首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
A bacterial strain (MM) utilizing methanol as the only carbon and energy source was isolated from corn mint rhizoplane. The cells of the strain were gram-negative colorless motile rods. Spores and prosthecae were not formed, reproduced by binary fission, and did not require vitamins and growth factors. The organism was strictly aerobic, urease-, oxidase-, and catalase-positive. Used the KDPG variant of the ribulose monophosphate pathway. Possessed NAD+ dependent 6-phosphogluconate dehydrogenase activity and enzymes of the glutamate cycle. The activities of α-ketoglutarate dehydrogenase and of the glyoxylate bypass enzymes (isocitrate lyase and malate synthase) were absent. Palmitic (C16:0) and palmitoleic (C16:1) acids were predominant in the cell fatty-acid composition. The dominant phospholipids were phosphatidylethanolamine, phosphatidylglycerol, and phosphatidylcholine. The dominant ubiquinone was Q8. The strain formed indole from tryptophan. The DNA G + C content was 54.5 mol % (T m). According to the data of the 16S rRNA gene sequencing, strain MM showed high similarity (98–99%) to Methylovorus glucosotrophus VKM B-1745T and Methylovorus mays VKM B-2221T, but the level of DNA-DNA homology with these cultures was only 40 and 58%, respectively. The strain was classified as a new species, Methylovorus menthalis sp. nov. (VKM B-2663T).  相似文献   

2.
We propose a new set of approaches, which allow identifying the primary enzymes of glyphosate (N-phosphonomethyl-glycine) attack, measuring their activities, and quantitative analysis of glyphosate degradation in vivo and in vitro. Using the developed approach we show that glyphosate degradation can follow different pathways depending on physiological characteristics of metabolizing strains: in Ochrobactrum anthropi GPK3 the initial cleavage reaction is catalyzed by glyphosate-oxidoreductase with the formation of aminomethylphosphonic acid and glyoxylate, whereas Achromobacter sp. MPS12 utilize C-P lyase, forming sarcosine. The proposed methodology has several advantages as compared to others described in the literature.  相似文献   

3.
Oil-polluted soils were sampled from National Iranian South Oil Company (NISOC) for isolation and screening of C–S and not C–C targeted Dibenzothiophene (DBT) degrading microorganisms. Microbacterium sp. NISOC-06, a C–S targeted DBT degrading bacterium, was selected and its desulfurization ability was studied in aqueous phase and water-gasoline biphasic systems. The 16srRNA gene was amplified using universal eubacteria-specific primers, PCR product was sequenced and the sequence of nearly 1,500 bp 16srDNA was studied. Based on Gas Chromatography results Microbacterium sp. NISOC-06 utilized 94.8% of 1 mM DBT during the 2 weeks of incubation. UV Spectrophotometry and biomass production measurements showed that the Microbacterium sp. NISOC-06 was not able to utilize DBT as a carbon source. There was no accumulation of phenolic compounds as Gibb’s assay showed. Biomass production in a biphasic system for which DBT-enriched gasoline was used as the sulfur source indicated the capability of Microbacterium sp. NISOC-06 to desulfurize gasoline.  相似文献   

4.
A comparative study of the structures of carbohydrate-containing cell wall polymers isolated from the strains of the Bacillus subtilis group was performed by means of chemical and NMR spectroscopic meth ods. Polymers of different structure were revealed, namely, 1,3-poly(glycerol phosphates) with β-glucopyranose in Bacillus subtilis strains VKM B-520, VKM B-723, and VKM B-763 (= VKM B-911); 1,5-poly(ribitol phosphate) with α-glucopyranose in B. subtilis strains VKM B-722 and VKM B-922 (the structure is reported for the first time); and simultaneously two polymers in B. subtilis VKM B-761, 1,5-poly(ribitol phosphate) with β-glucopyranose and the disaccharide 1-phosphate polymer with the following repeating unit: -6)-α-D-Galp-(1-P-4)-gB-D-GlcpNAc-(1-, in which the hydroxyls at C3 and C6 of glucosamine residues are partially O-acetylated (the structure is reported for the first time). Heterogeneity of the B. subtilis group is con firmed by variations in the structure and composition of the cell wall polymers. The cell surface polymers are useful for discrimination of closely related bacilli strains and are cell wall marker components that may be an indispensable element of the Bacillus subtilis group taxonomy along with the genomosystematic methods.  相似文献   

