In vitro and in silico cholinesterase inhibitory and antioxidant effects of essential oils and extracts of two new Salvia fruticosa mill. cultivars (Turgut and Uysal) and GC-MS analysis of the essential oils.

The EtOH extracts of the leaves of two new cultivars (Uysal-SFU and Turgut-SFT) of Salvia fruticosa Mill. was tested against acetylcholinesterase (IC50: 30.62 ± 3.27 and 32.97 ± 2.33 µg/mL for SFU and SFT, respectively) and butyrylcholinesterase (IC50: 69.91 ± 1.08 µg/mL and 86.55 ± 1.26 µg/mL), respectively, relevant to Alzheimer's disease. The essential oils showed a stumpy inhibition against AChE and no inhibition against BChE. DPPH radical scavenging activity of the extracts (86.70 ± 0.17% and 86.14 ± 1.13% for SFU and SFT, respectively) was stronger than that of quercetin (85.51 ± 0.17%): Their (1.24 ± 0.05 and 1.04 ± 0.16 for SFU and SFT, respectively) ferric-reducing antioxidant power were close to that of the reference (e.g. quercetin, 1.42 ± 0.14). Molecular docking simulations were performed on their major monoterpenes. Our findings revealed that the leaf EtOH extracts of two cultivars are promising inhibitors of both AChE and BChE.

Inducing Nucleophilic Reactivity at Beryllium with an Aluminyl Ligand.

The reactions of anionic aluminium or gallium nucleophiles {K[E(NON)]}2 (E = Al, 1; Ga, 2; NON = 4,5-bis(2,6-diisopropylanilido)-2,7-ditert-butyl-9,9-dimethylxanthene) with beryllocene (BeCp2) led to the displacement of one cyclopentadienyl ligand at beryllium and the formation of compounds containing Be-Al or Be-Ga bonds (NON)EBeCp (E = Al, 3; Ga, 4). The Be-Al bond in the beryllium-aluminyl complex [2.310(4) Å] is much shorter than that found in the small number of previous examples [2.368(2) to 2.432(6) Å], and quantum chemical calculations suggest the existence of a non-nuclear attractor (NNA) for the Be-Al interaction. This represents the first example of a NNA for a heteroatomic interaction in an isolated molecular complex. As a result of this unusual electronic structure and the similarity in the Pauling electronegativities of beryllium and aluminium, the charge at the beryllium center (+1.39) in 3 is calculated to be less positive than that of the aluminium center (+1.88). This calculated charge distribution suggests the possibility for nucleophilic behavior at beryllium and correlates with the observed reactivity of the beryllium-aluminyl complex with N,N'-diisopropylcarbodiimide─the electrophilic carbon center of the carbodiimide undergoes nucleophilic attack by beryllium, thereby yielding a beryllium-diaminocarbene complex.

A Preference for Heterolepticity - Schlenk Type Equilibria in Organometallic Beryllium Systems.

The reaction of homoleptic beryllium halide with diphenyl beryllium complexes leads to the clean formation of heteroleptic beryllium Grignard compounds [(L)1-2 BePhX]1-2 (X=Cl, Br, I; L=C-, N-, O-donor ligand). The influence of ligands and solvent on these compounds, their formation and exchange equilibria in solution were investigated, together with the factors determining the complex constitution.

Evaluation of Anti-Alzheimer Activity of Synthetic Coumarins by Combination of in Vitro and in Silico Approaches.

Series of synthetic coumarin derivatives (1-16) were tested against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), two enzymes linked to the pathology of Alzheimer's disease (AD). Compound 16 was the most active AChE inhibitor with IC50 32.23±2.91 µM, while the reference (galantamine) had IC50 =1.85±0.12 µM. Compounds 9 (IC50 75.14±1.82 µM), 13 (IC50 =16.14±0.43 µM), were determined to be stronger BChE inhibitors than the reference galantamine (IC50 =93.53±2.23 µM). The IC50 value of compound 16 for BChE inhibition (IC50 =126.56±11.96 µM) was slightly higher than galantamine. The atomic interactions between the ligands and the key amino acids inside the binding cavities were simulated to determine their ligand-binding positions and free energies. The three inhibitory coumarins (9, 13, 16) were next tested for their effects on the genes associated with AD using human neuroblastoma (SH-SY5Y) cell lines. Our data indicate that they could be considered for further evaluation as new anti-Alzheimer drug candidates.

