Degradation of n-alkanes and polycyclic aromatic hydrocarbons in petroleum by a newly isolated Pseudomonas aeruginosa DQ8

A bacterial isolate, designated as DQ8, was found capable of degrading diesel, crude oil, n-alkanes and polycyclic aromatic hydrocarbons (PAHs) in petroleum. Strain DQ8 was assigned to the genus Pseudomonas aeruginosa based on biochemical and genetic data. The metabolites identified from n-docosane as substrate suggested that P. aeruginosa DQ8 could oxidize n-alkanes via a terminal oxidation pathway. P. aeruginosa DQ8 could also degrade PAHs of three or four aromatic rings. The metabolites identified from fluorene as substrate suggested that P. aeruginosa DQ8 may degrade fluorene via two pathways. One is monooxygenation at C-9 of fluorene, and the other is initiated by dioxygenation at C-3 and C-4 of fluorene. P. aeruginosa DQ8 should be of great practical significance both in bioremediation of oil-contaminated soils and biotreatment of oil wastewater.     

Morphological,biochemical and molecular identification of petroleum hydrocarbons biodegradation bacteria isolated from oil polluted soil in Dhahran,Saud Arabia

Accumulation of petroleum hydrocarbon residual considered a major environmental problem in the kingdom of Saudi Arabia cause of intensive efforts for oil detecting. Until now, In situ biodegradation considered the most effective method for petroleum hydrocarbon residual biodegradation. The aim of this study is isolation and identification biodegradable capability bacteria from contaminated sites in Khurais oil field, Dhahran, Saud Arabia via Different morphological and biochemical and molecular methods. Furthermore, degradation level in contaminated liquid medium and soil were evaluated. Three bacterial strains were selected from petroleum-contaminated soils of Khurais oil field depending on their capacity to grow in the existence of hydrocarbon components and identified according to morphological, biochemical. Interestingly, 16S rDNA sequencing fingerprinting results confirmed our bacterial identification as Bacillus subtilis, Pseudomonas aeruginosa and Bacillus cereu. Phyllogenetic tree was constructed and genetic similarity was calculated according to alignments results. Biodegradation patterns for different three isolates were reflected varied degradation ability for three isolates regarding incubation time. Different features were studied for three biodegrading bacterial strains and identified as Bacillus subtilis, Pseudomonas aeruginosa and Bacillus cereus. Remarkable degradation rate % patterns for hydrocarbons residual were recorded for all three isolates with varied.     

Genome Sequence of Pseudomonas aeruginosa DQ8, an Efficient Degrader of n-Alkanes and Polycyclic Aromatic Hydrocarbons

Pseudomonas aeruginosa DQ8, which was isolated from the crude oil polluted soil in the Daqing oilfield of China, can efficiently degrade diesel, crude oil, n-alkanes, and polycyclic aromatic hydrocarbons (PAHs). Here, we present a 6.8-Mb assembly of its genome sequence. We have annotated 23 coding sequences (CDSs) responsible for catabolism of n-alkanes and PAHs.     

Characterization of a diesel-degrading bacterium, <Emphasis Type="Italic">Pseudomonas aeruginosa</Emphasis> IU5, isolated from oil-contaminated soil in Korea

A diesel-degrading bacterium (strain IU5) isolated from oil-contaminated soil was characterized in this study. Fatty acid and 16s rDNA sequence analysis identified IU5 as a strain of Pseudomonas aeruginosa, and growth curve experiments identified the bacterium’s optimum conditions as pH 7 and 30 °C. P. aeruginosa IU5 degraded up to 60 of applied diesel (8500 mg/kg) over 13 days in a soil-slurry phase. In addition, this strain was able to grow on many other petroleum hydrocarbons as sole carbon sources, including crude oil, gasoline, benzene, toluene, xylene, and even PAHs such as naphthalene, phenanthrene and pyrene. Therefore, P. aeruginosa IU5 may be useful for bioremediation of soils and groundwater contaminated with a variety of hydrocarbons.     