5.
Bioremediation of glyphosate-contaminated soils   总被引:1,自引:0,他引:1  
Based on the results of laboratory and field experiments, we performed a comprehensive assessment of the bioremediation efficiency of glyphosate-contaminated soddy-podzol soil. The selected bacterial strains Achromobacter sp. Kg 16 (VKM B-2534D) and Ochrobactrum anthropi GPK 3 (VKM B-2554D) were used for the aerobic degradation of glyphosate. They demonstrated high viability in soil with the tenfold higher content of glyphosate than the recommended dose for the single in situ treatment of weeds. The strains provided a two- to threefold higher rate of glyphosate degradation as compared to indigenous soil microbial community. Within 1–2 weeks after the strain introduction, the glyphosate content of the treated soil decreased and integral toxicity and phytotoxicity diminished to values of non-contaminated soil. The decrease in the glyphosate content restored soil biological activity, as is evident from a more than twofold increase in the dehydrogenase activity of indigenous soil microorganisms and their biomass (1.2-fold and 1.6-fold for saprotrophic bacteria and fungi, respectively). The glyphosate-degrading strains used in this study are not pathogenic for mammals and do not exhibit integral toxicity and phytotoxicity. Therefore, these strains are suitable for the efficient, ecologically safe, and rapid bioremediation of glyphosate-contaminated soils.  相似文献   

6.
Two novel strains of budding bacteria, Z-0071T and Z-0072, were isolated from dystrophic humified waters formed by xylotrophic fungi in the course of spruce wood degradation. The cells of both strains are coccoid (0.95–1.80 μm), nonmotile, single or arranged in pairs. The cells have a complex system of intracellular membranes and are covered with fimbriae and surrounded by a mucous capsule up to 0.3 μm thick. Both strains are aerobic organoheterotrophic, mesophilic, and acid-tolerant microorganisms that are able to grow under microaerobic conditions. They utilize N-acetyl-glucosamine, carbohydrates, and lactate as growth substrates. The strains grow in a pH range of 4.0–7.5 with an optimum at 6.0–6.5. The temperature range for growth is 4–30°C, with an optimum at 25–28°C. Strains Z-0071T and Z-0072, inhabitants of dystrophic low-mineral waters, are NaCl-sensitive: the NaCl content in the media above 0.5 g/l inhibited growth. The main fatty acids of strains Z-0071T and Z-0072 are C16:0, C18:1ω9c, and C18:2ω9c, 12c. The DNA G + C base content is 51.2–51.7 mol %. The sequences of the 16S rRNA gene fragments (1310 bp) of strains Z-0071T and Z-0072 were found to be identical. The obtained sequences showed a 94.3% similarity with the sequences of the type strain of the most closely related species Singulisphaera acidiphila MOB10≅T. The phenotypic and phylogenetic properties of strains Z-0071T and Z-0072 support classification of these strains within the genus Singulisphaera as a new species Singulisphaera mucilagenosa sp. nov., with the type strain Z-0071T (VKM B-2626).  相似文献   

