Seawater carbonate chemistry and community metabolism during an experiment with a coral reef, 2003

The effect of elevated pCO2 on the metabolism of a coral reef community dominated by macroalgae has been investigated utilizing the large 2650 m3 coral reef mesocosm at the Biosphere-2 facility near Tucson, Arizona. The carbonate chemistry of the water was manipulated to simulate present-day and a doubled CO2 future condition. Each experiment consisted of a 1-2 month preconditioning period followed by a 7-9 day observational period. The pCO2 was 404 �� 63 ?atm during the present-day pCO2 experiment and 658 �� 59 ?atm during the elevated pCO2 experiment. Nutrient levels were low and typical of natural reefs waters (NO3? 0.5-0.9 ?M, NH4+ 0.4 ?M, PO43? 0.07-0.09 ?M). The temperature and salinity of the water were held constant at 26.5 �� 0.2��C and 34.4 �� 0.2 ppt. Photosynthetically available irradiance was 10 �� 2 during the present-day experiment and 7.4 �� 0.5 mol photons m?2 d?1 during the elevated pCO2 experiment. The primary producer biomass in the mesocosm was dominated by four species of macroalgae; Haptilon cubense, Amphiroa fragillisima, Gelidiopsis intricata and Chondria dasyphylla. Algal biomass was 10.4 mol C m?2 during the present-day and 8.7 mol C m?2 and during the elevated pCO2 experiments. As previously observed, the increase in pCO2 resulted in a decrease in calcification from 0.041 �� 0.007 to 0.006 �� 0.003 mol CaCO3 m?2 d?1. Net community production (NCP) and dark respiration did not change in response to elevated pCO2. Light respiration measured by a new radiocarbon isotope dilution method exceeded dark respiration by a factor of 1.2 �� 0.3 to 2.1 �� 0.4 on a daily basis and by 2.2 �� 0.6 to 3.9 �� 0.8 on an hourly basis. The 1.8-fold increase with increasing pCO2 indicates that the enhanced respiration in the light was not due to photorespiration. Gross production (GPP) computed as the sum of NCP plus daily respiration (light + dark) increased significantly (0.24 �� 0.03 vs. 0.32 �� 0.04 mol C m?2 d?1). However, the conventional calculation of GPP based on the assumption that respiration in the light proceeds at the same rate as the dark underestimated the true rate of GPP by 41-100% and completely missed the increased rate of carbon cycling due to elevated pCO2. We conclude that under natural, undisturbed, nutrient-limited conditions elevated CO2 depresses calcification, stimulates the rate of turnover of organic carbon, particularly in the light, but has no effect on net organic production. The hypothesis that an increase pCO2 would produce an increase in net production that would counterbalance the effect of decreasing saturation state on calcification is not supported by these data.

Biogeochemical and physico-chemical characteristics in the gulf of Trieste, Italy

In this paper we investigated, for two years and with a bi-monthly frequency, how physical, chemical, and biological processes affect the marine carbonate system in a coastal area characterized by high alkalinity riverine discharge (Gulf of Trieste, northern Adriatic Sea, Mediterranean Sea).

Pore water measurements of sediment cores from the Helgoland mud area, North Sea

Iron reduction in subseafloor sulfate-depleted and methane-rich marine sediments is currently a subject of interest in subsurface geomicrobiology. While iron reduction and microorganisms involved have been well studied in marine surface sediments, little is known about microorganisms responsible for iron reduction in deep methanic sediments. Here, we used quantitative PCR (Q-PCR)-based 16S rRNA gene copy numbers and pyrosequencing-based relative abundances of bacteria and archaea to investigate covariance between distinct microbial populations and specific geochemical profiles in the top 5 m of sediment cores from the Helgoland mud area, North Sea. We found that gene copy numbers of bacteria and archaea were specifically higher around the peak of dissolved iron in the methanic zone (250-350 cm. The higher copy numbers at these depths were also reflected by the relative sequence abundances of members of the candidate division JS1, methanogenic and Methanohalobium/ANME-3 related archaea. The distribution of these populations was strongly correlated to the profile of pore-water Fe2+ while that of Desulfobacteraceae corresponded to the pore-water sulfate profile. Furthermore, specific JS1 populations also strongly co-varied with the distribution of Methanosaetaceae in the methanic zone. Our data suggest that the interplay among JS1 bacteria, methanogenic archaea and Methanohalobium/ANME-3-related archaea may be important for iron reduction and methane cycling in deep methanic sediments of the Helgoland mud area and perhaps in other methane-rich depositional environments. .

