scholarly journals Potential of crude oil-degrading bacteria to co-resist heavy metals in soil

Author(s):  
S. Mustafa ◽  
A. Al-Douseri ◽  
K. Majki ◽  
E. Al-Saleh
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.


2016 ◽  
Vol 78 (11-2) ◽  
Author(s):  
Nur Hafizah Azizan ◽  
Kasing Ak Apun ◽  
Lesley Maurice Bilung ◽  
Micky Vincent ◽  
Hairul Azman Roslan ◽  
...  

Enrichment culture technique leads to the discovery of six presumptive TPH-degrading bacteria. Identification and characterization tests using morphological, biochemical and molecular techniques have successfully isolated Pseudomonas aeruginosa (UMAS1PF), Serratia marcescens (UMAS2SF) and Klebsiella spp. (UMAS3KF). All strains were able to use crude oil as sole carbon and energy source for their growth since they were able to survive in Minimal Salt medium supplemented with 1% (v/v) crude oil. Growth study showed that they produced the highest cell counts on the third or fourth day by 108 – 1011 CFU/ml. Six artificial consortium inoculums have been produced from the growth study. Gas chromatography analysis showed that all isolates had the ability to degrade aliphatic hydrocarbon with 100% degradation of nC19 – C24. Among the isolates, UMAS2SF was the best and fastest n-alkane degrader with degradation percentage between 55 – 90% of n-C14 – C18 in 14 days. This was followed by UMAS1PF and UMAS3KF with 11 – 82% and 1.3% degradation, respectively. Enhancement study showed that plot with inoculum and NPK addition successfully enhanced n-alkane degradation. Plot A2:B3+NPK degraded n-alkane the fastest followed by plot treated by C+NPK, A1:B2, B+NPK and A2:B3. Result showed that UMAS1PF was the best PAHs degrader as most of the high molecular weight PAHs was degraded. In the enhancement study, the plot amended with A2:B3 showed the highest PAHs degradation, followed by plots A1:B2, A3:B1:C2 and A1:C3 that was assigned as the third, fourth and fifth best in mineralizing PAHs, respectively.


Author(s):  
Tudararo-Aherobo Laurelta ◽  
Okotie Sylvester ◽  
Ataikiru Tega ◽  
Stephen Avwerosuoghene

Aim: The research aims to assess the biodegradability of crude oil polluted aquatic environment using indigenous hydrocarbon degrading bacteria. Place and Duration of Study: The research was conducted in the Environmental Management and Toxicology Laboratory, Federal University of Petroleum Resources, Effurun, Delta State. Methodology: Hydrocarbon degrading bacteria species were isolated from hydrocarbon contaminated soils, screened and used for the degradation of crude oil. 5% and 10% crude oil were used to spike the test microcosm. Physicochemical parameters such as, pH, turbidity, total petroleum hydrocarbon (TPH) and bacterial counts of the bioremediated crude oil contaminated water were monitored on Day 0, 7 and 14. The biodegradation of the crude oil was done with the various bacteria isolates singly and as a consortium. Standard methods of American Public Health Association (APHA) and American Society for Testing and Materials (ASTM) were used for the analysis. Results: The isolates identified and used for the biodegradation process were, Azomonas sp., Enterococcus sp., Klebsiella sp. and Rhizobactersp. On day 14, in the microcosms with 5% crude oil contamination, Azomonas sp. recorded the highest turbidity reading of 328 ± 2.0 NTU, while Rhizobacter sp. recorded the least with 57.67 ± 0.58 NTU. The bacterial countswere between 7.68 ± 0.002 CFU/ml and 8.05 ± 0.10x 107 CFU/ml for Rhizobacter sp. and Azomonas sp. respectively.The crude oil was also degraded most in the microcosm treated with Azomonas sp. with a residual TPH concentration of 0.0013± 0.005 mg/l.For the 10% crude oil contaminated microcosms, TPH was also biodegraded most by Azomonas sp. with a value of 0.0026 ± 0.002mg/l. Turbidity readings were between 82 ± 1.0 NTU and 375.33 ± 0.57 NTU for Rhizobacter sp. and Azomonas sp. respectively. Bacterial counts were between (7.71± 0.012)x 107CFU/ml – (8.13± 0.001) x 107CFU/ml for Rhizobacter sp. and Azomonassp. respectively. Conclusion:There wasincreased microbial countsand decrease of residual crude oil concentration, indicating degradation of the crude oil by all the isolates.However, Azomonas sp. recorded the highest TPH degradation for both the 5% and 10% crude oil contaminated microcosms.Thus, findings from the research indicate that hydrocarbon degrading bacteria exist in our environment and can be used in the remediation of aquatic polluted environment.