Biodegradation of petroleum hydrocarbons by filamentous fungi (Aspergillus ustus and Purpureocillium lilacinum) isolated from used engine oil contaminated soil

The use of microorganisms for remediation and restoration of hydrocarbons contaminated soils is an effective and economic solution. The current study aims to find out efficient telluric filamentous fungi to degrade petroleum hydrocarbons pollutants. Six fungal strains were isolated from used engine (UE) oil contaminated soil. Fungi were screened for their ability to degrade crude oil, diesel and UE oil using 2.6-dichlorophenol indophenol (DCPIP). Two isolates were selected, identified and registered at NCBI as Aspergillus ustus HM3.aaa and Purpureocillium lilacinum HM4.aaa. Fungi were tested for their tolerance to different concentration of petroleum oils using radial growth diameter assay. Hydrocarbons removal percentage was evaluated gravimetrically. The degradation kinetic of crude oil was studied at a time interval of 10 days. A.ustus was the most tolerant fungi to high concentration of petroleum oils in solid medium. Quantitative analysis showed that crude oil was the most degraded oil by both isolate; P. lilacinium and A. ustus removed 44.55% and 30.43% of crude oil, respectively. The two fungi were able to degrade, respectively, 27.66 and 21.27% of diesel and 14.39 and 16.00% of UE oil. As compared to the controls, these fungi accumulated high biomass in liquid medium with all petroleum oils. Likewise, crude oil removal rate constant (K) and half-lives (t_1/2) were 0.02 day⁻¹, 34.66 day and 0.015 day⁻¹, 46.21 day for P. lilacinium and A. ustus, respectively. The selected fungi appear interesting for petroleum oils biodegradation and their application for soil bioremediation require scale-up studies.     

陕北地区石油污染土壤中不动杆菌属的筛选、鉴定及降解性能

从陕北地区石油污染土壤中分离鉴定得到两株不动杆菌属(Acinetobacter sp.)的高效石油降解菌A.sp 1和A.sp 2,分别从盐浓度、pH值、氮源、磷源和接种量等因素进行研究以确定其最佳石油降解条件,并进一步通过GC-MS(Gas ChromatographyMass Spectrometer)方法分析其在最佳条件下对原油组分的不同降解性能。结果显示:A.sp 1在盐浓度为1%、pH值为6—7、磷源为KH2PO4和K2HPO4、氮源为尿素和接种量为4%的条件下,最高降解率可达到60%。A.sp 2在盐浓度为1%、pH值为7—9、磷源为KH2PO4和K2HPO4、氮源为硝酸铵和接种量为8%的条件下,最高降解率可达到67%。GC-MS分析结果表明,菌株A.sp 1对石油烃类C21—C25有明显的降解效果,菌株A.sp 2对石油烃类C20—C30的降解效果较好。     

Evaluation of Genetic Diversity among Pseudomonas citronellolis Strains Isolated from Oily Sludge-Contaminated Sites

The diversity among a set of bacterial strains that have the capacity to degrade total petroleum hydrocarbons (TPH) in soil contaminated with oily sludge (hazardous hydrocarbon waste from oil refineries) was determined. TPH is composed of alkane, aromatics, nitrogen-, sulfur-, and oxygen-containing compound, and asphaltene fractions of crude oil. The 150 bacterial isolates which could degrade TPH were isolated from soil samples obtained from diverse geoclimatic regions of India. All the isolates were biochemically characterized and identified with a Biolog microbial identification system and by 16S rDNA sequencing. Pseudomonas citronellolis predominated among the 150 isolates obtained from six different geographically diverse samplings. Of the isolates, 29 strains of P. citronellolis were selected for evaluating their genetic diversity. This was performed by molecular typing with repetitive sequence (Rep)-based PCR with primer sets ERIC (enterobacterial repetitive intergenic consensus), REP (repetitive extragenic palindromes), and BOXAIR and PCR-based ribotyping. Strain-specific and unique genotypic fingerprints were distinguished by these molecular typing strategies. The 29 strains of P. citronellolis were separated into 12 distinguishable genotypic groups by Rep-PCR and into seven genomic patterns by PCR-based ribotyping. The genetic diversity of the strains was related to the different geoclimatic isolation sites, type of oily sludge, and age of contamination of the sites. These results indicate that a combination of Rep-PCR fingerprinting and PCR-based ribotyping can be used as a high-resolution genomic fingerprinting method for elucidating intraspecies diversity among strains of P. citronellolis.     

