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André Luís Braghini Sá

Bio: André Luís Braghini Sá is an academic researcher from University of São Paulo. The author has contributed to research in topics: Nitrogen fixation & Rhizobia. The author has an hindex of 3, co-authored 3 publications receiving 89 citations. Previous affiliations of André Luís Braghini Sá include Empresa Brasileira de Pesquisa Agropecuária.

Papers
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Journal ArticleDOI
TL;DR: The diversity of culturable bacteria present over the seasons at two depths in a mangrove sediment and in a transect area from the land to the sea is assessed.
Abstract: Mangrove ecosystems are environments subject to substantial degradation by anthropogenic activities. Its location, in coastal area, interfacing the continents and the oceans makes it substantially important in the prospection for biotechnological applications. In this study, we assessed the diversity of culturable bacteria present over the seasons at two depths (0–10 and 30–40 cm) in a mangrove sediment and in a transect area from the land to the sea. In total, 238 bacteria were isolated, characterized by Amplified Ribosomal DNA Restriction Analysis (ARDRA) and further identified, by Fatty Acid Methyl Esther (FAME-MIDI), into the orders of Vibrionales, Actinomycetales and Bacillales. Also the ability of the isolates in producing economically important enzymes (amylases, proteases, esterases and lipases) was evaluated and the order Vibrionales was the main enzymatic source.

90 citations

Journal ArticleDOI
TL;DR: These bacteria revealed different activities in endoglucolysis and biofilm formation when exposed to specific NaCl concentrations, indicating modulated growth under natural variations in mangrove salinity.

7 citations

Book ChapterDOI
01 Jan 2012
TL;DR: The mechanisms of BFN have grown exponentially and alternative sources to carry out the process increasingly investigated, and new microbial sources such as nitrogen-fixing endophytic bacteria and not forming nodules are investigated.
Abstract: Plant production of high quality as well as the availability of foods rich in protein is crucially dependent on nitrogen. Tropical agricultural soils often have impaired production due to limited availability of nitrogen, which leads to use of nitrogen fertilizers and alternative resources such as biological nitrogen fixation (BNF). The latter has been used especially in grasses of economic importance, and this fact has initiated an important search in understanding these mechanisms in nonleguminous plants. Nitrogen-fixing bacteria such as rhizobia in turn aroused interest for research into new microbial sources such as nitrogen-fixing endophytic bacteria and not forming nodules. The mechanisms of BFN have grown exponentially and alternative sources to carry out the process increasingly investigated.

7 citations


Cited by
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Journal ArticleDOI
21 Jun 2012-PLOS ONE
TL;DR: A deep metagenomic survey that revealed the taxonomic and potential metabolic pathways aspects of mangrove sediment microbiology revealed that the microbial core involved in methane, nitrogen, and sulphur metabolism consists mainly of Burkholderiaceae, Planctomycetaceae, Rhodobacteraceae, and Desulfobacteria.
Abstract: Here we embark in a deep metagenomic survey that revealed the taxonomic and potential metabolic pathways aspects of mangrove sediment microbiology. The extraction of DNA from sediment samples and the direct application of pyrosequencing resulted in approximately 215 Mb of data from four distinct mangrove areas (BrMgv01 to 04) in Brazil. The taxonomic approaches applied revealed the dominance of Deltaproteobacteria and Gammaproteobacteria in the samples. Paired statistical analysis showed higher proportions of specific taxonomic groups in each dataset. The metabolic reconstruction indicated the possible occurrence of processes modulated by the prevailing conditions found in mangrove sediments. In terms of carbon cycling, the sequences indicated the prevalence of genes involved in the metabolism of methane, formaldehyde, and carbon dioxide. With respect to the nitrogen cycle, evidence for sequences associated with dissimilatory reduction of nitrate, nitrogen immobilization, and denitrification was detected. Sequences related to the production of adenylsulfate, sulfite, and H2S were relevant to the sulphur cycle. These data indicate that the microbial core involved in methane, nitrogen, and sulphur metabolism consists mainly of Burkholderiaceae, Planctomycetaceae, Rhodobacteraceae, and Desulfobacteraceae. Comparison of our data to datasets from soil and sea samples resulted in the allotment of the mangrove sediments between those samples. The results of this study add valuable data about the composition of microbial communities in mangroves and also shed light on possible transformations promoted by microbial organisms in mangrove sediments.

229 citations

Journal ArticleDOI
TL;DR: The state of the art on compost supplementation with nutrients and the role played by the microorganisms involved (or added) in their transformation during the composting process are reviewed.