Year-round chemical aerosol records at Kohnen, Antarctica obtained by automatic samplings

Aimed at year-round recording of the chemical aerosol composition in central Antarctica, an unattended operating aerosol sampler was successfully deployed at the EPICA deep drilling site in Dronning Maud Land (Kohnen Station). Analyses of teflon/nylon filter packs consecutively collected over bi-weekly intervals during the February 2003 to December 2005 period allowed to evaluate seasonal concentration variations of methane sulphonate (MS), Cl-, NO3-, non-sea salt (nss-)SO4**2- and Na+, while NH4+ and mineral dust related ion results remained below detection limits. For MS and nss-SO4**2 distinct late summer maxima around 44 and 200 ng/m**3, respectively, were found, while (total) NO3- showed a broad November maximum of about 52 ng m**-3. In contrast, the highest concentrations of Na+ with peak values of up to 160 ng/m**3 were observed during the winter half year. The seasonality of these species broadly coincided with long-term observations at the coastal Neumayer Station, including surprisingly comparable NO3- levels. However, the biogenic sulphur and sea salt concentrations were lower at Kohnen by typically a factor of 2-3 and 10, respectively. The arrival of sea ice derived sea salt particles at Kohnen could not clearly detected, since even during mid-winter the nss-SO4**2- to Na+ ratio was generally too high to unambiguously identify a sulphur depleted sea salt SO4**2- fraction.

Estudo do aerossol (poeira do Sara) na regi��o de Cabo Verde

No ��mbito do projeto CV-DUST foi desenvolvida uma campanha de medi����o do aerossol atmosf��rico na Cidade da Praia (14�� 55��� N, 23��29��� W), de janeiro de 2011 a janeiro de 2012. A concentra����o do aerossol foi determinada com base no m��todo gravim��trico, com a amostragem feita em termos de PM10 e em fra����es granulom��tricas, usando impactores. Complementarmente, foi usado um contador ��tico de part��culas que permite a monitoriza����o em cont��nuo e a classifica����o do n��mero de part��culas em 31 fra����es de tamanho na gama entre 0,25 e 32 ��m. A composi����o qu��mica do aerossol foi determinada com incid��ncia nos seguintes componentes: i��es inorg��nicos sol��veis em ��gua (Cl-, NO3-, SO42-, Na+, NH4+, K+, Mg2+ e Ca2+), carbonato total, elementos maiorit��rios da crosta (Si, Na, Al, Fe, Ca, Mg, K, Ti e Mn) e elementos vestigiais (Ba, Zn, Zr, Pb, Cu, Ce, Ni, Cr, V, Co, Sc, As, Sm e Sb), assim como a fra����o carbon��cea (carbono elementar ��� EC e o carbono org��nico - OC). Durante a campanha, a concentra����o de PM10 apresentou uma grande variabilidade temporal, com valores m��dios (�� escala di��ria) situados entre 10 ��g/m3 e 507 ��g/m3, sendo a concentra����o m��dia anual estimada em cerca de 59 ��g/m3. As concentra����es mais elevadas (tipicamente acima dos 100 ��g/m3) foram registadas durante os eventos de poeira proveniente do Norte de ��frica, sendo os mais intensos observados nos meses de janeiro, fevereiro e dezembro de 2011. Os registos do contador ��tico, feitos em intervalos de 5 min, revelaram que durante os eventos de poeira as concentra����es m��dias hor��rias das part��culas PM10 e PM2.5 podem ultrapassar os 700 ��g/m3 e 200 ��g/m3, respetivamente. Com base nos resultados do m��todo ��tico, as contribui����es das fra����es granulom��tricas PM1, PM(1-2.5) e PM(2.5-10) para a massa de PM10 foram estimadas em cerca de 11 %, 28 % e 61 %, respetivamente. A composi����o qu��mica do aerossol varia consideravelmente ao longo do ano e revela a predomin��ncia das part��culas minerais e do sal marinho. Com base em c��lculos do balan��o m��ssico das esp��cies qu��micas, as contribui����es dos dois constituintes maiorit��rios para a massa de PM10 foram estimadas em cerca de 47 % (part��culas minerais) e 17 % (sal marinho). O aerossol secund��rio (NO3-, NH4+ e fra����o n��o marinha do SO42) e o aerossol carbon��ceo (EC + OC) contribuem cada um com cerca de 4 % e 3 %, respetivamente. A fra����o m��ssica restante (cerca de 29 %), corresponde aos constituintes n��o analisados, podendo a ��gua ser a mais importante neste grupo. A an��lise qu��mica das amostras segregadas por tamanho revela a seguinte composi����o para as part��culas PM1, PM(1-2.5) e PM(2.5-10): 5,2, 11,8 e 20,7 % (constituintes do sal marinho); 8,6, 3,7 e 3,1 % (i��es secund��rios); 8,9, 1,5 e 1,3 % (EC + OC).

