Isolamento de bactérias hidrocarbonoclásticas de sedimento de manguezal contaminado com petróleo

Abstract

In August of 2019, there was a petrol leakage which hit the shore of 11 states of the northeast and southeast of Brazil. This leakage affected several coastal ecosystems mainly estuary and mangrove forests, besides exposing coastal species already under threat. Mangrove forests are ecosystems extremely sensitive to contamination by hydrocarbons. Therefore, this present proposal has aimed at isolating and featuring hydrocarbonclastic bacteria with degradation potential in sediment of mangrove, contaminated by petrol, in Cabo de Santo Agostinho. To do so, samples of superficial sediments of mangrove which were contaminated, those were collected and submitted to the tests of quantification of total heterotrophic bacteria, assertiveness of hydrocarbonclastic bacteria, selection of isolated decomposers of petrol and by-products. The physical- chemical pH parameters, temperature, salinity, and conductivity were also measured in the sediment. It was not observed significant variation in the physical-chemical parameters among the variables analysed. On the other hand, It was obtained a total of 30 bacterial isolates, 15 heterotrophic and 15 hydrocarbonclastic bacteria. Negative Gram bacilli were predominant among heterotrophic and hydrocarbonclastic bacteria. Two isolated ones, the group of heterotrophic bacteria stood out. (isolated 1 & 4) due to showing more relative frequency, making up of 64 % of total isolated together. With regards to the 15 isolate hydrocarbonclastic bacteria, 13 of those, were obtained in the diesel oil environment as source for carbon. Of 15 isolate hydrocarbonclastic bacteria assessed, 10 displayed potential for decomposition of diesel oil, gasoline and kerosene. The isolate 7 was prominent as it achieved the best decomposition results of the 3 fuels analysed.