225 citations

Journal ArticleDOI
TL;DR: Results show that co-inoculation of PGPR and Rhizobia has a synergistic effect on bean growth, which may improve effectiveness of Rhizobium biofertilizers for common bean production.
Abstract: Nitrogen (N) fixation through legume-Rhizobium symbiosis is important for enhancing agricultural productivity and is therefore of great economic interest. Growing evidence indicates that other soil beneficial bacteria can positively affect symbiotic performance of rhizobia. Nodule endophytic plant growth promoting rhizobacteria (PGPR) were isolated from common bean nodules from Nakuru County in Kenya and characterized 16S rDNA partial gene sequencing. The effect of co-inoculation of rhizobium and PGPR, on nodulation and growth of common bean (Phaseolus vulgaris L.) was also investigated using a low phosphorous soil under greenhouse conditions. Gram positive nodule endophytic PGPR belonging to the genus Bacillus were successfully isolated and characterized. Two PGPR strains (Paenibacillus polymyxa and Bacillus megaterium), two rhizobia strains (IITA-PAU 987 and IITA-PAU 983) and one reference rhizobia strain (CIAT 899) were used in the co-inoculation study. Two common bean varieties were inoculated with Rhizobium strains singly or in a combination with PGPR to evaluate the effect on nodulation and growth parameters. Co-inoculation of IITA-PAU 987 + B. megaterium recorded the highest nodule weight (405.2 mg) compared to IITA-PAU 987 alone (324.8 mg), while CIAT 899 + B. megaterium (401.2 mg) compared to CIAT 899 alone (337.2 mg). CIAT 899 + B. megaterium recorded a significantly higher shoot dry weight (7.23 g) compared to CIAT 899 alone (5.80 g). However, there was no significant difference between CIAT 899 + P. polymyxa and CIAT 899 alone. Combination of IITA-PAU 987 and B. megaterium led to significantly higher shoot dry weight (6.84 g) compared to IITA-PAU 987 alone (5.32 g) but no significant difference was observed when co-inoculated with P. polymyxa. IITA-PAU 983 in combination with P. polymyxa led to significantly higher shoot dry weight (7.15 g) compared to IITA-PAU 983 alone (5.14 g). Plants inoculated with IITA-PAU 987 and B. megaterium received 24.0 % of their nitrogen demand from atmosphere, which showed a 31.1 % increase compared to rhizobium alone. Contrast analysis confirmed the difference between the co-inoculation of rhizobia strains and PGPR compared to single rhizobia inoculation on the root dry weight. These results show that co-inoculation of PGPR and Rhibozia has a synergistic effect

208 citations

Journal ArticleDOI
TL;DR: The present paper makes an attempt to review the microbial diversity in mangrove ecosystems and explore their potential applications in various fields such as agriculture, pharmaceutical, industrial, environmental and medical sciences.
Abstract: Mangrove forests occurring at the interface of terrestrial and marine ecosystems represent a rich biological diversity of plants, animals and microorganisms. Microbes, being an important component of the mangrove environment, not only play a very critical role in creating and maintaining this biosphere but also serve as a source of biotechnologically valuable and important products. By participating in various steps of decomposition and mineralization of leaf litter, microbes make an essential contribution to the productivity of the mangrove ecosystem. They able to recycle nutrients, produce and consume gases that affect global climate, destroy pollutants, treat anthropogenic wastes and can also be used for biological control of plant and animal pests. Microorganisms from mangrove environments are a major source of antimicrobial agents and also produce a wide range of important medicinal compounds, including enzymes, antitumor agents, insecticides, vitamins, immunosuppressants, and immune modulators. However, the phylogenetic and functional description of microbial diversity in mangrove ecosystems has not been addressed to the same extent as for other environments. Even though the mangrove ecosystem is very rich in microbial diversity, less than 5% of species have been described; in many cases neither their ecological role nor their application potential is known. Recently developed technologies in molecular biology and genetics offer great promise to explore the potential of microbial diversity. Hence, the present paper makes an attempt to review the microbial diversity in mangrove ecosystems and explore their potential applications in various fields such as agriculture, pharmaceutical, industrial, environmental and medical sciences.

179 citations

Journal ArticleDOI
TL;DR: The results indicated that the culturable halophilic/halotolerant bacteria inhabiting salty and arid ecosystems have a potential to contribute to promoting plant growth under the harsh salinity and drought conditions.
Abstract: Soil salinity and drought are among the environmental stresses that most severely affect plant growth and production around the world. In this study the rhizospheres of Salicornia plants and bulk soils were collected from Sebkhet and Chott hypersaline ecosystems in Tunisia. Depiction of bacterial microbiome composition by Denaturing Gradient Gel Electrophoresis unveiled the occurrence of a high bacterial diversity associated with Salicornia root system. A large collection of 475 halophilic and halotolerant bacteria was established from Salicornia rhizosphere and the surrounding bulk soil, and the bacteria were characterized for the resistance to temperature, osmotic and saline stresses, and plant growth promotion (PGP) features. Twenty Halomonas strains showed resistance to a wide set of abiotic stresses and were able to perform different PGP activities in vitro at 5% NaCl, including ammonia and indole-3-acetic acid production, phosphate solubilisation, and potential nitrogen fixation. By using a gfp-labelled strain it was possible to demonstrate that Halomonas is capable of successfully colonising Salicornia roots in the laboratory conditions. Our results indicated that the culturable halophilic/halotolerant bacteria inhabiting salty and arid ecosystems have a potential to contribute to promoting plant growth under the harsh salinity and drought conditions. These halophilic/halotolerant strains could be exploited in biofertilizer formulates to sustain crop production in degraded and arid lands.

153 citations