Composici��n qu��mica del agua de lluvia y de niebla recolectada en la reserva biol��gica Monteverde

Se determin�� la composici��n qu��mica del agua de lluvia y de niebla en tres sitios en la Reserva Biol��gica Monteverde, Puntarenas; entre octubre 2009 y enero 2010. Debido a su estado de conservaci��n y a su ubicaci��n geogr��fica sobre la deriva continental, la Reserva Biol��gica Monteverde ofrece un sitio de estudio ideal, para el estudio de la composici��n de las aguas atmosf��ricas (agua de lluvia y de niebla). Las muestras de agua de niebla se recolectaron al utilizar muestreadores de niebla con l��neas de tefl��n, mientras que las de agua de lluvia se recogieron al emplear muestreadores de lluvia simples y uno de cascada. En ambos tipos de agua se analizaron las especies i��nicas m��s relevantes: H3O+, NH4 +, Ca2+, Mg2+, K+, Na+, Cl-, NO3 - y SO4 2-, al utilizar cromatograf��a de iones y detecci��n por conductividad el��ctrica. Las concentraciones promedio de estas especies en el agua de lluvia estuvieron entre 0,54 �� 0,02 ��eq L-1 y 101�� 3 ��eq L-1, mientras que en el agua de niebla variaron entre 1,00 �� 0,02 ��eq L-1 y 93 �� 4 ��eq L-1. Adem��s, se presentan el balance i��nico y los factores de enriquecimiento con respecto al mar y el suelo de ambos tipos de muestras.

Bioremediation of piggery effluents using Scenedesmus Obliquus microalga [Resumo]

Effluents from intensive pig farms present high nutrient concentration, mainly ammonium, contributing to water eutrophication and pollution. Microalgae ability to deplete inorganic nutrients makes them an efficient effluent bioremediation tool. Scenedesmus obliquus was grown in piggery effluent (without any pretreatment) diluted with tap water at 5%v/v (187��25mg/L N-NH4+) and compared with growth in synthetic Bristol media. A 21-days trial was performed in 1L bubble-column reactors illuminated by fluorescent and LED lamps(3klux). Microalgae growth was monitored through OD540nm, dry weight and Chlorophyll content and also by flow cytometry in terms of autofluorescence read in FL3 channel (>670 nm), cell size (FSC), internal complexity (SSC) and cell membrane integrity (PI). S. obliquus cells have grown slower in pig effluent (mmax=0.13-19d-1) than in Bristol media (mmax=0.46-0.50d-1) although after 15 days the biomass productivity observed for the pig waste cultivation, operated under LED (0.127gL-1d-1) was similar to those attained for the Bristol media after 8 and 12 days (0.130 and 0.129 gL-1d-1 using Fluorescent and LED lights, respectively). The Chlorophyll content was correlated to FL3 autofluorescence, with R2>0.97 for Bristol and R2>0.92 for pig waste cultures. Regarding cell size and complexity, Bristol cultures did not show significant differences along time, while cells grown on pig waste increased, attaining FSC and SSC values similar to those observed for Bristol cultures. However, pig waste led to higher percentage of cells with permeabilised membrane (up to 18%) than Bristol cultures (7%). For pig waste experiments, ammonium removal rates were 95% with final values within legal limits. S. obliquus cultivations proved to be an efficient system for direct piggery effluent bioremediation, attaining biomass productivities similar to those obtained in synthetic media. Using LED lighting enables to reduce the energy consumption while maintaining microalgae growth and bioremediation performance. Scale-up to an outdoor 150L photobioreactor is underway.

