Aquaculture biological waste as culture medium to cultivation of Ankistrodesmus gracilis (Reinsch) Korshikov / Resíduos biológicos de aquicultura como meio de cultura para o cultivo de Ankistrodesmus gracilis (Reinsch) Korshikov

Abstract Current study investigated the effectiveness of different macrophytes as culture media for Ankistrodesmus gracilis in laboratory conditions. Significant difference (p < 0.05) was reported in cell density with regard to conventional culture medium (CHU12) and macrophytes culture media. Mean cell density in NPK, Eichhornia crassipes and E. azurea media was higher (p < 0.05) than in conventional culture medium. Chlorophyll-a was higher than 1 g.L-1, except in CHU12 (0.7 ± 0.4 g.L-1) and T. domingensis (0.8 ± 0.3 g.L-1) media. Nitrate decreased sharply as from the 7th-day of the experiment. Ammonium and total phosphorus were highest in culture media and ranged between 0.4 g.L-1 (P. cordata medium) and 1.7 g.L-1 (CHU12 medium) for ammonium, and between 0.8 g.L-1 (CHU12 medium) and 1.9 g.L-1 (T. domingensis medium) for total phosphorus. Results revealed inorganic fertilizer and macrophytes combined with vitamins may be effective as culture media and strongly supports the growth of Ankistrodesmus gracilis, since cell density and biochemical composition are similar to or higher than conventional culture medium (CHU12). Macrophyte is a tool for aquaculture since biological wastes may be used with nutrients to improve the cultivation of microalgae.

Resumo O presente estudo investigou a eficácia na utilização de diferentes macrófitas como meio de cultura para Ankistrodesmus gracilis em condições laboratoriais. Foi observada diferença significativa (p < 0,05) entre a densidade celular em relação aos meios de cultura convencional (CHU12) e de macrófitas. Os meios de cultura com Eichhornia crassipes, E. azurea e NPK apresentaram densidade celular maiores (p < 0,05) que o meio de cultura convencional. Os teores de clorofila-a foram superiores a 1 g.L-1, exceto nos meios de cultura CHU12 (0.7 ± 0.4 g.L-1) e de T. domingensis (0.7 ± 0.3 g.L-1). O nitrato diminuiu acentuadamente a partir do 7º dia de experimento. Dentre os nutrientes, amônia e o fósforo total foram os mais elevados nos meios de cultura, variando entre 0.4 g.L-1 (meio de P. cordata) a 1,7 g.L-1 (meio CHU12) para amônia e, entre 0.8 g.L-1 (meio CHU12) e 1,9 gL-1 (meio de T. domingensis) para o fósforo total. Os resultados do presente estudo mostraram que o uso de fertilizantes inorgânicos e macrófitas, combinados com vitaminas, pode ser eficaz como meio de cultura no crescimento de Ankistrodesmus gracilis, uma vez que a densidade celular e a composição bioquímica foram semelhantes ou superiores ao meio de cultura convencional (CHU12). As macrófitas são ferramentas a serem adotadas na aquicultura, desde que os resíduos biológicos podem ser usados como nutrientes para melhorar o cultivo de microalgas.

Growth of Haematococcus pluvialis Flotow in alternative media / Crescimento de Haematococcus pluvialis Flotow em meios alternativos

