182 research outputs found
From plants to nematodes: Serratia grimesii BXF1 genome reveals an adaptation to the modulation of multi-species interactions
Serratia grimesii BXF1 is a bacterium with the ability to modulate the development of several eukaryotic hosts. Strain BXF1 was isolated from the pinewood nematode, Bursaphelenchus xylophilus, the causative agent of pine wilt disease affecting pine forests worldwide. This bacterium potentiates Bursaphelenchus xylophilus reproduction, acts as a beneficial pine endophyte, and possesses fungal and bacterial antagonistic activities, further indicating a complex role in a wide range of trophic relationships. In this work, we describe and analyse the genome sequence of strain BXF1, and discuss several important aspects of its ecological role. Genome analysis indicates the presence of several genes related to the observed production of antagonistic traits, plant growth regulation and the modulation of nematode development. Moreover, most of the BXF1 genes are involved in environmental and genetic information processing, which is consistent with its ability to sense and colonize several niches. The results obtained in this study provide the basis to a better understanding of the role and evolution of strain BXF1 as a mediator of interactions between organisms involved in a complex disease system. These results may also bring new insights into general Serratia and Enterobacteriaceae evolution towards multitrophic interactions
Initial in vitro evaluations of antibacterial activities of glucosinolate enzymatic hydrolysis products against plant pathogenic bacteria
Aims: The aim of the study was to evaluate the in vitro antibacterial effects of
glucosinolate hydrolysis products (GHP) against plant pathogenic micro-organisms
namely Agrobacterium tumefaciens, Erwinia chrysanthemi, Pseudomonas
cichorii, Pseudomonas tomato, Xanthomonas campestris and Xanthomonas
juglandis.
Methods and Results: Using a disc diffusion assay, seven different doses of 10
GHP were tested against each bacteria. The results showed that the isothiocyanates
were potent antibacterials, whilst the other GHP were much less efficient.
Moreover, the antibacterial effects were dose-dependent, increasing with the
dose applied; 2-phenylethylisothiocyanate and sulforaphane showed the strongest
inhibitory effects. The overall results show a great potential for using the
isothiocyanates as an alternative tool to control undesired bacterial growth in
plants.
Conclusions: Glucosinolate hydrolysis products and more specifically the
isothiocyanates: benzylisothiocyanate, 2-phenylethylisothiocyanate, the isothiocyanate
Mix and sulforaphane, were effective phytochemicals against the in vitro
growth of the phytopathogenic bacteria. The antibacterial activity exhibited by
these phytochemicals reinforces their potential as alternatives to the traditional
chemical control of phytopathogenic bacteria.
Significance and Impact of the Study: This current in vitro study is the first
providing comparative data on GHP as potential control agents for plant
pathogenic bacteria. However, more studies are needed to determine their
possible allelopathic impacts e.g. inhibition of plant growth and negative effects
on beneficial soil bacteria and fungi (mycorrhizae
Homocysteine levels in pediatric renal transplant recipients.
Transplant Proc. 2003 May;35(3):1093-5.
Homocysteine levels in pediatric renal transplant recipients.
Mota C, Fonseca I, Santos MJ, Costa T, Faria MS, Henriques AC, Sarmento AM, Pereira E, Pereira M.
Department of Paediatric Nephrology, Maria Pia Children's Hospital, R. da Boavista, 827, 4050-111, Porto, Portugal. [email protected]
PMID: 12947872 [PubMed - indexed for MEDLIN
Preservation of a highly perishable food, watermelon juice, at and above room temperature under mild pressure (hyperbaric storage) as an alternative to refrigeration
The feasibility of food preservation under pressure (hyperbaric storage) at and above room temperatures,
as an alternative to refrigeration was evaluated. Preservation of a highly perishable food, watermelon
juice, was studied at pressures of 25e150 MPa and temperatures ranging 20e37 C, being compared to
refrigeration and storage at atmospheric pressure at the same temperatures.