2019 ◽  
Vol 4 (1) ◽  
pp. 79-88
Author(s):  
Evi Octaviany ◽  
Suharjono Suharjono ◽  
Irfan Mustafa

A commercial saponin as biosurfactant can reduce the surface tension of water and increase of hydrocarbon degradation. However, this saponin can be toxic to some hydrocarbonoclastic bac-teria. This study aimed to obtain bacterial isolates that were tolerant and incapable to degrade saponin, and to identify them based on 16S rDNA sequence. Bacteria were isolated from petroleum contaminated soil in Wonocolo Village, Bojonegoro Regency, East Java, Indonesia. The soil samples were acclimated using Bushnell-Haas (BH) broth with 0.5% crude oil at room temperature for 3 weeks. The culture was spread onto BH agar incubated at 30°C for 7 days. The first screened, isolates were grown in nutrient broth with addition of sap-onin 0%, 8%, and 12% (v/v) then incubated at 30°C for three days. The bacterial cell density was measured using a spectrophotometer. Second screened, the isolates were grown on BH broth with addition of 0.5% saponin as a sole carbon source, and their cell densities were measured. The selected isolates were identified based on 16S rDNA sequences. Among 34 bacterial isolates, nine isolates were tol-erant to 12% saponin. Three bacterial isolates IHT1.3, IHT1.5, and IHT3.24 tolerant to high concentration of saponin and did not use this substance as growth nutrition. The IHT1.3, IHT1.5, and IHT3.24 isolates were identified as Ochrobactrum pseudogrignonense (99% similarity), Pseudomonas mendocina (99%), and Ochrobactrum pi-tuitosum; (97%), respectively. Those three selected isolates are good candidates as hydrocarbon-degrading bacteria to bioremediation of soil contaminated crude oil. However, the combined activity of bacteria and saponin to degrade hydrocarbon needs further study. 


Author(s):  
Muibat Fashola

Introduction: Indiscriminate dumping of spent oils enriched with heavy metals has led to increase in heavy metals load in the soil. Heavy metals exert toxic effects on biodegradation of organic pollutant in cocontaminated soil and there is need to find suitable strategies for their removal. Aim: The aim of this study was to assess the heavy metals resistance capability of indigenous Bacillus species in hydrocarbon polluted soil to nickel (Ni), Cadmium (Cd), Lead (Pb) and Chromium (Cr). Materials and Methods: Heavy metal tolerant bacteria were isolated from hydrocarbon polluted soil using Luria-Berthani agar supplemented with the respective metals and spread plate techniques. The isolates were putatively identified on the basis of their colonial morphology and biochemical characteristics and their antibiotics susceptibility pattern were evaluated using disc diffusion method. Results: The maximum tolerable concentration (MTC) of the four heavy metals to the selected isolates was 2 mM. Four bacteria isolates able to withstand the MTC were putatively identified as Bacillus subtilis, Bacillus megaterium, Bacillus laterosporus and Bacillus polymyxa. Out of the four Bacillus species, only B. laterosporus did not show multiple tolerance to the tested antibiotics which show that there is correlation between heavy metal tolerance and antibiotics resistance by the isolates. Conclusion: Multiple heavy metal tolerance Bacillus spp. were isolated from crude oil polluted soil. These bacteria could be suitable agents for bioaugmentation of hydrocarbon polluted soil co-contaminated with heavy metals.


2019 ◽  
Vol 10 (4) ◽  
pp. 3789-3795 ◽  
Author(s):  
Neeta Bhagat ◽  
Pranita Roy ◽  
Sohini Singh ◽  
Tanu Allen

Increasing soil pollution all over the world has instigated global concerns as enormous quantities of toxic chemicals and heavy metals like cadmium, lead, mercury, petrochemicals, insecticides, polycyclic aromatic hydrocarbons (PAHs) and chlorophenols are finding their way into the environment, affecting the land and soil, causing soil pollution and thus posing a threat and menace to health and well- being of people and ecosystem. The ubiquitous dissemination, low bioavailability, high perseverance of contaminants like poly-hydrocarbon and metals in soil have the potentially destructive effects to human health, envisages to study the biodegradation of PAHs (polycyclic aromatic hydrocarbons) and PACs (polycyclic aromatic compounds). The diversity of micro-organisms that diminish the PAHs/PACs can be utilized in the advancement of bioremediation techniques. The role of metal-tolerant, (PAH)-degrading bacteria helps in the biodegradation of organic compounds at miscellaneous polluted sites. The isolation of (PAHs)-degrading bacteria from contaminated soil samples collected from garages and petrol pumps of Delhi and NCR region was carried out in the present study.  Also, the bacterial samples were tested for the tolerance towards 4 heavy metals- arsenic (As), lead (Pb), cadmium (Cd), and mercury (Hg). Morphological studies and biochemical tests were conducted to find the genera of the bacterial samples. The study indicates that hydrocarbons were degraded by the isolates P1, P2, P4, P5, P5*, G1, G3. These isolates were also found to be tolerant at a high concentration of metals (Arsenic, Cadmium, Mercury, and Lead) as minimum inhibitory concentration (MIC) was also calculated. Antibiotic susceptibility of the isolates was tested against various antibiotics. Thus the study suggests that the isolates identified as Pseudomonas aeruginosa, Acinetobacter baumanii, and Klebsiella pneumoniae are not only PAH-degrading but metal-tolerant and antibiotic-resistant too and are of immense potential for bioremediation of contaminated soils.


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

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