Effects of oxygen on biodegradation of fuels in a corroding environment

doi:10.1016/j.ibiod.2012.05.006

International Biodeterioration & Biodegradation

Volume 81, July 2013, Pages 114-126

https://doi.org/10.1016/j.ibiod.2012.05.006 Get rights and content

Abstract

The relationship between corrosion and biodegradation of bio- and petroleum-based fuels was evaluated using aerobic seawater, fuel and unprotected carbon steel coupons under stagnant conditions to simulate a potential fuel storage condition. Aerobic respiration and corrosion reactions consumed oxygen in the incubations in a short time. The transient oxygen influenced the microbial biodegradation of all fuels and resulted in a suite of characteristic metabolites, including catechols. The corrosion was believed to be the result of biogenic sulfide production and in all cases, the black corrosion products contained chlorine and sulfur (presumed chloride and sulfide) in addition to iron. There were few differences in electrochemically measured corrosion rates in incubations amended with any of the fuels or their blends. Clone library analysis demonstrated higher proportions of Firmicutes, Deltaproteobacteria (primarily sulfate-reducing bacteria), Chloroflexi, and Lentisphaerae in incubations exposed to fuels than the original seawater. Relative proportions of sequences affiliated with these bacterial groups varied with fuel. Methanogen sequences similar to those of Methanolobus were also found in multiple incubations. Despite the dominance of characteristically anaerobic taxa, sequences coding for an alkane monooxygenase from marine hydrocarbon-degrading genera and aerobically produced intermediates were observed, indicative that organisms with this metabolic potential were active at some point during the incubation. Aerobic oxidation of fuel components resulted in the formation of a series of intermediates that could be used by anaerobic seawater microbial communities to support metabolism, sulfide production, and carbon steel corrosion.

Highlights

► The inherent susceptibility of hydrocarbons in hydroprocessed biofuels or petro-based fuels to biodegradation processes is fundamentally similar. ► Corrosion rates of hydroprocessed biofuels and traditional fuels were similar. ► The presence of diagnostic metabolites indicated that the incubations were transiently exposed to oxygen. ► Fuel components and/or oxygenated metabolites served as suitable electron donors supporting sulfate reduction-linked biocorrosion.

Introduction

Reducing dependence on fossil fuels requires not only increased energy efficiency and conservation, but also greater reliance on carbon neutral biofuels. First generation biofuels, a mixture of monoalkyl esters of long chain fatty acids (Ng et al., 2010), rapidly biodegrade under anaerobic conditions (Aktas et al., 2010). More recently, hydroprocessed (HP) bio-based lipids from renewable stocks (e.g. camelina and algae) are being considered as candidate alternative fuels. The HP fuels have chemical and physical characteristics that allow them to be readily blended with conventional petroleum products (Kalnes et al., 2007). However, the biological stability of HP fuels needs to be critically assessed under realistic storage and use conditions. Fuels are often stored for months in uncoated carbon steel tanks and exposed to varying amounts of fresh water and oxygen. Fuels can also come in direct contact with marine waters in ships equipped with seawater-compensated ballast tanks. In these systems, seawater is used to compensate for volume and weight loss as the ship's engines consume fuel.

Past experiments have demonstrated the following: 1) dissolved oxygen (DO) in stagnant seawater (8 ppm = 250 μM) exposed to corroding carbon steel, either with (Aktas et al., 2010) or without (Lee et al., 2004) fuel, will be depleted to detection limits (100 ppb = ∼3 μM) within 48 h, 2) most solid surfaces in contact with waters (Lee and de Beer, 1995) are anaerobic because of microbial respiration in a biofilm, 3) sulfate-reducing bacteria (SRB) dominate the microflora in marine biofilms and anaerobic seawaters (Lee et al., 2004,2005) and 4) sulfide influenced corrosion is the major mechanism for deterioration of metals used to transport and store fuels in contact with seawater (Aktas et al., 2010; Lee et al., 2010a). This study focused on the relationship between the biodegradability of petroleum- (petro-) and bio-based fuels and corrosion of carbon steel in fuel/seawater exposures. Observations were coupled with weight loss and instantaneous corrosion rate measurements for carbon steel coupons. Localized corrosion was evaluated using electrochemistry and electron microscopy. Alterations in microbial community composition were monitored before and after a 90 d incubation period and metabolite profiling was used to deduce biodegradation pathways.