Ino-Chloridolithates from Ionothermal Synthesis.

Anionic lithium-containing species were predicted to impact ionic liquid-based electrochemical applications but have hitherto never been isolated from ionic liquid systems. Here, we report the first representatives of this class of compounds, ino-chloridolithates, comprising [LiCl2]- and [Li2Cl3]- polyanions from ionothermal reactions. Such compounds are obtained at moderate temperatures with imidazolium-based ionic liquids and LiCl. The addition of an auxiliary ammonium salt enhances the lattice energy to yield an ammonium lithate in good yields, which enables extensive investigations including solid-state nuclear magnetic resonance, infrared, and Raman spectroscopy. The structural motifs of ino-lithates are related to ino-silicates, as 1D-extended anionic substructures are formed. Despite this analogy, according to density functional theory calculations with periodic boundary conditions, no evidence of covalent bonding in the anionic moieties is found-indicating packing effects to be the main cause for the formation. Based on an in-depth analysis of the different synthetic parameters, this class of compounds is discussed as an intermediate in ionic liquid applications and could serve as a model system for electrochemical lithium-based systems.

Outlining In Vitro and In Silico Cholinesterase Inhibitory Activity of Twenty-Four Natural Products of Various Chemical Classes: Smilagenin, Kokusaginine, and Methyl Rosmarinate as Emboldening Inhibitors.

Cholinesterase (ChE) inhibition is an important treatment strategy for Alzheimer's disease (AD) as acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) are involved in the pathology of AD. In the current work, ChE inhibitory potential of twenty-four natural products from different chemical classes (i.e., diosgenin, hecogenin, rockogenin, smilagenin, tigogenin, astrasieversianins II and X, astragalosides I, IV, and VI, cyclocanthosides E and G, macrophyllosaponins A-D, kokusaginin, lamiide, forsythoside B, verbascoside, alyssonoside, ipolamide, methyl rosmarinate, and luteolin-7-O-glucuronide) was examined using ELISA microtiter assay. Among them, only smilagenin and kokusaginine displayed inhibitory action against AChE (IC50 = 43.29 ± 1.38 and 70.24 ± 2.87 µg/mL, respectively). BChE was inhibited by only methyl rosmarinate and kokusaginine (IC50 = 41.46 ± 2.83 and 61.40 ± 3.67 µg/mL, respectively). IC50 values for galantamine as the reference drug were 1.33 ± 0.11 µg/mL for AChE and 52.31 ± 3.04 µg/mL for BChE. Molecular docking experiments showed that the orientation of smilagenin and kokusaginine was mainly driven by the interactions with the peripheral anionic site (PAS) comprising residues of hAChE, while kokusaginine and methyl rosmarinate were able to access deeper into the active gorge in hBChE. Our data indicate that similagenin, kokusaginine, and methyl rosmarinate could be hit compounds for designing novel anti-Alzheimer agents.

Norditerpenoids with Selective Anti-Cholinesterase Activity from the Roots of Perovskia atriplicifolia Benth.

Inhibition of cholinesterases remains one of a few available treatment strategies for neurodegenerative dementias such as Alzheimer's disease and related conditions. The current study was inspired by previous data on anticholinesterase properties of diterpenoids from Perovskia atriplicifolia and other Lamiaceae species. The acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibition by the three new natural compounds-(1R,15R)-1-acetoxycryptotanshinone (1), (1R)-1-acetoxytanshinone IIA (2), and (15R)-1-oxoaegyptinone A (3)-as well as, new for this genus, isograndifoliol (4) were assessed. Three of these compounds exhibited profound inhibition of butyrylcholinesterase (BChE) and much weaker inhibition of acetylcholinesterase (AChE). All compounds (1-4) selectively inhibited BChE (IC50 = 2.4, 7.9, 50.8, and 0.9 µM, respectively), whereas only compounds 3 and 4 moderately inhibited AChE (IC50 329.8 µM and 342.9 µM). Molecular docking and in silico toxicology prediction studies were also performed on the active compounds. Natural oxygenated norditerpenoids from the traditional Central Asian medicinal plant P. atriplicifolia are selective BChE inhibitors. Their high potential makes them useful candidate molecules for further investigation as lead compounds in the development of a natural drug against dementia caused by neurodegenerative diseases.

Novel pyridazinone derivatives as butyrylcholinesterase inhibitors.

