scholarly journals Isolation and Characterization of Oil-Degrading Enterobacter sp. from Naturally Hydrocarbon-Contaminated Soils and Their Potential Use against the Bioremediation of Crude Oil

2021 ◽  
Vol 11 (8) ◽  
pp. 3504
Author(s):  
Mukkaram Ejaz ◽  
Baowei Zhao ◽  
Xiukang Wang ◽  
Safdar Bashir ◽  
Fasih Ullah Haider ◽  
...  

The contamination of crude oil in soil matrices is a persistent problem with negative repercussions because of the recalcitrant, hazardous, and mutagenic properties of its constituents. To mitigate the effect of crude oil contamination in soil, the use of microorganisms is a cheap and feasible option. In the current study, bacterial species from numerous polluted oil field surfaces were isolated and examined for their ability to degrade crude oil. Random soil samples polluted with hydrocarbons were collected and various bacterial isolates were isolated. Results revealed that 40% of total isolates had potential use for hydrocarbon biodegradation, the synthesis of exopolysaccharides and the solubilization of phosphorous. Following isolation and characterization to degrade crude oil, a pot trial was conducted using maize inoculated with the four best strains—i.e., S1 (PMEL-63), S2 (PMEL-67), S3 (PMEL-80), and S4 (PMEL-79)—in artificially hydrocarbon-polluted soil with concentrations of crude oil of 0, 1000, and 2000 ppm. Results revealed that S4 (PMEL-79) had significant potential to degrade hydrocarbon in polluted soils. The root length, shoot length, and fresh biomass of maize were increased by 65%, 45%, and 98%, respectively, in pots inoculated with S4 (PMEL-79) Enterobacter cloacae subsp., whereas the lowest root length was observed where no strain was added and the concentration of crude oil was at maximum. Moreover, S4 (PMEL-79) Enterobacter cloacae subsp. was found to be the most effective strain in degrading crude oil and increasing maize growth under polluted soil conditions. It was concluded that the isolation of microorganisms from oil-contaminated sites should be considered in order to identify the most effective microbial consortium for the biodegradation of naturally hydrocarbon-contaminated soils.

2017 ◽  
Vol 42 (3) ◽  
pp. 1149-1156 ◽  
Author(s):  
Ali Ebadi ◽  
Mohsen Olamaee ◽  
Nayer Azam Khoshkholgh Sima ◽  
Reza Ghorbani Nasrabadi ◽  
Maryam Hashemi

2018 ◽  
Vol 17 ◽  
pp. 104-109 ◽  
Author(s):  
Adnan B. Al-Hawash ◽  
Jawadayn T. Alkooranee ◽  
Hayder A. Abbood ◽  
Jialong Zhang ◽  
Jin Sun ◽  
...  

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Boutheina Gargouri ◽  
Najla Mhiri ◽  
Fatma Karray ◽  
Fathi Aloui ◽  
Sami Sayadi

Two yeast strains are enriched and isolated from industrial refinery wastewater. These strains were observed for their ability to utilize several classes of petroleum hydrocarbons substrates, such asn-alkanes and aromatic hydrocarbons as a sole carbon source. Phylogenetic analysis based on the D1/D2 variable domain and the ITS-region sequences indicated that strains HC1 and HC4 were members of the generaCandidaandTrichosporon, respectively. The mechanism of hydrocarbon uptaking by yeast,Candida,andTrichosporonhas been studied by means of the kinetic analysis of hydrocarbons-degrading yeasts growth and substrate assimilation. Biodegradation capacity and biomass quantity were daily measured during twelve days by gravimetric analysis and gas chromatography coupled with mass spectrometry techniques. Removal ofn-alkanes indicated a strong ability of hydrocarbon biodegradation by the isolated yeast strains. These two strains grew on long-chainn-alkane, diesel oil, and crude oil but failed to grow on short-chainn-alkane and aromatic hydrocarbons. Growth measurement attributes of the isolates, usingn-hexadecane, diesel oil, and crude oil as substrates, showed that strain HC1 had better degradation for hydrocarbon substrates than strain HC4. In conclusion, these yeast strains can be useful for the bioremediation process and decreasing petroleum pollution in wastewater contaminated with petroleum hydrocarbons.