Section snippets

Fuel/seawater incubations

Fuels (petro-F76, petro-JP5, algal-F76, camelina-JP5, ultra low sulfur diesel (ULSD) and soy-based biodiesel (BD)) were obtained from Naval Fuels and Lubes Cross Functional Team, NAVAIR (47,123 Buse Road, Building 2272 Suite 540, Patuxent River, MD, 20670). Four neat fuels were used in these experiments including petro-F76, petro-JP5, camelina-JP5 and ULSD. Neat algal-F76 was not included due to limited availability. Three blended fuels were also used including 80:20 mix ULSD and soy biodiesel

Before incubation

Fuel components partitioned to seawater and, in the case of blends, qualitatively reflected both the petro- and bio-based parent fuels. A comparison of petro- and algal-based F76 and their 50:50 mix showed that a qualitatively comparable suite of n-alkanes (C₁₀–C₂₃) partitioned to seawater, regardless of the parent fuel (Fig. 1). Compared to the algal-F76, the petro-F76 exhibited a more complex gas chromatographic profile and more components resolved at both relatively early and late retention

Discussion

The role of oxygen in accelerating the rate of corrosion by SRB is well established. Hamilton (2003) developed the hypothesis that oxygen was required as the terminal electron acceptor in sulfide influenced corrosion, i.e., sulfides produced by SRB react with carbon steel (in this case) to form a sulfide corrosion product. In the absence of oxygen, corrosion will slow or cease as surface ions are derivatized whereas in its presence the surface-bound sulfides are oxidized and more surface

Conclusions

Observations related to fuel biodegradation and carbon steel corrosion in fuel/seawater combinations for petroleum-based fuels were similar to those for bio-based fuels with the same basic chemistry. The metabolic fate of the water-soluble fuel components from all fuels was influenced by the presence of oxygen. The presence of diagnostic catechols confirmed that aerobic microorganisms in the seawater initiated the aerobic metabolism of the parent aromatic hydrocarbons.

Acknowledgments

NRL personnel were funded by Sharon Beermann-Curtin at the Office of Naval Research (ONR Code 332) under award N0001411WX21441. NRL publication JA/7330-11-1006. The study was also supported by grant N000141010946 from the Office of Naval Research.

References (42)

S.F. Altschul et al.
Basic local alignment search tool
Journal of Molecular Biology
(1990)
K. Kloos et al.
A new method for the detection of alkane-monooxygenase homologous genes (alkB) in soils based on PCR-hybridization
Journal of Microbiological Methods
(2006)
M.M. Yakimov et al.
Obligate oil-degrading marine bacteria
Current Opinion in Biotechnology
(2007)
D.F. Aktas et al.
Anaerobic metabolism of biodiesel and its Impact on metal corrosion
Energy and Fuels
(2010)
ASTM G1
Standard practice for preparing, cleaning, and evaluating corrosion test specimens
ASTM G59
Standard test method for conducting potentiodynamic polarization resistance measurements
E. Ben-Dov et al.
Quantification of sulfate-reducing bacteria in industrial wastewater, by real-time polymerase chain reaction (PCR) using dsrA and apsA genes
Microbiology Ecology
(2007)
J.B. Broderick
Catechol dioxygenases
Essays in Biochemistry
(1999)
A.V. Callaghan et al.
Diversity of benzyl- and alkylsuccinate synthase genes in hydrocarbon-impacted environments and enrichment cultures
Environmental Science and Technology
(2010)
J.C. Cho et al.
Lentisphaera araneosa gen. nov., sp. nov, a transparent exopolymer producing marine bacterium, and the description of a novel bacterial phylum, Lentisphaerae
Environmental Microbiology
(2004)

J.R. Davis

T.Z. DeSantis et al.

