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1.
The consortium of Bacillus cereus (DQ002384), Serratia marcescens (AY927692) and Serratia marcescens (DQ002385) were used for pentachlorophenol (PCP) degradation. The consortia showed better overall removal efficiencies than single strains by utilization of PCP as a carbon and energy source confirmed by pH dependent dye indicator bromocresol purple (BCP) in mineral salt media (MSM). Mixed culture was found to degrade up to 93% of PCP (300 mg/l) as compared to single strains (62.75–90.33%), at optimized conditions (30 ± 1°C, pH 7 ± 0.2, 120 rpm) at 168 h incubation. PCP degradation was also recorded at 20°C (62.75%) and 37°C (83.33%); pH 6 (70%) and pH 9 (75.16%); 50 rpm (73.33%) and 200 rpm (91.63%). The simultaneous release of chloride ion up to 90.8 mg/l emphasized the bacterial dechlorination in the medium. GC–MS analysis revealed the formation of low molecular weight compound, i.e., 6-chlorohydroxyquinol, 2,3,4,6-tetrachlorophenol and tetrachlorohydroquinone, from degraded sample as compared to control.  相似文献   

2.
The bacterium Serratia marcescens isolated from surface-sterilised Psoroptes cuniculi was found sensitive to the antibiotic Amikacin. Mites placed in this antibiotic for 48–72 h and then washed by centrifugation were found to be alive and S. marcescens-free. Two experimental infestations were undertaken in order to verify the ability of the S. marcescens-free mites to infect and to give ear skin lesions in healthy rabbits and to evaluate the differential ability of the S. marcescens-free and S. marcescens-infected mites to give ear skin lesions. All rabbits were found to be infested, but only rabbits infested with S. marcescens-free mites presented crusts in their ears, whereas mites and/or eggs were only detected in the ear cerumen of all rabbits infested with S. marcescens-infected mites. S. marcescens was isolated only from P. cuniculi mites taken from these latter rabbits. Results indicate that P. cuniculi mites do not need S. marcescens to live and to be able to infest a healthy rabbit. In addition, S. marcescens was not isolated from eggs and newly born larvae of S. marcescens-infected P. cuniculi, demonstrating that in a population of P. cuniculi this bacterium is not transmitted transovarially.  相似文献   

3.
The aim of this study was to identify and characterize Cronobacter spp. isolated from a range of foods. A total of 71 Cronobacter strains were isolated from 602 foods in our laboratory. The highest contamination was observed in foods of plant origin, e.g. spices, teas, chocolate, nuts, pastries and vegetables. On the basis of genus and species identification performed using genus-specific PCR, 16S rRNA sequencing and AFLP genotyping, most of the strains belonged to Cronobacter sakazakii. Biochemical profiling by the tests included in API 20E, complemented with relevant additional tests, classified the strains into 13 biogroups. AFLP genotyping facilitated discrimination of six main groups at the 70% similarity level and strain grouping correlated clearly with species identification. Our results indicate that molecular typing by AFLP may be applied as a useful tool not only for direct comparison of Cronobacter isolates, providing traceability, but also for the reliable species classification. Moreover, tracing of these bacteria in a wider variety of foods should be important to enhance the knowledge of their transmission.  相似文献   

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5.
Heavy metals–organics mixture pollution is increasingly concerned and simultaneous removal of organic pollutants and heavy metals is becoming significant. In this study, a strain was isolated from the sediment of a tannery effluent outfalls, which can remove o-dichlorobenzene (o-DCB) and Cr(VI) simultaneously. The bacterial isolate was identified as Serratia marcescens by the 16S rRNA gene sequences. The strain removed about 90% of o-DCB and more than 80% of Cr(VI) at the concentration of 1.29 g L?1 o-DCB and 20 mg L?1 Cr(VI). In the presence of concomitant pollutant o-DCB, the optimal pH (8.0) and temperature (30 °C) were determined for Cr(VI) removal. Changes of the bacterial cells and intracellular black Cr(III) sediments were observed by the TEM auxiliary analysis. The results of the FTIR spectroscopy analysis indicated that hydroxyl, amide and polysaccharides were involved in the process of Cr(VI) removal.  相似文献   

