1
|
Hemamali EH, Weerasinghe LP, Tanaka H, Kurisu G, Perera IC. LcaR: a regulatory switch from Pseudomonas aeruginosa for bioengineering alkane degrading bacteria. Biodegradation 2022; 33:117-133. [PMID: 34989928 DOI: 10.1007/s10532-021-09970-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Accepted: 12/22/2021] [Indexed: 11/26/2022]
Abstract
Application of genetically engineered bacterial strains for biodegradation of hydrocarbons is a sustainable solution for treating pollutants as well as in industrial applications. However, the process of bioengineering should be carefully carried out to optimize the output. Investigation of regulatory genes for bioengineering is essential for developing synthetic circuits for effective biocatalysts. Here we focus on LcaR, a putative transcriptional regulator affecting the expression of alkB2 and lcaR operon that has a high potential to become a tool in designing such pathways. Four LcaR dimers bind specifically to the upstream regulatory region where divergent promoters of alkB2 and lcaR genes are located with high affinity at a Kd of 0.94 ± 0.17 nM and a Hill coefficient is 1.7 ± 0.3 demonstrating cooperativity in the association. Ligand binding alters the conformation of LcaR, which releases the regulator from its cognate DNA. Tetradecanal and hexadecanal act as natural ligands of LcaR with an IC50 values of 3.96 ± 0.59 µg/ml and 0.68 ± 0.21 µg/ml, respectively. The structure and function of transcription factors homologous to LcaR have not been characterized to date. This study provides insight into regulatory mechanisms of alkane degradation with a direction towards potential applications in bioengineering for bioremediation and industrial applications.
Collapse
Affiliation(s)
- Erandika H Hemamali
- Synthetic Biology Laboratory, Department of Zoology and Environment Sciences, Faculty of Science, University of Colombo, Colombo, Sri Lanka
| | - Laksiri P Weerasinghe
- Department of Chemistry, Faculty of Applied Science, University of Sri Jayewardenapura, Colombo, Sri Lanka
| | - Hideaki Tanaka
- Institute for Protein Research, Osaka University, Osaka, Japan
| | - Genji Kurisu
- Institute for Protein Research, Osaka University, Osaka, Japan
| | - Inoka C Perera
- Synthetic Biology Laboratory, Department of Zoology and Environment Sciences, Faculty of Science, University of Colombo, Colombo, Sri Lanka.
| |
Collapse
|
2
|
Martins VR, Freitas CJB, Castro AR, Silva RM, Gudiña EJ, Sequeira JC, Salvador AF, Pereira MA, Cavaleiro AJ. Corksorb Enhances Alkane Degradation by Hydrocarbonoclastic Bacteria. Front Microbiol 2021; 12:618270. [PMID: 34489874 PMCID: PMC8417381 DOI: 10.3389/fmicb.2021.618270] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 07/26/2021] [Indexed: 11/13/2022] Open
Abstract
Biosorbent materials are effective in the removal of spilled oil from water, but their effect on hydrocarbonoclastic bacteria is not known. Here, we show that corksorb, a cork-based biosorbent, enhances growth and alkane degradation by Rhodococcus opacus B4 (Ro) and Alcanivorax borkumensis SK2 (Ab). Ro and Ab degraded 96 ± 1% and 72 ± 2%, respectively, of a mixture of n-alkanes (2 g L–1) in the presence of corksorb. These values represent an increase of 6 and 24%, respectively, relative to the assays without corksorb. The biosorbent also increased the growth of Ab by 51%. However, no significant changes were detected in the expression of genes involved in alkane uptake and degradation in the presence of corksorb relative to the control without the biosorbent. Nevertheless, transcriptomics analysis revealed an increased expression of rRNA and tRNA coding genes, which confirms the higher metabolic activity of Ab in the presence of corksorb. The effect of corksorb is not related to the release of soluble stimulating compounds, but rather to the presence of the biosorbent, which was shown to be essential. Indeed, scanning electron microscopy images and downregulation of pili formation coding genes, which are involved in cell mobility, suggest that cell attachment on corksorb is a determinant for the improved activity. Furthermore, the existence of native alkane-degrading bacteria in corksorb was revealed, which may assist in situ bioremediation. Hence, the use of corksorb in marine oil spills may induce a combined effect of sorption and stimulated biodegradation, with high potential for enhancing in situ bioremediation processes.