Valora����o do efluente da ind��stria processadora de pescado por incorpora����o de nutrientes em aphanothece microscopica n��geli

Nesta tese procurou-se demonstrar a valora����o do efluente do processamento de pescado por incorpora����o dos nutrientes em Aphanothece microscopica N��geli a diferentes temperaturas. Para tanto o trabalho �� composto de cinco artigos que objetivaram avaliar sob o ponto de vista do tratamento do efluente pela cianobact��ria Aphanothece e a separa����o e avalia����o da biomassa gerada. O primeiro artigo intitula-se ���Influ��ncia da temperatura na remo����o de nutrientes do efluente da ind��stria de pescado por Aphanothece microscopica N��geli���, e teve por objetivo avaliar a influ��ncia da temperatura (10, 20 e 30��C) em um sistema de tratamento pela cianobact��ria Aphanothece na remo����o de mat��ria org��nica, nitrog��nio e f��sforo do efluente oriundo do processamento de pescado. A an��lise dos resultados mostrou que a temperatura influenciou significativamente na remo����o de DQO, NTK, N-NH4 + e P-PO4 -3 . Para os experimentos a 20 e 30��C todos os limites estabelecidos para os par��metros avaliados foram atingidos. O segundo artigo intitulado ���Efeito de coagulantes no efluente da ind��stria da pesca visando �� separa����o de biomassa quando tratado por cianobact��ria��� avaliou o efeito da concentra����o e pH de dois tipos de coagulantes, cloreto f��rrico (FeCl3) e sulfato de alum��nio (Al2(SO4)3), na separa����o da biomassa da cianobact��ria Aphanothece microscopica N��geli cultivada em efluente da ind��stria da pesca, assim como a remo����o de mat��ria org��nica e nutrientes do efluente. Os resultados indicaram que o coagulante FeCl3 foi mais eficaz na remo����o de todos os par��metros testados. No que concerne �� separa����o da biomassa, com um n��mero de seis lavagens foi removido cerca de 97,6% da concentra����o de FeCl3 adicionado inicialmente. O terceiro artigo com o t��tulo ���Caracteriza����o da biomassa de Aphanothece microscopica N��geli gerada no efluente da ind��stria da pesca em diferentes temperaturas de cultivo��� avaliou a composi����o qu��mica da biomassa da cianobact��ria Aphanothece microscopica N��geli quando desenvolvida em meio de cultivo padr��o BG11 e no efluente do processamento de pescado. O quarto artigo teve como t��tulo ���Influ��ncia do meio de cultivo e temperatura em compostos nitrogenados na cianobact��ria Aphanothece microscopica N��geli��� objetivou avaliar o teor de compostos nitrogenados presentes na biomassa da cianobact��ria Aphanothece microscopica N��geli quando cultivada em meio padr��o e no efluente da ind��stria da pesca nas diferentes fases de crescimento. Para o estudo da composi����o qu��mica e nitrogenados no efluente foram realizados experimentos nas temperaturas de 10, 20 e 30��C. As concentra����es de prote��na, cinzas e pigmentos aumentaram com o aumento da temperatura. Por outro lado, foi observada uma redu����o do teor de lip��dios e carboidratos com o aumento da temperatura. O ��on am��nio juntamente com os ��cidos nucl��icos representa uma importante fra����o do nitrog��nio n��o prot��ico presente na biomassa da cianobact��ria Aphanothece. Ficou demonstrada a influ��ncia do meio de cultivo na concentra����o de nitrog��nio, bem como a determina����o de prote��na pelo m��todo de Kjeldahl superestima a concentra����o prot��ica em cianobact��rias. O quinto artigo intitulado ���Produ����o de prote��na unicelular a partir do efluente do processamento do pescado: modelagem preditiva e simula����o��� avaliou a produ����o de prote��na unicelular atrav��s do cultivo da cianobact��ria Aphanothece microscopica N��geli no efluente da ind��stria da pesca. Os dados cin��ticos de crescimento celular foram ajustados a quatro modelos matem��ticos (Log��stico, Gompertz, Gompertz Modificado e Baranyi). Os resultados demonstraram que o modelo Log��stico foi considerado o mais adequado para descrever a forma����o de biomassa. A an��lise preditiva mostrou a possibilidade da obten����o de 1,66, 18,96 e 57,36 kg.m-3.d-1 de biomassa por volume do reator em 1000 h de processo cont��nuo, para as temperaturas de 10, 20 e 30��C, respectivamente.