Abstract Current study investigates the effect of two alternative media NPK (20-5-20) fertilizer and NPK plus macrophyte (M+NPK) compared to the commercial medium (WC) under growth rate and physiological parameters in batch culture mode (2-L), and verifies whether the use of fertilizer (NPK) and macrophyte (Eichhornia crassipes) would be a good tool for Haematococcus pluvialis culture in the laboratory. The highest number of cells of H. pluvialis has been reported in NPK medium (5.4 × 105cells.mL–1) on the 28th day, and in the M+NPK and WC media (4.1 × 105 cells.mL–1 and 2.1 × 105 cells.mL–1) on the 26th day, respectively. Chlorophyll-a contents were significantly higher (p<0.05) in NPK medium (41-102 µg.L–1) and lower in WC and M+NPK media (14-61 µg.L–1). The astaxanthin content was less than 0.04 mg.L–1. Production cost of 10-L of H. pluvialis was low in all media, and NPK and M+NPK media had a cost reduction of 65% and 82%, respectively when compared with commercial medium (WC). The use of a medium based on commercial fertilizer and macrophyte (E. crassipes) produced a new medium formulation that proved to be efficient, at least in batch culture mode, in promoting high density culture of H. pluvialis. NPK and macrophyte (E. crassipes) medium seems to be an adequate alternative to replace the conventional one (WC).

Resumo O presente estudo investigou o efeito de dois meios alternativos, NPK (20-5-20) e NPK mais macrófita (M+NPK), em relação ao meio comercial (WC) para avaliar a taxa de crescimento e parâmetros fisiológicos em cultivo estático (2-L), a fim de verificar se o fertilizante (NPK) e a macrófita (Eichhornia crassipes) podem ser utilizados no cultivo de Haematococcus pluvialis em laboratório. O maior número de células de H. pluvialis foi observado no meio NPK (5,4 × 105 células.mL–1) no vigésimo oitavo dia, e nos meios M+NPK e WC foi de 4,1 × 105 células.mL–1 e 2,1 × 105.celulas.mL–1 no vigésimo sexto dia, respectivamente. Os teores de clorofila-a foram significativamente maiores (p<0,05) em meio NPK (41-102 g.L–1) quando comparado aos meios WC e M+NPK (14-61 g.L–1). O teor de astaxantina foi menor que 0,04 mg.L–1. O custo de produção de 10-L de H. pluvialis foi baixo em todos os meios sendo que os meios NPK e M+NPK apresentaram uma redução de custos de 65% e 82%, respectivamente, quando comparados ao meio comercial. O meio contendo fertilizante e o de macrófita (E. crassipes) obtiveram resultados eficientes em cultivo estático, com alta densidade celular de H. pluvialis. O meio NPK e o de macrófita (E. crassipes) demonstraram ser uma alternativa adequada para substituir o meio comercial (WC).

Effects of some parameters in upscale culture of Haematococcus pluvialis Flotow / Efeito de alguns parâmetros no cultivo em larga escala de Haematococcus pluvialis Flotow

Growth rate and medium parameters between two bench scale volumes (13-L and 250-L) were compared. Experiments were maintained batch mode and culture parameters were periodically measured during a 13-day period. Culture growth during the cultivation of algae Haematococcus pluvialis was determined qualitatively by cell counting, optical density, dry weight, ash content, amount of chlorophyll-a, total organic carbon content and by direct measuring of medium nutrients and some abiotic aspects. Vegetative cell growth was higher when cultured in 13-L with 1.33 x 105 cells.mL−1 on the 12th day than when cultured in 250-L. Significant difference (p < 0.05) in the biology and water culture of H. pluvialis, with the exception of dry weight, ash, nitrite and ammonia, was reported between the volumes. Data obtained in current study for the upscale culture maintenance of H. pluvialis in laboratory conditions shows that it should be undertaken in a 13-L volume due to a greater time span of cells in a vegetative state, greater cell density, lipids and chlorophyll-a contents. Light was of paramount importance on the direct performance of H. pluvialis on the algal biological conditions.