Collapse
Affiliation(s)
- Valdo R Martins
- CEB - Centre of Biological Engineering, University of Minho, Braga, Portugal
| | - Carlos J B Freitas
- CEB - Centre of Biological Engineering, University of Minho, Braga, Portugal
| | - A Rita Castro
- CEB - Centre of Biological Engineering, University of Minho, Braga, Portugal
| | - Rita M Silva
- CEB - Centre of Biological Engineering, University of Minho, Braga, Portugal
| | - Eduardo J Gudiña
- CEB - Centre of Biological Engineering, University of Minho, Braga, Portugal
| | - João C Sequeira
- CEB - Centre of Biological Engineering, University of Minho, Braga, Portugal
| | - Andreia F Salvador
- CEB - Centre of Biological Engineering, University of Minho, Braga, Portugal
| | - M Alcina Pereira
- CEB - Centre of Biological Engineering, University of Minho, Braga, Portugal
| | - Ana J Cavaleiro
- CEB - Centre of Biological Engineering, University of Minho, Braga, Portugal
| |
Collapse
|
3
|
Galitskaya P, Biktasheva L, Kuryntseva P, Selivanovskaya S. Response of soil bacterial communities to high petroleum content in the absence of remediation procedures. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:9610-9627. [PMID: 33155112 DOI: 10.1007/s11356-020-11290-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 10/18/2020] [Indexed: 06/11/2023]
Abstract
Oil spills are events that frequently lead to petroleum pollution. This pollution may cause stress to microbial communities, which require long adaption periods. Soil petroleum pollution is currently considered one of the most serious environmental problems. In the present work, processes occurring in the bacterial communities of three soil samples with different physicochemical characteristics, artificially polluted with 12% of crude oil, were investigated in 120-day laboratory experiment. It was found that the total petroleum hydrocarbon content did not decrease during this time; however, the proportion of petroleum fractions was altered. Petroleum pollution led to a short-term decrease in the bacterial 16S rRNA gene copy number. On the basis of amplicon sequencing analysis, it was concluded that bacterial community successions were similar in the three soils investigated. Thus, the phyla Actinobacteria and Proteobacteria and candidate TM7 phylum (Saccaribacteria) were predominant with relative abundances ranging from 35 to 58%, 25 to 30%, and 15 to 35% in different samples, respectively. The predominant operational taxonomic units (OTUs) after pollution belonged to the genera Rhodococcus and Mycobacterium, families Nocardioidaceae and Sinobacteraceae, and candidate class ТМ7-3. Genes from the alkIII group encoding monoxygenases were the most abundant compared with other catabolic genes from the alkI, alkII, GN-PAH, and GP-PAH groups, and their copy number significantly increased after pollution. The copy numbers of expressed genes involved in the horizontal transfer of catabolic genes, FlgC, TraG, and OmpF, also increased after pollution by 11-33, 16-63, and 11-71 times, respectively. The bacterial community structure after a high level of petroleum pollution changed because of proliferation of the cells that initially were able to decompose hydrocarbons, and in the second place, because proliferation of the cells that received these catabolic genes through horizontal transfer.