Reator de leito estruturado com recircula����o submetido �� aera����o intermitente no tratamento de esgoto sanit��rio

The release of nitrogen compounds in water bodies can result in many environmental problems, so treat wastewater, such as sewage in order to remove not only organic matter but also nitrogen has been studied a few decades. From the above, the objective of this study was to evaluate the performance of a structured bed reactor, continuous flow, with recirculation, in removing organic matter and nitrogen present in wastewater under different cycles of intermittent aeration (AI) and to evaluate the influence of these cycles in the development of nitrifying bacteria (Oxidizing Bacteria Ammonia - BOA and Bacteria Oxidizing Nitrite - BON) and denitrifying (DESN) adhered (Support Material - MS) and suspension (Effluent - EF and sludge - LD). The reactor used has usable volume of 9.4 L. As support materials (MS) polyurethane foam was used, cut and fixed in PVC rods. 3 were worked aeration phases (AE) and non-aeration (AN) at different stage: Stage 1 (4 h EA / AN 2H); Stage 2 (2H EA / AN 1 h) and Phase 3 (2H EA / AN 2 h). During all hydraulic detention time phases was kept at 16 h and the effluent recirculated at a rate of 3 times the inflow. Were analyzed: pH, total alkalinity, temperature, chemical oxygen demand (COD), Biochemical Oxygen Demand (BOD), nitrogen Kjeldhl Total (NKT), ammonia-N-N-NH4+, nitrito-N-NO2+andnitrato-NO3-. The concentration of BOA, BON and DESN was determined using the number More Prov��vel.gSSV-1 (NMP.gSSV-1). In phase 1 the percentage removal NTK N-NH4+ and NT was 76��10%, 70��21% and 67��10% respectively. In Phase 2 80��15% of removel NKT, 86��15% of N-NH4+ e 68��9% of removel NT e na Fase 3 de 58��20%, 72��28% and 41��6% of NKT, N-NH4+ of NT, respectively. The denitrification efficiency in stage 3 was over 70%, indicating that occurred in the reactor the process of simultaneous nitrification and denitrification (NDS). DQOT the removal percentages were 88 �� 4% in Phase 1, 94 �� 7 in Phase 2 and 90�� 11% in Phase 3. The multivariate ANOVA applied to NMP.gSSV-1, it indicated that there was significant (F: 20,2, p <0,01) between the analyzed concentration of organisms AI in different cycles, but the differences between NMP.gSSV-1 depends not only isolated factors but of which means, and phase groups being analysis. From the results it is concluded that the working system is efficient in terms of nitrogen removal and organic matter, and that the stage with the highest availability of Dissolved Oxygen (DO) and C/N ratio (Step 2), was the one obtained the lower concentrations of organic matter effluents and N-NH4+. Hinted that there was a significant difference between the concentration (NMP.100mL-1) of the analyzed organizations (BOA, BON and DESN), but this difference does not depend on factors alone but of which means (MS, EF or LD), stages (1, 2 or 3) and groups (BOA, BON and DESN) is being considered.