Greengenes, a chimera-checked 16S rRNA gene database and workbench compatible with ARB

Applied and Environmental Microbiology

(2006)

J. Felsenstein

Confidence limits on phylogenies: an approach using the bootstrap

Evolution

(1985)

W. Fritsche et al.

Aerobic degradation by microorganisms

L.M. Gieg et al.

Bioenergy production via microbial conversion of residual oil to natural gas

Applied and Environmental Microbiology

(2008)

W.A. Hamilton

Microbiologically influenced corrosion as a model system for the study of metal microbe interactions: a unifying electron transfer hypothesis

Biofouling

(2003)

T.C. Hazen et al.

Deep-sea oil plume enriches indigenous oil-degrading bacteria

Science

(2010)

T. Kalnes et al.

Green diesel: a second generation biofuel

International Journal of Chemical Reactor Engineering

(2007)

M. Kimura

A simple method for estimating evolutionary rates of base substitutions through comparative studies of nucleotide sequences

Journal of Molecular Evolution

(1980)

W.C. Lee et al.

Oxygen and pH microphiles above corroding mild steel covered with a biofilm

Biofouling

(1995)

W.C. Lee et al.

Corrosion of mild steel under anaerobic biofilm

Corrosion

(1993)

Cited by (35)

Discovery, development and implementation of biomarker-specific peptide BRE for biosensing hydrocarbon-degrading fungi
2023, International Biodeterioration and Biodegradation
Fuel biocontamination is a significant problem that demands new tools for detection and mitigation. Due to the complexity of fuel microbiome, it is critical to differentiate the type of microorganisms present to apply appropriate countermeasures, and fuel-degrading fungi are among the main culprits of biodeterioration. To establish robust biosensors for detection of fuel biocontaminants, a conserved cell surface biomarker must be identified before selection of high-affinity peptide biorecognition elements (BRE) can be screened. To address this need, we applied functional genomics and transcriptomics to characterize a conserved cell surface protein of fuel-degrading fungi, Cytochrome P450 Alkane Hydroxylase (Alk), which is highly expressed during growth in fuel and is critical for alkane degradation. Multiple conserved extracellular ALK epitopes were used to screen a phage-displayed peptide library and a single BRE (5ALK-23) was identified. Molecular and fluorescence assays demonstrated high affinity and specificity of 5ALK-23 for fungi and a low limit of detection that ranged from 1 × 10¹ cells/mL to 9 × 10⁵ cells/mL. 5ALK-23 remained stable in fuel and detected both planktonic cells and biofilms. The validated 5ALK-23 BRE can be used for functionalization of biosensors for detection of fungi in fuel.
Genomic and transcriptomic characterization revealed key adaptive mechanisms of Marinobacter hydrocarbonoclasticus NI9 for proliferation and degradation of jet fuel
2022, International Biodeterioration and Biodegradation
Marinobacter hydrocarbonoclasticus NI9 has the ability to degrade short-chain alkanes (n-C6 to n-C8), which provides a competitive advantage over other microorganisms. Therefore, we sequenced NI9's genome and analyzed its transcriptome using RNAseq when growing in jet fuel. The genome (3.98 Mb) has at least two alkane monooxygenase genes that are differentially expressed with monooxygenase FH712_RS17105 being highly induced compared to monooxygenase FH712_RS06210. FH712_RS17105 is clustered in an operon with a long-chain-fatty-acid--CoA ligase, an aldehyde dehydrogenase family protein, and rubredoxin. The entire gene cluster was induced along with several dioxygenase and cytochrome P450 genes. Genome analyses further revealed aupA and aupB genes encoding proteins involved in the uptake of micelle-solubilized alkanes. M. hydrocarbonoclasticus NI9 cells achieved fuel tolerance through the activation of efflux pumps and blockage of the efflux pumps with an efflux pump inhibitor significantly reduced NI9 growth in fuel. We identified a fuel-inducible RND-efflux pump, which is an orthologue of the P. aeruginosa MexB. M. hydrocarbonoclasticus NI9 also induced ABC iron transport mechanisms suggesting that there is a high demand for iron during fuel degradation. The results collectively suggest that M. hydrocarbonoclasticus NI9 employ similar adaptive mechanisms to those in P. aeruginosa to proliferate in hydrocarbon-containing environments.
Effects of sample preservation on marine microbial diversity analysis
2019, Journal of Microbiological Methods
Citation Excerpt :
