In vitro selection of effective microbial strains for bioaugmentation on oil polluted sediment from Cilacap coastal, Indonesia

Abstract

Application of bioremediation technique have not been used in Indonesian coastal and marine environment. Information in regard with bioremediation agent which can be survive and alter degradation rate in the field is still questionable. Therefore, we did a research to select a good candidate for bioremediation agent and to understand the intrinsic capability of this area for coping oil pollution by microcosm approach. Target area was oil contaminated sediment in Cilacap coastal. Selection of potential bacteria in the form of a single culture or consortium for the purpose of bioremediation has been carried out in vitro using microcosm approach. The experiment was conducted with three replications for 28 days with 6 different sampling times, using 50 ml Falcon tubes as reactor. Five (5) strains of bacteria and four (4) consortia of bacteria isolated from sediments port of Jakarta has been used in this study. The unsterilized mixture of sediment and seawater collected from Cilacap coastal have been used as a substrate. Arabian light crude oil in ‘mousse oil’ form used as a pollutant with nominal oil concentration in each tube was 100000 ppm (10%). The results showed that addition of the bacteria at a concentration of 108 cells / ml was able to significantly increase the rate of oil degradation. Giving a bacterial culture in the form of a consortium showed better results in improving the rate of oil degradation than the single strain. Decreasing the concentration of oil in controls ranged from 34.45-36.7%, whereas the treatment of single strain and consortium bioaugmentation respectively reached 35.68-41.27% and 38.5-44.3%. Alcanivorax sp.TE-9 is proven as an important bacterium in degrading oil in marine environment. Alcanivorax sp.TE-9 is effective as a bioremediation agent in the form of single or consortium culture. Alcanivorax sp.TE-9 and Consortium B can be proposed as bioremediation agent for bioremediation oil polluted coastal in Cilacap.