ISOLASI BAKTERI PENDEGRADASI FRAKSI SARA (SATURATE, AROMATIC, RESIN, ASPHALTENE) DARI SUMUR MINYAK BUMI DI JAWA BARAT UNTUK STUDI BIOREMEDIASI TANAH TERCEMAR MINYAK MENTAH

• Main Author: Meriani, Evita
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/46739
• Institution: Institut Teknologi Bandung

Biodiversity of petroleum well indigenous bacteria can be utilized to restore the environment contaminated by petroleum waste due to increased exploration and production of petroleum in line with the rapid development of the oil industry in the world. In order for the bioremediation process to proceed well, microbial isolates which have the ability to degrade and mineralize the four petroleum hydrocarbon fractions: saturate, aromatic, resin, and asphaltene (SARA) are required. This research focuses on screening hydrocarbonoclastic bacteria with the best degradation ability of the four petroleum fractions, generating mixedculture inoculums (consortium) of selected isolates, then continued with the simulation process of bioremediation of crude oil-contaminated soils for 4 weeks by calculating changes in Total Petroleum Hydrocarbon (TPH) value of test soil, bacterial population dynamics, SARA fraction distribution, and GC/MS analysis results. A total of 35 isolates of indigenous bacteria from West Java petroleum wells were successfully recovered through two stages of isolation by using Stone Mineral Salt Solution plus yeast extract (SMSSe). Based on SARA analysis and biometric tests, isolate 61 was the best in degrading asphalt and resin fractions with the degradation percentage of 78.66% and 75.45%, isolate 48 was best in degrading aromatic hydrocarbons (91.94%), and isolate 27 was best in degrading saturated hydrocarbons based on its mineralization ability with cumulative CO2 gas production of 3900 ppm. All three isolates also had excellent growth patterns with the highest growth rates of 0.086/hour (isolate 61 and 27) and 0.099/hour (isolate 48). The composition of mixedculture bacteria with a ratio of 1: 1: 1 was made using the three selected isolates which were then identified as Micrococcus sp-1 (isolate 27), Bacillus sp-1 (isolate 61), and Micrococcus sp-2 (isolate 48). The consortium's performance in degrading the oil fraction during bioremediation process carried out by regulating environmental conditions at soil pH of 6- 8, soil humidity of 50-70%, at a room temperature (28-30?C) are able to lower TPH from a concentration of around 5% to 2% within 4 weeks. Variations of treatment using inoculums of 5%, 10%, and 15% (v/w) with a cell consortium density of around 108 cfu/mL were able to degrade hydrocarbon compounds that have toxic properties of up to 46.58%, 48.60%, and 46.08% at the end of the bioremediation process. Population dynamics of total petrophilic bacteria increased during the 4-week test period. SARA analysis of the bioremediated oil showed that there is a decrease in the relative percentage of fraction of asphalt, resin, and saturated hydrocarbons from all treatment variations compared to the control unit. GC/MS analysis showed a decrease in the number and abundance of light fraction hydrocarbon compounds. Based on the research results, a consortium of three selected hydrocarbonoclastic isolates has the potential to be utilized in bioremediation technology.