Vitor Gonsalez Chiozzini - Academia.edu (original) (raw)

Papers by Vitor Gonsalez Chiozzini

Marine Ecology Progress Series, Jun 8, 2023

Microbial dinitrogen (N2) fixation and intense bioturbation by macrofauna can contribute to reduc... more Microbial dinitrogen (N2) fixation and intense bioturbation by macrofauna can contribute to reduce nitrogen (N) limitation in mangrove systems. In particular, crabs are important ecosystem engineers that rework sediments, redistribute organic matter, accelerate nutrient cycling and shape microbial communities in mangrove sediments. Hosting functionally diverse microbial communities, crabs form a discrete ecological unit (a holobiont). In this study, we report rates of respiration, inorganic N fluxes, net N2 fixation, denitrification and dissimilatory nitrate reduction to ammonium (DNRA) measured in the fiddler crab Leptuca thayeri and sesarmid crab Armases rubripes holobionts, which are dominant in oligotrophic and eutrophic mangrove systems of southeast Brazil, respectively. We measured lower biomass-specific rates of respiration and ammonium (NH4+) production for the larger L. thayeri compared to A. rubripes, with very different molar ratios of O2 respiration to NH4+ production (152:1 vs. 20:1, respectively). This suggests a size-metabolism relationship, different food quality or different coupling of N excretion and assimilation by the crab holobionts in the 2 systems. Both crab holobionts contributed to net denitrification and DNRA, with faster N cycling in A. rubripes in the eutrophic system. Net N2 fixation was also detected, with nearly 4-fold higher rates in A. rubripes compared to L. thayeri. Overall, our results illustrate active and complex N cycling associated with the 2 dominant crab holobionts and highlight their potential and overlooked role as important conduits of fixed N, which may double N2 fixation rates in the mangrove’s rhizosphere.

Editora Blucher eBooks, 2022

Com o objetivo de colaborar com o registro de trabalhos em diferentes áreas do conhecimento prest... more Com o objetivo de colaborar com o registro de trabalhos em diferentes áreas do conhecimento prestado pelo reator IEA-R1 ao longo de anos, faz-se

Este trabalho teve como objetivo avaliar os ciclos biogeoquímicos (C, Si, N e P) em uma estação f... more Este trabalho teve como objetivo avaliar os ciclos biogeoquímicos (C, Si, N e P) em uma estação fixa no sistema estuarino de Cananéia-Iguape, verificando interações entre processos físicos e biogeoquímicos e fluxos de partículas, que foram quantificados através de um cilíndrico Sediment Trap. Os resultados levantaram relações entre fluxos de partículas e flutuações de nutrientes, revelando-se uma metodologia importante para verificar os nutrientes limitantes e os fluxos de carbono em coluna de água de estuários.

O fosfato é normalmente o nutriente limitante da produtividade da maioria das águas continentais,... more O fosfato é normalmente o nutriente limitante da produtividade da maioria das águas continentais, o que torna relevante o seu estudo associado aos processos de formação e degradação da matéria orgânica em sistemas eutrofizados urbanos a fim de aprimorar os limites estabelecidos pela legislação vigente, bem como para se obter viáveis medidas de recuperação. O presente estudo avaliou esses processos em quatro córregos que cruzam a cidade de Mogi das Cruzes (SP), considerando os seguintes parâmetros ambientais: pH, oxigênio dissolvido (Winkler), fosfato (colorimétrico), matéria orgânica particulada (Gravimétrico), clorofila-a e feofitina (colorimétrico). De forma geral, os baixos valores de saturação de oxigênio e clorofila-a demonstraram que o fosfato (e demais nutrientes) não proporcionou o processo de eutrofização nas estações desses córregos urbanos, evidenciando assim uma elevada fonte alóctone de MOP. Com base nisso, conclui-se que importantes fontes antrópicas de matéria orgânica, principalmente as difusas, estão atuando no sistema hídrico que cruza a cidade de Mogi das Cruzes, alertando assim para a falta de saneamento básico em determinados bairros, principalmente àqueles que margeiam o sistema hídrico. Palavras-chave: Matéria Orgânica; Fosfato; Sistemas aquáticos urbanos; Eutrofização. Relationship between phosphate and the formation and degradation of organic matter in the water system that crosses the municipality of Mogi das Cruzes