6.
A novel strain, DCY108T was isolated from soil of a Panax ginseng field, Yeoncheon province (38°04′N 126°57′E), Republic of Korea. Strain DCY108T is Gram-negative, non-motile, non-flagellate, rod-shaped, and aerobic. The bacterium grows optimally at 25–30 °C, pH 6.5–7.0 and 1 % NaCl. Phylogenetically, strain DCY108T is closely related to Pedobacter jejuensis JCM 18824T, Pedobacter aquatilis JCM 13454T, Pedobacter kyungheensis LMG 26577T and the type strain of the genus Pedobacter heparinus DSM 2366T. The DNA–DNA relatedness values between strain DCY108T and its close phylogenetic neighbors were below 30.0 %. The DNA G+C content of strain DCY108T was determined to be 45.1 mol%. The predominant quinone was menaquinone 7 (MK-7). The major polar lipids were identified as phosphatidylethanolamine and three unidentified aminolipids AL1, AL13 and AL17. Iso-C15:00, iso-C17:03OH and summed feature 3 (C16:1 ω7c/C16:1 ω6c) were identified as the major fatty acids present in strain DCY108T. The results of physiological and biochemical tests allowed strain DCY108T to be differentiated phenotypically from other recognized species belonging to the genus Pedobacter. Therefore, it is suggested that the newly isolated organism represents a novel species, for which the name Pedobacter panacis sp. nov is proposed with the type strain designated as DCY108T (=CCTCCAB 2015196T = KCTC 42748T).  相似文献   

7.
New combinations are proposed in anticipation of the Polygonaceae treatment in the forthcoming volume of Intermountain Flora: Polygonum kelloggii var. esotericum, P. kelloggii var. watsonii , Rumex densiflorus var. pycnanthus , R. salicifolius var. utahensis, and R. occidentalis var. tomentellus. Typifications are proposed to facilitate ongoing studies in Polygonaceae and to maintain current usage.  相似文献   

8.
Two repeated DNA sequences isolated from a partial genomic DNA library of Helianthus annuus, p HaS13 and p HaS211, were shown to represent portions of the int gene of a Ty3 /gypsy retroelement and of the RNase-Hgene of a Ty1 /copia retroelement, respectively. Southern blotting patterns obtained by hybridizing the two probes to BglII- or DraI-digested genomic DNA from different Helianthus species showed p HaS13 and p HaS211 were parts of dispersed repeats at least 8 and 7 kb in length, respectively, that were conserved in all species studied. Comparable hybridization patterns were obtained in all species with p HaS13. By contrast, the patterns obtained by hybridizing p HaS211 clearly differentiated annual species from perennials. The frequencies of p HaS13- and p HaS211-related sequences in different species were 4.3x10(4)-1.3x10(5) copies and 9.9x10(2)-8.1x10(3) copies per picogram of DNA, respectively. The frequency of p HaS13-related sequences varied widely within annual species, while no significant difference was observed among perennial species. Conversely, the frequency variation of p HaS211-related sequences was as large within annual species as within perennials. Sequences of both families were found to be dispersed along the length of all chromosomes in all species studied. However, Ty3 /gypsy-like sequences were localized preferentially at the centromeric regions, whereas Ty1/ copia-like sequences were less represented or absent around the centromeres and plentiful at the chromosome ends. These findings suggest that the two sequence families played a role in Helianthusgenome evolution and species divergence, evolved independently in the same genomic backgrounds and in annual or perennial species, and acquired different possible functions in the host genomes.  相似文献   

9.
A revision of Penstemon sect. Saccanthera subsect. Serrulati includes a new species (P. salmonensis), a new variety (P. triphyllus var. infernalis), and the elevation of a subspecies to species (P. curtiflorus), bringing the total number of species to eight, which are keyed and described, complete with nomenclature and type citations.  相似文献   