Collapse
Affiliation(s)
- Polina Galitskaya
- Institute of Environmental Sciences, Kazan Federal University, Kazan, Russia, 420008
| | - Liliya Biktasheva
- Institute of Environmental Sciences, Kazan Federal University, Kazan, Russia, 420008.
| | - Polina Kuryntseva
- Institute of Environmental Sciences, Kazan Federal University, Kazan, Russia, 420008
| | | |
Collapse
|
4
|
Domingues PM, Oliveira V, Serafim LS, Gomes NCM, Cunha Â. Biosurfactant Production in Sub-Oxic Conditions Detected in Hydrocarbon-Degrading Isolates from Marine and Estuarine Sediments. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17051746. [PMID: 32156011 PMCID: PMC7084516 DOI: 10.3390/ijerph17051746] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 03/02/2020] [Accepted: 03/04/2020] [Indexed: 11/16/2022]
Abstract
Hydrocarbon bioremediation in anoxic sediment layers is still challenging not only because it involves metabolic pathways with lower energy yields but also because the production of biosurfactants that contribute to the dispersion of the pollutant is limited by oxygen availability. This work aims at screening populations of culturable hydrocarbonoclastic and biosurfactant (BSF) producing bacteria from deep sub-seafloor sediments (mud volcanos from Gulf of Cadiz) and estuarine sub-surface sediments (Ria de Aveiro) for strains with potential to operate in sub-oxic conditions. Isolates were retrieved from anaerobic selective cultures in which crude oil was provided as sole carbon source and different supplements were provided as electron acceptors. Twelve representative isolates were obtained from selective cultures with deep-sea and estuary sediments, six from each. These were identified by sequencing of 16S rRNA gene fragments belonging to Pseudomonas, Bacillus, Ochrobactrum, Brevundimonas, Psychrobacter, Staphylococcus, Marinobacter and Curtobacterium genera. BSF production by the isolates was tested by atomized oil assay, surface tension measurement and determination of the emulsification index. All isolates were able to produce BSFs under aerobic and anaerobic conditions, except for isolate DS27 which only produced BSF under aerobic conditions. These isolates presented potential to be applied in bioremediation or microbial enhanced oil recovery strategies under conditions of oxygen limitation. For the first time, members of Ochrobactrum, Brevundimonas, Psychrobacter, Staphylococcus, Marinobacter and Curtobacterium genera are described as anaerobic producers of BSFs.
Collapse
Affiliation(s)
- Patrícia M. Domingues
- Department of Chemistry and CICECO, University of Aveiro, 3810-193 Aveiro, Portugal
- Department of Biology and CESAM, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Vanessa Oliveira
- Department of Biology and CESAM, University of Aveiro, 3810-193 Aveiro, Portugal
| | | | - Newton C. M. Gomes
- Department of Biology and CESAM, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Ângela Cunha
- Department of Biology and CESAM, University of Aveiro, 3810-193 Aveiro, Portugal
- Correspondence: ; Tel.: +351-234-370-784
| |
Collapse
|
5
|
Diversity and degradative capabilities of bacteria and fungi isolated from oil-contaminated and hydrocarbon-polluted soils in Kazakhstan. Appl Microbiol Biotechnol 2019; 103:7261-7274. [PMID: 31346684 DOI: 10.1007/s00253-019-10032-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 07/09/2019] [Accepted: 07/13/2019] [Indexed: 01/03/2023]
Abstract
Bacteria and fungi were isolated from eight different soil samples from different regions in Kazakhstan contaminated with oil or salt or aromatic compounds. For the isolation of the organisms, we used, on the one hand, typical hydrocarbons such as the well utilizable aliphatic alkane tetradecane, the hardly degradable multiple-branched alkane pristane, and the biaromatic compound biphenyl as enrichment substrates. On the other hand, we also used oxygenated derivatives of alicyclic and monoaromatic hydrocarbons, such as cyclohexanone and p-tert-amylphenol, which are known as problematic pollutants. Seventy-nine bacterial and fungal strains were isolated, and 32 of them that were clearly able to metabolize some of these substrates, as tested by HPLC-UV/Vis and GC-MS analyses, were characterized taxonomically by DNA sequencing. Sixty-two percent of the 32 isolated strains from 14 different genera belong to well-described hydrocarbon degraders like some Rhodococci as well as Acinetobacter, Pseudomonas, Fusarium, Candida, and Yarrowia species. However, species of the bacterial genus Curtobacterium, the yeast genera Lodderomyces and Pseudozyma, as well as the filamentous fungal genera Purpureocillium and Sarocladium, which have rarely been described as hydrocarbon degrading, were isolated and shown to be efficient tetradecane degraders, mostly via monoterminal oxidation. Pristane was exclusively degraded by Rhodococcus isolates. Candida parapsilosis, Fusarium oxysporum, Fusarium solani, and Rhodotorula mucilaginosa degraded cyclohexanone, and in doing so accumulate ε-caprolactone or hexanedioic acid as metabolites. Biphenyl was transformed by Pseudomonas/Stenotrophomonas isolates. When p-tert-amylphenol was used as growth substrate, none of the isolated strains were able to use it.