In the current study, forty-four new [3-(2/3/4-methoxyphenyl)-6-oxopyridazin-1(6H)-yl]methyl carbamate derivatives were synthesized and evaluated for their ability to inhibit electric eel acetylcholinesterase (EeAChE) and equine butyrylcholinesterase (eqBuChE) enzymes. According to the inhibitory activity results, [3-(2-methoxyphenyl)-6-oxopyridazin-1(6H)-yl]methyl heptylcarbamate (16c, eqBuChE, IC50 = 12.8 µM; EeAChE, no inhibition at 100 µM) was the most potent eqBuChE inhibitor among the synthesized compounds and was found to be a moderate inhibitor compared to donepezil (eqBuChE, IC50 = 3.25 µM; EeAChE, IC50 = 0.11 µM). Kinetic and molecular docking studies indicated that compounds 16c and 14c (hexylcarbamate derivative, eqBuChE, IC50 = 35 µM; EeAChE, no inhibition at 100 µM) were mixed-type inhibitors which accommodated within the catalytic active site (CAS) and peripheral anionic site (PAS) of hBuChE through stable hydrogen bonding and π-π stacking. Furthermore, it was determined that [3-(2-methoxyphenyl)-6-oxopyridazin-1(6H)-yl]methyl (4-methylphenyl)carbamate 7c (eqBuChE, IC50 = 34.5 µM; EeAChE, 38.9% inhibition at 100 µM) was the most active derivative against EeAChE and a competitive inhibitor binding to the CAS of hBuChE. As a result, 6-(2-methoxyphenyl)pyridazin-3(2H)-one scaffold is important for the inhibitory activity and compounds 7c, 14c and 16c might be considered as promising lead candidates for the design and development of selective BuChE inhibitors for Alzheimer's disease treatment.

Combined molecular modeling and cholinesterase inhibition studies on some natural and semisynthetic O-alkylcoumarin derivatives.

Coumarins of synthetic or natural origins are an important chemical class exerting diverse pharmacological activities. In the present study, 26 novel O-alkylcoumarin derivatives were synthesized and have been tested at 100 µM for their in vitro inhibitory potential against acetylcholinesterase (AChE) and butyrlcholinesterase (BChE) targets which are the key enzymes playing role in the pathogenesis of Alzheimer's disease. Among the tested coumarins, none of them could inhibit AChE, whereas 12 of them exerted a marked and selective inhibition against BChE as compared to the reference (galanthamine, IC50 = 46.58 ±â€¯0.91 µM). In fact, 10 of the active coumarins showed higher inhibition (IC50 = 7.01 ±â€¯0.28 µM - 43.31 ±â€¯3.63 µM) than that of galanthamine. The most active ones were revealed to be 7-styryloxycoumarin (IC50 = 7.01 ±â€¯0.28 µM) and 7-isopentenyloxy-4-methylcoumarin (IC50 = 8.18 ±â€¯0.74 µM). In addition to the in vitro tests, MetaCore/MetaDrug binary QSAR models and docking simulations were applied to evaluate the active compounds by ligand-based and target-driven approaches. The predicted pharmacokinetic profiles of the compounds suggested that the compounds reveal lipophilic character and permeate blood brain barrier (BBB) and the ADME models predict higher human serum protein binding percentages (>50%) for the compounds. The calculated docking scores indicated that the coumarins showing remarkable BChE inhibition possessed favorable free binding energies in interacting with the ligand-binding domain of the target. Therefore, our results disclose that O-alkylcoumarins are promising selective inhibitors of cholinesterase enzymes, particularly BChE in our case, which definitely deserve further studies.

Profiling Auspicious Butyrylcholinesterase Inhibitory Activity of Two Herbal Molecules: Hyperforin and Hyuganin C.

Cholinergic therapy based on cholinesterase (ChE) inhibitory drugs is the mainstay for the treatment of Alzheimer's disease. Therefore, an extensive research has been continuing for the discovery of drug candidates as inhibitors of acetyl- and butyrylcholinesterase. In this study, two natural molecules, e. g. hyperforin and hyuganin C were tested in vitro for their AChE and BChE inhibitory activity. Both of the compounds were ineffective against AChE, whereas hyperforin (IC50 =141.60±3.39 µm) and hyuganin C (IC50 =38.86±1.69 µm) were found to be the highly active inhibitors of BChE as compared to galantamine (IC50 =46.58±0.91 µm) which was used as the reference. Then, these molecules were further proceeded to molecular docking experiments in order to establish their interactions at the active site of BChE. The molecular docking results indicated that both of them are able to block the access to key residues in the catalytic triad of the enzyme, while they complement some of the hydrophobic residues of the cavity, what is consistent with our in vitro data. While both compounds were predicted as mutagenic, only hyuganin C showed hepatotoxicity in in silico analysis. According to whole outcomes that we obtained, particularly hyuganin C besides hyperforin are the promising BChE inhibitors, which can be the promising compounds for AD therapy.

