum. 相似文献
8.
The regulatory function of global regulator NtrC on curdlan biosynthesis and nitrogen consumption under nitrogen-limited condition
in Agrobacterium sp. ATCC 31749 was investigated. The ntrC mutant of Agrobacterium sp. was constructed by homologous recombination. The ability to utilize NH4Cl and KNO3 was impaired in the mutant. Other nitrogenous compounds, such as glutamic acid and glutamine, were utilized normally. Curdlan
production capability was impaired severely in the mutant. Curdlan production was 5-fold lower than the wild type strain in
batch fermentation with NH4Cl as the sole nitrogen source. However, up to 6.5 g l−1 of a newly found alkali-insoluble biopolymer was produced by the ntrC mutant when glutamic acid was used as nitrogen source. The new biopolymer had glycosidic bond and hydroxyl group but no β-configuration
absorption peak on IR spectrum was found as different from curdlan. In addition, the mutant exhibited a rapid morphological
change from the dot to rod form. These results deduced that the global regulator NtrC was involved in curdlan and other biopolymer
biosynthesis in Agrobacterium sp. ATCC 31749 in response to nitrogen-limited condition. 相似文献
9.
White-rot basidiomycetes are the main decomposers of woody biomass in forest ecosystems. Little is known, however, about the
interactions between white-rot fungi and other microorganisms in decayed wood. A wood-rotting fungus, Stereum sp. strain TN4F, was isolated from a fruit body, and its coexisting cultivable bacteria were isolated from its substrate;
natural white-rot decayed wood. The effects of bacteria on fungal growth were examined by confrontational assay in vitro.
A growth-promoting bacterium for this Stereum strain was identified as Curtobacterium sp. TN4W-19, using 16SrRNA sequencing. A confrontational assay revealed that Curtobacterium sp. TN4W-19 significantly promoted the mycelial growth of Stereum sp. TN4F in the direction of the bacterial colony, without direct contact between the mycelium and bacterial cells. This
is the first report of a positive interaction between a white-rot fungus and a coexisting bacterial strain in vitro. 相似文献
10.
Julie Kaye Ardley Graham W. O’Hara Wayne G. Reeve Ron J. Yates Michael J. Dilworth Ravi P. Tiwari John G. Howieson 《Archives of microbiology》2009,191(4):311-318
The South African legumes Lotononis bainesii, L. listii and L. solitudinis are specifically nodulated by highly effective, pink-pigmented bacteria that are most closely related to Methylobacterium nodulans on the basis of 16S rRNA gene homology. Methylobacterium spp. are characterized by their ability to utilize methanol and other C1 compounds, but 11 Lotononis isolates neither grew on methanol as a sole carbon source nor were able to metabolize it. No product was obtained for PCR
amplification of mxaF, the gene encoding the large subunit of methanol dehydrogenase. Searches for methylotrophy genes in the sequenced genome
of Methylobacterium sp. 4-46, isolated from L. bainesii, indicate that the inability to utilize methanol may be due to the absence of the mxa operon. While methylotrophy appears to contribute to the effectiveness of the Crotalaria/M. nodulans symbiosis, our results indicate that the ability to utilize methanol is not a factor in the Lotononis/Methylobacterium symbiosis. 相似文献
11.
Yesenia Herrera Anthony I. Okoh Laura Alvarez Norma Robledo María R. Trejo-Hernández 《World journal of microbiology & biotechnology》2008,24(1):55-60
As part of our effort at establishing microbial consortia of relevance for the bioremediation of xenobiotics polluted environments
in Mexico, we assessed the aerobic biodegradation of 2,4-dichlorophenol (2,4-DCP) by a consortium of four Bacillus species
that were isolated from a polluted soil by enrichment using a mixture of chlorophenols. The bacterial consortium effectively
biodegraded 2-chlorophenol, 3-chlorophenol and 2,4-dichlorophenol at degradation rates of between 1.7 and 6.7 μmoles l−1 h−1. In the presence of NH4Cl or KNO2 as nitrogen sources, 2,4-DCP was variously degraded. Under both conditions, cell biomass attained highest values of 350 and 450 mg l−1 respectively, while the amounts of 2,4-DCP metabolized in 21 days reached peak values of 2.1 and 2.5 mM representing between
70 and 85% degradation respectively. Chloride releases during the same period were highest at 4.7 mM and 5.3 mM in the presence
of the two nitrogen sources. The presence of free-chloride in the culture medium had a significant impact on the catabolism
of 2,4-dichlorophenol. 相似文献
12.
