Mixotrophic Production of Marine Microalga Phaeodactylum tricornutum on Various Carbon Sources Ceron, Garcia (Universidad de Almeria, Almeria, Spain), E-mail: mcceron@ual.es; Camacho, F. Garcia (Universidad de Almeria, Almeria, Spain); Miron, A. Sanchez (Universidad de Almeria, Almeria, Spain) ...
Journal of microbiology and biotechnology,
05/2006, Volume:
16, Issue:
5
Journal Article
Peer reviewed
We investigated the potential use of various carbon sources (fructose, glucose, mannose, lactose, and glycerol) for culturing Phaeodactylum tricornutum UTEX-640 in mixotrophic and heterotrophic batch ...cultures. Concentrations of carbon substrates tested ranged from 0.005 M to 0.2 M. P. tricornutum did not grow heterotrophically on any of the C-sources used, but successive additions of organic carbon in mixotrophic growth mode substantially increased the biomass concentration and productivity relative to photoautotrophic controls.
Nearly a century after Einstein first predicted the existence of gravitational waves, a global network of Earth-based gravitational wave observatories is seeking to directly detect this faint ...radiation using precision laser interferometry. Photon shot noise, due to the quantum nature of light, imposes a fundamental limit on the attometre-level sensitivity of the kilometre-scale Michelson interferometers deployed for this task. Here, we inject squeezed states to improve the performance of one of the detectors of the Laser Interferometer Gravitational-Wave Observatory (LIGO) beyond the quantum noise limit, most notably in the frequency region down to 150 Hz, critically important for several astrophysical sources, with no deterioration of performance observed at any frequency. With the injection of squeezed states, this LIGO detector demonstrated the best broadband sensitivity to gravitational waves ever achieved, with important implications for observing the gravitational-wave Universe with unprecedented sensitivity.
Background
More than 10 years after the introduction of combination antiretroviral therapy (cART), we examined the trend in the proportion of deaths caused by end‐stage liver disease (ESLD) in ...HIV‐infected adults in France between 1995 and 2005.
Design and methods
In 2005, 34 departments prospectively recorded all deaths in HIV‐infected patients who were followed in those departments (around 24 000). Results were compared with those of four previous cross‐sectional surveys conducted since 1995 using the same methodology.
Results
Among 287 reported deaths in 2005, 100 (35%) were related to AIDS, and 48 (17%) to ESLD. Three out of four patients who died from ESLD‐related causes had chronic hepatitis C. Excessive alcohol consumption was reported in approximately half of the patients (48%). At death, 62% of patients had undetectable HIV viral load and the median CD4 count was 237 cells/μL. From 1995 to 2005, the proportion of deaths caused by ESLD increased from 2 to 17% (P<0.001). The proportion of deaths caused by hepatocellular carcinoma increased from 5% in 1995 to 25% in 2005 (P=0.0337).
Conclusions
Over the 10 years from 1995 to 2005, the proportion of deaths caused by hepatitis C virus‐related ESLD has increased in HIV‐infected patients. ESLD is currently a leading cause of death in this population, with hepatocellular carcinoma representing a quarter of liver‐related deaths. Recommendations for the detection of hepatocellular carcinoma should be strictly applied in these patients.
The effect of culture conditions on the productivity of biomass and high value products by microalgae has been studied in order to maximise these parameters and meet the nutritional requirements for ...aquaculture. To this end, a range of temperatures (15–30°C), incident photon flux densities (PFD) (250–1600μmol·s−1·m−2) and dilution rates (0.1–0.5d−1) have been tested in indoor Nannochloropsis gaditana cultures. Predictive models for biomass and high value product productivities are presented. Photoinhibition was observed in cultures at both high incident PFD and temperature. The maximum biomass, EPA, vaucheriaxanthin and β-carotene productivities (0.429g·L−1·d−1 and 17.2, 1.05 and 1.31mg·L−1·d−1, respectively) were achieved at 25°C, with an average irradiance of 170μmol·s−1·m−2 and a dilution rate of 0.3d−1.
•The combined effect of temperature and irradiance on N. gaditana growth was studied.•The effect of dilution rate on N. gaditana growth has also been studied.•High irradiance in cultures at high temperature leads to photoinhibition.•Optimal culture conditions for N. gaditana growth has been established.•Predicting models for biomass and high value product generation have been set.
We report on follow-up observations of the gamma-ray burst GRB 060927 using the robotic ROTSE-IIIa telescope and a suite of larger aperture ground-based telescopes. An optical afterglow was detected ...20 s after the burst, the earliest rest-frame detection of optical emission from any GRB. Spectroscopy performed with the VLT about 13 hr after the trigger shows a continuum break at lambda approximately 8070 AA, produced by neutral hydrogen absorption at unk approximately 5.6. We also detect an absorption line at 8158 AA, which we interpret as Si II lambda 1260 at unk = 5.467. Hence, GRB 060927 is the second most distant GRB with a spectroscopically measured redshift. The shape of the red wing of the spectral break can be fitted by a damped Lya profile with a column density with log(N sub(H)/cm super(-2)) = 22.50 plus or minus 0.15. We discuss the implications of this work for the use of GRBs as probes of the end of the dark ages and draw three main conclusions: (1) GRB afterglows originating from unk unk unk should be relatively easy to detect from the ground, but rapid near-infrared monitoring is necessary to ensure that they are found; (2) the presence of large H I column densities in some GRB host galaxies at unk > 5 makes the use of GRBs to probe the reionization epoch via spectroscopy of the red damping wing challenging; and (3) GRBs appear crucial to locate typical star-forming galaxies at unk > 5, and therefore the type of galaxies responsible for the reionization of the universe.
