Maria Do Carmo Silva Barreto

Maria Do Carmo Silva Barreto

*This is an algorithmically generated author record based on publicly available information.

Maria Do Carmo Silva Barreto has a total of 30 co-authors. Here are the top co-authors by number of shared publications:


Latest Publications

  • Open Access

    From Agro-Industrial Waste to Gold Lixiviant: Evaluating Cassava Wastewater Applications in Artisanal Mining

    by Emiliano Mendonça Silva, Maria Do Carmo S. Barreto, Marcello M. Veiga, Giorgio De Tomi

    Artisanal and Small-Scale Gold Mining (ASGM) is a primary source of global mercury pollution, creating an urgent need for sustainable, low-cost alternatives to amalgamation. This study investigates the use of cassava wastewater (manipueira), a cyanogenic agricultural byproduct, as a lixiviant for a gold concentrate (14.30–15.87 ppm Au) from an artisanal mine. Two approaches were evaluated: direct leaching with manipueira in natura (250 ppm CN−) in single and double 8 h and 12 h cycles, and leaching with a cyanide solution concentrated from dilute manipueira (100 ppm CN−) via a simplified air-stripping system. Results were benchmarked against the mine’s amalgamation (44.7% recovery) and 30-day heap leach (75.8% recovery) processes. The most effective method observed was a two-cycle, 8 h leach with manipueira in natura, which achieved a mean gold recovery of 76.75±4.71%. This result is comparable to the efficiency of the site’s lengthy heap leach process and suggests a promising, faster, route to eliminating mercury use. Longer (12 h) leaching cycles yielded lower recoveries, suggesting process limitations such as preg-robbing. The cyanide concentration method proved inefficient, recovering a maximum of 12.40% of the available cyanide and resulting in a weaker lixiviant. The findings demonstrate that while direct leaching is a viable alternative to mercury, the inherent instability of manipueira necessitates a focus on developing efficient, controlled systems to extract and concentrate its cyanide content, thereby creating a standardized “green” reagent from a large-volume agricultural waste stream.


  • Open Access

    Effect of Digitaria eriantha Endophytic Bacteria on Maize Growth in a Hydroponic System

    by Johny J. Mendonça, Michelle J. G. Alves, Gisely M. Vitalino, Maria C. S. Barreto, Eric X. Carvalho, José P. Oliveira, Maria L. R. B. Silva, Felipe J. C. Fracetto, Giselle G. M. Fracetto, Mario A Lira Junior

    Brazil is one of the largest grain producers worldwide, with yields heavily dependent on ecologically and financially expensive inputs. One possible approach to reduce these inputs is inoculation with plant-growth-promoting bacteria, whose large-scale use depends on a continual search for new genotypes for inoculant production. Several bacteria with potential for this have been isolated from plants that are more adapted to stressful environments. Thus, we aimed to evaluate the potential of pangolão grass (Digitaria eriantha cv. Suvernola) endophytic bacteria both in vitro and on maize growth. To this end, endophytic bacteria were isolated from pangolão grass of a tropical semiarid climate and a random subset of 80 strains was evaluated for biological nitrogen fixation, HCN, IAA and siderophore production and calcium phosphate solubilization, and later for maize growth promotion. All strains were positive for at least one of these in vitro growth promotion mechanisms and some strains increased maize plant height and root length, including some with better results than plants receiving commercial inoculants, confirming the potential of endophytic bacteria from stress-adapted plants. In vitro results had poor correlation with plant growth promotion, which indicates that the common practice of using these laboratory techniques as a pre-selection tool before a subset of strains is evaluated for plant growth promotion might result in the rejection of potentially interesting strains.