Chino-Flores C Dantán-González E Vázquez-Ramos A Tinoco-Valencia R Díaz-Méndez R Sánchez-Salinas E Castrejón-Godínez ML Ramos-Quintana F Ortiz-Hernández ML 《Biodegradation》2012,23(3):387-397
Microbial enzymes that can hydrolyze organophosphorus compounds have been isolated, identified and characterized from different
microbial species in order to use them in biodegradation of organophosphorus compounds. We isolated a bacterial strain Cons002
from an agricultural soil bacterial consortium, which can hydrolyze methyl-parathion (MP) and other organophosphate pesticides.
HPLC analysis showed that strain Cons002 is capable of degrading pesticides MP, parathion and phorate. Pulsed-field gel electrophoresis
and 16S rRNA amplification were performed for strain characterization and identification, respectively, showing that the strain
Cons002 is related to the genus Enterobacter sp. which has a single chromosome of 4.6 Mb and has no plasmids. Genomic library was constructed from DNA of Enterobacter sp. Cons002. A gene called opdE (Organophosphate Degradation from E
nterobacter) consists of 753 bp and encodes a protein of 25 kDa, which was isolated using activity methods. This gene opdE had no similarity to any genes reported to degrade organophosphates. When kanamycin-resistance cassette was placed in the
gene opdE, hydrolase activity was suppressed and Enterobacter sp. Cons002 had no growth with MP as a nutrients source. 相似文献
13.
Novel rhamnolipid-producing strains of three thermophilic bacteria, Thermus sp., T. aquaticus and Meiothermus ruber were identified that have not been previously described as rhamnolipid producers. Rhamnolipids were extracted from supernatant
and further purified by thin-layer chromatography. Mass spectrometry with negative electrospray ionization revealed 77 rhamnolipid
homologues varying in chain length and unsaturation. Tandem mass spectrometry identified mono-rhamnolipid and di-rhamnolipid
homologues containing one or two 3-hydroxy-fatty acids, saturated, monounsaturated or diunsaturated, even- or odd-chain, up
to unusual long chains with 24 carbon atoms. The stereochemistry of rhamnose was L and that of 3-hydroxy-fatty acids was R, the position of double bonds in monoenoic acids was cis ω-9. All three strains produced a rhamnolipid that differs in structure from Pseudomonas aeruginosa rhamnolipids and exhibits excellent surfactant properties. Importantly, in comparison to P. aeruginosa both strains, i.e., Thermus and Meiothermus, are Biosafety level 1 microorganisms and are not pathogenic to humans. 相似文献
14.
Busayo D. Ayodeji Clara Piccirillo Vincenza Ferraro Patrícia R. Moreira Adewale O. Obadina Lateef O. Sanni Maria M. E. Pintado 《Annals of microbiology》2017,67(1):123-133
Bacterial strains were isolated from cassava-derived food products and, for the first time, from cassava by-products, with a focus on gari, a flour-like product, and the effluents from the production processes for gari and fufu (a dough also made from cassava flour). A total of 47 strains were isolated, all of which were tested to determine their resistance to acidic pH and to bile salt environments. Four of the 47 isolates tested positive in both environments, and these four isolates also showed antibacterial behaviour towards both Gram-positive and Gram-negative microbial pathogens (i.e. Methicillin-resistance Staphylococcus aureus, Listeria monocytogenes, Bacillus cereus, Salmonella enteritidis, Escherichia coli, Escherichia coli (O157), Yersinia enterocolitica). In most cases, the antibacterial activity was related to bacteriocin production. Molecular identification analysis (16S rDNA and randomly amplified polymorphic DNA-PCR) revealed that the four isolates were different strains of the same species, Lactobacillus fermentum. These results demonstrate that bacteria isolated from cassava-derived food items and cassava by-products have interesting properties and could potentially be used as probiotics. 相似文献
15.