Nitrog��nio mineral em um latossolo em fun����o de sistemas de manejo do solo e de culturas de cobertura de inverno

The increasing advancement of agriculture makes providing adequate conditions for the growth and development of plants is the primary purpose of soil management systems. Much of the success of PD is attributed to cultural remains left by cover crops that do not require high nitrogen inputs and can thus be used to reduce nitrogen input in the agro- ecosystem. The nitrogen is one of the elements applied in agriculture, it is absorbed in higher quantities and limiting the yield of grain crops such as corn. Thus, there has been the influence of the no-till and conventional tillage combined with different crops of winter cover and bare soil when in succession to corn, on mineral nitrogen content. The experimental work was made at the experimental station of the Agronomic Institute of Paran�� - Iapar. The implemented design was blocks at random split plot with three replications in factorial 6 x 2 x 3 x 5. The main plots were as treatment, beyond the bare soil, 5 winter species (ryegrass, vetch, vetch + oat, oat and radish), while in the subplots were used two tillage systems (No-till and conventional tillage). Three collections made were (before management, the urea before and after the urea), these being held in 5 depths (0-5, 5-10, 10-20, 20-40 and 40-60 cm). So a layer 0-5 cm and a que presents increased amount to NH4 + ion. The use of associated PD system in the presence of winter cover crops decreased as NO3 - losses in soil profile.

Estudo comparativo de dois tipos de cultivo: monocultivo (camar��es) versus cultivo integrado (algas/camar��es)

The integrated culture of seaweed and aquatic animals is an ancient practice in Asian countries. The expansion of this practice to western countries is consequence of the recognition of this system as a sustainable alternative that allows economical diversification and mitigation of environmental impacts generated by effluents of aquaculture. This study evaluated the growth of the seaweed Gracilaria caudata and of the shrimp Litopenaeus vannamei in monoculture (shrimps) and integrated culture (shrimps and algae) systems, and accessed the effect of the seaweed in the water quality. There were two treatments in the experiment: monoculture (shrimps) and integrated culture (shrimps/ algae). The organisms were cultured in 6 aquaria (10L) filled with seawater (35.0��0.0 PSU and 28.1��0.4��C) for 28 days. The nutrients of water (PO43-, NH4+, NO2-, NO3- and DIN), the biomass and the relative growth rate (RGR, % day-1) of seaweed and shrimps were measured weekly. The parameters pH, temperature, salinity and dissolved oxygen were measured daily. The concentration of NH4+ in integrated culture (62.8��25.2��M) was lower (Mann-Whitney p<0.001) than in monoculture (85.6��24.3��M). The mean of PO4- in monoculture (10.4��4.6��M) was markedly higher (Mann-Whitney; p=0.024) than that in integrated culture (8.7��4.1��M). The level of dissolved oxygen in integrated culture (6.0��0.6mg/L) was higher (t-Student; P=0.014) than that in shrimp monoculture (5.8��0.6mg/L). The mean values of the parameters pH, NO2-, NO3- and DIN were 7.5��0.2, 10.1��12.2��M, 24.5��3.2��M and 120.17��30.76��M in monoculture, and 7.5��0.2, 10.5��13.2��M, 27.4��3.5��M and 100.76��49.59��M in integrated culture. There were not differences in these parameters between treatments. The biomass and RGR of seaweed reached 15.0��1.9g and 7.4��2.8% day-1 at the end of the experiment. The performance of shrimp was favorable in monoculture (1.5��0.8g; 5.7��1.6% dia-1) and in integrated culture (1.5��0.7g; 5.2��1.2% dia-1), and the rate of survival was 100% in both treatments. The tolerance and favorable performance of Gracilaria caudata suggest that this seaweed might be integrated into shrimp (Litopenaeus vannamei) culture systems

Din��mica de nitrog��nio em cultivo heterotr��fico a partir de cianobact��ria sob o escopo de biorrefinarias agroindustriais

