Geochemical characteristics and localization of heavy oil fields in the Republic of Tatarstan, Russia

High-viscosity oil belong to unconventional sources of hydrocarbon raw materials, the share of which is growing every year. The development of this complex type of raw material requires modern scientific technologies in order to maintain the production of hydrocarbons at the same level. Technologies for the extraction and processing of heavy oil are different from traditional ones. First of all, these deposits are located at a shallow depth, but are classified as difficult to recover due to the complex geological structure and high anomalous oil viscosity. The objective of this work is a deeper understanding of the geochemical composition of heavy oil deposits, taking into account the peculiarities of their geological structure. This is important for the successful development of new and improvement of existing technologies for the extraction and processing of heavy oil and the implementation of the resource potential of heavy oils in the Republic of Tatarstan. Keywords: heavy oil; unconventional oil; biodegradation; GC-MS; geochemical methods.

Biosurfactant-Producing Bacteria Isolated from Oil Contaminated Soil and its Media Optimization for Enzyme Production

Oil bio-degradation mechanism by microorganisms is requested for an effective microbial remediation of soil contamination by oil spills. The current examination pointed the identification of a biosurfactant producing bacteria for biosurfactant production from oil contaminated sites from Tamil Nadu. The biosurfactant testing screening methods were used to screen the potent strains and sequencing studies were used for Pseudomonas species identification. The bacterial isolate BS17 subjected to be the potent enzyme (Protease, Lipase and Esterase) producer. Among the tested production media, the ground nut oil cake was identified to be the optimum media for protease (0.47069 Unit/ml), lipase (9 Unit/ml) and esterase activity (3.891 Unit/ml) for bacterial isolate BS17. The bacterial isolate BS17 showed greatest lipase (15 Unit/mL) protease (0.8067 Unit/mL) and esterase (4.756 Unit/mL) enzyme activity at pH 9.0. At 35 ℃ bacterial isolate BS17 showed greatest enzyme action in protease (1.2772 Unit/mL), lipase (17 Unit/mL) and esterase (5.2972 Unit/mL) enzyme activity. At 48hrs of incubation period bacterial isolate BS17 showed most extreme enzyme activity in protease (3.361 Unit/mL), lipase (28 Unit/mL) and esterase (8.918 Unit/mL). The sequence of BS17 was deposited in NCBI and Accession number was received [MT337593.1]. Statistical analysis with the minimum significant difference (LSD) test of ANOVA was carried out to determine the oil degradation efficiency. This paper demonstrated the isolated P. aeruginosa (BS17) crude oil biodegradation from oil contaminated land soil sample. Strain BS17 was proved as potent bio-surfactant producer using crude oil by utilizing carbon and energy source in oil degradation mechanism.

Effects of Adding Laccase to Bacterial Consortia Degrading Heavy Oil

High-efficiency bioremediation technology for heavy oil pollution has been a popular research topic in recent years. Laccase is very promising for the remediation of heavy oil pollution because it can not only convert bio-refractory hydrocarbons into less toxic or completely harmless compounds, but also accelerate the biodegradation efficiency of heavy oil. However, there are few reports on the use of laccase to enhance the biodegradation of heavy oil. In this study, we investigated the effect of laccase on the bacterial consortia degradation of heavy oil. The degradation efficiencies of bacterial consortia and the laccase-bacterial consortia were 60.6 ± 0.1% and 68.2 ± 0.6%, respectively, and the corresponding heavy oil degradation rate constants were 0.112 day−1 and 0.198 day−1, respectively. The addition of laccase increased the heavy oil biodegradation efficiency (p < 0.05) and biodegradation rate of the bacterial consortia. Moreover, gas chromatography–mass spectrometry analysis showed that the biodegradation efficiencies of the laccase-bacterial consortia for saturated hydrocarbons and aromatic hydrocarbons were 82.5 ± 0.7% and 76.2 ± 0.9%, respectively, which were 16.0 ± 0.3% and 13.0 ± 1.8% higher than those of the bacterial consortia, respectively. In addition, the degradation rate constants of the laccase-bacterial consortia for saturated hydrocarbons and aromatic hydrocarbons were 0.267 day−1 and 0.226 day−1, respectively, which were 1.07 and 1.15 times higher than those of the bacterial consortia, respectively. The degradation of C15 to C35 n-alkanes and 2 to 5-ring polycyclic aromatic hydrocarbons by laccase-bacterial consortia was higher than individual bacterial consortia. It is further seen that the addition of laccase significantly improved the biodegradation of long-chain n-alkanes of C22–C35 (p < 0.05). Overall, this study shows that the combination of laccase and bacterial consortia is an effective remediation technology for heavy oil pollution. Adding laccase can significantly improve the heavy oil biodegradation efficiency and biodegradation rate of the bacterial consortia.

Response and oil degradation activities of a northeast Atlantic bacterial community to biogenic and synthetic surfactants

Background Biosurfactants are naturally derived products that play a similar role to synthetic dispersants in oil spill response but are easily biodegradable and less toxic. Using a combination of analytical chemistry, 16S rRNA amplicon sequencing and simulation-based approaches, this study investigated the microbial community dynamics, ecological drivers, functional diversity and robustness, and oil biodegradation potential of a northeast Atlantic marine microbial community to crude oil when exposed to rhamnolipid or synthetic dispersant Finasol OSR52. Results Psychrophilic Colwellia and Oleispira dominated the community in both the rhamnolipid and Finasol OSR52 treatments initially but later community structure across treatments diverged significantly: Rhodobacteraceae and Vibrio dominated the Finasol-amended treatment, whereas Colwellia, Oleispira, and later Cycloclasticus and Alcanivorax, dominated the rhamnolipid-amended treatment. Key aromatic hydrocarbon-degrading bacteria, like Cycloclasticus, was not observed in the Finasol treatment but it was abundant in the oil-only and rhamnolipid-amended treatments. Overall, Finasol had a significant negative impact on the community diversity, weakened the taxa-functional robustness of the community, and caused a stronger environmental filtering, more so than oil-only and rhamnolipid-amended oil treatments. Rhamnolipid-amended and oil-only treatments had the highest functional diversity, however, the overall oil biodegradation was greater in the Finasol treatment, but aromatic biodegradation was highest in the rhamnolipid treatment. Conclusion Overall, the natural marine microbial community in the northeast Atlantic responded differently to crude oil dispersed with either synthetic or biogenic surfactants over time, but oil degradation was more enhanced by the synthetic dispersant. Collectively, our results advance the understanding of how rhamnolipid biosurfactants and synthetic dispersant Finasol affect the natural marine microbial community in the FSC, supporting their potential application in oil spills.