Foram avaliadas a taxa de crescimento e condições do meio de cultura em volumes de 13-L e 250-L em sistema estático, durante o período de 13 dias para a microalga Haematococcus pluvialis. Foi determinada qualitativamente a contagem de células, densidade, peso seco, teor de cinzas, clorofila-a, teor de carbono orgânico total e avaliação de nutrientes e fatores abióticos do meio de cultura. O crescimento foi mais elevado em volume de 13-L com 1,33 x 105 células.mL−1 no décimo segundo dia, do que em volume de 250-L. Em relação ao meio de cultivo e aspectos biológicos de H. pluvialis, foram observadas diferenças significativas (p < 0,05) entre os dois volumes com exceção do peso seco, cinzas, nitrito e amônia. Para cultivo em larga escale de H. pluvialis é recomendado nestas condições laboratoriais, o volume de 13-L devido ao maior tempo das células em estado vegetativo, maior densidade celular e elevados teores de lipídios e clorofila-a. A luz interferiu diretamente nas condições biológicas de H. pluvialis.

Large scale laboratory cultures of Ankistrodesmus gracilis (Reisch) Korsikov (Chlorophyta) and Diaphanosoma biergei Korinek, 1981 (Cladocera) / Cultivo em large escala de Ankistrodesmus gracilis (Reisch) Korsikov (Chlorophyta) and Diaphanosoma biergei Korinek, 1981 (Cladocera) em laboratório

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 6th day, with approximately 144 x 10(4) cells.mL-1, followed by a sharp decrease to 90 x 10(4) cells.mL-1 (8th day). Algae cells tended to increase again from the 11th day and reached a maximum of 135 x 10(4) cells.mL-1 on the 17th day. D. birgei culture showed exponential growth until the 9th day with 140 x 10² individuals.L-1, and increased again as from the 12th day. Algae A. gracilis and zooplankton D. birgei contain 47 to 70 percent dry weight protein and over 5 percent dry weight carbohydrates. The most expensive items in the context of variable costs were labor and electricity. Data suggested that temperature, nutrients, light availability and culture management were determining factors on productivity. Results indicate that NPK (20-5-20) may be used directly as a good alternative for mass cultivation when low costs are taken into account, promoting adequate growth and nutritional value for cultured A. gracilis and D. birgei.

O objetivo deste trabalho foi avaliar o cultivo em larga escala de Ankistrodesmus gracilis e Diaphanososma birgei em laboratório através do estudo da biologia das espécies, composição bioquímica e custo operacional de produção. A. gracilis apresentou um crescimento exponencial até o sexto dia, ao redor de 144 x 10(4) células mL-1. Logo em seguida, sofreu um brusco decréscimo apresentando 90 x 10(4) células mL-1 (oitavo dia). A partir do décimo primeiro dia, as células algais tenderam a crescer novamente, apresentando um máximo de 135 x 10(4) células mL-1 no 17º dia. No cultivo de D. birgei, foi observado o primeiro pico de crescimento no nono dia com 140 x 10² indivíduos L-1, aumentando novamente a partir do décimo segundo dia. A alga clorofícea A. gracilis e o zooplâncton D. birgei possuem aproximadamente 50 e 70 por cento de proteína (PS), respectivamente, com teor de carboidrato acima de 5 por cento. 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.

Flora béntica y reproducción de las algas Batophora spp. (Chlorophyta: Dasycladaceae) de una laguna costera contaminada (Bahía de Chetumal, México) / Benthic flora and reproduction of Batophora spp. algae (Chlorophyta: Dasycladaceae) in a polluted coastal lagoon (Chetumal Bay, Mexico)

The benthic flora, and the vegetative and reproductive characters of the algae Batophora oerstedii and B. occidentalis (Chlorophyta) were recorded from five sites of Chetumal Bay, Quintana Roo, Mexico. A sewage gradient has been reported along those sites. Plants were sampled in May and October 1999, which corresponded to dry and rainy seasons, respectively. Forty taxa were found, 11 are new records for the Chetumal Bay, and 6 are new records for the Mexican Caribbean. Enteromorpha species were present in sites known as rich in organic matter (both from anthropogenic and natural sources). Batophora spp. is the dominant algae in all Chetumal Bay. However, it was absent next to sewage outfalls. The morphological characters of B. oerstedii and B. occidentalis did not change significantly along the sites reported as polluted. The length and width of gametophores, as well as the diameter of the gametangia were clearly different for both species. Different reproductive strategies may help B. oerstedii and B. occidentalis to closely coexist in the Chetumal Bay.