Isolation and Characterization of Novel Strains of <Emphasis Type="Italic">Pseudomonas aeruginosa</Emphasis> and <Emphasis Type="Italic">Serratia marcescens</Emphasis> Possessing High Efficiency to Degrade Gasoline,Kerosene, Diesel Oil,and Lubricating Oil

Bacteria possessing high capacity to degrade gasoline, kerosene, diesel oil, and lubricating oil were screened from several areas of Hokkaido, Japan. Among isolates, two strains, WatG and HokM, which were identified as new strains of Pseudomonas aeruginosa and Serratia marcescens species, respectively, showed relatively high capacity and wide spectrum to degrade the hydrocarbons in gasoline, kerosene, diesel, and lubricating oil. About 90-95% of excess amount of total diesel oil and kerosene added to mineral salts media as a sole carbon source could be degraded by WatG within 2 and 3 weeks, respectively. The same amount of lubricating oil was 60% degraded within 2 weeks. Strain HokM was more capable than WatG in degrading aromatic compounds in gasoline. This strain could also degrade kerosene, diesel, and lubricating oil with a capacity of 50-60%. Thus, these two isolates have potential to be useful for bioremediation of sites highly contaminated with petroleum hydrocarbons.     

Biodegradation of Nitriles in Shale Oil

Enrichment cultures were obtained, after prolonged incubation on a shale oil as the sole source of nitrogen, that selectively degraded nitriles. Capillary gas chromatographic analyses showed that the mixed microbial populations in the enrichments degraded the homologous series of aliphatic nitriles but not the aliphatic hydrocarbons, aromatic hydrocarbons, or heterocyclic-nitrogen compounds found in this oil. Time course studies showed that lighter nitriles were removed more rapidly than higher-molecular-weight nitriles. A Pseudomonas fluorescens strain isolated from an enrichment, which was able to completely utilize the individual nitriles undecyl cyanide and undecanenitrile as sole sources of carbon and nitrogen, was unable to attack stearonitrile when provided alone as the growth substrate. A P. aeruginosa strain, also isolated from one of the enrichments, used nitriles but not aliphatic or aromatic hydrocarbons when the oil was used as a sole nitrogen source. However, when the shale oil was used as the sole source of carbon, aliphatic hydrocarbons in addition to nitriles were degraded but aromatic hydrocarbons were still not attacked by this P. aeruginosa strain.     

Effect of biosurfactant and fertilizer on biodegradation of crude oil by marine isolates of Bacillus megaterium, Corynebacterium kutscheri and Pseudomonas aeruginosa

This study was conducted to investigate the effects of fertilizers and biosurfactants on biodegradation of crude oil by three marine bacterial isolates; Bacillus megaterium, Corynebacterium kutscheri and Pseudomonas aeruginosa. Five sets of experiments were carried out in shake flask and microcosm conditions with crude oil as follows: Set 1-only bacterial cells added (no fertilizer and biosurfactant), Set 2-with additional fertilizer only, Set 3-with additional biosurfactant only, Set 4-with added biosurfactant + fertilizer, Set 5-with no bacterial cells added (control), all the above experimental sets were incubated for 168 h. The biosurfactant + fertilizer added Set 4, resulted in maximum crude oil degradation within shake flask and microcosm conditions. Among the three bacterial isolates, P. aeruginosa and biosurfactant produced by this strain resulted in maximum crude oil degradation compared to the other two bacterial strains investigated. Interestingly, when biosurfactant and bacterial cells were used (Set 3), significant oil biodegradation activity occurred and the difference between this treatment and that in Set 4 with added fertilizer + biosurfactant were only 4-5% higher degradation level in shake flask and 3.2-7% in microcosm experiments for all three bacterial strains used. It is concluded that, biosurfactants alone capable of promoting biodegradation to a large extent without added fertilizers, which will reduce the cost of bioremediation process and minimizes the dilution or wash away problems encountered when water soluble fertilizers used during bioremediation of aquatic environments.     