Author(s):  
D. N. Ogbonna ◽  
S. I. Douglas ◽  
V. G. Awari

Many substances known to have toxic properties are regularly introduced into the environment through human activity. These substances which include hydrocarbons range in degree of toxicity and danger to human health. Frequent oil spills incidents have become a problem to ecological protection efforts. Conventional methods to remove, reduce or mitigate toxic substances introduced into soil via anthropogenic activities suffer setbacks due to the level of risk involved but bioremediation offers an alternative method to detoxify contaminants especially if the soil conditions are amended with organic nutrients or growth enhancing co-substrates. This study was therefore aimed characterizing hydrocarbon utilizing microorganisms associated with crude oil contaminated soils. Soils were obtained from the Rivers State University Agricultural farm contaminated deliberately with crude oil and allowed for 21 days to mimic the natural polluted soil. Sample collection and analyses were carried out according to standard microbiological procedures while characterization of the isolates was done using genomic studies. The results of microbial counts obtained from the soil samples for total heterotrophic bacteria ranged from 2.10 x108 to 2.58 x108 cfu/g, Total heterotrophic fungi had 1.6 x105 to 2.0 x105 cfu/g while the hydrocarbon utilizing bacteria ranged from 8.0 x103 to 5.0 x104 cfu/g and total hydrocarbon utilizing fungi ranged from 9.0 x103 to 7.0 x104 cfu/g in the contaminated soil. Five hydrocarbon utilizing bacterial species were identified as Staphylococcus saprophyticus, Bacillus amyloliquefaciens, Pseudomonas aeruginosa, Comamonas testosteroni and Chryseobacterium cucumeris while five hydrocarbon utilizing fungal species were identified as Penicillium citrinum, Penicillium brocae, Fusarium solani, Kodamaea ohmeri and Lentinus squarrosulus. Bacillus and Penicillium species were predominantly isolated from the soil. This may be due to the ability of the organisms to produce spores, which may shield them from the toxic effects of the hydrocarbons. Since these organisms are able to utilize crude oil as their sole carbon source. Hence, can be used for bioremediation of crude oil polluted environment.


2021 ◽  
Vol 11 (16) ◽  
pp. 7474
Author(s):  
Sazan Nariman Abdulhamid ◽  
Ahmed Mohammed Hasan ◽  
Shuokr Qarani Aziz

Currently, the primary source of pollution is crude oil production. Crude oil production has dramatic consequences for farmlands, communities, and in terms of the construction materials required for earthworks. The main aims of the present study were to reduce the level of pollution caused by oil production in the Khurmala soil and then reuse it as a construction material. Soil remediation using the solidification/stabilization method was applied in the field using Portland limestone cement (CEM II). The performance of using CEM II in the remediation process was then investigated in the laboratory by taking the natural, contaminated, and treated soils from the Khurmala site. Furthermore, the results of the soils were compared with their corresponding soil samples using ordinary Portland cement (OPC). The comparison was performed by investigating the physical, chemical, and mechanical properties of the soils. The discussion was supported using the scanning electron microscopy (SEM) results. Chemical and SEM results revealed that there were fourfold and tenfold decreases in the percentage of oil and grease using OPC and CEM II, respectively, confirming the higher performance of using CEM II over OPC. The values of the coefficient of permeability, shear strength parameters, and California bearing ratio of the treated soils were significantly improved, compared to those of the contaminated soils.