7.
 A marine fungus was isolated from the black tiger prawn Penaeus monodon at Nha Trang, Vietnam, on March 20, 2001 and named isolate NJM 0131. The fungus was identified as Haliphthoros milfordensis from the characteristics of asexual reproduction, and its physiological characteristics were investigated. Although the optimum temperature for growth of the isolate was 25°–30°C, the fungus grew at a wide range of temperatures (15°–40°C). H. milfordensis grew well in 50%–100% seawater, but poorly in PYG agar containing 1.0%–5.0% NaCl and KCl. The fungus grew at a wide range of pH (4.0–11.0) with the optimum pH value of 7.0–9.0. The isolate also showed pathogenicity to swimming crab larvae (Portunus trituberculatus) by artificial infection, but mortality was not high. This is the first report of disease in the black tiger prawn P. monodon in Vietnam caused by H. milfordensis. Received: July 22, 2002 / Accepted: January 21, 2003 Correspondence to:K. Hatai  相似文献   

8.
9.
An aerobic gram-negative bacterial strain Z-0532 with ring-shaped cells forming spirals in the course of growth was isolated from the humified solution produced by spruce wood decomposition. The new isolate was a chemoorganotrophic, mesophilic, moderately acidophilic organism with the temperature range of 6–32°C (optimum at 25–28°C) and pH range from 4.7 to 7.2 (optimum at pH 5.5–6.5). A broad range of substrates was used as carbon and energy sources, including sugars, some organic acids and polyalcohols, and soluble polymeric compounds (gelatin, esculin, starch, xylan, laminarin, dextrin, casein hydrolysate, and Tween-40). According to its physiological and biochemical characteristics, strain Z-0532 is a typical member of the trophic group of oligotrophic bacteria, which utilize the products of wood hydrolysis dissipated by xylotrophic microorganisms. The G+C base content of strain Z-0532 was 52.1 mol %. Sequencing of the 16S rRNA gene of the new isolate revealed 98% similarity to Larkinella insperata LMG 22510T, which is a recently described species of the family Spirosomaceae of the phylum Bacteroidetes. The level of DNA: DNA homology between this species and strain Z-0532 was only 40%. The differences in the phenotypic and genotypic characteristics suggested classification of the isolate obtained from decomposing wood as a new species of the genus Larkinella, Larkinella arboricola sp. nov., with the type strain Z-0532T (=VKM B-2528T = DSM 21851T).  相似文献   

10.
Humulus japonicus in communities of Miscanthus sacchariflorus and Phragmites australis can grow large enough to overtop other species in the Amsa-dong floodplain. Because of strong winds and the weight of Humulus, plants of M. sacchariflorus and P. australis fell in mid-August and were subject to decomposition under its dense shading. To assess the effects of H. japonicus on nutrient cycling in these communities, we collected fresh samples of M. sacchariflorus and P. australis in litterbags and decomposed them under H. japonicus for 9 months, beginning in August. Biomass and organic contents from M. sacchariflorus during this incubation period were 49–51% and 44–48%, whereas those of P. australis were 49–61% and 32–52%, respectively. Their annual k values were 1.61–1.74 and 1.46–3.54, respectively. Initial N concentrations in M. sacchariflorus and P. australis were 13 and 20 mg g−1, while C:N ratios were 31 and 21, respectively. These results indicate that H. japonicus is responsible for the collapse of M. sacchariflorus and P. australis in August and also accelerates their nutrient cycling through rapid decomposition, thereby increasing nutrient circulation in floodplains.  相似文献   

11.
We report here the degradation of a pesticide, malathion, by Brevibacillus sp. strain KB2 and Bacillus cereus strain PU, isolated from soil samples collected from malathion contaminated field and an army firing range respectively. Both the strains were cultured in the presence of malathion under aerobic and energy-limiting conditions. Both strains grew well in the medium having malathion concentration up to 0.15%. Reverse phase HPLC–UV analysis indicated that Strain KB2 was able to degrade 72.20% of malaoxon (an analogue of malathion) and 36.22% of malathion, while strain PU degraded 87.40% of malaoxon and 49.31% of malathion, after 7 days of incubation. The metabolites mal-monocarboxylic acid and mal-dicarboxylic acid were identified by Gas chromatography/mass spectrometry. The factors affecting biodegradation efficiency were investigated and effect of malathion concentration on degradation rate was also determined. The strain was analyzed for carboxylesterase activity and maximum activity 210 ± 2.5 U ml−1 and 270 U ± 2.7 ml−1 was observed for strains KB2 and PU, respectively. Cloning and sequencing of putative malathion degrading carboxylesterase gene was done using primers based PCR approach.  相似文献   