Characteristics of the microbial community in rhizosphere of <Emphasis Type="Italic">Camptotheca acuminata</Emphasis> cultured with exotic invasive plant <Emphasis Type="Italic">Eupatorium adenophorum</Emphasis>
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Zu YuanGang Gao ChongYang Wang WenJie Yang FengJian Liu Ying Wang Min Zhao YangGuo 《中国科学C辑(英文版)》2007,50(1):22-30
The traditional culture-dependent plate counting and culture-independent small-subunit-ribosomal RNA gene-targeted molecular
techniques, Single-Strand Conformation Polymorphism (SSCP) and terminal Restriction Fragment Length Polymorphism (tRFLP) combined
with 16S rDNA clone library were adopted to investigate the impacts of secretion from Camptotheca acuminata (abbreviated to Ca) roots on the quantities and structure of eukaryotic microbes and bacteria in the rhizosphere, and the
possibility that Ca controls exotic invasive plant Eupatorium adenophorum (Ea). The counting results indicated that the number of bacteria increased in turn in rhizospheres of Ea, Ca-Ea mixed culture
and Ca, while that of eukaryotic microbes decreased. PCR-SSCP profiles showed eukaryotic microbial bands (corresponding to
biodiversity) in rhizosphere of Ea were more complex than those of Ca and CE. Meristolohmannia sp., Termitomyces sp. and Rhodophyllus sp. were the dominant populations in the rhizosphere of Ca. Bacterial terminal restriction fragments (TRFs) profiles showed
no difference among three kinds of rhizospheres, and the sequences of the 16S rDNA clone library from Ca rhizospheres were
distributed in 10 known phyla, in which phylum Proteobacteria were the absolute dominant group and accounted for 24.71% of
the cloned sequences (δ-Proteobacteria accounted for up to 17.65%), and phyla Acidobacteria and Bacteroidetes accounted for
16.47% and 10.59% of the cloned sequences, respectively. In addition, high performance liquid chromatography detected a trace
amount of camptothecin and hydroxycamptothecin in the rhizospheric soil of Ca and CE, but examined neither camptothecin nor
hydroxycamptothecin in rhizospheric soil of Ea. Therefore, invasion and diffusion of Ea evidently depended on distinguishing
the eukaryotic community structure, but not on that of the bacterial pattern. Ca was able to alter the eukaryotic community
structure of invasive Ea by secreting camptothecin and hydroxycamptothecin into rhizospheres, and may benefit the control
of overspread of Ea. This study provided theoretical evidence for rhizospheric microbial aspects on substituting Ca for Ea. 相似文献
16.
17.
Pseudomonas desmolyticum NCIM 2112 (Pd 2112) and Nocardia hydrocarbonoxydans NCIM 2386 (Nh 2386) demonstrated an ability to degrade diesel and kerosene. Triton X-100 had enhanced the diesel degradation
process by reducing the time required for the maximum utilization of total petroleum hydrocarbon. Fourier transform infrared
spectroscopy spectrum of degraded diesel indicates the presence of aliphatic and aromatic aldehydes, C=C aromatic nuclei,
and substituted benzenes. Surface tension reduction and stable emulsification was increased using consortium when compared
to individual strains. Triton X-100 showed increase in microbial attachment to hydrocarbon among the various chemical surfactants
tested. For generating a rapid assay to screen microorganisms capable of degrading kerosene, the acetaldehyde produced in
the degradation process could be used as an indicator of degradation. These results indicate diesel and kerosene degradation
ability of both of the strains. 相似文献
18.
