This paper presents pure glycerol and raw glycerol as additional carbon sources in the production of carotenoids by Phaffia rhodozyma NRRL Y-17268. Batch cultures in shaken flasks were performed in order to verify the effects of temperature cultivation (20 and 25ºC) and pure glycerol concentration (0, 10 and 40 g.L-1). The increase from 20 to 25ºC led to a significant increase (p<0.05) in cell concentration for all the pure glycerol concentrations, reaching the maximum levels of 8.9 g.L-1 of biomass (168 h), specific production of carotenoids (SPC) of 91.0 μg.g-1 (72 h) and volumetric production of carotenoids (VPC) of 2.0 μg.mL-1 (168 h) with 40 g.L-1 of pure glycerol at 25ºC. The use of 40 g.L-1 of raw glycerol at the same temperature resulted in a carotenogenic production showing no significant difference (p>0.05) in pure glycerol, reaching the maximum values of 8.3 g.L-1 of biomass (168 h) and within 120 h SPC 275.5 μg.g-1 and VPC 1.7 μg.mL-1. Therefore, the pure glycerol and raw glycerol can be used as additional carbon sources in the culture medium of P. rhodozyma.
Candidemia is a frequent condition in Neonatal Intensive Care Units (NICU) and usually complicates the newborns clinical course. Several factors are responsible for candidiasis, such as prematurity and use of broad-spectrum antibiotics, and in these cases, there are the involvement of various Candida species, as C. albicans, and C. parapsilosis. However, other species as C. haemulonii has been rarely described in candidemia cases, being considered an emergent pathogen. Thus, we report a case of neonatal candidemia by C. haemulonii and a review of literature of fungemia by this yeast. The patient was a neonate with gestational age of 26 weeks and birth weight of 660 g hospitalized in a NICU from a Brazilian hospital. The identification of the etiological agent was performed by phenotypic methods, scanning electron microscopy, sequencing of the ITS region of rDNA, and mass spectrometry. Antifungal susceptibility testing was carried out according to the Clinical Laboratories and Standards Institute guidelines. The newborn was diagnosed with candidemia by C. haemulonii resistant to amphotericin B with minimal inhibitory concentration (MIC) of 8 µg/mL, sensitive to fluconazole (MIC: 8 µg/mL) and voriconazole (MIC: 0.12 µg/mL). The treatment with fluconazole (12 mg/kg/day) was established with good outcome. Candidemia by C. haemulonii is still being limited to a few sporadic cases in adults with endemic and restricted occurrences in neonates. Usually, the therapy with amphotericin B is ineffective against this species. Our results showed the importance of the mycological diagnosis associated to antifungigrama for the successful clinical management followed by important epidemiological data.
Lignocellulosic materials have been considered as an alternative source from which liquid biofuel and fine chemicals can be produced with a moderate environmental impact. However, they can be contaminated with metals, soil, and ash, owing incrustation and corrosion of industrial reactors and pipelines. In this work, the use of ultrasound energy was applied for the removal of metals and nonmetals (Ba, Ca, Mg, Mn, P, S, Si, and Sr) from sugarcane straw. Ultrasound-assisted demineralization (UAD) experiments were carried out in ultrasonic baths in several frequencies (from 25 up to 130 kHz). The following experimental conditions were evaluated: demineralization solution (HNO3, HCl, H2SO4, H2O2, and H2O), H2O2 concentration (from 5 to 30% v v−1), extraction temperature (from 30 to 70 °C), sonication time (from 5 to 45 min), and ultrasound amplitude (from 10 to 70%). Better demineralization efficiencies (66%) were obtained employing an ultrasound bath operating at 25 kHz for 30 min, ultrasound amplitude of 60%, and using a diluted H2O2 solution (15% v v−1) at 70 °C. When the obtained results were compared with those obtained by mechanical stirring (MS, 500 rpm), it was observed that the use of ultrasound energy increased the demineralization efficiency up to 16%. Furthermore, acid hydrolysis was performed to evaluate the influence of US and mechanical stirring in fermentable sugars’ production. The total sugars’ yield (glucose, xylose, and arabinose) increased around 55% for both systems (US and MS). To prove the applicability of the proposed process, some experiments for scaling up were performed using several reaction loads (0.5 to 3 L). An attempt for scaling the proposed process up was well succeeded up to a 3 L load. Therefore, the proposed ultrasound-assisted procedure can be considered as a suitable alternative for high-efficiency demineralization from sugarcane straw.
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