A carregar...
Projeto de investigação
Pockmarks and fluid seepage in the Estremadura Spur: implications for regional geology, biology, and petroleum systems
Financiador
Autores
Publicações
Screening of exopolysaccharides (EPS) and polyhydroxyalkanoates (PHA) from sediments from the Azores Archipelago, Canay Islands and Estremadura Spur
Publication . Batista, Maria Rita Nicolau; Torres, Cristiana; Gaudêncio, Susana
Oceans are still largely unexplored as a source of new and interesting biomolecules.
Among these, exopolysaccharides (EPS) and polyhydroxyalkanoates (PHA) are being widely
studied for their interesting biotechnological applications in various industrial fields. EPS are
produced by bacteria as a defense mechanism against biotic or abiotic stress, like low
temperatures or high salinity. PHA are also produced as a survival mechanism, but against
carbon shortage, they accumulate as intracellular granules, in order to be used as energy source
in the absence of some nutrients.
In this work, bacteria were isolated from sediments from the Azores Archipelago, Canary
Islands and Estremadura Spur and screened for the production of EPS and PHA. Growth assays
were performed in glucose, glycerol, fructose, xylose and lactose, as well as 16°C and 30°C, two
different nitrogen concentrations were also tested. The majority of the cultures grew better at
30°C, but produced more EPS at 16°C. All cultures presented fluorescence under the light
microscope, meaning they all produce PHA. Different cultures showed different preferences of
carbon source, and also the bacteria that produced more biomass, were not the one that
produced more EPS.
Three of the cultures with the most interesting results were cultivated in a bioreactor, at
standard operating conditions. From all of the bacteria, C3 showed the most balanced results of
EPS and PHA production, reaching biomass concentration of 2.013 g/L, a specific growth rate
of 0.370 h-1 and volumetric productivities of 78.89 mgEPS/L.h-1 and 40.83 mgPHA/L.h-1. Az4
was taxonomically identified a Bacillus sp., and presented similar growth results to culture C3,
but with lower biopolymer production. Az7 produced the highest biomass, but both productions
of polymer were low, also to notice that this culture produced a bright orange pigment, which
we could not yet identify.
Exopolysaccharide Production from Marine-Derived Brevundimonas huaxiensis Obtained from Estremadura Spur Pockmarks Sediments Revealing Potential for Circular Economy
Publication . Catalão, Marta; Fernandes, Mafalda; Galdon, Lorena; Rodrigues, Clara F.; Sobral, Rita G.; Gaudêncio, Susana P.; Torres, Cristiana A. V.; DQ - Departamento de Química; DCV - Departamento de Ciências da Vida; UCIBIO - Applied Molecular Biosciences Unit; MDPI - Multidisciplinary Digital Publishing Institute
Marine environments represent an enormous biodiversity reservoir due to their numerous different habitats, being abundant in microorganisms capable of producing biomolecules, namely exopolysaccharides (EPS), with unique physical characteristics and applications in a broad range of industrial sectors. From a total of 67 marine-derived bacteria obtained from marine sediments collected at depths of 200 to 350 m from the Estremadura Spur pockmarks field, off the coast of Continental Portugal, the Brevundimonas huaxiensis strain SPUR-41 was selected to be cultivated in a bioreactor with saline culture media and glucose as a carbon source. The bacterium exhibited the capacity to produce 1.83 g/L of EPS under saline conditions. SPUR-41 EPS was a heteropolysaccharide composed of mannose (62.55% mol), glucose (9.19% mol), rhamnose (19.41% mol), glucuronic acid (4.43% mol), galactose (2.53% mol), and galacturonic acid (1.89% mol). Moreover, SPUR-41 EPS also revealed acyl groups in its composition, namely acetyl, succinyl, and pyruvyl. This study revealed the importance of research on marine environments for the discovery of bacteria that produce new value-added biopolymers for pharmaceutical and other biotechnological applications, enabling us to potentially address saline effluent pollution via a sustainable circular economy.