Author(s):  
O. Ule ◽  
D. N. Ogbonna ◽  
R. N. Okparanma ◽  
R. R. Nrior

Aim: To assess the Mycoremediation potential of Mucor racemosus and Aspergillus niger in open field crude oil contaminated soils in Rivers State, Nigeria.  Study Design: The study employs experimental design, statistical analysis of the data and interpretation. Place and Duration of Study: Rivers State University demonstration farmland in Nkpolu-Oroworukwo, Mile 3 Diobu area of Port Harcourt, was used for this study. The piece of land is situated at Longitude 4°48’18.50” N and Latitude 6ᵒ58’39.12” E measuring 5.4864 m x 5.1816 m with a total area of 28.4283 square meter. Mycoremediation process monitoring lasted for 56 days, analyses were carried out weekly at 7 days’ interval. Methodology: Five (5) experimental plots were employed using a Randomized Block Design each having dimensions of 100 x 50 x 30 cm (Length x Breadth x Height) and were formed and mapped out on agricultural soil, each plot was contaminated with 22122.25g of Crude Oil except Control 1 and left fallow for 6 days after contamination for proper contamination and exposure to natural environmental factors to mimic crude oil spill site. On the seventh day bio-augmentation process commenced using two (2) fungal isolates namely Aspergillus niger [Asp] and Mucor rasemosus [Muc]). Two (2) control plots (P1: Uncontaminated and unamended soil - CTRL 1 US) and P2: Crude Oil contaminated but unamended soil - CTRL 2 CS); P3 = P5 were contaminated and amended/bioaugmented (P3: CS+Asp, P4: CS+Muc, P5: CS+Asp+Muc respectively. Soil profile before and after contamination was assayed while parameters like Temperature, pH, Nitrogen, Phosphorus, Potassium and Total Petroleum Hydrocarbon (TPH) contents were monitored throughout the experimental period. Microbial analyses such as Total Heterotrophic Bacteria (THB), Total Heterotrophic Fungi (THF), Hydrocarbon Utilizing Bacteria (HUB) and Hydrocarbon Utilizing Fungi (HUF) were recorded. Bioremediation efficiency was estimated from percentage (%) reduction of Total Petroleum Hydrocarbon (TPH) from day 1 to the residual hydrocarbon at day 56 of bio- augmentation/ biostimulation plots with the control. Results: Results revealed actual amount of remediated hydrocarbon and % Bioremediation Efficiency at 56 days in the different treatment plots (initial TPH contamination value of 8729.00mg/kg) in a decreasing order as follows: CS+Muc (8599.19mg/kg; 33.66%) > CS+Asp+Muc (8357.31mg/kg; 33.04%) > CS+Asp (8341.58mg/kg; 32.98%) > CTRL 2 -CS (Polluted soil without amendment) (81.06mg/kg; 0.32%). Microbiological results After fifty-six (56) days of bioremediation monitoring; %HUB were as follows; CS+Asp+Muc (45.30%) > CS+Asp (40.32%) > CS+Muc (35.01%) > CTRL 2 –CS (30.43%) > CTRL 1 – US (0%). These results indicate that the presence of the contaminated crude oil stimulated and sustained the growth of Hydrocarbon Utilizing Bacteria (HUB) in the contaminated plots (P2 - P3); more so, the higher growth in the enhanced bio-augmented plots (P3 – P5) shows the positive impact of fungal bio-augmentation in bioremediation of crude oil polluted soil. It was further observed that treatment plots with higher HUB or HUF had higher percentage (%) bioremediation efficiency; that is, the higher the sustained HUB and HUF population, the higher the %Bioremediation process. Hydrocarbon Utilizing Bacteria (Log10 CFU/g): CS+Asp (4.20) (Day 35) > CS+Muc+Asp (4.18) (Day 35) > CS+Muc (4.08) (Day 28) > CTRL 2 – CS (3.95) (Day 21) > CTRL 1 – US (3.78) (Day 35). (Fig. 3). Hydrocarbon Utilizing Fungi (Log10 CFU/g): CS+Asp (4.68) (Day 35) > CS+Muc+Asp (4.58) (Day 35) > CS+Muc (4.48) (Day 35) > CTRL 2 – CS (4.23) (Day 21) > CTRL 1 – US (2.85) (Day 42). Conclusion: Study showed that bioremediation of crude oil-contaminated soils with Bioaugmenting fungus singly may be more effective than combination with others depending on the type of substrate used, nature of the hydrocarbon utilizing organism and environmental conditions prevalent as seen in Mucor racemosus having higher bioremediation potential than when combined with Aspergillus niger. Notably, Hydrocarbon Utlilizing Bacteria (HUB) and Hydrocarbon Utilizing Fungi (HUF) which are the key players in Bioremediation has its peak count value on Day 35, this confers that nutrient renewal on bioremediation site should be at interval of 35 days for continuous effective bioremediation of hydrocarbon pollutants. It is therefore recommended that single microbes of high bioremediation potential could be used since its more effective than consortium of many hydrocarbon utilizing microbes. Also, nutrient or bio-augmenting microbes’ renewal on bioremediation site should be at an interval of 35 days for continuous effective bioremediation of hydrocarbon pollutants.