10.
Under the present study, an attempt was made to characterize rhizobacteria i.e. Pseudomonas and Bacillus species isolated from rhizosphere of carnation to evaluate their growth promoting effect on carnation so as to select and develop more efficient indigenous plant growth promoting and disease suppressing bioagents of specific soil type and specific plant type. Maximum strains of Pseudomonas and Bacillus sp. showed significant antimicrobial activities against most of the microorganisms tested. On the basis of in vitro antagonistic activities, the best strains were selected and used in field trial to study the influence of these strains on the growth of carnation. Results have shown marked effect on growth parameters and disease incidence has also been reduced significantly.  相似文献   

11.
Summary   Funastrum rupicola Goyder, a new species of Apocynaceae: Asclepiadoideae from Bolivia, is described and illustrated. The conservation status of this species is assessed.  相似文献   

12.
Summary  A new monotypic bamboo genus Phuphanochloa (Poaceae: Bambusoideae) from north-eastern Thailand is described, together with a new species, P. speciosa.  相似文献   

13.
Traditionally viewed as an Andean grain crop,Chenopodium quinoa Willd. includes domesticated populations that are not Andean, and Andean populations that are not domesticated. Comparative analysis of leaf morphology and allozyme frequencies have demonstrated that Andean populations, both domesticated(quinua) and free-living(ajara), represent an exceptionally homogeneous unit that is well differentiated from allied domesticates of coastal Chile(quingua) and freeliving populations of the Argentine lowlands(C. hircinum). This pattern of relationships indicates that Andean populations represent a monophyletic crop/weed system that has possibly developed through cyclic differentiation (natural vs. human selection) and introgressive hybridization. Relative levels of variation suggest that this complex originated in the southern Andes, possibly from wild types allied withC. hircinum, with subsequent dispersal north to Colombia and south to the Chilean coast. Coastal populations were apparently isolated from post-dispersal differentiation and homogenization that occurred in the Andes. Other data point toward a center of origin in the northern Andes with secondary centers of genetic diversity subsequently developing in the southern Andes and the plains of Argentina. Comparative linkage of South American taxa, all tetraploid, with North American tetraploids of the subsection will eventually clarify this problem. While the possibility of a direct phyletic connection betweenC. quinoa and the Mexican domesticate(C. berlandieri subsp. nuttalliae,) cannot be excluded, available evidence indicates that the latter represents an autonomous lineage that is associated with the basal tetraploid, C. b. subsp.berlandieri, through var.sinuatum, whereas South American taxa show possible affinities to either var. zschackei or var.berlandieri. An extinct domesticate of eastern North America,C. b. subsp.jonesianum, represents either another instance of independent domestication, possibly from subsp. b. var.zschackei, or a northeastern outlier of subsp.nuttalliae.  相似文献   

14.

Background

Gonadotropin releasing hormone (GnRH) is responsible for stimulation of gonadotropic hormone (GtH) in the hypothalamus-pituitary-gonadal axis (HPG). The regulatory mechanisms responsible for brain specificity make the promoter attractive for in silico analysis and reporter gene studies in zebrafish (Danio rerio).

Results

We have characterized a zebrafish [Trp7, Leu8] or salmon (s) GnRH variant, gnrh 3. The gene includes a 1.6 Kb upstream regulatory region and displays the conserved structure of 4 exons and 3 introns, as seen in other species. An in silico defined enhancer at -976 in the zebrafish promoter, containing adjacent binding sites for Oct-1, CREB and Sp1, was predicted in 2 mammalian and 5 teleost GnRH promoters. Reporter gene studies confirmed the importance of this enhancer for cell specific expression in zebrafish. Interestingly the promoter of human GnRH-I, known as mammalian GnRH (mGnRH), was shown capable of driving cell specific reporter gene expression in transgenic zebrafish.

