Occurrence of crude oil degrading bacteria in gasoline and diesel station soils

Cruz-Noriega M.D., Otiniano N.M., Rojas-Villacorta W., Rojas-Flores S., Cabanillas-Chirinos L., Abanto Marin M.

The present study evaluated the effect of two inoculum concentrations on the degradation of crude oil by Corynebacterium stationis CsPe-1. To this end, two treatment systems were utilized, each containing Davies Minimum Medium, 1% crude oil, and bacterial inoculum at concentrations of 10% and 15%, respectively. The degree of oil biodegradation was determined by evaluating the biochemical oxygen demand (BOD5), the chemical oxygen demand (COD), the concentration and fractions of oil and grease, and the total petroleum hydrocarbons (TPH). The results indicated that both BOD5 and COD exhibited an increase after a 20-day treatment period. For the 10% and 15% inoculum concentrations, a statistically significant difference was observed between the initial and final values of oils and fats (p < 0.05). In both systems, the levels of oils and fats decreased by 61%, contrasting with the control system, which exhibited minimal variation. A significant difference (p < 0.05) was observed in the degradation of TPH at the two inoculum concentrations. The findings indicated that the biodegradation of TPH was more efficient with an inoculum of 15%, resulting in a 79.94% reduction in fraction 3 (28–40 carbon chains). Fraction 1 exhibited less degradation, attributable to the toxicity of short-chain n-alkanes. Genomic analysis identified the pcaG and pcaH genes, which have been linked to the degradation of polycyclic aromatic hydrocarbons. This study underscores the biotechnological potential of strain CsPe-1 for the remediation of hydrocarbon-contaminated environments, thereby contributing to the realization of Sustainable Development Goals 14 and 15.

Kopalle P., Pothana S.A.

Sathya R., Arasu M.V., Al-Dhabi N.A., Vijayaraghavan P.

A biosurfactant is described as a “biosurface active” compound synthesized by various microbes. The purified microbial form of biosurfactant is called surfactin. Biosurfactant is safer for the environment, less poisonous, and easily decomposable than chemical surfactants. Several microbial enzymes are involved in the process of bioremediation (lyases, oxidoreductases, peroxidases, cellulase, protease, dehalogenases, hydrolases, etc.). Biosurfactants are surface dynamic molecules synthesized by microbes with numerous features such as being nontoxic, easily biodegradable, reducing surface tension, stabilizing emulsions, and enhancing foam. The main role of biosurfactants is to reduce the interface and surface tension of hydrocarbon and water solutions. Biosurfactants have recently gained much attention due to their high utility in industrial and environmental processes. It has numerous applications in the food industry, including lecithin, additives, ethoxyated byproducts, and monoglycerides. The biosurfactant is very smart in the healthcare and cosmetic industry. Numerous primary and secondary metabolites are produced by microbes that possess several biological applications. Many hydrocarbons are released into the environment from animals, plants, and microbes. According to existing reports, biosurfactants are being used for oil cleanup, soil remediation, pesticide manufacturing, plant growth promoters, drug delivery, medicine, agriculture, and environmental safety. So the application of biosurfactants and enzymes is of great value to the industrial sector.

Márquez-Villa J.M., Rodríguez-Sierra J.C., Amtanus Chequer N., Cob-Calan N.N., García-Maldonado J.Q., Cadena S., Hernández-Núñez E.

Microbial degradation of aromatic hydrocarbons is an emerging technology, and it is well recognized for its economic methods, efficiency, and safety; however, its exploration is still scarce and greater emphasis on cyanobacteria–bacterial mutualistic interactions is needed. We evaluated and characterized the phenanthrene biodegradation capacity of consortium dominated by Fischerella sp. under holoxenic conditions with aerobic heterotrophic bacteria and their molecular identification through 16S rRNA Illumina sequencing. Results indicated that our microbial consortium can degrade up to 92% of phenanthrene in five days. Bioinformatic analyses revealed that consortium was dominated by Fischerella sp., however different members of Nostocaceae and Weeksellaceae, as well as several other bacteria, such as Chryseobacterium, and Porphyrobacter, were found to be putatively involved in the biological degradation of phenanthrene. This work contributes to a better understanding of biodegradation of phenanthrene by cyanobacteria and identify the microbial diversity related.

Khalid S., Iqbal A., Javed A., Rashid J., ul Haq I., Barakat M.A., Kumar R.

