Aireación en la tecnología Biofloc (BTF): principios básicos, aplicaciones y perspectivas

In a globalized world with growing population avid for nutrients for their feeding, the aquatic originated protein emerges as the big nutritional alternative of the century. The reduction of their resources to the farming (water, field and human resource) implies that the fish and shrimp production has to be intensify and one of the possibilities for this development is Biofloc Technology (BFT). Nevertheless, this intensification has to be given with principles of economic and technical efficiency, therefore, a correct design of the aeration is a big principal to maintain the suspended particles, oxygenate and move the water correctly. The electricity (aeration included) join with the feed are the most important production costs using BFT. With water changes low or none of it, the number, type and distribution of the mechanical oxygenator devices are crucial to maintain the water quality for the cultivated species and for the microorganisms that are included on the system. In this context this revision pretends to present the basis for the study and implementation of the aeration systems on BFT, also drawing future perspectives for these components.En un mundo globalizado de creciente población ávido por nutrientes para su alimentación, la proteína de origen acuática emerge como la gran alternativa nutricional del siglo. La disminución de sus recursos para la explotación (agua, tierra y personal) implica que se deba intensificar la producción de peces y camarones y una posibilidad para dicho establecimiento es la tecnología de biofloc (BFT en su sigla en inglés). Sin embargo, esta intensificación debe ser dada con principios de eficiencia técnica y económica, por lo tanto, un correcto diseño de la aeración es de fundamental importancia para mantener las partículas en suspensión, oxigenar y mover correctamente el agua. Unido a los alimentos concentrados, el costo energético (incluyendo la aeración) son de los más importantes costos de producción usados en la tecnología BFT. Utilizando recambios mínimos o nulos, el número, tipo y distribución de los aparatos mecánicos de aeración son cruciales para el mantenimiento de la calidad de agua para las especies cultivadas y para los microorganismos que se encuentran inmiscuidos en el sistema. En este contexto, esta revisión pretende brindar una base teórica para el estudio e implementación de los sistemas de aireación en los sistemas BFT, además de trazar perspectivas futuras para estos componentes.En un mundo globalizado de creciente población ávido por nutrientes para su alimentación, la proteína de origen acuática emerge como la gran alternativa nutricional del siglo. La disminución de sus recursos para la explotación (agua, tierra y personal) implica que se deba intensificar la producción de peces y camarones y una posibilidad para dicho establecimiento es la tecnología de biofloc (BFT en su sigla en inglés). Sin embargo, esta intensificación debe ser dada con principios de eficiencia técnica y económica, por lo tanto, un correcto diseño de la aeración es de fundamental importancia para mantener las partículas en suspensión, oxigenar y mover correctamente el agua. Unido a los alimentos concentrados, el costo energético (incluyendo la aeración) son de los más importantes costos de producción utilizando la tecnología BFT. Utilizando recambios mínimos o nulos, el número, tipo y distribución de los aparatos mecánicos de aeración son cruciales para el mantenimiento de la calidad de agua para las especies cultivadas y para los microorganismos que se encuentran inmiscuidos en el sistema. En este contexto, esta revisión pretende brindar una base teórica para el estudio e implementación de los sistemas de aireación en los sistemas BFT, además de trazar perspectivas futuras para estos componentes.In a globalized world with growing population avid for nutrients for their feeding, the aquatic originated protein emerges as the big nutritional alternative of the century. The reduction of their resources to the farming (water, field and human resource) implies that the fish and shrimp production has to be intensify and one of the possibilities for this development is Biofloc Technology (BFT). Nevertheless, this intensification has to be given with principles of economic and technical efficiency, therefore, a correct design of the aeration is a big principal to maintain the suspended particles, oxygenate and move the water correctly. The electricity (aeration included) join with the feed are the most important production costs using BFT. With water changes low or none of it, the number, type and distribution of the mechanical oxygenator devices are crucial to maintain the water quality for the cultivated species and for the microorganisms that are included on the system. In this context this revision pretends to present the basis for the study and implementation of the aeration systems on BFT, also drawing future perspectives for these components

Avaliação de técnicas de defumação para mexilhão Perna perna: análise sensorial e rendimento

The objective of the present work was evaluate two techniques of smoking, the hot traditional and with use of smoke natural aroma or "liquid smoke", having as control Perna perna mussels vapor cooked. Sensorial characteristics were appraised (appearance, color, aroma, texture, flavor and salt tenor) and yield processing. The experimental design was completely randomized with three treatments (T1 = smoked with liquid smoke; T2 = traditional smoked and T3 = just cooked, control), with nine repetitions. For sensorial analysis 30 people were used, where each one was considered a block. There was significant difference for processing performance among treatments (P<0.05), however there was not significant difference independent of smoked technique applied. Nevertheless, smoking technique using smoke natural aroma was more attractive, presenting better results with relationship to sensorial characteristics and final product packaged for commercialization