Conclusions

The characterized zebrafish Gnrh3 decapeptide exhibits complete homology to the Atlantic salmon (Salmo salar) GnRH-III variant. In silico analysis of mammalian and teleost GnRH promoters revealed a conserved enhancer possessing binding sites for Oct-1, CREB and Sp1. Transgenic and transient reporter gene expression in zebrafish larvae, confirmed the importance of the in silico defined zebrafish enhancer at -976. The capability of the human GnRH-I promoter of directing cell specific reporter gene expression in zebrafish supports orthology between GnRH-I and GnRH-III.
  相似文献   

15.
We have investigated the floral ontogeny of Arillastrum, Allosyncarpia, Stockwellia and Eucalyptopsis (of the eucalypt group, Myrtaceae) using scanning electron microscopy and light microscopy. Several critical characters for establishing relationships between these genera and to the eucalypts have been determined. The absence of compound petaline primordia in Arillastrum, Allosyncarpia, Stockwellia and Eucalyptopsis excludes these taxa from the eucalypt clade. Post-anthesis circumscissile abscission of the hypanthium above the ovary in Stockwellia, Eucalyptopsis and Allosyncarpia is evidence that these three taxa form a monophyletic group; undifferentiated perianth parts and elongated fusiform buds are characters that unite Stockwellia and Eucalyptopsis as sister taxa. No floral characters clearly associate Arillastrum with either the eucalypt clade or the clade of Stockwellia, Eucalyptopsis and Allosyncarpia.We gratefully acknowledge Clyde Dunlop and Bob Harwood (Northern Territory Herbarium) for collecting specimens of Allosyncarpia, and Bruce Gray (Atherton) for collecting specimens of Stockwellia. The Australian National Herbarium (CANB) kindly lent herbarium specimens of Eucalyptopsis for examination. This research was supported by a University of Melbourne Research Development Grant to Andrew Drinnan.  相似文献   

16.
A genetic transformation system has been developed for callus cells of Crataegus aronia using Agrobacterium tumefaciens. Callus culture was established from internodal stem segments incubated on Murashige and Skoog (MS) medium supplemented with 5 mg l−1 Indole-3-butyric acid (IBA) and 0.5 mg l−1 6-benzyladenine (BA). In order to optimize the callus culture system with respect to callus growth and coloration, different types and concentrations of plant growth regulators were tested. Results indicated that the best average fresh weight of red colored callus was obtained on MS medium supplemented with 2 mg l−1 2,4-dichlorophenoxyacetic acid (2,4-D) and 1.5 mg l−1 kinetin (Kin) (callus maintenance medium). Callus cells were co-cultivated with Agrobacterium harboring the binary plasmid pCAMBIA1302 carrying the mgfp5 and hygromycin phosphotransferase (hptII) genes conferring green fluorescent protein (GFP) activity and hygromycin resistance, respectively. Putative transgenic calli were obtained 4 weeks after incubation of the co-cultivated explants onto maintenance medium supplemented with 50 mg l−1 hygromycin. Molecular analysis confirmed the integration of the transgenes in transformed callus. To our knowledge, this is the first time to report an Agrobacterium-mediated transformation system in Crataegus aronia.  相似文献   

17.
18.
Summary  A new species of Macroptilium sect. Microcochle (Benth.) J. A. Lackey is herein described from the states of Piauí and Bahia, Brazil. Macroptilium cochleatum is characterized by few-flowered inflorescences, calyx teeth longer than the tube, a tightly four-coiled keel, and linear, patent fruits. The discovery of this unique Macroptilium species, with its distally coiled keel, expands the diagnostic features of the genus. A key to the Brazilian species of sect. Microcochle is provided.  相似文献   

19.
Single (unpaired) vegetative cells of freshwater pennate diatom Neidium cf. ampliatum differentiated into gametangia and produced a single zygote (auxospore) via a pedogamic process. The gametic nuclei fused after auxospore expansion had begun. The auxospore expanded in parallel to the apical axis of the gametangium.  相似文献   

20.
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