Morphological evolution caused by many subtle-effect substitutions in regulatory DNA.

Morphology evolves often through changes in developmental genes, but the causal mutations, and their effects, remain largely unknown. The evolution of naked cuticle on larvae of Drosophila sechellia resulted from changes in five transcriptional enhancers of shavenbaby (svb), a transcript of the ovo locus that encodes a transcription factor that governs morphogenesis of microtrichiae, hereafter called 'trichomes'. Here we show that the function of one of these enhancers evolved through multiple single-nucleotide substitutions that altered both the timing and level of svb expression. The consequences of these nucleotide substitutions on larval morphology were quantified with a novel functional assay. We found that each substitution had a relatively small phenotypic effect, and that many nucleotide changes account for this large morphological difference. In addition, we observed that the substitutions had non-additive effects. These data provide unprecedented resolution of the phenotypic effects of substitutions and show how individual nucleotide changes in a transcriptional enhancer have caused morphological evolution.

Anaerobic Biodegradation of Alternative Fuels and Associated Biocorrosion of Carbon Steel in Marine Environments.

Fuels that biodegrade too easily can exacerbate through-wall pitting corrosion of pipelines and tanks and result in unintentional environmental releases. We tested the biological stability of two emerging naval biofuels (camelina-JP5 and Fischer-Tropsch-F76) and their potential to exacerbate carbon steel corrosion in seawater incubations with and without a hydrocarbon-degrading sulfate-reducing bacterium. The inclusion of sediment or the positive control bacterium in the incubations stimulated a similar pattern of sulfate reduction with different inocula. However, the highest rates of sulfate reduction were found in incubations amended with camelina-JP5 [(57.2 ± 2.2)-(80.8 ± 8.1) µM/day] or its blend with petroleum-JP5 (76.7 ± 2.4 µM/day). The detection of a suite of metabolites only in the fuel-amended incubations confirmed that alkylated benzene hydrocarbons were metabolized via known anaerobic mechanisms. Most importantly, general (r(2) = 0.73) and pitting (r(2) = 0.69) corrosion were positively correlated with sulfate loss in the incubations. Thus, the anaerobic biodegradation of labile fuel components coupled with sulfate respiration greatly contributed to the biocorrosion of carbon steel. While all fuels were susceptible to anaerobic metabolism, special attention should be given to camelina-JP5 biofuel due to its relatively rapid biodegradation. We recommend that this biofuel be used with caution and that whenever possible extended storage periods should be avoided.

Multinuclear beryllium amide and imide complexes: structure, properties and bonding.

The beryllium amide and imide complexes [Be(HNMes)2]3, [(py)2Be(HNMes)2], [Be(HNDipp)2]2, [Be(NPh2)(µ2-HNDipp)]2 and [Be(NCPh2)2]3 have been prepared and characterised with NMR and IR spectroscopy as well as single crystal X-ray diffraction. Analysis of the localised molecular orbitals (LMOs) and intrinsic atomic orbital (IAO) atomic charges in the framework of the intrinsic bond orbital (IBO) localization method revealed a covalent bonding network consisting of 2-electron-2-centre and 2-electron-3-centre σ bonds, in which one electron pair of the anionic N-donor ligands is involved. The electron deficiency at the beryllium atoms is partially compensated through additional electron donation from the lone pair at the nitrogen atoms.

Impact of organosulfur content on diesel fuel stability and implications for carbon steel corrosion.