12.
A method for isolation and shoot regeneration from electrofused protoplasts of L. angustifolius and L. subcarnosus was developed. Viable protoplasts were isolated from leaves of in-vitro grown seedlings at an average yield of 6 × 105 protoplasts g−1 fresh weight. Liquid and agarose solidified B5 media were used for protoplast culture. In the liquid-culture system, all tested media, VKM, P1 and KM8p, were applicable for inducing cell division (84% of all tested petri dishes at four weeks) and colony formation. Media containing additional carbohydrates were suitable to produce compact calli with green and brown pigmentations in different combinations. Analysis of callus with molecular markers allowed to identify six somatic hybrids. However, none of the parental-protoplast derived cell colonies could develop shoots. This is the first report on protoplast fusion of L. angustifolius and L. subcarnosus with subsequent shoot regeneration.  相似文献   

13.
This study examines the effect of four herbicides, quizalafop-p-ethyl, clodinafop, metribuzin and glyphosate, on plant growth promoting activities like phosphate solubilization, siderophores, indole acetic acid, exo-polysaccharides, hydrogen cyanide and ammonia production by herbicide tolerant Klebsiella sp. strain PS19. The strain was isolated from mustard rhizosphere. The selected herbicides were applied two to three times at the recommended rates. Klebsiella sp. strain PS19 tolerated a concentration of 1600 μg/ml each of quizalafop-p-ethyl and clodinafop, and 3200 and 2800 μg/ml of metribuzin and glyphosate, respectively. The activities of Klebsiella sp. strain PS19 observed under in vitro environment were persistent in the presence of all herbicides at lower rates. The plant growth promoting activities even-though decreased regularly, but was not lost completely, as the concentration of each herbicide was increased from the recommended to three times of higher doses. Among all herbicides, quizalafop-p-ethyl, generally, showed maximum toxicity to plant growth promoting activities of Klebsiella sp. strain PS19. As an example, 40, 80 and 120 μg/l of quizalafop-p-ethyl added to liquid culture Pikovskaya medium, decreased phosphate solubilizing activity of strain PS19 by 93, 95 and 97%, respectively over untreated control. The study revealed that the higher rates of herbicides though decreased the plant growth promoting activity but it did not completely inhibit the metabolic activities of strain PS19. The herbicide tolerance together with growth promoting activities observed under herbicide stress suggests that Klebsiella sp. strain PS19 could be used as bacterial preparation for facilitating the growth and yields of crops even in soils polluted with herbicides.  相似文献   