O trabalho teve por objetivo avaliar a din��mica de nitrog��nio, em cultivo heterotr��fico, a partir da cianobact��ria Aphanothece microscopica N��geli, sob o escopo de uma biorrefinaria. Neste sentido, foi avaliada a contribui����o dos compostos nitrogenados n��o proteicos, na din��mica de distribui����o do nitrog��nio, na biomassa gerada pelo micro-organismo em estudo, quando cultivado em sistema autotr��fico e heterotr��fico. Para o cultivo em condi����es autotr��ficas, foi utilizado o meio padr��o BG-11, enquanto que, para o cultivo em condi����es heterotr��ficas, foi empregado o efluente da ind��stria de latic��nios. Inicialmente, foi avaliada a contribui����o dos pigmentos na fra����o nitrogenada n��o proteica tendo como base dois experimentos. No primeiro experimento foi selecionada a melhor condi����o para a produ����o de pigmentos, expressos pela clorofila-a em sistema heterotr��fico, tendo como base os par��metros C/N (20, 40 e 60), N/P (5, 10 e 15) e concentra����o de in��culo (100, 200 e 300 mg.L-1), mediante um planejamento fatorial 23 . Os experimentos foram conduzidos em biorreator heterotr��fico a 20��C, pH 7,6 e aera����o cont��nua de 1VVM. A melhor condi����o de produ����o de pigmento foi indicada como sendo a 200 mg.L-1 de concentra����o celular, raz��es C/N 20 e N/P 10. Com base nestes resultados, um segundo experimento foi delineado, visando avaliar a contribui����o de pigmentos na fra����o de nitrog��nio n��o proteico, bem como avaliar a produ����o de clorofila-a e ficobiliprote��nas (ficocianina, aloficocianina e ficoeritrina), sob influ��ncia da luz e do meio de cultivo. Foi poss��vel destacar teores superiores de ficobiliprote��nas na biomassa gerada no cultivo heterotr��fico. No entanto, com notada diferen��a (p���0,05) nos teores de clorofila-a, quando s��o comparadas as concentra����es na biomassa de meios autotr��ficos (10,7 mg.g-1) e heterotr��ficos (1,0 mg.g-1). Fato este compensado pelo menor tempo de cultivo registrado para atingir o final do experimento, quando o micro-organismo �� cultivado em condi����es heterotr��ficas. Fica demonstrado assim, ainda, a importante contribui����o dos pigmentos na fra����o de nitrog��nio n��o proteico. Na sequ��ncia, um terceiro e quarto experimentos foram delineados, visando avaliar a influ��ncia do nitrog��nio inorg��nico intracelular na fra����o n��o proteica e na produ����o de prote��na, assim como a caracteriza����o da fra����o proteica quanto ao seu perfil aminoac��dico. O estudo da din��mica do nitrog��nio intracelular demonstrou que o N-NH4 + foi a forma nitrogenada predominante, perfazendo importante fra����o de N-NP, sendo, portanto, os teores de N-NP significativamente dependente dos teores de pigmentos e nitrog��nio intracelular. Os aminogramas das biomassas geradas pelos cultivos autotr��ficos e heterotr��ficos indicaram como amino��cidos majorit��rios o ��cido glut��mico e asp��rtico, seguidos por valina, leucina e isoleucina, e como minorit��rios, lisina, glicina e metionina. O perfil aminoac��dico caracterizou-se por apresentar amino��cidos essenciais como isoleucina, metionina + ciste��na, fenilalanina + tirosina, valina e treonina em concentra����es superiores ao preconizado pela FAO/WHO. A caracteriza����o da fra����o proteica quanto ao perfil aminoac��dico qualificou esta biomassa como fonte potencial de prote��na. Os resultados obtidos neste trabalho demonstram a influ��ncia e din��mica de distribui����o dos compostos nitrogenados em Aphanothece microscopica N��geli. Fica demonstrado, ainda, que a implementa����o do conceito de biorrefino, no tipo de agroind��stria estudado, poder�� representar importantes possibilidades de aproveitamento sustent��vel do efluente gerado.