Collapse
|
6
|
Anyasi RO, Atagana HI, Sutherland R. Identification and characterization of PAH-degrading endophytes isolated from plants growing around a sludge dam. INTERNATIONAL JOURNAL OF PHYTOREMEDIATION 2019; 21:672-682. [PMID: 30942084 DOI: 10.1080/15226514.2018.1556585] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
This study involved the isolation of bacteria endophytes with PAH-degrading ability from plants growing around a sludge dam. A total of 19 distinct isolates that were morphologically identified were isolated from 4 species of plant with a follow-up confirmatory identification using the molecular technique. Polymerase chain reaction (PCR) of the 16S rRNA gene with specific primers (16S-27F PCR and 16S-1491R PCR) was carried out. The sequence of the PCR products was carried out, compared with similar nucleotides available in GenBank. Results of the phylogenetic analysis of the isolates indicated their belonging to 4 different clades including Proteobacteria, Actinobacteria, Cyanobacteria, and Firmicutes. These were related to the genera Bacillus, Pseudomonas, Terribacillus, Virgibacillus, Stenotrophomonas, Paenibacillus, Brevibacterium, Geobacillus, Acinetobacter. From the result, Pseudomonas demonstrated a high incidence in the plants sampled. The in-vitro degradation study and the presence of dioxygenase genes indicated that these lists of endophytes are able to use the list of PAHs tested as their source of food and energy leading to their breakdown. This means that the bacterial endophytes contributed to the remediation of petroleum hydrocarbons in planta, a situation that may have been phytotoxic to plant alone. Therefore, these bacteria endophytes could be potential organisms for enhanced phytoremediation of PAHs.
Collapse
Affiliation(s)
- Raymond O Anyasi
- a Department of Environmental Sciences, Institute for Science and Technology Education , University of South Africa , Pretoria , South Africa
| | - Harrison I Atagana
- a Department of Environmental Sciences, Institute for Science and Technology Education , University of South Africa , Pretoria , South Africa
| | - Rene Sutherland
- b Plant Protection Unit , Agricultural Research Council , Pretoria , South Africa
| |
Collapse
|
7
|
Djahnit N, Chernai S, Catania V, Hamdi B, China B, Cappello S, Quatrini P. Isolation, characterization and determination of biotechnological potential of oil-degrading bacteria from Algerian centre coast. J Appl Microbiol 2019; 126:780-795. [PMID: 30586234 DOI: 10.1111/jam.14185] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 10/31/2018] [Accepted: 12/20/2018] [Indexed: 11/26/2022]
Abstract
AIMS The Algerian coastline is exposed to several types of pollution, including hydrocarbons. The aim of this work was to isolate oil-degrading bacteria and to explore the intrinsic bioremediation potential of part of its contaminated harbour. METHODS AND RESULTS A collection of 119 strains, capable to grow on mineral medium supplemented with hydrocarbons, were obtained from polluted sediment and seawater collected from Sidi Fredj harbour (Algiers). Twenty-three strains were selected for further studies. Sequencing of the 16S rRNA gene showed that most isolates belong to genera of hydrocarbonoclastic bacteria (Alcanivorax), generalist hydrocarbons degraders (Marinobacter, Pseudomonas, Gordonia, Halomonas, Erythrobacter and Brevibacterium) and other bacteria not known as hydrocarbon degraders (Xanthomarina) but were able to degrade hydrocarbons. Strains related to Marinobacter and Alcanivorax were frequently isolated from our samples and resulted the most effective in degrading crude oil. Screening of catabolic genes alkB and xylA revealed the presence of alkB gene in several bacterial strains; one isolate harboured both catabolic genes while other isolates carried none of the studied genes. However, they grew in the presence of crude oil implying the existence of other biodegradation pathways. CONCLUSIONS The samples of seawater and sediment from the Algerian coast contain high level of hydrocarbon-degrading bacteria that could be interesting and useful for future bioremediation purposes. SIGNIFICANCE AND IMPACT OF THE STUDY This investigation demonstrates the diversity of hydrocarbon-degrading bacteria from a marine-contaminated area in Algeria, and their variable biodegradation abilities.