van Overbeek LS Franke AC Nijhuis EH Groeneveld RM da Rocha UN Lotz LA 《Microbial ecology》2011,62(2):257-264
The bacterial community compositions in Chenopodium album and Stellaria media seeds recovered from soil (soil weed seedbank), from bulk soil, and from seeds harvested from plants grown in the same soils
were compared. It was hypothesized that bacterial communities in soil weed seedbanks are distinct from the ones present in
bulk soils. For that purpose, bacterial polymerase chain reaction denaturing gradient gel electrophoresis (PCR–DGGE) fingerprints,
made from DNA extracts of different soils and seed fractions, were analyzed by principal component analysis. Bacterial fingerprints
from C. album and S. media seeds differed from each other and from soil. Further, it revealed that bacterial fingerprints from soil-recovered and plant-harvested
seeds from the same species clustered together. Hence, it was concluded that microbial communities associated with seeds in
soil mostly originated from the mother plant and not from soil. In addition, the results indicated that the presence of a
weed seedbank in arable soils can increase soil microbial diversity. Thus, a change in species composition or size of the
soil weed seedbank, for instance, as a result of a change in crop management, could affect soil microbial diversity. The consequence
of increased diversity is yet unknown, but by virtue of identification of dominant bands in PCR–DGGE fingerprints as Lysobacter oryzae (among four other species), it became clear that bacteria potentially antagonizing phytopathogens dominate in C. album seeds in soil. The role of these potential antagonists on weed and crop plant growth was discussed. 相似文献
19.
Although microbially induced calcium carbonate precipitation (MICP) through ureolysis has been widely studied in environmental engineering fields, urea utilization might cause environmental problems as a result of ammonia and nitrate production. In this study, many non-ureolytic calcium carbonate-precipitating bacteria that induced an alkaline environment were isolated from the rhizosphere of Miscanthus sacchariflorus near an artificial stream and their ability to precipitate calcium carbonate minerals with the absence of urea was investigated. MICP was observed using a phase-contrast microscope and ion-selective electrode. Only Lysinibacillus sp. YS11 showed MICP in aerobic conditions. Energy dispersive X-ray spectrometry and X-ray diffraction confirmed the presence of calcium carbonate. Field emission scanning electron microscopy analysis indicated the formation of morphologically distinct minerals around cells under these conditions. Monitoring of bacterial growth, pH changes, and Ca2+ concentrations under aerobic, hypoxia, and anaerobic conditions suggested that strain YS11 could induce alkaline conditions up to a pH of 8.9 and utilize 95% of free Ca2+ only under aerobic conditions. Unusual Ca2+ binding and its release from cells were observed under hypoxia conditions. Biofilm and extracellular polymeric substances (EPS) formation were enhanced during MICP. Strain YS11 has resistance at high pH and in high salt concentrations, as well as its spore-forming ability, which supports its potential application for self-healing concrete. 相似文献
20.
Two bacterial consortia were developed by continuous enrichment of microbial population of tannery and pulp and paper mill
effluent contained Serratia mercascens, Pseudomonas fluorescence, Escherichia coli, Pseudomonas aeruginosa and Acinetobacter sp. identified by 16S rDNA method. The consortia evaluated for removal of chromate [(Cr(VI)] in shake flask culture indicated
pulp and paper mill consortium had more potential for removal of chromate. Acinetobacter sp. isolated from pulp and paper mill consortium removed higher amount of chromate [Cr(VI)] under aerobic conditions. Parameters
optimized in different carbon, nitrogen sources, and pH, indicated maximum removal of chromate in sodium acetate (0.2%), sodium
nitrate (0.1%) and pH 7 by Acinetobacter sp. Bacteria was applied in 2-l bioreactor significantly removed chromate after 3 days. The results of the study indicated
removal of more than 75% chromium by Acinetobacter sp. determined by diphenylcarbazide colorimetric assay and atomic absorption spectrophotometer after 7 days. Study of microbial
[Cr(VI)] removal and identification of reduction intermediates has been hindered by the lack of analytical techniques. Therefore,
removal of chromium was further substantiated by transmission electron microscopy (TEM), scanning electron microscopy (SEM)
and energy-dispersive X-ray spectroscopy (EDX) which indicated bioaccumulation of chromium in the bacterial cells. 相似文献