Industrialization and urbanization have increased the demand for petroleum hydrocarbons; hence the likelihood of contamination of air, soil, and water bodies increases. The survival and biodegradation capabilities of fifteen bacterial isolates were tested in a harsh diesel environment. The bacteria were isolated from soil samples and identified by 16S rRNA gene sequencing. The biodegradation capability of isolates was performed in batch experiments, and diesel degradation analyses were conducted on gas chromatography-mass spectroscopy (GC-MS). The results revealed that only two bacterial isolates (A1 and E5) sufficiently consumed diesel hydrocarbons as a carbon-based energy source. 16S rRNA sequencing identified both isolates as Bacillus genera. An average of 60% of 3% (v/v) diesel was degraded in about 16 hours. Bacillus sp. E5 strain could degrade about 72% and 68% heavier compounds of C24 and C26. The Monod kinetic model for Bacillus sp. E5 utilizing diesel as a substrate showed maximum specific bacterial growth rate (μmax) as 0.1131 hr-1 at 1%, while 0.1287 hr-1 for 3% diesel. Results suggest that the isolated bacterial strain Bacillus sp. E5 has bioremediation potential and can be used as an alternative method for cleaning contaminated petroleum hydrocarbon field sites for sustainable development.

Banet G., Turaani A.K., Farber R., Armoza- Zvuloni R., Rotem N., Stavi I., Cahan R.

This study deals with two adjacent terrestrial oil spills, with similar properties, located in a hyper-arid region in Israel, one from 1975 and the other from 2014. It tests the effect of biostimulation on crude oil degradation in both spills and whether biostimulated sediments from the 1975 spill can bioaugment crude oil degradation in the 2014 spill. Soil hydrophobicity, expressed as Water Drop Penetration Time (WDPT), and Gasoline Range Organics (GRO) and Diesel Range Organics (DRO) content in sediments were measured in one-month ex-situ experiments. No significant reduction in hydrophobicity and GRO + DRO content was observed in non-biostimulated controls. A combined treatment of mineral fertilization at t 0 and maintaining 50% water saturation, significantly accelerated the decrease in hydrophobicity and GRO + DRO content in sediments of both spills. The addition of biostimulated sediments from the 1975 spill failed to accelerate the reduction of GRO + DRO content and hydrophobicity in the 2014 spill. Surprisingly, the GRO + DRO degradation rate in biostimulated sediments from the 2014 spill was 36% higher than in biostimulated sediments from the 1975 spill. Crude oil composition in both spills changes during its degradation and is characterized by an increase in the GRO fraction. To a certain range, WDPT was found to serve as a reliable indicator for oil content in the soil. We conclude that even in a hyper-arid region, oil bio-degradation capabilities develop in a relatively short time. Moreover, while biostimulation was effective in accelerating biodegradation, bioaugmentation with biostimulated sediments from a nearby older spill was found ineffective. • Biostimulation is crucial for effective crude oil degradation in hyper-arid soils. • In such soils, effective crude oil degradation develops in less than 4 years. • Bioaugmentation with biostimulated sediments from an adjacent older spill is ineffective. • The composition of crude oil changes during its degradation. • Soil hydrophobicity, to some extent, is a god indicator for oil content in the soil.

Gao J., Ming J., Xu M., Fu X., Duan L., Xu C., Gao Y., Xue J., Xiao X.

AbstractIn the recent 50 years, marine oil spills had resulted in severe environmental pollution problems worldwide. In this study, 12 petroleum-degrading strains named MJ1 to MJ12, which can use diesel oil as the sole carbon source for growth, were isolated from the seawater in Jiaozhou Bay, China. Strain MJ4 has the highest diesel-degrading rate which is up to 26.54% in 5 days with the diesel oil concentration of 10 g/L. According to the BLAST research, 16SrRNA sequence of MJ4 showed 99% similarity to Bacillus megaterium strain. Single-factor experiments and response surface methodology were carried out to optimize the environmental factors and their reciprocal action for affecting the diesel oil degradation process of Bacillus sp. MJ4. Results of single-factor experiments revealed that the highest degradation rate was obtained with temperature of 28 °C, pH of 8.8, diesel oil concentration of 25 g/L, P/N ratio of 0.56, nitrogen and phosphorus dosage quantity of 0.35 g/L and 0.18 g/L, respectively. A nonlinear regression equation of diesel oil degradation rate and pH, temperature, P/N ratio was obtained. The model predicted the maximum degradation rate of 72.21% with temperature of 28 °C, pH of 8.88, P/N ratio of 0.31, respectively.

Peltek S.E., Bryanskaya A.V., Uvarova Y.E., Rozanov A.S., Ivanisenko T.V., Ivanisenko V.A., Lazareva E.V., Saik O.V., Efimov V.M., Zhmodik S.M., Taran O.P., Slynko N.M., Shekhovtsov S.V., Parmon V.N., Dobretsov N.L., et. al.