Composición y abundancia de comunidades microbianas asociadas al biofloc en un cultivo de tilapia

The goal of this study was to identify and estimate the abundance of microorganisms associated to biofloc culture system, developed from a `macrocosm-microcosm' system type. In first section (cylinder 1000 L), 75 juveniles tilapias were inoculated with 5.0 ± 0.95 cm mean length and 4.2 ± 1.08 g mean weight were placed. Daily, the fishes were fed with commercial diet, maintaining a C/N = 15:1 ratio, carbon (molasses and rice dust) and nitrogen (from commercial feed) supply was controlled. This culture condition was maintained during 14 weeks. Several microorganisms associated to the flocs were identified using conventional microbiological tests. To estimate the abundance of organisms associated to flocs, a stereoscopic and optical microscopes were used. Both microscopes were connected to an interphase program for images counting (Image ProPlus v.7.0). The results shown changes in abundance of different microorganisms communities associated to flocs during 14 weeks of experiment. The main groups found in flocs were: bacteria, algae, ciliates, rotifers and nematodes. The results confirm that the bioflocs contributes significantly as in situ natural food source, because a great number of organisms may be associated to them including heterotrophic microbial communities like genus Sphingomonas, Pseudomonas, Bacillus, Nitrospira, Nitrobacter and yeast Rhodotorula sp. The literature show that these microorganisms favoring water quality and physiological good health at organisms in culture.El objetivo de este trabajo fue identificar y estimar la abundancia de microrganismos asociados a un sistema de cultivo biofloc desarrollado a partir de un sistema del tipo `macrocosmo-microcosmo'. En la primera sección (cilindro de 1000 L), se colocaron 75 tilapias con una longitud aproximada de 5,0 ± 0,95 cm y un peso promedio de 4,2 ± 1,08 g. Los peces fueron alimentados diariamente con una dieta comercial, manteniendo una relación C/N= 15:1, mediante el aporte controlado de carbono (melaza y pulido de arroz) y nitrógeno (proveniente del alimento comercial). Esta condición fue mantenida durante 14 semanas. Se identificaron los diversos microrganismos asociados a los flóculos, utilizando pruebas microbiológicas convencionales. Se determinó la abundancia de los organismos asociados a los flóculos utilizando microscopio óptico y estereoscópico, ambos conectados con el programa de imágenes y de conteo (Image ProPlus v.7.0). Los resultados obtenidos indican cambios en la abundancia de las diversas comunidades de organismos asociados a los flóculos durante las 14 semanas del experimento. Los principales grupos encontrados fueron: bacterias, microalgas, ciliados, rotíferos y nematodos. Los resultados confirman que los flóculos contribuyen como fuente de alimento natural in situ, debido a que gran cantidad de organismos pueden estar asociados incluyendo comunidades microbianas heterótrofas de los géneros Sphingomonas, Pseudomonas, Bacillus, Nitrospira, Nitrobacter y la levadura Rhodotorula sp. La bibliografía menciona que estos microorganismos favorecen la calidad del agua y el bienestar fisiológico de los organismos en cultivo

Taxonomic profile of bacterial communities detected with 16S-rRNA in mature phototrophic and heterotrophic marine biofilms used for aquaculture

Bacterial diversity of phototrophic (PAb) and heterotrophic (Hb) biofilms was studied over time (0, 15 and 30 days of culture) using high throughput sequencing and considering the V3 and V4 hypervariable regions of the 16S rRNA gene. Bacterial composition in terms of relative abundance and diversity showed slight changes during the trial. Proteobacteria was the most abundant phylum in both biofilms during the experimental period. Chlamidiae-Verrucomicrobia, Bacteriodetes, and Planctomycetes were also abundant phyla in the PAb, whereas Planctomycetes, Bacteriodetes, Actinobacteria, and Chlamydiae were the abundant phyla in the Hb. Of the reads assigned up to species level, a total of 27 heterotrophic and autotrophic species were detected in both biofilms, most of them associated with the metabolism of nitrogenous and sulfurous metabolites and organic matter, and the rest with the structural functions in the biofilm. This is the first time some of these species have been reportedly detected in these biofilms or in the marine environment. Results suggest complex interaction networks in microbial conglomerates formed in biofilms, in which bacterial populations seem to play important metabolic and physiological roles