Innovative polyhydroxybutyrate production by Chlorella fusca grown with pentoses.

The current study aimed to evaluate if the addition of pentoses along with variations in light intensity and photoperiod can stimulate the production of polyhydroxybutyrate (PHB) and other biomolecules by Chlorella fusca LEB 111. The variables evaluated were the addition of xylose and arabinose as sources of organic carbon, different photoperiods (18 h, 12 h and 6 h light) and variations in light intensities (58, 28 and 9 µmolphotons m-2 s-1). The highest PHB accumulation (17.4% w w-1) and protein production (53.2% ww-1) were observed in assays with xylose addition and a photoperiod of 6 h of light provided at 28 and 58 µmolphotons m-2 s-1, respectively. The highest lipid content (24.7% w w-1) was obtained with 18 h of light. The current study contributes to the development of sustainable alternatives for the use of wastes and the production of biomolecules from algae.

Chlorella minutissima cultivation with CO2 and pentoses: Effects on kinetic and nutritional parameters.

CO2 emissions and the large quantity of lignocellulosic waste generated by industrialized nations constitute problems that may affect human health as well as the global economy. The objective of this work was to evaluate the effects of using CO2 and pentoses on the growth, protein profile, carbohydrate content and potential ethanol production by fermentation of Chlorella minutissima biomass. CO2 and pentose supplementation can induce changes in the microalgal protein profile. A biomass production of 1.84g.L-1 and a CO2 biofixation rate of 274.63mg.L-1.d-1 were obtained with the use of 20% (v.v-1) CO2. For cultures with 20% (v.v-1) CO2 and reduced nitrogen, the carbohydrate content was 52.3% (w.w-1), and theoretically, 33.9mL.100g-1 of ethanol can be produced. These results demonstrate that C. minutissima cultured with the combined use of CO2 and pentoses generates a biomass with high bioenergetic potential.

Pentoses and light intensity increase the growth and carbohydrate production and alter the protein profile of Chlorella minutissima.

High concentrations of carbon, which is considered a necessary element, are required for microalgal growth. Therefore, the identification of alternative carbon sources available in large quantities is increasingly important. This study evaluated the effects of light variation and pentose addition on the carbohydrate content and protein profile of Chlorella minutissima grown in a raceway photobioreactor. The kinetic parameters, carbohydrate content, and protein profile of Chlorella minutissima and its theoretical potential for ethanol production were estimated. The highest cellular concentrations were obtained with a light intensity of 33.75µmol.m-2.s-1. Arabinose addition combined with a light intensity of 33.75µmol.m-2.s-1 increased the carbohydrate content by 53.8% and theoretically produced 39.1mL·100g-1 ethanol. All of the assays showed that a lower light availability altered the protein profile. The luminous intensity affects xylose and arabinose assimilation and augments the carbohydrate content in C. minutissima, making this microalga appropriate for bioethanol production.

Nitrogen balancing and xylose addition enhances growth capacity and protein content in Chlorella minutissima cultures.

This study aimed to examine the metabolic changes in Chlorella minutissima cells grown under nitrogen-deficient conditions and with the addition of xylose. The cell density, maximum photochemical efficiency, and chlorophyll and lipid levels were measured. The expression of two photosynthetic proteins, ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) and the beta subunit (AtpB) of adenosine triphosphate synthase, were measured. Comparison of cells grown in medium with a 50% reduction in the nitrogen concentration versus the traditional medium solution revealed that the cells grown under nitrogen-deficient conditions exhibited an increased growth rate, higher maximum cell density (12.7×10(6)cellsmL(-1)), optimal PSII efficiency (0.69) and decreased lipid level (25.08%). This study has taken the first steps toward protein detection in Chlorella minutissima, and the results can be used to optimize the culturing of other microalgae.

Prospective randomized double blind placebo-controlled evaluation of azithromycin for treatment of cat-scratch disease.

OBJECTIVE: To determine the efficacy of azithromycin in the treatment of patients with typical cat-scratch disease. DESIGN: Prospective, randomized, double blind, placebo-controlled clinical trial. SETTING: Large military medical center and its referring clinics. PATIENTS: Active duty military members and their dependents with laboratory-confirmed, clinically typical cat-scratch disease. INTERVENTION: Study participants assigned by randomization to treatment with oral azithromycin or placebo for 5 days. OUTCOME MEASURES: Lymph node volume was calculated using three dimensional ultrasonography at entry and at weekly intervals. The ultrasonographer was blinded to the treatment groups. Endpoint evaluations were predetermined as time in days to 80% resolution of the initial total lymph node volume. RESULTS: Demographic and clinical data showed that the azithromycin and placebo treatment groups were comparable at entry although the placebo group tended to be older. Eighty percent decrease of initial lymph node volume was documented in 7 of 14 azithromycin-treated patients compared with 1 of 15 placebo-treated controls during the first 30 days of observation (P = 0.026). After 30 days there was no significant difference in rate or degree of resolution between the two groups. CONCLUSIONS: Treatment of patients with typical cat-scratch disease with oral azithromycin for five days affords significant clinical benefit as measured by total decrease in lymph node volume within the first month of treatment.