Effects of Microalgae Addition and Fish Feed Supplementation in the Integrated Rearing of Pacific White Shrimp and Nile Tilapia Using Biofloc Technology.

This study aims to evaluate a Pacific white shrimp and Nile tilapia integrated system using biofloc technology with or without the addition of the microalgae Scenedesmus obliquus and with or without fish feed supplementation in a two-factor 62-day experiment. The shrimp (2.16 ± 0.01 g) were reared under a density of 400 shrimp m−3 and the fish (1.53 ± 0.12 g) were reared under a density of 522 fish m−3. The microalgae was added to the culture water two times a week. Growth performance, sludge production, and water microbiology were evaluated. Fish feed and the microalgae addition improved fish final biomass in 58% and 14%, respectively (p < 0.05). Fish survival was significantly higher when microalgae was added (93.9 ± 1.8%) compared with the treatments without microalgae addition (86.2 ± 7.6%) (p < 0.05). The yield of the overall system was higher in the treatments with fish feed supplementation (4.2 ± 0.2 kg m−3) compared with no addition (3.9 ± 0.2 kg m−3) (p < 0.05). These results suggest that fish feed supplementation at the rate of 1% of the biomass and microalgae inoculation can improve fish growth performance and system yield, without affecting sludge production and water microbiology. This work is an expansion of a conference paper with the same title.

Synergistic effect of growth conditions and organic carbon sources for improving biomass production and biodiesel quality by the microalga Choricystis minor var. minor.

In the search for microalgae species with potential for biodiesel production, Choricystis minor var. minor has been seen as a promising source of biomass due to its high lipid content and the satisfactory characteristics of its fatty acid methyl esters (FAMEs). For this reason, the objective of this study was to investigate the synergistic effect of growth conditions and organic carbon sources on cultivation of this microalga. To do so, experimental cultivations were conducted in photoautotrophic, heterotrophic and mixotrophic metabolisms using glucose, fructose, glycerol or sucrose - in growth conditions that use organic carbon. Thus, growth parameters of the cultures were evaluated and at the end of the cultivations, FAMEs yield and profile were determined by gas chromatography, the efficiency of carbon conversion into biomass was evaluated and a microbial analysis was conducted. Regarding growth conditions, the findings have confirmed that, regardless of the organic carbon source used, the heterotrophic and mixotrophic metabolisms can present advantages over the photoautotrophic one. In addition, biomass production was higher with the use of glucose than with other organic carbon sources, regardless of growth condition (heterotrophic or mixotrophic). Moreover, cultivations with the addition of CO2 have converted carbon into biomass less efficiently. On the other hand, photoautotrophic cultures presented the lowest bacterial load. In comparison to photoautotrophic and mixotrophic, heterotrophic cultures have led to lower FAMEs content and higher yields of unsaturated fatty acids. The most satisfactory FAMEs profile for biodiesel production was obtained with mixotrophic growth using fructose.

The secreted acid trehalase encoded by the CgATH1 gene is involved in Candida glabrata virulence.

BACKGROUND: Candida glabrata yeast is the second cause of candidiasis worldwide. Differs from other yeasts since assimilates only glucose and trehalose (a characteristic used in rapid identification tests for this pathogen) by secreting into the medium a highly active acid trehalase encoded by the CgATH1 gene. OBJECTIVE: This study aimed to characterise the function of the acid trehalase in the physiopathology of C. glabrata. METHODS: Gene deletion was performed to obtain a mutant ath1Δ strain, and the ability of the ath1Δ strain to grow in trehalase, or the presence of trehalase activity in the ath1Δ yeast cells, was verified. We also tested the virulence of the ath1Δ strain in a murine model of infection. FINDINGS: The ath1Δ mutant strain grows normally in the presence of glucose, but loses its ability to grow in trehalose. Due to the high acid trehalase activity present in wild-type cells, the cytoplasmic neutral trehalase activity is only detected in the ath1Δ strain. We also observed a significantly lower virulence of the ath1Δ strain in a murine model of infection with either normal or immunocompromised mice. MAIN CONCLUSIONS: The acid trehalase is involved in the hydrolysis of external trehalose by C. glabrata, and the enzyme also plays a major virulence role during infectivity.

Tratamento cirúrgico do paciente com síndrome de Barraquer-Simon: revisão bibliográfica e relato de caso / Surgical treatment of patient with Barraquer-Simon syndrome: review of literature and related case

Barraquer e Simon descreveram no começo do século uma doença caracterizada por progressiva atrofia da gordura do tecido subcutâneo, limitada à parte superior do corpo, incluindo face. É uma síndrome rara, de origem obscura, também conhecida como lipodistrofia céfalotorácica. Os pacientes com a síndrome perdem progressivamente sua gordura subcutânea em direção craniocaudal simetricamente, começando na face e progredindo até uma determinada área da coxa. Freqüentemente estes pacientes apresentam uma hipertrofia de tecido celular subcutâneo nas suas extremidades inferiores. A doença começa no final da primeira década de vida ou no começo da segunda década, e é rara em pacientes do sexo masculino. Os autores descrevem um caso da síndrome de Barraquer-Simon com envolvimento facial e torácico, sem outras anomalias. Durante o seguimento cirúrgico, foram realizadas lipoenxertias, cirurgia para colocação de bioimplantes malares e cirurgia ortognática. A síndrome de Barraquer-Simon, classificada como lipodistrofia parcial, ainda é pouco compreendida. Mais estudos serão necessários para confirmar a base genética.

Barraquer and Simon described at the beginning of the century a disease characterized by progressive atrophy of the fat tissue of the sub-cutaneous limited to upper body including face. It is a rare syndrome of obscure origin, also known as lipodystrophy cefalochest. The patients with the syndrome gradually lose their fat sub-cutaneous toward craniocaudal symmetrically, starting on the face and progresses to a certain area of the thigh. Often these patients have a hypertrophy of cellular sub-cutaneous tissue in their lower extremities. The disease begins at the end of the first decade of life or at the beginning of the second decade, and is rare in patients male. The authors describe a case of the syndrome Barraquer-Simon involvement with facial and chest with no other abnormalities. During the surgical follow up, was performed lipoenxertias, surgery for placement of bioimplantes malares and surgery orthognathic. The syndrome Barraquer-Simon, classified as partial lipodystrophy, is still little understood. More studies are needed to confirm the genetic basis.