Mycoremediation of crude oil contaminated soil by specific fungi isolated from Dhahran in Saudi Arabia

Crude oil biodegrading microorganism considers the key role for environmental preserving. In this investigation, crude oil biodegrading fungal strains have been isolated in polluted soil of crude-oil at khurais oil ground in Kingdom of Saudi Arabia. Among of 22 fungal isolates, only three isolates reflected potential capability for oil degradation. These isolates were identified and submitted to GenBank as (A1) Aspergillus polyporicola (MT448790), (A2) Aspergillus spelaeus (MT448791) and (A3) Aspergillus niger (MT459302) through internal-transcribed spacer-regions (ITS1&ITS2) for sequencing in molecular marker. Comparing with controls, strain (A1) Aspergillus niger was superior for biodegradation ability (58%) comparing with Aspergillus polyporicola and Aspergillus spelaeus degrading were showed 47 and 51% respectively. Employed CO₂ evolution as indicator for petroleum oil biodegradation by the fungal isolates reflected that, Aspergillus niger emission highest CO2 (28.6%) comparing with Aspergillus spelaeus and Aspergillus polyporicola which showed 13% and 12.4% respectively. capability of Aspergillus sp. to tolerate and adapted oil pollutants with successful growth rate on them, indicated that it can be employed as mycoremediation agent for recovering restoring ecosystem when contaminated by crude oil.     

Comparison of bacterial community in aqueous and oil phases of water-flooded petroleum reservoirs using pyrosequencing and clone library approaches

Bacterial communities in both aqueous and oil phases of water-flooded petroleum reservoirs were characterized by molecular analysis of bacterial 16S rRNA genes obtained from Shengli Oil Field using DNA pyrosequencing and gene clone library approaches. Metagenomic DNA was extracted from the aqueous and oil phases and subjected to polymerase chain reaction amplification with primers targeting the bacterial 16S rRNA genes. The analysis by these two methods showed that there was a large difference in bacterial diversity between the aqueous and oil phases of the reservoir fluids, especially in the reservoirs with lower water cut. At a high phylogenetic level, the predominant bacteria detected by these two approaches were identical. However, pyrosequencing allowed the detection of more rare bacterial species than the clone library method. Statistical analysis showed that the diversity of the bacterial community of the aqueous phase was lower than that of the oil phase. Phylogenetic analysis indicated that the vast majority of sequences detected in the water phase were from members of the genus Arcobacter within the Epsilonproteobacteria, which is capable of degrading the intermediates of hydrocarbon degradation such as acetate. The oil phase of reservoir fluid samples was dominated by members of the genus Pseudomonas within the Gammaproteobacteria and the genus Sphingomonas within the Alphaproteobacteria, which have the ability to degrade crude oil through adherence to hydrocarbons under aerobic conditions. In addition, many anaerobes that could degrade the component of crude oil were also found in the oil phase of reservoir fluids, mainly in the reservoir with lower water cut. These were represented by Desulfovibrio spp., Thermodesulfovibrio spp., Thermodesulforhabdus spp., Thermotoga spp., and Thermoanaerobacterium spp. This research suggested that simultaneous analysis of DNA extracted from both aqueous and oil phases can facilitate a better understanding of the bacterial communities in water-flooded petroleum reservoirs.     

Variability in Pseudomonas aeruginosa Lipopolysaccharide Expression during Crude Oil Degradation

Bacterial utilization of crude oil components, such as the n-alkanes, requires complex cell surface adaptation to allow adherence to oil. To better understand microbial cell surface adaptation to growth on crude oil, the cell surface characteristics of two Pseudomonas aeruginosa strains, U1 and U3, both isolated from the same crude oil-degrading microbial community enriched on Bonny Light crude oil (BLC), were compared. Analysis of growth rates demonstrated an increased lag time for U1 cells compared to U3 cells. Amendment with EDTA inhibited U1 and U3 growth and degradation of the n-alkane component of BLC, suggesting a link between cell surface structure and crude oil degradation. U1 cells demonstrated a smooth-to-rough colony morphology transition when grown on BLC, while U3 cells exhibited rough colony morphology at the outset. Combining high-resolution atomic force microscopy of the cell surface and sodium dodecyl sulfate-polyacrylamide gel electrophoresis of extracted lipopolysaccharides (LPS), we demonstrate that isolates grown on BLC have reduced O-antigen expression compared with that of glucose-grown cells. The loss of O-antigen resulted in shorter LPS molecules, increased cell surface hydrophobicity, and increased n-alkane degradation.     

