Instituto de Ciências Agrárias - CAF

URI permanente desta comunidadehttps://locus.ufv.br/handle/123456789/11784

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Resultados da Pesquisa

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    Selection of diazotrophic bacteria isolated from wastewater treatment plant sludge at a poultry slaughterhouse for their effect on maize plants
    (Revista Ceres, 2018-01) Lozada, Jorge Avelino Rodriguez; Silveira, Klever Cristiano; Silva, Libério Junio da; Baldotto, Marihus Altoé; Baldotto, Lílian Estrela Borges
    The economic and environmental costs of nitrogen fertilization have intensified the search for technologies that reduce mineral fertilization, for example atmospheric nitrogen-fixing (diazotrophic) bacteria inoculation. In this context, the present study addressed the isolation and quantification of diazotrophic bacteria in the sludge from treated wastewater of a poultry slaughterhouse; a description of the bacteria, based on cell and colony morphology; and an assessment of growth and N content of maize plants in response to inoculation. Sixteen morphotypes of bacteria were isolated in six N-free culture media (JMV, JMVL, NFb, JNFb, LGI, and LGI-P). The bacteria stained gram-positive, with 10 rod- and six coccoid-shaped isolates. To evaluate the potential of bacteria to promote plant growth, maize seeds were inoculated. The experiment consisted of 17 treatments (control plus 16 bacterial isolates) and was carried out in a completely randomized design with six replicates. The experimental units consisted of one pot containing two maize plants in a greenhouse. Forty-five days after planting, the variables plant height, leaf number, stem diameter, root and shoot fresh and dry weight, and N content were measured. The highest values ​​were obtained with isolate UFV L-162, which produced 0.68 g total dry matter per plant and increased N content to 22.14 mg/plant, representing increments of 74 and 133%, respectively, compared with the control. Diazotrophs inhabit sludge from treated wastewater of poultry slaughterhouses and can potentially be used to stimulate plant development and enrich inoculants.
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    Prospecting for sludge bacteria from a poultry slaughterhouse, with potential for degrading organic substances
    (Semina: Ciências Agrárias, 2016-08-21) Lozada, Jorge Avelino Rodriguez; Silveira, Klever Cristiano; Silva, Libério Junio da; Baldotto, Marihus Altoé; Baldotto, Lílian Estrela Borges
    The sludge produced in wastewater treatment plants of slaughterhouses is a rich source of chemical, organic, and microbiological constituents that can be biotechnologically exploited. The purpose of this study was to (i) conduct a chemical analysis of the sludge, and (ii) isolate, quantify, and describe the amylolytic, cellulolytic, ligninolytic, proteolytic, and keratinolytic bacteria in the sludge. Sludge samples were collected at the wastewater treatment plant of the Francap SA poultry company. The nutrient contents, C/N ratio, and pH were determined. For the bacterial count, 10 g sludge was diluted in 90 mL saline solution, which was serially diluted to 10-12. Aliquots of 100 µL of each dilution were transferred to selective media for isolation of bacteria that degrade organic substances. The colony-forming units were determined for each culture medium. Individual colonies were purified and characterized morphologically. The sludge contained 9.5, 1.21, and 0.45 dag kg-1 of N, P, and K, respectively. Fifty-two isolates were purified and characterized, with 2.11 × 1012 to 9.55 ×1015 colony-forming units per g sludge. In conclusion, the sludge generated in poultry slaughterhouse wastewater treatment plants is a rich source of organo-mineral constituents and bacteria with biotechnological potential for degrading organic substances.