Biodegradation of Petroleum Oil Effluents and Production of Biosurfactants: Effect of Initial Oil Concentration

Abstract

Biosurfactants have been used in the petroleum oil industry for oil storage tank cleaning, for reducing the viscosity of heavy oil, thereby facilitating recovery, transportation, and pipelining. Also, they are used for microbial enhanced oil recovery either from residual oil in reservoirs or from oily wastewater. The present study is an investigation of biodegradation of petroleum oil effluents using Pseudomonas aeruginosa ATCC 9027 for producing rhamnolipid biosurfactants. The processes were performed in a mechanically agitated, fully baffled, air-sparged 10 L glass fermenter with a 5 L working volume. The effect of oil concentration (1%, 1.5%, 2%, and 2.5%) on the efficiency of oil biodegradation, rhamnolipid production, surface tension, and bacterial biomass was studied. The fermentation with 1.5% oil concentration gave the highest biodegradation for aliphatic hydrocarbons (98.85%), followed by 2% oil concentration (95% degradation), then with 2.5% oil concentration (80% degradation), and finally with 1% oil concentration (66.8% degradation). Also, the complete biodegradation of polyaromatic hydrocarbons was achieved for all tested oil concentrations. On the other hand, maximum rhamnolipid production of 2.7 g L −1 as rhamnose equivalent and lower surface tension (30.2 mN m −1 ) were achieved at 2% oil concentration.

Conversion of Waste Cooking Oil to Rhamnolipid by a Newly Oleophylic Pseudomonas aeruginosa WO2

“…After 5 days of fermentation, the final WCO utilization rate reached 92.25%, and 3.03 g of rhamnolipid was produced. As shown in Table 2, the utilization rate of WCO and the production of rhamnolipid were better than or comparable with results from other studies [33,35,[40][41][42]. In addition, during the decline period of the strain, the utilization rate of WCO decreased, only 14.49% WCO was consumed from 48 to 120 h. However, there was a slight decrease in rhamnolipid production in the later stage of fermentation, which indicated that Pseudomonas aeruginosa WO2 utilized rhamnolipid.…”

Short-Term Biodegradation of Crude Petroleum Oil in Water by Photostimulated Janibacter terrae Strain S1N1

“… 1 It is evident that microbial communities which were exposed to hydrocarbon pollutants become more adapted and can exhibit higher biodegradation rates than other communities. 9 Accordingly, microorganisms isolated from contaminated areas are active oil degraders and can be used in bioremediation techniques. In addition, both physicochemical and biological variables influence the rate of microbial growth and enzymatic activity.…”

“…As noted, the success of bioremediation technology highly depends on the presence of native microorganisms with appropriate metabolic capabilities . It is evident that microbial communities which were exposed to hydrocarbon pollutants become more adapted and can exhibit higher biodegradation rates than other communities . Accordingly, microorganisms isolated from contaminated areas are active oil degraders and can be used in bioremediation techniques.…”

Optimization and characterization of rhamnolipid production by Pseudomonas aeruginosa NY3 using waste frying oil as the sole carbon

“…Many studies have evaluated low‐cost substrates for the RL production by Pseudomonas aeruginosa , resulting in RL yield of 13.31 g/L using waste frying oil (WFO) 12 and 3.4 g/L using palm oil agricultural refinery waste 13 . The use of coconut husks and petroleum oil wastes have also been studied 14,15 . WFO is waste produced each year by restaurants, households, and industries that is harmful to human health and the environment.…”

“…13 The use of coconut husks and petroleum oil wastes have also been studied. 14,15 WFO is waste produced each year by restaurants, households, and industries that is harmful to human health and the environment.…”