Hydrocarbon degradation in relation to cell-surface hydrophobicity among bacterial hydrocarbon degraders from petroleum-contaminated Kuwait desert environment

Forty six bacterial isolates able to grow on crude oil were isolated from various hydrocarbon-contaminated sites in Kuwait. The extent of crude oil degradation varied over a wide range (1–87%) among the isolates. Isolates were predominantly Gram-positive bacteria (79% of total isolates) belonging to the genera Bacillus (93%) and Paenibacillus (7%). Among the few Gram-negative isolates were from the genera Acinetobacter, Alcaligenes, Klebsiella, Burkholderia, Pseudomonas, and Williamsia. Analyses of their cell-surface hydrophobicity (CSH) by various methods equally showed a wide variation among the isolates. About 74% of isolates that degraded significant amounts of crude oil (>40% degradation) possessed high level of CSH, while 58% of all the isolates exhibited high levels of CSH. Statistical analyses showed significantly high correlation between the ability to degrade crude oil and CSH. The ability of the isolates to bind to polystyrene and salt-aggregation test as measures of CSH were more strongly correlated with hydrocarbon-degrading ability than adherence to hydrocarbons.     

Comparative hydrocarbon utilization by hydrophobic and hydrophilic variants of Pseudomonas aeruginosa

Aims: To investigate hydrocarbon degradation by hydrophobic, hydrophilic and parental strains of Pseudomonas aeruginosa. Methods and Results: Partitioning of hydrocarbon‐degrading P. aeruginosa strain in a solvent/aqueous system yielded hydrophobic and hydrophilic fractions. Exhaustive partitioning of aqueous‐phase cells yielded the hydrophilic variants (L), while sequential fractionation of the hydrophobic phase cells yielded successive fractions exhibiting increasing cell‐surface hydrophobicity (CSH). In hydrocarbon adherence assays (bacterial attachment to hydrocarbon), L had a value of 20%, which increased from 61·7% in first hydrophobic fraction (H₁) to 72·2% in the third (H₃). Crude oil degradation by L was 70%, but increased from 82% in H₁ to 93% in H₃. L variant produced most exopolysaccharides and reduced surface tension from about 73 to 49 mN m^?1. Rhamnolipid production was highest in L, but was not detected in all crude oil cultures. Conclusions: Hydrophobic subpopulations of hydrocarbon‐degrading P. aeruginosa exhibited greater hydrocarbon‐utilizing ability than hydrophilic ones, or the parental strain. Significance and Impact of the Study: Results demonstrate that a population of P. aeruginosa consists of cells with different CSH which affect hydrocarbon utilization. This potentially provides the population with the capacity to utilize different hydrophobic substrates found in petroleum. Judicious selection of such hydrophobic subpopulations can enhance hydrocarbon pollution bioremediation.     

Degradation of petroleum hydrocarbons (C6-C40) and crude oil by a novel Dietzia strain

A novel bacterial strain, DQ12-45-1b, was isolated from the production water of a deep subterranean oil-reservoir. Morphological, physiological and phylogenetic analyses indicated that the strain belonged to the genus Dietzia with both alkB (coding for alkane monooxygenase) and CYP153 (coding for P450 alkane hydroxylase of the cytochrome CYP153 family) genes and their induction detected. It was capable of utilizing a wide range of n-alkanes (C6-C40), aromatic compounds and crude oil as the sole carbon sources for growth. In addition, it preferentially degraded short-chain hydrocarbons (?C25) in the early cultivation phase and accumulated hydrocarbons with chain-lengths from C23 to C27 during later cultivation stage with crude oil as the sole carbon source. This is the first study to report the different behaviors of a bacterial species toward crude oil degradation as well as a species of Dietzia degrading a wide range of hydrocarbons.     

Biosurfactant synthesis by Pseudomonas aeruginosa LBI isolated from a hydrocarbon-contaminated site

Aims: Pseudomonas aeruginosa LBI (Industrial Biotechnology Laboratory) was isolated from hydrocarbon-contaminated soil as a potential producer of biosurfactant and evaluated for hydrocarbon biodegradation. The emulsifying power and stability of the product was assessed in the laboratory, simulating water contamination with benzene, toluene, kerosene, diesel oil and crude oil at various concentrations. Methods and Results: Bacteria were grown at 30°C and shaken at 200 rpm for 168 h, with three repetitions. Surface tension, pH and biosurfactant stability were observed in the cell-free broth after 168 h of incubation. The strain was able to produce biosurfactant and grow in all the carbon sources under study, except benzene and toluene. When cultivated in 30% (w/v) diesel oil, the strain produced the highest quantities (9·9 g l⁻¹) of biosurfactant. The biosurfactant was capable of emulsifying all the hydrocarbons tested. Conclusion: The results from the present study demonstrate that Ps. aeruginosa LBI can grow in diesel oil, kerosene, crude oil and oil sludge and the biosurfactant produced has potential applications in the bioremediation of hydrocarbon-contaminated sites. Significance and Impact of the Study: Pseudomonas aeruginosa LBI or the biosurfactant it produces can be used in the bioremediation of environmental pollution induced by industrial discharge or accidental hydrocarbon spills.     