The Uzon Caldera is one of the places on our planet with unique geological, ecological, and microbiological characteristics. Uzon oil is the youngest on Earth. Uzon oil has unique composition, with low proportion of heavy fractions and relatively high content of saturated hydrocarbons. Microbial communities of the «oil site» have a diverse composition and live at high temperatures (up to 97 °C), significant oscillations of Eh and pH, and high content of sulfur, sulfides, arsenic, antimony, and mercury in water and rocks. The study analyzed the composition, structure and unique genetics characteristics of the microbial communities of the oil site, analyzed the metabolic pathways in the communities. Metabolic pathways of hydrocarbon degradation by microorganisms have been found. The study found statistically significant relationships between geochemical parameters, taxonomic composition and the completeness of metabolic pathways. It was demonstrated that geochemical parameters determine the structure and metabolic potential of microbial communities. There were statistically significant relationships between geochemical parameters, taxonomic composition, and the completeness of metabolic pathways. It was demonstrated that geochemical parameters define the structure and metabolic potential of microbial communities. Metabolic pathways of hydrocarbon oxidation was found to prevail in the studied communities, which corroborates the hypothesis on abiogenic synthesis of Uzon hydrothermal petroleum.

Osei-Twumasi D., Fei-Baffoe B., Anning A.K., Danquah K.O.

Bioremediation has gained global prominence as an effective method for treating hydrocarbon-contaminated drill mud waste (HCDW). However, the problem of low nutrient content, bioavailability and microbial presence remain largely unresolved. In this study, the synergistic effects of compost, cow bile and bacterial culture on the degradation rate of HCDW was investigated. A homogenized HCDW sample (80 kg) obtained from 25 different drill mud tanks was divided into 20 portions (4 kg each) and each adjusted to 1.4% nitrogen content + 20 ml cow bile (i.e., basic treatment). Pure cultures of Brevibacterium casei (Bc) and Bacillus zhangzhouensi (Bz) and their mixture (BcBz) were subsequently added to 12 of the amended HCDW (basic) to undergo a 6-week incubation. A portion of the unamended HCDW (2 kg) was used as control. Initial pH, electrical conductivity and surface tension values of the HCDW were 8.83, 2.34 mS/cm and 36.5 mN/m, respectively. Corresponding values for total petroleum hydrocarbon (TPH), total nitrogen and total plate count bacteria were 165 g/kg, 0.04% and 4.4 × 102 cfu/ml. The treatments led to a substantial reduction in TPH (p < 0.05) while the control had no significant effect (p > 0.05). TPH reduction after the experimental period occurred in the order: basic + BcBz (99.7%) > basic + Bz (99.5%) > basic + Bc (99.2%) > basic (95.2%) > control (0.06%). Multiple regression analysis revealed significant effect of total plate count, pH, CN ratio and electrical conductivity (R2 = 0.87, p = 0.05) on the degradation of TPH in the HCDW. The study demonstrates strong interactive effects of compost, cow bile and bacteria culture on the remediation of HCDW, which can be applied to boost the efficiency of the bioremediation technique.

Guerrero-Chávez A.C., Alarcón A., Ferrera-Cerrato R., Díaz-Aguilar I., Mendoza-López M.R., Rios-Galicia B., Arteaga-Garibay R.I., Larsen J.

Phytoremediation of contaminated soils relies on the ability of plants to stimulate microbial rhizosphere diversity, by releasing root exudates. This work assessed the impact of diesel contamination on soil populations of culturable bacterial groups (fast growing, N2-fixing, phosphate (P) solubilizing, and lipolytic bacteria), and collembolans under mesocosm conditions with and without the influence Medicago sativa. We set up six treatments sampled initially within 24 h and examined at 4, 8, and 12 months. Bacterial groups were isolated and identified with 16S rRNA sequencing, while collembolans were classified using taxonomic keys. The populations of P-solubilizing and fast-growing bacteria were stimulated after 4 months in the polluted treatments in absence of M. sativa. On the M. sativa treatments, P-solubilizing and lipolytic bacteria increased after 8 months. Stenotrophomonas and Achromobacter were the most predominant bacterial genera. Collembolans mainly belonging to Poduromorpha and Entomobryomorpha orders, were observed in contaminated treatments on the 12th month, while in the uncontaminated control were found at the 4th month. Hydrocarbon degradation was higher than 80% in all treatments after 12 months. Diesel contamination and soil management reduced significantly the collembolan abundance; these organisms may be considered as biological indicators of soil quality and recovery after an event of diesel contamination.