The barcodes for each sample are listed in Suppl. Tables 1 and 2. Several biocorrosion and naval research studies used seawater collected from the Key West Naval Research Laboratory (Lee et al., 2004; Lee and Little, 2007; Lee et al., 2010; Aktas et al., 2012; First et al., 2013; among others). Readings of several parameters important for microbial communities are taken most days.
Three replicate seawater samples were collected on three different days, filtered immediately and preserved with one of two guanidinium thiocyanate-based preservatives (DNAzol™ or RNA Lysis Buffer™ plus β-mercaptoethanol (RLA+)) and were kept frozen while being shipped to a lab. In parallel, a carboy of seawater was collected on each of the three days and maintained at ambient temperature while being shipped to a lab. Upon receipt the samples were filtered and treated in the same manner as for immediate preservation. Significantly more DNA was obtained from samples immediately preserved with DNAzol than the corresponding shipped samples for 2 of the 3 days. More DNA was extracted from DNAzol preserved samples but more RNA was obtained from RLA+ preserved samples. A protocol was designed to extract both DNA and RNA from split samples preserved with RLA+ and cDNA was synthesized from the RNA. Three high-throughput 16S rRNA gene libraries were constructed, one from DNA preserved with DNAzol, one from DNA preserved with RLA+ and one from cDNA (RLA+ preserved). Greater alpha diversity was found for libraries constructed from immediately preserved vs. shipped samples for both preservation types, with immediate preservation with DNAzol obtaining the highest level of diversity. Libraries constructed from immediately preserved (RLA+) DNA had greater alpha diversity than libraries constructed from shipped preserved (RLA+) DNA or cDNA. Unifrac measures of beta diversity showed clearer separation of sample types and a greater % variance explained for weighted than for unweighted principal coordinate analysis (PCoA) plots, indicating sample types varied more in their relative abundance of taxa than the presence/absence of particular taxa. We recommend immediate preservation of seawater samples, with DNAzol as the preferred preservative if quantification via qPCR will be performed or the highest alpha diversity is desired but preservation with RLA+ if RNA will be extracted.
Evaluation of the deteriogenic microbial community using qPCR, n-alkanes and FAMEs biodegradation in diesel, biodiesel and blends (B5, B10, and B50) during storage
2018, Fuel
Citation Excerpt :
Besides being produced from renewable energy sources, the biodiesel has other characteristics that make it the most environmentally feasible and cleaner fuel in the transport sector [1,18–23]. Compared with the diesel oil, biodiesel has higher susceptibility to biodegradation by microorganisms, which is an important aspect to be considered during the storage [17,24–31]. Recent studies have shown that biodiesel has higher biodegradability capacity than diesel oil; it is able to create a synergistic effect that increases the biodegradation of diesel oil components [17,24–32].
Understanding the changes in microbial community structure and its impact during the storage of diesel and biodiesel is critical to prevent damage to the system and to ensure a good quality product to consumers. In this study, the storage of pure diesel (B0), diesel and biodiesel blends (B5, B10, and B50), and pure biodiesel (B100) was simulated. During the simulation, and after contamination with inoculum, microbial growth was monitored through biomass formation. Fungi and bacteria were quantified by qPCR. The effect of contamination on the biodegradation of fatty acid methyl esters (FAMEs) and n-alkanes was assessed by GC/qMS. After 60 days of incubation, B100 and B50 had the highest biomass production at the oil-water interface. Microorganism abundance was estimated by the amplification of 16S rRNA and 18S rRNA genes using qPCR. The fungal population formed at the oil-water interface was larger than the bacterial population, in all treatments. The abundance of bacteria with the alkB gene found in the blends was one or two orders of magnitude higher than that of the total bacteria estimated. The highest biodegradation rates of the C16:0, C18:0, C18:1 cis and C18:2 FAMEs (25.5, 17.5%, 34.5%, and 27.7%, respectively) occurred in the B5 blend. The highest n-alkane degradation occurred in the B50 and B10 blends. The n-alkanes C₂₀, C₁₈, C₁₅, C₁₄, and C₁₃ had 72.1%, 57.1%, 18.5%, 21.8%, and 19.6% degradation in B50, respectively. The n-alkanes C19, C12, and C10 had 61.3%, 6.9%, and 22.97% degradation in B10, respectively. The results indicate that knowledge about the microbial contamination of fuels is important for a correct management and to reduce the associated economic losses.