Fine Focus ◽  
2016 ◽  
Vol 2 (1) ◽  
pp. 7-14
Author(s):  
Chioma Blaise Chikere ◽  
Chinyere Augusta Ajuzieogu ◽  
Michael Chukwugoziem Miller

Hydrocarbon utilizers are expected to be indigenous in crude-oil polluted environments. The isolation and characterization of hydrocarbon utilizers is often a key strategy in bioremediation of hydrocarbon-polluted environments. In this study, crude-oil polluted soil samples from Obagi town, Onelga, Rivers state were enumerated and characterized for putative hydrocarbon utilizing bacterial populations. Biochemical characterization identified five bacterial species representative of five genera: Bacillus, Pseudomonas, Acinetobacter, Micrococcus and Staphylococcus. Amongst the genera of bacteria isolated, Bacillus had the highest frequency of occurrence (40%). The mean count of total heterotrophic bacteria was 1.7 X 107 cfu/g, while hydrocarbon utilizing bacteria (HUB) count mean density was 1.0 X 107 cfu/g for the three soil samples. Statistical analyses revealed no significant difference at p>0.05 between Total Heterotrophic Bacterial (THB) and Hydrocarbon Utilizing Bacterial (HUB) counts, suggesting that most of the bacteria present in the sampled sites were hydrocarbon utilizers. Findings from this study suggest the presence of indigenous putative hydrocarbon utilizing bacteria in the crude-oil polluted soil of Obagi town. Hence, a promising potential exists for future bioremediation studies on the site.


2021 ◽  
Vol 9 (6) ◽  
pp. 1200
Author(s):  
Gareth E. Thomas ◽  
Jan L. Brant ◽  
Pablo Campo ◽  
Dave R. Clark ◽  
Frederic Coulon ◽  
...  

This study evaluated the effects of three commercial dispersants (Finasol OSR 52, Slickgone NS, Superdispersant 25) and three biosurfactants (rhamnolipid, trehalolipid, sophorolipid) in crude-oil seawater microcosms. We analysed the crucial early bacterial response (1 and 3 days). In contrast, most analyses miss this key period and instead focus on later time points after oil and dispersant addition. By focusing on the early stage, we show that dispersants and biosurfactants, which reduce the interfacial surface tension of oil and water, significantly increase the abundance of hydrocarbon-degrading bacteria, and the rate of hydrocarbon biodegradation, within 24 h. A succession of obligate hydrocarbonoclastic bacteria (OHCB), driven by metabolite niche partitioning, is demonstrated. Importantly, this succession has revealed how the OHCB Oleispira, hitherto considered to be a psychrophile, can dominate in the early stages of oil-spill response (1 and 3 days), outcompeting all other OHCB, at the relatively high temperature of 16 °C. Additionally, we demonstrate how some dispersants or biosurfactants can select for specific bacterial genera, especially the biosurfactant rhamnolipid, which appears to provide an advantageous compatibility with Pseudomonas, a genus in which some species synthesize rhamnolipid in the presence of hydrocarbons.


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