14.
A moderately thermophilic, sporeforming bacterium able to reduce amorphous Fe(III)-hydroxide was isolated from ferric deposits of a terrestrial hydrothermal spring, Kunashir Island (Kurils), and designated as strain Z-0001. Cells of strain Z-0001 were straight, Gram-positive rods, slowly motile. Strain Z-0001 was found to be an obligate anaerobe. It grew in the temperature range from 45 to 70°C with an optimum at 57–60°C, in a pH range from 5.9 to 8.0 with an optimum at 7.0–7.2, and in NaCl concentration range 0–3.5% with an optimum at 0%. Molecular hydrogen, acetate, peptone, yeast and beef extracts, glycogen, glycolate, pyruvate, betaine, choline, N-acetyl-d-glucosamine and casamino acids were used as energy substrates for growth in presence of Fe(III) as an electron acceptor. Sugars did not support growth. Magnetite, Mn(IV) and anthraquinone-2,6-disulfonate served as the alternative electron acceptors, supporting the growth of isolate Z-0001 with acetate as electron donor. Formation of magnetite was observed when amorphous Fe(III) hydroxide was used as electron acceptor. Yeast extract, if added, stimulated growth, but was not required. Isolate Z-0001 was able to grow chemolithoautotrophicaly with molecular hydrogen as the only energy substrate, Fe(III) as electron acceptor and CO2 as the carbon source. Isolate Z-0001 was able to grow with 100% CO as the sole energy source, producing H2 and CO2, requiring the presence of 0.2 g l−1 of acetate as the carbon source. The G+C content of strain Z-0001T DNA G+C was 47.8 mol%. Based on 16S rRNA sequence analyses strain Z-0001 fell into the cluster of family Peptococcaceae, within the low G+C content Gram-Positive bacteria, clustering with Thermincola carboxydophila (98% similarity). DNA–DNA hybridization with T. carboxydophila was 27%. On the basis of physiological and phylogenetic data it is proposed that strain Z-0001T (=DSMZ 14005, VKM B-2307) should be placed in the genus Thermincola as a new species Thermincola ferriacetica sp. nov. The GenBank accession number for the sequence reported in the paper is AY 631277.  相似文献   

15.
Phylogeographic analyses using chloroplast DNA (cpDNA) variation were performed for Pedicularis ser. Gloriosae (Orobanchaceae). Eighty-one plants of 18 populations of 6 species (P. gloriosa, P. iwatensis, P. nipponica, P. ochiaiana, P. sceptrum-carolinum and P. grandiflora) were analyzed. Fifteen distinct haplotypes were identified based on six cpDNA regions: the intergenic spacer between the trnT and trnL 3′exon, trnL 3′exon-trnF, atpB-rbcL, accDpsaI, the rpl16 intron and the trnK region (including the matK gene). Via phylogenetic analyses of the haplotypes, two continental species, P. sceptrum-carolinum and P. grandiflora, were placed at the most ancestral position in the trees. The former species is widely distributed in the Eurasian continent, and the latter is distributed in Far East Asia. Two robust major cpDNA clades (clades I and II) were revealed in the Japanese archipelago, although the statistical values of monophyly of these clades were weak. Clade I included the haplotypes (A-1, A-2, B-1, B-2 and J) of three species (P. gloriosa, P. iwatensis and P. ochiaiana), and Clade II included seven haplotypes (C-D, E-1, E-2 and F-H) of P. nipponica. These results suggest that this series originated on the Eurasian continent and that subsequently populations at the eastern edge of the continent differentiated into the two Japanese lineages. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   

16.
Previously, a new Cordyceps species was isolated from a low altitude area in Chongqing, China, and named Cordyceps chongqingensis sp. nov. In this study, its anamorph was isolated and designated CQM1T. It grew optimally on Czapek medium supplied with 0.5% silkworm flour and 0.5% soybean oil meal at 25°C, pH 5.0–5.5. The phenotypic and molecular characteristics were investigated for its identification and typing. Morphological observations under a microscope revealed that this anamorph of Cordyceps chongqingensis sp. nov. was a new species of Metarhizium. Moreover, it was identified as one of the variants of Metarhizium taii based on sequences of 26S rDNA D1/D2 and ITS regions, and thus named Metarhizium taii var. chongqingensis nov.  相似文献   