Collapse
Affiliation(s)
- N Djahnit
- Laboratoire de Conservation et de Valorisation des Ressources Marines, Ecole Nationale Supérieure des Sciences de la Mer et l'Aménagement du Littoral, ENSSMAL, Alger, Algérie
| | - S Chernai
- Laboratoire de Conservation et de Valorisation des Ressources Marines, Ecole Nationale Supérieure des Sciences de la Mer et l'Aménagement du Littoral, ENSSMAL, Alger, Algérie
| | - V Catania
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, Palermo, Italy
| | - B Hamdi
- Laboratoire de Conservation et de Valorisation des Ressources Marines, Ecole Nationale Supérieure des Sciences de la Mer et l'Aménagement du Littoral, ENSSMAL, Alger, Algérie
| | - B China
- Sciensano, J. Wytsmanstreet, Brussels, Belgium
| | - S Cappello
- Istituto per l'Ambiente Marino Costiero (IAMC) - C.N.R. U.O.S. di Messina Sp., Messina, Italy
| | - P Quatrini
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, Palermo, Italy
| |
Collapse
|
8
|
Anwar Y, El-Hanafy AA, Sabir JSM, Al-Garni SMS, Al-Ghamdi K, Almehdar H, Waqas M. Characterization of Mesophilic Bacteria Degrading Crude Oil from Different Sites of Aramco, Saudi Arabia. Polycycl Aromat Compd 2017. [DOI: 10.1080/10406638.2017.1382542] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Yasir Anwar
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Amr A. El-Hanafy
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
- Department of Nucleic Acid Research, Genetic Engineering and Biotechnology Research Institute, City for Scientific Research &Technology Applications, Borg El-Arab, Alexandria, Egypt
| | - Jamal S. M. Sabir
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Saleh M. S. Al-Garni
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Khalid Al-Ghamdi
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Hussein Almehdar
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Muhammad Waqas
- Department of Environmental Sciences, Faculty of Meteorology, Environment and Arid Land Agriculture, King Abdulaziz University, Jeddah, Saudi Arabia
| |
Collapse
|
9
|
Shahab S, Shafi I, Ahmed N. Indigenous Oil Degrading Bacteria: Isolation, Screening and Characterization. ACTA ACUST UNITED AC 2017. [DOI: 10.21089/njhs.23.0100] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
10
|
Al-Sayegh A, Al-Wahaibi Y, Joshi S, Al-Bahry S, Elshafie A, Al-Bemani A. Bioremediation of Heavy Crude Oil Contamination. ACTA ACUST UNITED AC 2016. [DOI: 10.2174/1874070701610010301] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Crude oil contamination is one of the major environmental concerns and it has drawn interest from researchers and industries. Heavy oils contain 24-64% saturates and aromatics, 14-39% resins and 11-45% asphaltene. Resins and asphaltenes mainly consist of naphthenic aromatic hydrocarbons with alicyclic chains which are the hardest to degrade. Crude oil biodegradation process, with its minimal energy need and environmentally friendly approach, presents an opportunity for bioremediation and as well for enhanced oil recovery to utilize heavy oil resources in an efficient manner. Biodegradation entails crude oil utilization as a carbon source for microorganisms that in turn change the physical properties of heavy crude oil by oxidizing aromatic rings, chelating metals and severing internal bonds/chains between molecules. Biodegradation does not necessarily lower quality of crude oil as there are cases where quality was improved. This paper provides information on heavy crude oil chemistry, bioremediation concept, biodegradation enzymes, cases of Microbial Enhanced heavy crude Oil Recovery (MEOR) and screening criteria towards a better understanding of the biodegradation application. Through the utilization of single microorganisms and consortia, researchers were able to biodegrade single pure hydrocarbon components, transform heavy crude oil fractions to lighter fractions, remove heavy metals and reduce viscosity of crude oil.
