Prospecção e avaliação do potencial de degradação de petróleo por bactérias biodegradadoras extraídas da rizosfera de Sporobolus virginicus (L.) Kunth coletada em área litorânea sujeita à contaminação por petróleo

• Autor(a) principal: Silva, Brício Marcelino da
• Data de Publicação: 2017
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório do Centro Universitário Braz Cubas
• Texto Completo: https://repositorio.cruzeirodosul.edu.br/handle/123456789/2528
• topic: Gestão ambiental; Água - Poluição por petróleo; Hidrocarbonetos; Recuperação e remediação ambiental; Biorremediação; CNPQ::CIENCIAS BIOLOGICAS; CNPQ::ENGENHARIAS::ENGENHARIA SANITARIA

Oil is the main source of energy today and is also the cause of several environmental problems. Therefore, there is a need to develop strategies to combat contamination caused by daily use, as well as from the accidents and those resulting from oil extraction operations. In order to aid in the improvement of biological strategies to combat oil contamination, it was possible to prospect, isolate and identify bacteria associated with rhizosphere of Sporobolus virginicus (L.) Kunth collected in environments subject to oil contamination. Six samples (root and rhizospheric soil) were collected from four sites on the northern coast of the state of Rio de Janeiro, Brazil, totaling 24 samples. Extraction of the microorganisms resulted in the isolation of 46 morphotypes. Those in which colony forming units (CFUs) were observed in more than 2.5% (n = 336) of the total plaques were selected for identification. Fifteen morphotypes with different morphologies were characterized by means of Gram staining, of which 12 were Grampositive and three Gram-negative. Identification through genomic sequencing revealed that Bacillaceae (73.7%), Staphylococcaceae (6.7%), Xanthomonadaceae (6.7%) and Enterobacteriaceae (13,4%) are bacteria belonging to four families. Exiguobacterium sp., Staphylococcus sp., Pantoea sp., Stenotrophomonas sp. and Serratia sp. had their oil degradation efficiency (ED) of petroleum (4% v / v) measured, for up to 96 hours. The pH, the electrical conductivity and the dissolved oxygen concentration were monitored. Cellular concentration was estimated by absorbance and biomass increase measured by gravimetry. In the time intervals of higher cell concentration samples were collected to evaluate the efficiency of the oil degradation by gas chromatography with flame ionization detector (CG-FID). The results suggest that there was degradation of the crude oil promoted by the bacteria Exiguobacterium sp., Staphylococcus sp., Pantoea sp., Stenotrophomonas sp. and Serratia sp. verified from the chromatograms, where a reduction in the area of some peaks in different retention times (RT) was observed. The largest reduction measured was for Stenotrophomonas sp. with the value of 73.12% and the lowest for Exiguobacterium sp. with the value of 6.8%. These results broaden the knowledge about the use of the microbial community for the biodegradation of petroleum and petroderivatives, which may allow environmental managers to diversify the strategies that can be applied to techniques for recovering contaminated areas, particularly in coastal environments.