17.
Enhanced nitrogen (N) levels accelerate expansion of Calamagrostis epigejos and Arrhenatherum elatius, highly aggressive expanders displacing original dry acidophilous grassland vegetation in the Podyjí National Park (Czech Republic). We compared the capability of Calamagrostis and Arrhenatherum under control and N enhanced treatments to (i) accumulate N and phosphorus (P) in plant tissues, (ii) remove N and P from above-ground biomass during senescence and (iii) release N and P from plant material during decomposition of fresh formed litter. In control treatment, significantly higher amounts of total biomass and fresh aboveground litter were observed in Calamagrostis than in Arrhenatherum. Contrariwise, nutrient concentrations were significantly higher (11.6–14.3 mg N g−1 and 2.3 mg P g−1) in Arrhenatherum peak aboveground biomass than in Calamagrostis (8.4–10.3 mg N g−1 and 1.6–1.7 mg P g−1). Substantial differences between species were found in resorption of nutrients, mainly P, at the ends of growing seasons. While P concentrations in Arrhenatherum fresh litter were twice and three times higher (1.6–2.5 mg P g−1) than in Calamagrostis (0.7–0.8 mg P g−1), N concentrations were nearly doubled in Arrhenatherum (13.1–15.6 mg N g−1) in comparison with Calamagrostis (7.4–8.7 mg N g−1). Thus, the nutrients (N and mainly P) were retranslocated from the aboveground biomass of Calamagrostis probably more effectively in comparison with Arrhenatherum at the end of the growing season. On the other hand, Arrhenatherum litter was decomposed faster and consequently nutrient release (mainly N and P) was higher in comparison with Calamagrostis which pointed to different growth and nutrient use strategies of studied grass species.  相似文献   

18.
Johnius (Johnius) majan sp. nov. is described on the basis of 8 specimens (117–158 mm in standard length) from Oman, Indian Ocean. The new species is distinguished from its congeners by the following combination of characters: black axillary spot on upper pectoral fin base; dorsal soft rays 29–32; anal soft rays 8; scales above lateral line 6, below 11; eye diameter 22.9–28.9% HL; interorbital width 32.0–38.0% HL; gill rakers 5–6 + 15–18 = 21–24; no mental barbel; last well developed pleural rib on 7th vertebra; swim bladder appendages 11; vertebrae 10 + 14 = 24.  相似文献   

19.
This study was designed to identify rhizobial strains specific to greengram expressing higher tolerance against insecticides, fipronil and pyriproxyfen, and synthesizing plant growth regulators even amid insecticide-stress. Of the 50 bradyrhizobial isolates, the Bradyrhizobium sp. strain MRM6 showed tolerance up to 1,600 μg mL−1 against each of fipronil and pyriproxyfen. The tolerant Bradyrhizobium sp. (vigna) produced plant growth promoting substances in substantial amounts, both in the presence and absence of insecticides. The strain MRM6 was further used to investigate its impact on greengram grown in soils treated with 200 (the recommended dose), 400 and 600 μg kg−1 soil of fipronil and 1,300 (the recommended dose), 2,600 and 3,900 μg kg−1 soil of pyriproxyfen. Fipronil at 600 μg kg−1 soils and pyriproxyfen at 3,900 μg kg−1 soils had greatest toxic effects and decreased plant biomass, symbiotic efficiency, nutrient uptake and seed yield of greengram plants. The Bradyrhizobium sp. (vigna) inoculant when used with fipronil and pyriproxyfen significantly increased the measured parameters compared to the plants grown in soils treated solely with the same concentration of each insecticide. This study inferred that the Bradyrhizobium sp. (vigna) strain MRM6 may be exploited as bio-inoculant to increase the productivity of greengram exposed to insecticide-stressed soils.  相似文献   

20.
Peltigera rufescens (Weis) Humb. with a prokaryotic photobiont Nostoc sp. and Cladina arbuscula subsp. mitis (Sandst.) Ruoss with a eukaryotic photobiont Trebouxia sp. were studied to determine the copper sensitivity of lichens with different algal symbionts. Samples growing on historic copper mine-spoil heaps at Ľubietová–Podlipa, Slovakia were assessed for physiological parameters, including total and intracellular uptake of copper, assimilation pigmentation, activity of photosystem II, ergosterol levels, thiobarbituric acid reactive substances and water-soluble protein content. Our results indicate that P. rufescens was more sensitive to copper exposure than C. arbuscula subsp. mitis.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号