Biotechnological Potential of Bacillus salmalaya 139SI: A Novel Strain for Remediating Water Polluted with Crude Oil Waste

Environmental contamination by petroleum hydrocarbons, mainly crude oil waste from refineries, is becoming prevalent worldwide. This study investigates the bioremediation of water contaminated with crude oil waste. Bacillus salamalaya 139SI, a bacterium isolated from a private farm soil in the Kuala Selangor in Malaysia, was found to be a potential degrader of crude oil waste. When a microbial population of 10⁸ CFU ml^-1 was used, the 139SI strain degraded 79% and 88% of the total petroleum hydrocarbons after 42 days of incubation in mineral salt media containing 2% and 1% of crude oil waste, respectively, under optimum conditions. In the uninoculated medium containing 1% crude oil waste, 6% was degraded. Relative to the control, the degradation was significantly greater when a bacteria count of 99 × 10⁸ CFU ml^-1 was added to the treatments polluted with 1% oil. Thus, this isolated strain is useful for enhancing the biotreatment of oil in wastewater.     

Occurrence, production, and export of lipophilic compounds by hydrocarbonoclastic marine bacteria and their potential use to produce bulk chemicals from hydrocarbons

Petroleum (or crude oil) is a complex mixture of hydrocarbons. Annually, millions of tons of crude petroleum oil enter the marine environment from either natural or anthropogenic sources. Hydrocarbon-degrading bacteria (HDB) are able to assimilate and metabolize hydrocarbons present in petroleum. Crude oil pollution constitutes a temporary condition of carbon excess coupled to a limited availability of nitrogen that prompts marine oil-degrading bacteria to accumulate storage compounds. Storage lipid compounds such as polyhydroxyalkanoates (PHAs), triacylglycerols (TAGs), or wax esters (WEs) constitute the main accumulated lipophilic substances by bacteria under such unbalanced growth conditions. The importance of these compounds as end-products or precursors to produce interesting biotechnologically relevant chemicals has already been recognized. In this review, we analyze the occurrence and accumulation of lipid storage in marine hydrocarbonoclastic bacteria. We further discuss briefly the production and export of lipophilic compounds by bacteria belonging to the Alcanivorax genus, which became a model strain of an unusual group of obligate hydrocarbonoclastic bacteria (OHCB) and discuss the possibility to produce neutral lipids using A. borkumensis SK2.     

Biosurfactant production and hydrocarbon-degradation by halotolerant and thermotolerant Pseudomonas sp.

A hydrocarbon degrading and biosurfactant producing, strain DHT2, was isolated from oil-contaminated soil. The organism grew and produced biosurfactant when cultured in variety of substrates at salinities up to 6 g l⁻¹ and temperatures up to 45°C. It was capable of utilizing crude oil, fuels, alkanes and PAHs as carbon source across the wide range of temperature (30–45°C) and salinity (0–6%). Over the range evaluated, the salinity and temperature did not influence the degradation of hydrocarbon and biosurfactant productions. Isolate DHT2 was identified as Pseudomonas aeruginosa by analysis of 16S rRNA sequences (100% homology) and biochemical analysis. PCR and DNA hybridization studies revealed that enzymes involved in PAH metabolism were related to the naphthalene dioxygenase pathway. Observation of both tensio-active and emulsifying activities indicated that biosurfactants were produced by DHT2 during growth on both, water miscible and immiscible substrates, including PAH. The biosurfactants lowered the surface tension of medium from 54.9 to 30.2 dN/cm and formed a stable emulsion. The biosurfactant produced by the organism emulsified a range of hydrocarbons with hexadecane as best substrate and toluene was the poorest. These findings further indicate that the isolate could be useful for bioremediation and bio-refining application in petroleum industry.