Large-scale lab culture of Ankistrodesmus gracilis and Diaphanososma birgei were evaluated by studying the biology and biochemical composition of the species and production costs. Ankistrodesmus gracilis presented exponential growth until the 6 th day, with approximately 144 x 10 4 cells.mL , aumentando novamente a partir do décimo segundo dia. A alga clorofícea A. gracilis e o zooplâncton D. birgei possuem aproximadamente 50 e 70% de proteína (PS), respectivamente, com teor de carboidrato acima de 5%. A eletricidade e mão de obra foram os itens mais dispendiosos e, de acordo com os dados obtidos, a temperatura, nutrientes, disponibilidade de luz e manejo do cultivo, foram fatores determinantes sobre a produtividade. Os resultados indicam que o meio NPK (20-5-20) pode ser utilizado diretamente como uma alternativa de cultivo em larga escala, considerando o baixo custo de produção, promovendo adequado crescimento e valor nutricional para A. gracilis e D. birgei.

ABSTRACT:The present work describes the antibacterial activity of the essential oil and the ethanol extract from leaves of Alpinia zerumbet (colônia) on Staphylococcus aureus strains isolated from cows with subclinical mastitis and standard strains ATCC 29213 and ATCC 25923, using the agar diffusion method. Ten treatments containing different concentrations of essential oil and ethanol extract (100.0; 50.0; 25.0; 12.5 and 6.3 mg.mL ) and the control group (50% ethyl alcohol and 1% Tween solutions) were used for antimicrobial testing. The major constituents of the essential oil were p-cimeno (32.72%), 1.8-cineol (24.05%) and 4-terpineol (20.23%), which were determined by gas chromatographymass spectrometry and gas chromatography -flame ionization detector (CG-MS/FID). Ellagic acid and three flavonoids (rutin, quercetin and campferol) were detected in the ethanol extract by means of high performance liquid chromatography-photodiode array detector (HPLC-PDA). All strains showed sensitivity to the treatments with essential oil and the ethanol extract. The best response was obtained with A. zerumbet essential oil at a 100 mg.mL ) e o grupo controle (álcool etílico a 50% e Tween a 1%). Os constituintes majoritários do óleo essencial foram p-cimeno (32,72%), 1,8-cineol (24,05%) e 4-terpineol (20,23%), sendo esses determinados por cromatografia a gás acoplada a espectrometria de massas e cromatografia a gás com detector de ionização de chama (CG-EM/DIC). No extrato etanólico foi detectado o ácido elágico e três flavonoides: rutina, quercetina e campferol, por meio de cromatografia a líquido de alta eficiência acoplada a detector de arranjo de diodo (CLAE-DAD). Todas as cepas apresentaram sensibilidade aos tratamentos com óleo essencial e extrato etanólico. A melhor resposta foi obtida com o óleo essencial de A. zerumbet que, na concentração de 100 mg.mL -1 proporcionou inibição total do crescimento bacteriano. Esses resultados sugerem o potencial antibacteriano do óleo essencial e do extrato etanólico de A. zerumbet no controle da mastite bovina. Composição química e eficácia do óleo essencial e do extrato etanólico de Alpinia zerumbet sobre Staphylococcus aureus PALAVRAS-CHAVE:

Despite the economic impact of the infectious myonecrosis virus (IMNV) on shrimp farms in several countries, no method for immunological detection is currently available. With the aim of developing immunodiagnostic methods for IMNV detection in infected shrimps, a recombinant fragment of the IMNV major capsid protein gene encoding amino acids 105-297 (rIMNV₁₀₅₋₂₉₇ was heterologously expressed in Escherichia coli and used to immunize Balb/c mice, generating monoclonal antibodies (MAbs). Six hybridomas were obtained, and four of these recognized the presence of IMNV in tissue homogenates from naturally infected shrimps by immunodot blot assay. Among these MAbs, three were able to detect a ~100-kDa protein, which corresponds to the predicted mass of the IMNV major capsid protein, as well as viral inclusion bodies in muscle fibroses by western blot and immunohistochemistry. Two MAbs showed high specificity and sensitivity, showing no cross-reaction with healthy shrimp tissues in any assays, indicating their usefulness for IMNV detection.

Infectious myonecrosis virus (IMNV) has been causing a progressive disease in farm-reared shrimps in Brazil and Indonesia. Immunodiagnostic methods for IMNV detection, although reliable, are not employed currently because monoclonal antibodies (MAbs) against this virus are not available. In this study, a fragment of the IMNV major capsid protein gene, comprising amino acids 300-527 (IMNV(300-527)), was cloned and expressed in Escherichia coli. The nucleotide sequence of the recombinant IMNV(300-527) fragment displayed a high degree of identity to the major capsid protein of IMNV isolates from Brazil (99%) and Indonesia (98%). Ten MAbs were generated against the expressed fragment, and eight of these, mostly IgG(2a) or IgG(2b), were able to bind to IMNV in tissue extracts from shrimps infected naturally in immunodot-blot assays. Six of these MAbs recognized a approximately 100 kDa protein in a Western-blot, which is the predicted mass of IMNV major capsid protein, and also bound to viral inclusions present in muscle fibroses and in coagulative myonecrosis, as demonstrated by immunohistochemistry. Among all those MAbs created, four did not cross-react with non-infected shrimp tissues; this observation supports their applicability as a sensitive and specific immunodiagnosis of IMNV infection in shrimps.

Development of a quality index scheme and shelf-life study for whole tambaqui (Colossoma macropomum) ABSTRACTThe study developed a sensory scheme based on the Quality Index (QI) and estimated the shelf-life for whole tambaqui, Colossoma macropomum (Cuvier, 1818), stored in ice, assessing and determining the most appropriate chemical, physical, bacteriological and quality sensory parameters and their changes during storage time. Ninety six fish were evaluated at 1, 3, 5, 8, 10, 12, 15, 17, 19 and 22 days of ice-storage. The developed quality index (QI) showed four main quality attributes with a total of 29 demerit scores. The skin mucus and odor, as well as general appearance and ventral elasticity had a great importance for the statistical model applied, while eyes, gills mucus and dorsal elasticity showed lower significance for tambaqui QI. The pH showed few variations during the ice storage. The nitrogen bases, as well as the total count of specific spoilage bacteria, had a linear correlation with the storage time. The QI proved to be efficient to assess tambaqui quality and loss of sensory quality over the storage period. The results suggest that whole, ice-stored Colossoma macropomum is fit for consumption until the 22 nd day.

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We investigated the effect of Alpinia zerumbet essential oil on the quality and shelf life of tambaqui (Colossoma macropomum) fillets stored under refrigeration (10.0 ± 0.5 °C) for 14 days. The treatments were A. zerumbet essential oil at 0.75% v v-1 (AEO 0.75%), A. zerumbet essential oil at 1.5% v v-1 (AEO 1.5%) and a control (no essential oil). The sample quality and shelf life were determined by the total psychrotrophic count (TPC) and chemical parameters (pH, total volatile basic nitrogen, centesimal composition and thiobarbituric acid reactive substances - TBARS) at zero, seven and 14 days of storage time. The TPC decreased significantly (p < 0.05) with an A. zerumbetessential oil level of 1.5% until seven days of storage. The concentration of A. zerumbet essential oil at 0.75% resulted in lower pH, TBARS, and TVBN values in comparison with the other treatment and the control. Thus, A. zerumbet essential oil was efficient in extending the shelf life of refrigerated tambaqui fillets up to approximately seven days.

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