  • Open Access

    Inoculation of arbuscular mycorrhizal fungi as a strategy to improve annatto (Bixa orellana L.) growth

    by Marília Malta Cavalcante Mendes Pontes, José de Paula Oliveira, Maria Do Carmo Silva Barreto, Eric Xavier de Carvalho, Adalia Cavalcanti Do Espírito Santo Mergulhão, Maria Luiza Ribeiro Bastos da Silva, Jadson Emanuel Lopes Antunes, Ademir Sergio Ferreira de Araújo, Márcia Do Vale Barreto Figueiredo

    This study aimed to assess the occurrence of arbuscular mycorrhizal fungi (AMF) in annatto (Bixa orellana L.) cultivars and their response to AMF inoculation using biometric parameters. The occurrence surveys were conducted in annatto fields in three municipalities from Pernambuco Forest Zone: Lagoa de Itaenga, Gloria de Goitá, and Vitoria de Santo Antão, and in four cultivars (Red Piave, Green Piave, Red Peruvian Paulista, and Green Peruvian Paulista). In a greenhouse, biometric parameters of annatto seedlings of Red Piave, Red Peruvian Paulista, Embrapa-36, and Embrapa-37 cultivars inoculated with AMF isolated from annatto fields. The Red Piave cultivar exhibited greater root colonization than the Green Peruvian Paulista in the Lagoa de Itaenga and Vitoria de Santo Antão municipalities. The cultivar Red Piave showed a more beneficial association with AMF in plants and soil than cultivar Green Peruvian Paulista did, in both Lagoa de Itaenga and Vitoria de Santo Antão. AMF inoculation was effective in promoting the growth of annatto plants, particularly those inoculants with S. heterogama and C. etunicatum.

  • Inoculation of endophlytic diazotrophic bacteria in micropropagated seedlings of sugarcane (Saccharum officinarum sp.)

    by Maria Do Carmo Silva Barreto, Márcia Do Vale Barreto Figueiredo, Márcia Vanusa Silva, José de Paula de Oliveira, Arnóbio Gonçalves Andrade, Clébia Maria Alves Almeida, Manoel Urbano Ferreira Junior, Carolina Etiene Rosália e Silva Santos, Odemar Vicente dos Reis Junior, Vera Lúcia de Menezes Lima


  • Open Access

    Sinergismo Bacillus, Brevibacillus e, ou, Paenibacillus na simbiose Bradyrhizobium-caupi

    by André Suêldo Tavares De Lima, Maria Do Carmo Silva Barreto, Janete Magali Araújo, Lucy Seldin, Hélio Almeida Burity, Márcia Do Vale Barreto Figueiredo

    O feijão-caupi Vigna unguiculata [L.] Walp. é a principal cultura de subsistência do semiárido brasileiro, sendo fonte de proteínas de baixo custo, notadamente, para populações carentes. A produção dessa cultura no Nordeste é baixa devido à não utilização de insumos agrícolas - entre eles, o fertilizante nitrogenado. Por outro lado, bactérias promotoras de crescimento em plantas (BPCPs) vêm sendo estudadas, de forma a maximizar a fixação de N2, disponibilizar nutrientes como P ou fito-hormônios e inibir doenças. Os objetivos deste trabalho foram verificar a viabilidade da coinoculação das sementes de feijão-caupi usando Paenibacillus, Brevibacillus e, ou, Bacillus e Bradyrhizobium-caupi; caracterizar as estirpes quanto à produção de ácido indol acético (AIA) e solubilização de fosfato; e avaliar o sinergismo entre os microrganismos como alternativa para otimizar a FBN. Os experimentos foram conduzidos em laboratório e em casa de vegetação do Instituto Agronômico de Pernambuco (IPA), utilizando o feijão-caupi cv. "IPA - 206". As estirpes utilizadas foram: Bacillus sp. - 449, 450, 451, 461 e ANBE 31; B. cereus - 440; B. subtilis - 438, 441, 454, 455 e 459; B. pumilus - 444, 445 e 448; B. megaterium - 462; Brevibacillus brevis - 447; Paenibacillus brasilensis - 24, 172 e 177; P. graminis - MC 04.21, MC 22.13 e BR 60106; P. polymyxa - S21; e P. durus - RBN4. Os microrganismos não apresentaram capacidade para produzir AIA nem solubilizar fosfato. Ocorreu sinergismo das estirpes de Bacillus sp. (449) e Bacillus pumilus (444) coinoculadas com a estirpe de Bradyrhizobium sp. (BR 3267) no feijão-caupi.