Hyperbaric storage at 75 MPa (20e37 C) revealed an inhibitory effect on microbial growth, with at
least an equal performance compared to refrigeration. An additional inactivation effect was verified for
storage at 100 and 150 MPa, with reduction of the initial microbial counts to 1.00 Log CFU/mL for
enterobacteriaceae and yeasts and moulds, and from 4.43 ± 0.04 to 3.31 ± 0.04 and 2.99 ± 0.07 Log CFU/
mL, respectively, for total aerobic mesophiles (25 C).
In general, pH, titratable acidity and total soluble solids did not show a clear variation trend with
pressure and no considerable differences among storage conditions were verified. Cloudiness decreased
for samples stored under pressure and browning degree was in general lower in samples stored under
pressure compared to refrigeration.
This work demonstrates the potentiality of hyperbaric storage as a new preservation methodology, at
variable (uncontrolled) room temperature without energetic costs during storage, as an alternative to
refrigeration
Terapêutica intravesical com bacilo de Calmette-Guérin no tratamento do carcinoma da bexiga / o que sabemos até agora
AbstractIntroductionThe use of intravesical Bacillus Calmette-Guérin is a valid option in the treatment of non-muscle invasive bladder tumors, making it the main subject of a lot of publications. The aim of the present study is to review and consolidate the data available about this subject.MethodsA review of the data available was made on PubMed with the keywords: “intravesical BCG” and “non-muscle invasive bladder cancer”. Original and review articles written in English or Portuguese were selected. We present the discussion alongside the results for structural purposes.Results and discussionScientific evidence strongly advises in favor of BCG use on intermediate and high risk tumors, due to its impact on the recurrence and possibly on the progression rates. It is important to be watchful for possible local and systemic side effects, that when detected call for a rightful therapeutically decision alongside the recommended schemes.ConclusionThe use of intravesical BCG with therapeutically purposes has strong evidence on the non-muscle invasive bladder tumors. More studies are needed in order to better understand the best administration scheme and its mechanism of action
Early Dark Energy at High Redshifts: Status and Perspectives
Early dark energy models, for which the contribution to the dark energy
density at high redshifts is not negligible, influence the growth of cosmic
structures and could leave observable signatures that are different from the
standard cosmological constant cold dark matter (CDM) model. In this
paper, we present updated constraints on early dark energy using geometrical
and dynamical probes. From WMAP five-year data, baryon acoustic oscillations
and type Ia supernovae luminosity distances, we obtain an upper limit of the
dark energy density at the last scattering surface (lss), (95% C.L.). When we include higher redshift
observational probes, such as measurements of the linear growth factors,
Gamma-Ray Bursts (GRBs) and Lyman- forest (\lya), this limit improves
significantly and becomes (95%
C.L.). Furthermore, we find that future measurements, based on the
Alcock-Paczy\'nski test using the 21cm neutral hydrogen line, on GRBs and on
the \lya forest, could constrain the behavior of the dark energy component and
distinguish at a high confidence level between early dark energy models and
pure CDM. In this case, the constraints on the amount of early dark
energy at the last scattering surface improve by a factor ten, when compared to
present constraints. We also discuss the impact on the parameter , the
growth rate index, which describes the growth of structures in standard and in
modified gravity models.Comment: 11 pages, 9 figures and 4 table
Large-scale production of cellulose-binding domains : adsorption studies using CBD-FITC conjugates
A method for the gram-scale production of cellulose-binding domains (CBD) through the proteolytic digestion of a commercial nzymatic preparation (Celluclast) was developed. The CBD obtained, isolated
from Trichoderma reesei cellobiohydrolase I, is highly pure and heavily glycosylated. The purified peptide has a molecular weight of 8.43 kDa, comprising the binding module, a part of the linker, and about 30%
glycosidic moiety. Its properties may thus be different from recombinant ones expressed in bacteria. CBDfluorescein isothiocyanate conjugates were used to study the CBD-cellulose interaction. The presence of
fluorescent peptides adsorbed on crystalline and amorphous cellulose fibers suggests that amorphous regions have a higher concentration of binding sites. The adsorption is reversible, but desorption is a very
slow process.Fundação para a Ciência e a Tecnologia (FCT
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