Efeito dos nutrientes (nitrog��nio e f��sforo) sobre o desenvolvimento da Gracilaria birdiae: crescimento e poss��vel uso como biofiltro

Marine shrimp farming has grown exponentially during the last years in Brazil. In spite of the promising economical situation, this activity is facing an increasing criticism due to its environmental impact. Thus, the necessity of alternatives to mitigate environmental degradation caused by this activity. An alternative that is being studied is the policulture that is the integrated culture of two or more organisms, normally one of them a filtering organism. Among filtering organisms, macroalgae are very practicable because they are efficient in the removal of the exceeding nutrients of the water and do not leave residues in the water. Besides, the integrated culture with macroalgae allows the economical exploration of the seaweed (for the manufacture of jelly and jam, for the dairy industry, pharmaceuticals, etc.) along with possibility of a sustainable aquaculture. In the present experiment, the development of the seaweed Gracilaria birdiae, the influence and tolerance of this species to the environmental parameters, and its absorption efficiency in relation with the three kinds of macronutrients (NH4+, NO3- and PO4-3) found in the effluents of marine shrimp farming was studied. The experiment was divided in two parts: a laboratorial part and one part carried under natural conditions. The water used in the laboratory trial was collected in the shrimp ponds of Tecnar��o farm and distributed in aquaria containing 20 g of G. birdiae. In the field trial, 0.5 kg of G. birdiae was inserted in PVC cages cultivated in the farm. The results of the study showed a modest growth of G. birdiae, probably due to its low tolerance to highly eutrophicated environments. However, the removal of nutrients was very expressive. Ammonia was reduced in approximately 34 %. Ortho-phosphate showed a reduction of 93.5 %. The capacity of biofiltration of the NO3- by the macro algae was of 100 %, showing that G. birdiae is a seaweed-filtered with a high level of removal for this nutrient under laboratorial conditions. In spite of the low growth of the macro algae in the experiment, the results in relation to the removal of nutrients of the water was encouraging, suggesting that this species can be an efficient biofilter and thus, a strong candidate to be used in a sustainable aquaculture

Estudo do crescimento, efici��ncia de biofiltra����o e cin��tica de absor����o de nutrientes (N-NH, N-NO e P-PO4��) da macroalga Gracilaria cervicornis (Turner) J. Agardh

The objective of this study was to examine the growth of Gracilaria cervicornis cultured in a shrimp (Litopenaeus vannamei) pond and to determine the absorption efficiency and the kinetics parameters (Vmax, Ks e Vmax:Ks) of this macroalgae for the nutrients N-NO3-, N-NH4+ and P-PO4-3, aiming at its use as bioremediatory of eutrophicated environments. For this study, two experiments (field and laboratory) were developed. In the field study, the seaweed was examined in relation to the growth and the biomass. In the laboratory experiment, the absorption efficiency of G. cervicornis was measured through the monitoring of the concentration of the three nutrients (N-NO3-, N-NH4+ e P-PO4-3) during 5 hours and the kinetic parameters were determined through the formula of Michaelis-Menten. The results obtained in this study demonstrated that G. cervicornis benefited from the available nutrients in the pond, increasing 52.4% of its biomass value after 30 days of culture. It was evidenced that the variability of the biomass could be explained through the salinity, availability of light (transparency and solid particle in suspension) and concentration of N-NO3- in the environment. In the laboratory experiment, the highest absorption efficiency was found in the treatments with low concentration (5 ��mol.L-1), being evidenced a reduction of up to 85,3%, 97,5% and 81,2% of N-NH4+, N-NO3- and P-PO43-, respectively. Regarding the kinetic parameters, G. cervicornis presented better ability in absorbing N-NH4+ in high concentrations (Vmax = 158,5 ��mol g-1 dry wt h-1) and P-PO43- in low concentrations (Ks = 5 ��mol.L-1 e Vmax:Ks = 10,3). The results of this study show that G. cervicornis could be cultivated in shrimp ponds, presents a good capacity of absorption for the tested nutrients and is a promising candidate for biorremediation in shrimp pond effluent