Ultralow sulfur diesel (ULSD) fuel has been integrated into the worldwide fuel infrastructure to help meet a variety of environmental regulations. However, desulfurization alters the properties of diesel fuel in ways that could potentially impact its biological stability. Fuel desulfurization might predispose ULSD to biodeterioration relative to sulfur-rich fuels and in marine systems accelerate rates of sulfate reduction, sulfide production, and carbon steel biocorrosion. To test such prospects, an inoculum from a seawater-compensated ballast tank was amended with fuel from the same ship or with refinery fractions of ULSD, low- (LSD), and high sulfur diesel (HSD) and monitored for sulfate depletion. The rates of sulfate removal in incubations amended with the refinery fuels were elevated relative to the fuel-unamended controls but statistically indistinguishable (∼50 µM SO4/day), but they were found to be roughly twice as fast (∼100 µM SO4/day) when the ship's own diesel was used as a source of carbon and energy. Thus, anaerobic hydrocarbon metabolism likely occurred in these incubations regardless of fuel sulfur content. Microbial community structure from each incubation was also largely independent of the fuel amendment type, based on molecular analysis of 16S rRNA sequences. Two other inocula known to catalyze anaerobic hydrocarbon metabolism showed no differences in fuel-associated sulfate reduction or methanogenesis rates between ULSD, LSD, and HSD. These findings suggest that the stability of diesel is independent of the fuel organosulfur compound status and reasons for the accelerated biocorrosion associated with the use of ULSD should be sought elsewhere.

Reactivity of free N-heterocyclic carbenes in dichloromethane.

The reactivity of free 1,3-diisopropyl-4,5-dimethylimidazol-2-ylidene (MeIPr) and 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene (IDipp) in dichloromethane was investigated. MeIPr reacts relatively slowly and selectively with the solvent under the formation of imidazolium salt [MeIPrH]Cl, which was characterised through NMR and IR spectroscopy as well as single crystal X-ray diffraction. Through deuterium labelling experiments the reaction rate was determined. In contrast IDipp reacts unselectively to various imidazolium salts. Due to the slow decomposition rates of MeIPr and IDipp in CH2Cl2, reactions of the free carbenes with BeBr2 to [(MeIPr)BeBr2], [(MeIPr)2BeBr2] and [(IDipp)BeBr2] can be performed.

Cholinesterase Inhibitory and In Silico Toxicity Assessment of Thirty-Four Isoquinoline Alkaloids - Berberine as the Lead Compound.

BACKGROUND: Cholinesterase (ChE) inhibitors used currently in clinics for the treatment of Alzheimer's disease (AD) are the most prescribed drug class with nitrogen-containing chemical formula. Galanthamine, the latest generation anti-ChE drug, contains an isoquinoline structure. OBJECTIVE: The aim of the current study was to investigate the inhibitory potential of thirty-four isoquinoline alkaloids, e.g. (-)-adlumidine, ß-allocryptopine, berberine, (+)-bicuculline, (-)-bicuculline, (+)-bulbocapnine, (-)-canadine, (±)-chelidimerine, corydaldine, (±)-corydalidzine, (-)-corydalmine, (+)-cularicine, dehydrocavidine, (+)-fumariline, (-)-fumarophycine, (+)-α-hydrastine, (+)-isoboldine, 13-methylcolumbamine, (-)-norjuziphine, norsanguinarine, (-)-ophiocarpine, (-)-ophiocarpine-N-oxide, oxocularine, oxosarcocapnine, palmatine, (+)-parfumine, protopine, (+)-reticuline, sanguinarine, (+)-scoulerine, (±)-sibiricine, (±)-sibiricine acetate, (-)-sinactine, and (-)-stylopine isolated from several Fumaria (fumitory) and Corydalis species towards acetyl- (AChE) and butyrylcholinesterase (BChE) by microtiter plate assays. The alkaloids with strong ChE inhibition were proceeded to molecular docking simulations as well as in silico toxicity screening for their mutagenic capacity through VEGA QSAR (AMES test) consensus model and VEGA platform as statistical approaches. The inputs were evaluated in a simplified molecular input-line entry system (SMILES). RESULTS: ChE inhibition assays indicated that the highest AChE inhibition was caused by berberine (IC50: 0.72 ± 0.04 µg/mL), palmatine (IC50: 6.29 ± 0.61 µg/mL), ß-allocryptopine (IC50: 10.62 ± 0.45 µg/mL), (-)-sinactine (IC50: 11.94 ± 0.44 µg/mL), and dehydrocavidine (IC50: 15.01 ± 1.87 µg/mL) as compared to that of galanthamine (IC50: 0.74 ± 0.01 µg/mL), the reference drug with isoquinoline skeleton. Less number of the tested alkaloids exhibited notable BChE inhibition. Among them, berberine (IC50: 7.67 ± 0.36 µg/mL) and (-)-corydalmine (IC50: 7.78 ± 0.38 µg/mL) displayed a stronger inhibition than that of galanthamine (IC50: 12.02 ± 0.25 µg/mL). The mutagenic activity was shown for ß-allocryptopine, (+)- and (-)-bicuculline, (±)-corydalidzine, (-)-corydalmine, (+)-cularicine, (-)-fumarophycine, (-)-norjuziphine, (-)-ophiocarpine-N-oxide, (+)-scoulerine, (-)-sinactine, and (-)-stylopine by means of in silico experiments. The results obtained by molecular docking simulations of berberine, palmatine, and (-)-corydalmine suggested that the estimated free ligand-binding energies of these compounds inside the binding domains of their targets are reasonable to make them capable of establishing strong polar and nonpolar bonds with the atoms of the active site amino acids. CONCLUSION: Our findings revealed that berberine, palmatin, and (-)-corydalmine stand out as the most promising isoquinoline alkaloids in terms of ChE inhibition. Among them, berberine has displayed a robust dual inhibition against both ChEs and could be evaluated further as a lead compound for AD.

