Bioremediation of diesel oil: potential use of bacteria consortium Lactobacillus fermentum and Clostridium beijerinckii in degrading Total Petroleum Hydrocarbon (TPH)

Abstract

Diesel oil is a major petroleum-refined product known as the primary environmental pollutant due to its toxic complex hydrocarbons and difficulty in decomposing naturally. This study aims to determine the efficiency of TPH (Total Petroleum Hydrocarbon) removal in the bioremediation process of diesel oil pollution by utilizing a bacteria consortium of Lactobacillus fermentum and Clostridium beijerinckii as biocatalysts. The diesel oil degradation test was conducted on a laboratory scale using Stone Mineral Salt Solution (SMSs) liquid media with a batch system (limited culture). The temperature was set at 30°C with a rotation speed of 150 rpm for 10 days. Different treatments of pH (5, 7, 9) and contact time (10, 20, 30 days) were applied to varied diesel oil concentrations (5, 10, 20%, v/v). The oil components were measured using Gas Chromatography-Flame Ionization Detector. Diesel oil samples were put into SMSs containing 10% bacterial consortium and 10% NPK fertilizer. The sensitivity test showed that the bacterial consortium was resistant, proven by the absence of an inhibition zone around the disc paper area containing diesel oil. The highest TPH removal efficiency found was 97.3% when 5% diesel oil was degraded by the bacterial consortium at pH 7 for 20 days. This study proves that the bacterial consortium can be recommended in bioremediation to alleviate diesel oil pollution in the environment.