Objectives
Enterococcus spp. account for 10% of infective endocarditis (IE). Although daptomycin is a bactericidal drug with in vitro activity against Enterococcus, there is little experience of its ...use in IE. We analysed the effectiveness of daptomycin in the treatment of enterococcal IE (EIE).
Methods
This was a retrospective descriptive study comparing the efficacy of daptomycin versus ampicillin/ceftriaxone versus conventional antibiotic regimens (ampicillin or vancomycin ± gentamicin) in EIE.
Results
From January 2007 to December 2011, 6 patients with EIE treated with daptomycin monotherapy were compared with 21 patients treated with ampicillin/ceftriaxone and 5 patients treated with ampicillin or vancomycin ± gentamicin. The three groups had similar epidemiological and clinical characteristics. Daptomycin indications were allergy to β-lactams (n = 3), therapy simplification (n = 2), renal failure (n = 2) and Enterococcus faecium resistant to ampicillin/gentamicin (n = 1). Daptomycin MICs ranged from 1 to 2 mg/L and the doses were 6–10 mg/kg/day intravenously. Daptomycin patients had longer duration of bacteraemia (6 versus 1 day, P < 0.01) and greater need of therapy switch due to complications (66.7% versus 0%, P < 0.01). There were no differences regarding duration of hospital stay or mortality.
Conclusions
Daptomycin-treated patients more frequently required a therapeutic change due to worse microbiological and clinical response, although mortality was not increased. Our findings do not support the use of daptomycin as single therapy in the treatment of EIE. Its role in combined strategies should be further investigated.
The prevention of biofouling in the inner walls of closed photobioreactors (PBRs) becomes a critical step in improving the performance of photosynthetic microalgae bioprocesses. Selection of ...antifouling materials implies approaches at laboratory scale. This work reports the use of a flow cell of the modified Robbins device (MRD) type coupled to a PBR, operated in both batch and continuous modes with the model marine microalgae Nannochloropsis gaditana to study the biofouling formation on diverse materials. The fluid-dynamics within the MRD was studied via CFD-aided simulations. At separation distances lower than the cells' diffusion layer thickness, a diffusion-controlled transport of the cells to the material surface was postulated. Results suggested that the flow density of cells in the MRD (Jz), governed by cell concentration gradients, is a significant factor in the adhesion intensity (B) when the PBR is operated in batch mode; not in the continuous mode where the differences observed in B between materials were mainly attributed to the type of material. Polyvinylchloride (PVC) was clearly the best anti-biofouling material compared to polycarbonate, polystyrene, borosilicate glass and stainless steel. The B maximum occurred at the end of the stationary phase in batch culture mode. Continuous culture operation seemed to be preferable since once steady state is achieved, the B value remained low and constant, indicating equilibrium between the number of adhered cells per surface unit and the cell concentration in the culture broth – this was because the adhered cells did not grow on the surface due to phosphate limitation. The PBR-coupled MRD has demonstrated to be well-suited for the screening of antifouling materials under fluid-dynamic conditions relevant in PBRs.
•Microalgal biofouling was monitored with a flow cell attached in closed loop to a PBR•PBR biofouling was interpreted using CFD and modelling adhesion dynamics in a flow cell•Polyvinyl chloride and stainless steel presented less biofouling than other materials•Biofouling may be controlled by limiting the flow of nutrients to the PBR surface
We describe 7 cases of renal tubular injury in HIV-infected patients receiving an antiretroviral regimen containing tenofovir. Our patients (5 women and 2 men) developed renal tubular dysfunction, ...with hypophosphatemia, normoglycemic glycosuria, proteinuria, and decrease of creatinine clearance. The first biologic signs of renal toxicity were observed after duration of tenofovir treatment from 5 weeks to 16 months, and they resolved less than 4 months after discontinuation of tenofovir. Six patients had a low body weight (<60 kg). Five patients received low doses of ritonavir, and 1 received didanosine. In 5 patients, the signs resolved with the discontinuation of only the tenofovir. A renal biopsy performed in 1 patient was consistent with tubulointerstitial injury. Proximal tubulopathy appears to be a rare adverse effect of long-term tenofovir therapy. In patients with low weight or mild preexisting renal impairment, regular monitoring of tubulopathy markers could lead to early detection of this dysfunction.
Measurements of the differential production cross sections dσ/dpBT and dσ/dyB for B⁰ mesons produced in pp collisions at √s=7 TeV are presented. The data set used was collected by the CMS experiment ...at the LHC and corresponds to an integrated luminosity of 40 pb⁻¹. The production cross section is measured from B⁰ meson decays reconstructed in the exclusive final state J/ψK0S, with the subsequent decays J/ψ→μ⁺μ⁻ and K0S→π⁺π⁻. The total cross section for pBT>5 GeV and |yB|<2.2 is measured to be 33.2±2.5±3.5 μb, where the first uncertainty is statistical and the second is systematic.
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