Energéticas e Nucleares (IPEN-CNEM), por me premiar com a permissão para a realização deste estud... more Energéticas e Nucleares (IPEN-CNEM), por me premiar com a permissão para a realização deste estudo. Ao Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) pelo fomento e apoio aos projetos "Estudo ambiental de sistemas costeiros expostos a importantes ações antrópicas na região sudeste por meio de ferramentas biogeoquímicas" (478890/2011-7) e "Instituto Nacional de Ciência e Tecnologia-Transferência de Materiais Continente-Oceano" (573601/2008-9). À Profa. Dra. Elisabete de Santis Braga da Graça Saraiva, pela orientação, apoio, confiança, oportunidades, amizade, perseverança, compreensão nos momentos difíceis e também pela convivência nestes últimos 15 anos. À Profa. Dra. Deborah Inês Teixeira Fávaro, pela co-orientação, atenção, parceria e apoio nas muitas atividades realizadas no Laboratório de Ativação Neutrônica e no Laboratório de Absorção Atômica do Centro do Reator de Pesquisa do IPEN. Ao Prof. Dr. Rubens Cesar Lopes Figueira, por disponibilizar a estrutura do Laboratório de Espectrometria Gama do IOUSP, pela ajuda na interpretação dos resultados obtidos para datação dos perfis de sedimento, apoio e diversas discussões pertinentes e sinceras, e também no aprazimento nas disciplinas ministradas, fundamentais na confecção deste trabalho. À Profa. Dra. Cassiana Seimi Nomura e ao Prof. Dr. Pedro Vitoriano, do Grupo de Análise e Pesquisas em Espectrometria do Instituto de Química da USP, pela confiança, parceria e disponibilização integral de seus laboratórios e equipamentos. Ao Prof. Dr. Cássio Hamilton Abreu-Junior, do Laboratório de Fertilidade do Solo do Centro de Energia Nuclear na Agriculatura (CENA-USP) pela receptividade, atenção, interesse no trabalho e disponibilização integral de toda a estrutura laboratorial que gerencia. À Profa. Dra. Juliana de Souza Azevedo, pela revisão desta tese, pelo apoio, reflexões acadêmicas, preocupação, ponto de vista sincero, amizade, convivência e ouvidos sempre dispostos à ouvir o meu chororô ao longo destes anos. Ao Prof. Dr. Michel Michaelovitch de Mahiques, pela permissão para utilização do difratômetro laser na determinação da granulometria das amostras de sedimento deste estudo, pela ajuda na interpretação dos resultados obtidos, pela disponibilidade em receber minhas dúvidas e pelo seu grande entusiasmo em ensinar. À Profa. Dra. Samara Cazzoli y Goya, por dividir seu conhecimento, recomendar e emprestar livros e trabalhos que ajudaram na confecção deste estudo, pelas palavras amigas e pela serenidade que transmitiu em momentos tensos e intensos ao longo desta jornada. À Profa. Dra. Gláucia Bueno Benedetti, pela amizade, conselhos e momentos divertidos vividos após o meu "único dia de paz no IOUSP". À Profa. Dra. Barbara Paci Mazzilli e ao Prof. Dr. Christian Millo pelas sugestões feitas na qualificação. Ao Prof. Dr. Guilherme Soares Zahn, pelos valiosos conhecimentos transmitidos com relação à análise por ativação neutrônica, propriedades dos sistemas de detecção gama, físicas de partículas, e papos descontraídos sobre as perspectivas da pesquisa e da política no Brasil.