Anaerobic biodegradation of biofuels and their impact on the corrosion of a Cu-Ni alloy in marine environments
2018, Chemosphere
Citation Excerpt :
However, the biological stability of biofuels and their compatibility with the existing fuel storage and distribution infrastructure are insufficiently documented (Liang et al., 2016; Liang et al., 2015). Recent studies on the biostability of several alternative fuels and their potential impact on the biocorrosion of carbon steel have been reported (Aktas et al., 2013; Lee et al. 2012, 2014; Liang et al., 2016, Liang et al., 2015; Liang and Suflita, 2015). This led to the conclusion that first-generation biodiesel can deteriorate rapidly and exacerbate metal corrosion when in contact with marine microorganisms (Aktas et al., 2010; Lee et al., 2012).
Fuel biodegradation linked to sulfate reduction can lead to corrosion of the metallic infrastructure in a variety of marine environments. However, the biological stability of emerging biofuels and their potential impact on copper-nickel alloys commonly used in marine systems has not been well documented. Two potential naval biofuels (Camelina-JP5 and Fisher-Tropsch-F76) and their petroleum-derived counterparts (JP5 and F76) were critically assessed in seawater/sediment incubations containing a metal coupon (70/30 Cu-Ni alloy). Relative to a fuel-unamended control (1.2 ± 0.4 μM/d), Camelina-JP5 (86.4 ± 1.6 μM/d) and JP5 (77.6 ± 8.3 μM/d) stimulated much higher rates of sulfate reduction than either FT-F76 (11.4 ± 2.7 μM/d) or F76 (38.4 ± 3.7 μM/d). The general corrosion rate (r² = 0.91) and pitting corrosion (r² = 0.92) correlated with sulfate loss in these incubations. Despite differences in microbial community structure on the metal or in the aqueous or sediment phases, sulfate reducing bacteria affiliated with Desulfarculaceae and Desulfobacteraceae became predominant upon fuel amendment. The identification of alkylsuccinates and alkylbenzylsuccinates attested to anaerobic metabolism of fuel hydrocarbons. Sequences related to Desulfobulbaceae were highly enriched (34.2–64.8%) on the Cu-Ni metal surface, regardless of whether the incubation received a fuel amendment. These results demonstrate that the anaerobic metabolism of biofuel linked to sulfate reduction can exacerbate the corrosion of Cu-Ni alloys. Given the relative lability of Camelina-JP5, particular precaution should be taken when incorporating this hydroprocessed biofuel into marine environments serviced by a Cu-Ni metallic infrastructure.
Microbial activities in hydrocarbon-laden wastewaters: Impact on diesel fuel stability and the biocorrosion of carbon steel
2017, Journal of Biotechnology
Citation Excerpt :
Marine diesels regularly come into contact with oxygenated seawater, particularly in seawater-compensated fuel ballast tanks common on many warships (Lyles et al., 2013). Several studies have focused on the biodegradation of fuels and its impact on the steel corrosion under transiently aerobic conditions (Aktas et al., 2013; Lee et al., 2014). However, oxygen consumption by microbial heterotrophic respiration and abiotic reactions with iron cause the development of anaerobic conditions in naval ballast tanks and other storage facilities (Aktas et al., 2013; Lee et al., 2014).
Anaerobic hydrocarbon biodegradation not only diminishes fuel quality, but also exacerbates the biocorrosion of the metallic infrastructure. While successional events in marine microbial ecosystems impacted by petroleum are well documented, far less is known about the response of communities chronically exposed to hydrocarbons. Shipboard oily wastewater was used to assess the biotransformation of different diesel fuels and their propensity to impact carbon steel corrosion. When amended with sulfate and an F76 military diesel fuel, the sulfate removal rate in the assay mixtures was elevated (26.8 μM/d) relative to incubations receiving a hydroprocessed biofuel (16.1 μM/d) or a fuel-unamended control (17.8 μM/d). Microbial community analysis revealed the predominance of Anaerolineae and Deltaproteobacteria in F76-amended incubations, in contrast to the Beta- and Gammaproteobacteria in the original wastewater. The dominant Smithella-like sequences suggested the potential for syntrophic hydrocarbon metabolism. The general corrosion rate was relatively low (0.83 − 1.29 ± 0.12 mpy) and independent of the particular fuel, but pitting corrosion was more pronounced in F76-amended incubations. Desulfovibrionaceae constituted 50–77% of the sessile organisms on carbon steel coupons. Thus, chronically exposed microflora in oily wastewater were differentially acclimated to the syntrophic metabolism of traditional hydrocarbons but tended to resist isoalkane-laden biofuels.