Los componentes de la flora béntica, y mediciones de partes vegetativas y reproductivas de Batophora oerstedii y B. occidentalis (Chlorophyta) se registraron en cinco sitios de la costa Oeste de la Bahía de Chetumal, donde se ha registrado la existencia de un gradiente de contaminación orgánica. La colecta de flora se realizó en mayo y Octubre de 1999, meses incluidos en las épocas climáticas e secas y lluvias, respectivamente. Se registraron 40 taxa de vegetación béntica, de los cuales 11 representan nuevos registros para la Bahía de Chetumal, y 6 para el Caribe Mexicano. Especies de Enteromorpha estuvieron presentes en ambientes ricos en materia orgánica, tanto de origen urbano, como natural. En los desagües de la Bahía de Chetumal existen especies indicadoras de contaminación, pero la ausencia de Batophora spp., dominante en esta laguna costera. Los caracteres morfológicos de B. occidentalis y B. oerstedii a lo largo de los cinco sitios de muestreo no reflejaron la presencia de contaminantes. Ambas especies presentaron diferencias significativas en su largo y ancho de gametóforos, y en el diámetro de gametangios Las diferencias en estrategias reproductivas probablemente ayudan a que B. oerstedii y B. occidentalis puedan coexistir cercanamente en la Bahía de Chetumal.

Efecto de metales pesados en el crecimiento de la microalga tropical Tetraselmis chuii (Prasinophyceae) / Efect of heavy metals on the growth of the tropical microalga Tetrasermis chuii (Prasinophyceae)

El presente trabajo determina el efecto tóxico de los metales cadmio (Cd), cobre (Cu), mercurio (Hg) y plomo (Pb) en la microalga tropical Tetraselmis chuii (Butcher, 1959). Se expuso, por triplicado, 50 ml de cultivo (f/2 Guillard) de la microalga en fase de crecimiento logarítmica ante las concentraciones de 0 (control); 0.1; 1.0; 5.0; 10.0 y 20.0 mg· l-1 durante 96 hr. La evaluación del efecto letal se realizó diariamente, mediante recuento celular con una cámara de Neubauer. En el tratamiento control, sin exposición al metal, se observó un incremento de la densidad celular, en contraste con un decrecimiento en los tratamientos con exposición a los metales, los cuales fueron acelerados hasta las 48 hr, a partir de cuando el decrecimiento se hizo menos pronunciado. Una excepción se produjo con el Cd y el Cu a las 24 h, donde no se determinó decrecimiento significativo, probablemente debido a su capacidad de actuar como micronutriente a bajas concentraciones. El metal que produjo mayor efecto fue el Pb, produciendo una letalidad al 50% de la población microalgal a 0.40 mg· l-1, la cual fue casi tres veces menor que la establecida para el Hg y más de 13 veces menor que la del Cd y Cu. Se recomienda la microalga Tetraselmis chuii como especie modelo para la utilización en pruebas en función estimar efectos tóxicos por xenobióticos en el ambiente acuático marino tropical

We determined the toxic effect of four metals, cadmium (Cd), copper (Cu), mercury (Hg) and lead (Pb), on the tropical microalga Tetraselmis Chuii (Butcher, 1959). We exposed 50 ml of cultivated microalgae (f/2 Guillard) in the exponential growth phase, with three replicates, to concentrations of 0 (control), 0.1, 1.0, 5.0, 10.0 and 20.0 mg· l-1 with each metal for 96 hr. We evaluated the lethal effect daily, through the cellular count. In the control treatment (not exposed to any metal) we observed an increase in cellular density. In all treatments exposed to metals, we observed a decrease in cellular density, which accelerated in 48 h, after which it became less pronounced. There were exceptions with low concentrations of Cd and Cu at 24 h, as there was no significant decrease, probably due to their use as micronutrients at these low concentrations. The metal that caused the most lethal effect was Pb, which killed 50% of the microalgal population at a concentration of 0.40 mg· l-1. This concentration was 3 times lower than that of mercury and 13 times lower than those of cadmium and copper. The microalga Tetraselmis chuii is recommended as a model species to estimate the toxic effects of xenobiotics on tropical seawater environments