Scientific Reports, Aug 18, 2020

Mangrove forests are among the most productive and diverse ecosystems on the planet, despite limi... more Mangrove forests are among the most productive and diverse ecosystems on the planet, despite limited nitrogen (N) availability. Under such conditions, animal-microbe associations (holobionts) are often key to ecosystem functioning. Here, we investigated the role of fiddler crabs and their carapaceassociated microbial biofilm as hotspots of microbial N transformations and sources of N within the mangrove ecosystem. 16S rRNA gene and metagenomic sequencing provided evidence of a microbial biofilm dominated by Cyanobacteria, Alphaproteobacteria, Actinobacteria, and Bacteroidota with a community encoding both aerobic and anaerobic pathways of the N cycle. Dinitrogen (N 2) fixation was among the most commonly predicted process. Net N fluxes between the biofilm-covered crabs and the water and microbial N transformation rates in suspended biofilm slurries portray these holobionts as a net N 2 sink, with N 2 fixation exceeding N losses, and as a significant source of ammonium and dissolved organic N to the surrounding environment. N stable isotope natural abundances of fiddler crab carapace-associated biofilms were within the range expected for fixed N, further suggesting active microbial N 2 fixation. These results extend our knowledge on the diversity of invertebratemicrobe associations, and provide a clear example of how animal microbiota can mediate a plethora of essential biogeochemical processes in mangrove ecosystems. Among coastal ecosystems, mangrove forests are of great importance as they account for three quarters of the tropical coastline and provide different ecosystem services 1,2. Mangrove ecosystems generally act as a net sink of carbon, although they release organic matter to the sea in the form of dissolved refractory macromolecules, leaves, branches and other debris 3,4. In pristine environments, mangroves are among the most productive ecosystems on the planet, despite growing in tropical waters that are often nutrient depleted 5. The refractory nature of the organic matter produced and retained in mangroves can slow the recycling of nutrients, particularly of nitrogen (N) 3,6. Nitrogen limitation in such systems may be overcome by microbial dinitrogen (N 2) fixation when combined with high rates of bioturbation by macrofauna 7,8. Bioturbation by macrofauna affect N availability and multiple N-related microbial processes through sediment reworking, burrow construction and bioirrigation, feeding and excretion 9. Macrofauna mix old and fresh organic matter, extend oxic-anoxic sediment interfaces, increase the availability of energy-yielding electron acceptors and increase N turnover via direct excretion 10,11. Thus, macrofauna may alleviate N limitation by priming the remineralization of refractory N, reducing plants-microbe competition 12,13. Such activity ultimately promotes N-recycling, plant assimilation and high N retention, as well as favours it loss by stimulating coupled nitrification and denitrification 14. Mangrove sediments are highly bioturbated by decapods such as crabs 15. Crab populations continuously rework sediment by constructing burrows, creating new niches, transporting or selectively grazing on sediment microbial communities 15-18. In addition, crabs can affect organic matter turnover by assimilating leaves and producing finely fragmented faeces, or by carrying them into their burrows 19,20. Therefore, crabs are considered

Journal of Applied Phycology, Oct 8, 2016

Along with the search for new species of seaweeds with biofilter capacity, it is also necessary t... more Along with the search for new species of seaweeds with biofilter capacity, it is also necessary to understand the physiological and biochemical responses of these seaweeds cultivated in different availabilities of nitrate, ammonium, and phosphate. To accomplish this, a laboratory study was performed to evaluate the ability of Hypnea aspera Kützing (Gigartinales, Rhodophyta), to growth under different nitrate, ammonium, and phosphate availabilities and to uptake, assimilate, and remove these nutrients from seawater. Treatments were composed of sterilized seawater enriched with quarterstrength von Stosch's nutrient solution modified (without any nitrogen and phosphorus compounds). Nitrate or ammonium, together with phosphate, was added in combined N/P ratios of 100:1 and 10:1. Nitrate concentrations varied from 0 to 150 μM, and ammonium concentrations varied from 0 to 70 μM. Growth rates of H. aspera increased with nitrate addition, and the highest value was 4.68 ± 0.76 % day −1 in 150 μM, but the addition of high ammonium concentration (70 μM) in N/P ratio of 10:1 inhibited the growth rates (−3.89 ± 1.03 % day −1). Nitrogen was accumulated as proteins and phycobiliproteins, mainly phycoerythrin, at higher phosphate availability (N/P ratio of 10:1) for nitrate addition (150 μM for proteins and 50, 100, and 150 μM for phycoerythrin), and lower phosphate availability (N/P ratio of 100:1) for ammonium addition (50 and 70 μM for proteins and 50 μM for phycoerythrin). Nitrogen and phosphate were assimilated into thallus in all treatments with nutrient addition. Hypnea aspera showed high removal efficiency (higher than 90 %) of nitrate, nitrite, ammonium, and phosphate present in the seawater. These results suggest that H. aspera could be cultivated in integrated multitrophic aquaculture systems to reduce nutrient loading in eutrophic seawater.