Collapse
|
11
|
Obi LU, Atagana HI, Adeleke RA. Isolation and characterisation of crude oil sludge degrading bacteria. SPRINGERPLUS 2016; 5:1946. [PMID: 27933233 PMCID: PMC5102992 DOI: 10.1186/s40064-016-3617-z] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Accepted: 10/28/2016] [Indexed: 11/23/2022]
Abstract
Background The use of microorganisms in remediating environmental contaminants such as crude oil sludge has become a promising technique owing to its economy and the fact it is environmentally friendly. Polycyclic aromatic hydrocarbons (PAHs), as the major components of oil sludge, are hydrophobic and recalcitrant. An important way of enhancing the rate of PAH desorption is to compost crude oil sludge by incorporating commercial surfactants, thereby making them available for microbial degradation. In this study, crude oil sludge was composted for 16 weeks during which surfactants were added in the form of a solution. Results Molecular characterisation of the 16S rRNA genes indicated that the isolates obtained on a mineral salts medium belonged to different genera, including Stenotrophmonas, Pseudomonas, Bordetella, Brucella, Bacillus, Achromobacter, Ochrobactrum, Advenella, Mycobacterium, Mesorhizobium, Klebsiella, Pusillimonas and Raoultella. The percentage degradation rates of these isolates were estimated by measuring the absorbance of the 2,6-dichlorophenol indophenol medium. Pseudomonas emerged as the top degrader with an estimated percentage degradation rate of 73.7% after 7 days of incubation at 28 °C. In addition, the presence of the catabolic gene, catechol-2,3-dioxygenase was detected in the bacteria isolates as well as in evolutionary classifications based on phylogeny. Conclusions The bacteria isolated in this study are potential agents for the bioremediation of crude oil sludge.
Collapse
Affiliation(s)
- Linda U Obi
- Department of Environmental Sciences, University of South Africa, Johannesburg, South Africa ; Microbiology and Environmental Biotechnology Research Group, Agricultural Research Council - Institute for Soil, Climate and Water, Pretoria, South Africa
| | - Harrison I Atagana
- Institute for Science and Technology Education, University of South Africa, Pretoria, South Africa
| | - Rasheed A Adeleke
- Department of Environmental Sciences, University of South Africa, Johannesburg, South Africa ; Microbiology and Environmental Biotechnology Research Group, Agricultural Research Council - Institute for Soil, Climate and Water, Pretoria, South Africa ; Unit for Environment Science and Management, North-West University (Potchefstroom Campus), Potchefstroom, South Africa
| |
Collapse
|
12
|
Bazargan A, Sadeghi H, Garcia-Mayoral R, McKay G. An unsteady state retention model for fluid desorption from sorbents. J Colloid Interface Sci 2015; 450:127-134. [DOI: 10.1016/j.jcis.2015.02.036] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2014] [Revised: 02/08/2015] [Accepted: 02/12/2015] [Indexed: 12/14/2022]
|
13
|
Zehraoui A, Kapoor V, Wendell D, Sorial GA. Impact of alternate use of methanol on n-hexane biofiltration and microbial community structure diversity. Biochem Eng J 2014. [DOI: 10.1016/j.bej.2014.02.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|