Caracterización espacial y biogeográfica de las asociaciones de macroalgas de Bahía del Rincón, Baja California Sur, México / Spatial and biogeographic characterization of macroalgal assemblages from Bahía del Rincón, Baja California Sur, Mexico

Macroalgal studies in Baja California Sur have dealt mainly with occurrence and seasonality, but some areas are poorly known even for these basic data. Bahía del Rincón-La Rivera is an important high-productivity fisheries area where coastal infrastructure development is under way. A spatial characterization of the marine flora from Bahía del Rincón-La Rivera was done by intensive sampling at different depths and localities with skin and SCUBA diving. At least 500m2 were surveyed in each site. Additionally, quantitative sampling was done in ten random 25 cm2 quadrates per site. In the intertidal section, density and cover estimates were used. We also investigated the historical records and geographical affinities. A total of 72 species were identified (most were red algae: 62%). We found no general trend in the biogeographical affinities, which varied with each taxonomic group. Most brown algae species were tropical-endemic; red algae temperate- cosmopolite and green algae tropical-cosmopolite. In the spatial assemblage structure we found a high similarity between the intertidal areas, but a low similarity in shallow or deeper areas (3-5 m). This pattern was the same when we compared the abundance of the main species. We suggest that there are significant spatial differences in recruitment and development of the assemblages in relation to vertical distribution (depth)and position along the shore. There is a clear-cut Gelidium-Jania belt in the intertidal zone and a Padina-Dictyota belt below the low tide. Sporadic and year-round species occur in the intertidal zone, annual and perennial species below the low tide line. Sites differ in recruitment and this affects the abundance of other species (such as coraline and Caulerpa species). Temperature and sedimentation affect seasonality, but community structure is relatively constant throughout the year

Se caracterizó la flora marina de la zona de Bahía del Rincón -La Rivera por medio de prospecciones intensivas en diferentes localidades a varias profundidades. Además, se realizó un análisis intenso de la literatura y por este mismo medio la determinación de las afinidades geográficas de las especies. En total se encontraron 72 especies, donde la mayor proporción (62%) correspondió a las algas rojas. En el caso de las afinidades biogeográficas se observó que la mayor proporción varió en función de la división, donde para algas cafés las predominantes fueron de naturaleza tropical/ endémica y para las algas rojas fueron las templadas/ cosmopolitas. Espacialmente se encontró una alta similitud entre las zonas someras estudiadas más no así entre las someras y profundas donde existen diferencias significativas. En el caso de la zona intermareal se determinaron diferencias significativas con áreas submareales y entre sitios de la zona somera y profunda basados en las abundancias de los principales taxa. Con base en los resultados se sugiere que existen diferencias verticales en reclutamiento y desarrollo de las poblaciones en relación a su distribución

Antifouling activity of six nontoxic chemicals on spore attachment of Ulva fasciata.

Marine biofouling cause severe damage to all marine technologies. Indiscriminate use of toxic metallic antifouling (AF) chemicals (cuprous oxide and TBT) to control the biofouling in turn greatly affects the flora and fauna of the marine ecosystem. In search of environmentally safe and effective AF agents, six nontoxic AF candidates were studied against the spore attachment of Ulva fasciata. Spore attachment was inhibited at 100 microg of trans-cinnamic acid (TCA) and benzoic acid (BA). Sulfate-coumaric acid (SCA) had no significant effect on the spore attachment. The release rate of BA exhibited a constant release flow. Varied response of U. fasciata spores to AF chemicals and release rate to the surrounding medium are discussed.