Choden D., Pokethitiyook P., Poolpak T., Kruatrachue M.

Soil adulteration by organic and inorganic contaminants chiefly in industrial and agricultural area is one of the major problems faced by the world today. Phytoremediation using aromatic plant such...

Tazangi M.H., Ebrahimi S., Nasrabadi R.G., Naeeni S.A.

In the present study, total petroleum hydrocarbon biodegradation by wheat straw biochar and active carbon (TPH) was investigated in gasoil-polluted soil around oil refinery of Shiraz, Iran. The experiment was conducted as split-split-plot in time based on completely randomized design with three replications. Various weights of biochar and active carbon (0, 20, 40, 60, 80, and 100 g kg−1) were assigned to main plots, whereas particle sizes (1–2 mm for biochar and 0.05–2.05 mm for active carbon) were assigned to subplots, and the effects were monitored weekly. Biodegradation constant (K) for active carbon ranged from 0.0139 to 0.0328 day−1, whereas it varied from 0.0145 to 0.0369 day−1 for biochar. Also, this value was 0.0088 for control soil. Half-life for control soil was 78.7 days, which decreased as result of applying various size and weights of active carbon (21.13–49.8 days) and biochar (18.7–47.8 days). Thus, the technology used in this study provides a cheap, efficient, and environment friendly method which may be successfully applied in gasoil-polluted soils to enhance the environment for plants and soil microorganisms.

Devi S.P., Jha D.K.

Koshlaf E., Shahsavari E., Haleyur N., Osborn A.M., Ball A.S.

Hydrocarbon degradation is usually measured in laboratories under controlled conditions to establish the likely efficacy of a bioremediation process in the field. The present study used greenhouse-based bioremediation to investigate the effects of natural attenuation (NA) and necrophytoremediation (addition of pea straw (PS)) on hydrocarbon degradation, toxicity and the associated bacterial community structure and composition in diesel-contaminated soil. A significant reduction in total petroleum hydrocarbon (TPH) concentration was detected in both treatments; however, PS-treated soil showed more rapid degradation (87%) after 5 months together with a significant reduction in soil toxicity (EC50 = 91 mg diesel/kg). Quantitative PCR analysis revealed an increase in the number of 16S rRNA and alkB genes in the PS-amended soil. Substantial shifts in soil bacterial community were observed during the bioremediation, including an increased abundance of numerous hydrocarbon-degrading bacteria. The bacterial community shifted from dominance by Alphaproteobacteria and Gammaproteobacteria in the original soil to Actinobacteria during bioremediation. The dominance of two genera of bacteria, Sphingobacteria and Betaproteobacteria, in both NA- and PS-treated soil demonstrated changes occurring within the soil bacterial community through the incubation period. Additionally, pea straw itself was found to harbour a diverse hydrocarbonoclastic community including Luteimonas, Achromobacter, Sphingomonas, Rhodococcus and Microbacterium. At the end of the experiment, PS-amended soil exhibited reduced ecotoxicity and increased bacterial diversity as compared with the NA-treated soil. These findings suggest the rapid growth of species stimulated by the bioremediation treatment and strong selection for bacteria capable of degrading petroleum hydrocarbons during necrophytoremediation.

Park B.S., Erdner D.L., Bacosa H.P., Liu Z., Buskey E.J.

l A Prorocentrum dinoflagellate bloom occurred after the Texas City “Y” oil spill. l Altered bacterial communities due to oil exposure enhanced the growth of P. texanum . l Oil-degrading bacteria were isolated from the samples collected after the Texas City “Y” oil spill. l These isolates stimulated the growth of dinoflagellates through releasing unknown substances. l This study newly suggests that oil-degrading bacteria can play an important role in the formation of a dinoflagellate bloom after an oil spill. The association between phytoplankton blooms and oil spills is still controversial despite numerous studies. Surprisingly, to date, there have been no studies on the effect of bacterial communities (BCs) exposed to crude oil on phytoplankton growth, even though crude oil changes BCs, which can then affect phytoplankton growth and species composition. Co-culture with crude oil-exposed BCs significantly stimulated the growth of Prorocentrum texanum in the laboratory. To gain more direct evidence, oil-degrading bacteria from oil-contaminated sediment collected after the Texas City “Y” oil spill were isolated, and changes in dinoflagellate growth when co-cultured with single bacterial isolates was investigated. The oil-degrading bacterial isolates significantly stimulated the growth of dinoflagellates (axenic and xenic cultures) through releasing growth-promoting substances. This study provides new evidence for the potential role of oil-degrading bacteria in the formation of phytoplankton blooms after an oil spill.