Proteogenomic elucidation of the initial steps in the benzene degradation pathway of a novel halophile, Arhodomonas sp. strain Rozel, isolated from a hypersaline environment.

Lately, there has been a special interest in understanding the role of halophilic and halotolerant organisms for their ability to degrade hydrocarbons. The focus of this study was to investigate the genes and enzymes involved in the initial steps of the benzene degradation pathway in halophiles. The extremely halophilic bacteria Arhodomonas sp. strain Seminole and Arhodomonas sp. strain Rozel, which degrade benzene and toluene as the sole carbon source at high salinity (0.5 to 4 M NaCl), were isolated from enrichments developed from contaminated hypersaline environments. To obtain insights into the physiology of this novel group of organisms, a draft genome sequence of the Seminole strain was obtained. A cluster of 13 genes predicted to be functional in the hydrocarbon degradation pathway was identified from the sequence. Two-dimensional (2D) gel electrophoresis and liquid chromatography-mass spectrometry were used to corroborate the role of the predicted open reading frames (ORFs). ORFs 1080 and 1082 were identified as components of a multicomponent phenol hydroxylase complex, and ORF 1086 was identified as catechol 2,3-dioxygenase (2,3-CAT). Based on this analysis, it was hypothesized that benzene is converted to phenol and then to catechol by phenol hydroxylase components. The resulting catechol undergoes ring cleavage via the meta pathway by 2,3-CAT to form 2-hydroxymuconic semialdehyde, which enters the tricarboxylic acid cycle. To substantiate these findings, the Rozel strain was grown on deuterated benzene, and gas chromatography-mass spectrometry detected deuterated phenol as the initial intermediate of benzene degradation. These studies establish the initial steps of the benzene degradation pathway in halophiles.

Molecular tools to track bacteria responsible for fuel deterioration and microbiologically influenced corrosion.

Investigating the susceptibility of various fuels to anaerobic biodegradation has become complicated with the recognition that the fuels themselves are not sterile. Bacterial DNA could be obtained when various fuels were filtered through a hydrophobic teflon (0.22 µm) membrane filter. Bacterial 16S rRNA genes from these preparations were PCR amplified, cloned, and the resulting libraries sequenced to identify the fuel-borne bacterial communities. The most common sequence, found in algal- and camelina-based biofuels as well as in ultra-low sulfur diesel (ULSD) and F76 diesel, was similar to that of a Tumebacillus. The next most common sequence was similar to Methylobacterium and was found in the biofuels and ULSD. Higher level phylogenetic groups included representatives of the Firmicutes (Bacillus, Lactobacillus and Streptococcus), several Actinobacteria, Deinococcus-Thermus, Chloroflexi, Cyanobacteria, Bacteroidetes, Alphaproteobacteria (Methylobacterium and Sphingomonadales), Betaproteobacteria (Oxalobacteraceae and Burkholderiales) and Deltaproteobacteria. All of the fuel-associated bacterial sequences, except those obtained from a few facultative microorganisms, were from aerobes and only remotely affiliated with sequences that resulted from anaerobic successional events evident when ULSD was incubated with a coastal seawater and sediment inoculum. Thus, both traditional and alternate fuel formulations harbor a characteristic microflora, but these microorganisms contributed little to the successional patterns that ultimately resulted in fuel decomposition, sulfide formation and metal biocorrosion. The findings illustrate the value of molecular approaches to track the fate of bacteria that might come in contact with fuels and potentially contribute to corrosion problems throughout the energy value chain.