View all citing articles on Scopus

View full text

Effects of oxygen on biodegradation of fuels in a corroding environment

Abstract

Highlights

Introduction

Section snippets

Fuel/seawater incubations

Before incubation

Discussion

Conclusions

Acknowledgments

Journal of Molecular Biology

Journal of Microbiological Methods

Current Opinion in Biotechnology

Anaerobic metabolism of biodiesel and its Impact on metal corrosion

Energy and Fuels

Standard practice for preparing, cleaning, and evaluating corrosion test specimens

Standard test method for conducting potentiodynamic polarization resistance measurements

Quantification of sulfate-reducing bacteria in industrial wastewater, by real-time polymerase chain reaction (PCR) using dsrA and apsA genes

Microbiology Ecology

Catechol dioxygenases

Essays in Biochemistry

Diversity of benzyl- and alkylsuccinate synthase genes in hydrocarbon-impacted environments and enrichment cultures

Environmental Science and Technology

Lentisphaera araneosa gen. nov., sp. nov, a transparent exopolymer producing marine bacterium, and the description of a novel bacterial phylum, Lentisphaerae

Environmental Microbiology

Greengenes, a chimera-checked 16S rRNA gene database and workbench compatible with ARB

Applied and Environmental Microbiology

Confidence limits on phylogenies: an approach using the bootstrap

Evolution

Aerobic degradation by microorganisms

Bioenergy production via microbial conversion of residual oil to natural gas

Applied and Environmental Microbiology

Microbiologically influenced corrosion as a model system for the study of metal microbe interactions: a unifying electron transfer hypothesis

Biofouling

Deep-sea oil plume enriches indigenous oil-degrading bacteria

Science

Green diesel: a second generation biofuel

International Journal of Chemical Reactor Engineering

A simple method for estimating evolutionary rates of base substitutions through comparative studies of nucleotide sequences

Journal of Molecular Evolution

Oxygen and pH microphiles above corroding mild steel covered with a biofilm

Biofouling

Corrosion of mild steel under anaerobic biofilm

Corrosion