Marine-Derived Actinomycetes
Publication . Oliveira, Juliana; Almeida, Pedro L.; Sobral, Rita G.; Lourenço, Nídia D.; Gaudêncio, Susana P.; DQ - Departamento de Química; DCV - Departamento de Ciências da Vida; UCIBIO - Applied Molecular Biosciences Unit; CENIMAT-i3N - Centro de Investigação de Materiais (Lab. Associado I3N); DCM - Departamento de Ciência dos Materiais; MDPI - Multidisciplinary Digital Publishing Institute
Plastics are present in the majority of daily-use products worldwide. Due to society’s production and consumption patterns, plastics are accumulating in the environment, causing global pollution issues and intergenerational impacts. Our work aims to contribute to the development of solutions and sustainable methods to mitigate this pressing problem, focusing on the ability of marine-derived actinomycetes to accelerate plastics biodegradation and produce polyhydroxyalkanoates (PHAs), which are biodegradable bioplastics. The thin plastic films’ biodegradation was monitored by weight loss, changes in the surface chemical structure (Infra-Red spectroscopy FTIR-ATR), and by mechanical properties (tensile strength tests). Thirty-six marine-derived actinomycete strains were screened for their plastic biodegradability potential. Among these, Streptomyces gougerotti, Micromonospora matsumotoense, and Nocardiopsis prasina revealed ability to degrade plastic films—low-density polyethylene (LDPE), polystyrene (PS) and polylactic acid (PLA) in varying conditions, namely upon the addition of yeast extract to the culture media and the use of UV pre-treated thin plastic films. Enhanced biodegradation by these bacteria was observed in both cases. S. gougerotti degraded 0.56% of LDPE films treated with UV radiation and 0.67% of PS films when inoculated with yeast extract. Additionally, N. prasina degraded 1.27% of PLA films when these were treated with UV radiation, and yeast extract was added to the culture medium. The main and most frequent differences observed in FTIR-ATR spectra during biodegradation occurred at 1740 cm−1, indicating the formation of carbonyl groups and an increase in the intensity of the bands, which indicates oxidation. Young Modulus decreased by 30% on average. In addition, S. gougerotti and M. matsumotoense, besides biodegrading conventional plastics (LDPE and PS), were also able to use these as a carbon source to produce degradable PHA bioplastics in a circular economy concept
The diversity, metabolomics profiling, and the pharmacological potential of actinomycetes isolated from the estremadura spur pockmarks (Portugal)
Publication . Pinto-Almeida, António; Bauermeister, Anelize; Luppino, Luca; Grilo, Inês R.; Oliveira, Juliana; Sousa, Joana R.; Petras, Daniel; Rodrigues, Clara F.; Prieto-Davó, Alejandra; Tasdemir, Deniz; Sobral, Rita G.; Gaudêncio, Susana P.; UCIBIO - Applied Molecular Biosciences Unit; DCV - Departamento de Ciências da Vida; MDPI - Multidisciplinary Digital Publishing Institute
The Estremadura Spur pockmarks are a unique and unexplored ecosystem located in the North Atlantic, off the coast of Portugal. A total of 85 marine-derived actinomycetes were isolated and cultured from sediments collected from this ecosystem at a depth of 200 to 350 m. Nine genera, Streptomyces, Micromonospora, Saccharopolyspora, Actinomadura, Actinopolymorpha, Nocardiopsis, Saccharomonospora, Stackebrandtia, and Verrucosispora were identified by 16S rRNA gene sequencing analyses, from which the first two were the most predominant. Non-targeted LC-MS/MS, in combination with molecular networking, revealed high metabolite diversity, including several known metabolites, such as surugamide, antimycin, etamycin, physostigmine, desferrioxamine, ikarugamycin, piericidine, and rakicidin derivatives, as well as numerous unidentified metabolites. Taxonomy was the strongest parameter influencing the metabolite production, highlighting the different biosynthetic potentials of phylogenetically related actinomycetes; the majority of the chemical classes can be used as chemotaxonomic markers, as the metabolite distribution was mostly genera-specific. The EtOAc extracts of the actinomycete isolates demonstrated antimicrobial and antioxidant activity. Altogether, this study demonstrates that the Estremadura Spur is a source of actinomycetes with potential applications for biotechnology. It highlights the importance of investigating actinomycetes from unique ecosystems, such as pockmarks, as the metabolite production reflects their adaptation to this habitat.
Determinação de Ácidos Gordos Produzidos por Actinobactérias de Origem Marinha
Publication . Cunha, Marlene Brito; Gaudêncio, Susana; Paiva, Alexandre
Atualmente a investigação está voltada para o ambiente marinho, visto que as condições
distintas das terrestres oferecem maior diversidade estrutural e capacidade de produção de
metabolitos com atividade biológica única, de grande interesse biotecnológico. As actinobactérias
de origem marinha são potentes fontes de metabolitos, incluindo ácidos gordos. Os ácidos gordos
são principais constituintes das membranas celulares e são classificados em saturados (SFAs),
monoinsaturados (MUFAs) e polinsaturados (PUFAs), e podem ser ramificados (BCFAs).
Normalmente para a extração de lípidos são aplicados métodos tradicionais que, por sua
vez, usam solventes orgânicos que além de tóxicos, podem contaminar o produto extraído. Nesta
perspetiva, o SC-CO2 tem sido utilizado como uma alternativa promissora.
Na presente dissertação, foi estudado o perfil de ácidos gordos de 55 estirpes de
actinobactérias isoladas de sedimentos marinhos colhidos do Spur da Estremadura, ao largo da
costa portuguesa, utilizando GC-MS. Os BCFAs (47.54%), MUFAs (28.49%) e SFAs (22.16%)
foram predominantes, enquanto o PUFA e o ácido gordo de cadeia cíclica foram identificados
como menores componentes. A maior percentagem de BCFAs (83.10%) e MUFAs (49.24%) foi
observada nas respetivas amostras, 83PTE e 51PTE, pertencentes à espécie Micromonospora
saelicesensis e Streptomyces sampsonii, respetivamente. A estirpe 51PTE foi selecionada para o
crescimento em 10 L de cultura, posteriormente, para extração de lípidos utilizando SC-CO2 e
hexano. O maior rendimento de extração foi obtido do sobrenadante usando hexano (1.2%). Ao
contrário do resultado anterior, o SFA foi predominante, enquanto o conteúdo de MUFA foi
reduzido, correspondendo a 7.06% (extrato da biomassa com hexano), 3.14% (extrato da
biomassa com SC-CO2) e 1.33% (extrato de sobrenadante com hexano). A extração com hexano
mostrou ser mais eficiente, pois a maioria de ácidos gordos foram extraídos das células.
Os resultados indicam que actinobactérias do Spur da Estremadura da costa portuguesa
podem ser excelentes fontes de ácidos gordos com potencial aplicação biotecnológica.
Unidades organizacionais
Descrição
Palavras-chave
Contribuidores
Financiadores
Entidade financiadora
Fundação para a Ciência e a Tecnologia
Programa de financiamento
3599-PPCDT
Número da atribuição
PTDC/GEO-FIQ/5162/2014