Brazilian Journal of Oceanography, Mar 1, 2018

Brazilian Journal of Oceanography, Dec 1, 2017

Braga et al.: Dissolved Organic Nutrients 614 Dissolved organic nutrients (C, N, P) in seawater o... more Braga et al.: Dissolved Organic Nutrients 614 Dissolved organic nutrients (C, N, P) in seawater on the continental shelf in the Southwestern South Atlantic with emphasis State Marine Park of Laje de Santos (SMPLS)-São Paulo-Brazil* O principal objetivo deste trabalho é avaliar distribuição sazonal e espacial do carbono orgânico dissolvido (COD), nitrogênio orgânico (NOD), fósforo orgânico dissolvido (POD) e ureia em 10 estações do Parque Estadual Marinho da Laje de Santos (PE-MLS). As estações 1 a 4 (mais próximas do continente) e as estações de 5 a 10 (mais próximas do parque marinho), todas na plataforma continental. Os resultados mostram que não foram observadas variações sazonais estatisticamente significativas para o COD e POD, todavia, o COD e o NOD, no período de verão apresentaram um pequeno aumento mostrando o aumento da atividade biológica e a influencia continental. Por outro lado, o NOD apresentou valores elevados em junho (2014-inverno) e janeiro de 2015, variando de 12.51 a 32.76 µmol L-1 , segundo o método de análise ANOVA (p< 0,01). Foram observados baixos valores de NOD em janeiro de 2014 (0,32-8,98 µmol L-1), em um verão anormalmente seco, enquanto que os valores mais elevados foram observados em julho de 2014 (27.50 µmol L-1). Ureia apresentou valores baixos na região do PEMLS e zonas costeiras atingindo 4,00 µmol L-1. Muitas vezes, a concentração de ureia pode estar associada com atividade de mergulho no parque. COD, NOD e ureia apresentaram valores ou diferenças entre as estações no PEMLS (5-10) e aquelas mais costeiras (1-4). O COD nas estações costeiras atingiu 267 µmol L-1 , enquanto que no PEMLS, o va

Química Nova, 2023

Recebido em 16/12/2022; aceito em 17/03/2023; publicado na web 23/05/2023 THE ESTUARINE ENVIRONME... more Recebido em 16/12/2022; aceito em 17/03/2023; publicado na web 23/05/2023 THE ESTUARINE ENVIRONMENT AND pH VARIATION: NATURAL LIMTS AND EXPERIMENTAL OBSERVATION OF THE ACIDIFICATION EFFECT ON PHOSPHORUS BIOAVAILABILITY. This study shows the variation of pH in the Cananéia-Iguape Estuarine-Lagoon Complex (CIELC). Data from 3 years (2019, 2021, 2022) were obtained in 17 points presenting the following ranges: temperature (14.88-27.05 ºC), pH (7.16-8.40) and DIP (0.20-11.28 µmol L-1) along a saline gradient (0.05-32.09) under different hydrodynamics, biogeochemical processes and anthropogenic influence. The pH buffering capacity due to the presence of weak acid salts in saline water (S ≥ 30) was associated to the lowest DIP, decreasing with low salinity values, confirming the direct correlation among salinity and pH. The highest temperatures in the winter of 2021, corroborated with the abnormal climate event in that year. An in vitro experiment showed results of the interaction of PID and sediments with different textures, with and without the presence of the benthic microbiota under a considerable decreasing of the pH (acidification) in relation to the natural condition of this environment. The P sediment flux characterized Iguape sector as a P sink with or without biota, Ararapira sector as a P source with biota and Cananéia, as P source without biota. The salt water buffered the pH and sediment buffered DIP both associated to the biogeochemical and hydrodynamic processes contribute to the homeostasis in the system.

This study aims to show the influence of the Valo Grande Channel, artificially open at the North ... more This study aims to show the influence of the Valo Grande Channel, artificially open at the North part of the system (Iguape) to possibility the transport of rice in the imperial period. At the principle, this Channel was smaller than nowadays (>200m width). The erosion and the floods were responsible by a cycle of opening/closing processes that promoted variation in the physical and chemical estuarine water properties with reflex on the biota and on the human activities. The physical and chemical characteristics of the estuarine water were observed in two seasonal periods (summer and winter) in 1992 (Channel close) and in 2005 (Channel open) at the southern part of the system (Cananéia) considered the most preserved from the anthropic impact, under two different situations of Valo Grande Channel influence, i. e. under more or less river water input. The differences in salinity showed low values after the open overall considering the ranges. Nutrients concentrations were verified in the two seasonal periods, with significant changes in the nitrate specially in the summer sampling showing that under natural conditions (Channel close) the availability of this nitrogenous forms is high and nitrite and N-ammoniacal exhibited lower concentrations as foreseen to a normal nitrogen biogeochemical cycle, and the same were verified to phosphate and silicate. On the other hand, considering the Channel open, the influence diminish the average availability of nitrate and the presence of nitrite and N-ammoniacal, phosphate and silicate was high, mainly in summer period. This unbalanced situation revealed by the biogeochimical cycles of nutrients is primordial to advise the risks on the preservation of this ecosystem, important to maintain the biodiversity of the marine life. RESUMO

Journal of Applied Phycology, Jul 23, 2018

Where a licence is displayed above, please note the terms and conditions of the licence govern yo... more Where a licence is displayed above, please note the terms and conditions of the licence govern your use of this document. When citing, please reference the published version. Take down policy While the University of Birmingham exercises care and attention in making items available there are rare occasions when an item has been uploaded in error or has been deemed to be commercially or otherwise sensitive.