In vitro Degradation and Reduction of Aromatic Hydrocarbons by Marine Bacteria Isolated from Contaminated Marine Environments of Niger Delta

Abstract

Aims: To determine the in vitro degradation and reduction of aromatic hydrocarbons by marine bacteria isolated from contaminated marine environments of Niger Delta.
 Study Design: Nine treatments and nine controls designs were set up in triplicates containing 100 mL of sterile modified mineral basal medium in 500 mL conical flasks supplemented with 1 mg /L of xylene, anthracene and pyrene each; nine marine hydrocarbon degraders and incubated at 24 ºC for 24 days study. The nine treatments and control set ups designated as ANT1, XYL2, PYR3, ANT4, PYR5, ANT6, XYL7, XYL8, PYR9 and CTRL (Without hydrocarbons) were used to determine the aromatic hydrocarbons degradability and reduction by the marine bacteria. 
 Place and Duration of Study: The studied sites were Abonema Wharf Water Front in Akuku-Toru Local Government Area, Nembe Water-Side in Port Harcourt Local Government Area and Onne Light Flow Terminal Seaport located in Eleme Local Government Area of Rivers State, Nigeria between September, 2014 and March, 2017.
 Methodology: A laboratory scale study was carried on six composite samples of the sediment and water samples from the three studied areas using enrichment, screening, phenotypical, degradation and TLC techniques.
 Results: The results showed that the three studied areas harbour numerous promising aromatic degrading bacterial strains belonging to the genera: Providencia, Alcaligenes, Brevundimonas, Myroides, Serratia, and Bacillus. The bacterial strains especially Serratia marcescens XYL7 significantly (P = .05) had 99.50 ± 0.05 % and 60.00 ± 0.02 % degradations in weights of xylene and pyrene, respectively while Alcaligenes faecalis PYR5 significantly (P =.05) degraded 97.40 ± 0.01 % in weight of anthracene. TLC result revealed evidences of large spots size reductions or losses of test samples compare to control samples with minor spot sizes.
 Conclusion: Thus, the outstanding degradative abilities of these strains could be exploited in bioremediation campaigns in Nigeria.