Transformations of <Emphasis Type="Italic">n</Emphasis>-alkanes from petroleum pollutants in alluvial groundwaters

Investigations presented in this paper were aimed at defining the alterations of n-alkane composition in cases of oil-polluted alluvial sediments. Therefore, oil-polluted groundwater samples, taken in five different time intervals during a period of 28 months, were investigated. Samples of alluvial sediments were taken from two boreholes within an oil refinery at Pancevo, Yugoslavia. In both boreholes significant alterations with characteristic degradation of "oil" n-alkanes with no odd- or even-member predominance were observed, as well as subsequent synthesis of new ones with pronounced even-member predominance, and with maxima at C₁₆ and C₁₈. Since no additional contamination of boreholes was observed by analyses of steranes and triterpanes, the observed changes can only be attributed to microbial activity. It is assumed that for the degradation of oil n-alkanes, as well as for the synthesis of "new" n-alkanes, algae such as dinoflagellates are responsible. This assumption was confirmed by identification of n-alcohols with even-member predominance (C₁₄–C₂₀), by identification of cholesterol, as well as of n-fatty acids with even-member predominance (C₁₄–C₁₈) in the extract with n-alkane even-member predominance. Electronic Publication     

Isotopic evidences for microbiologically mediated and direct C input to soil compounds from three different leaf litters during their decomposition

We show the potentiality of coupling together different compound-specific isotopic analyses in a laboratory experiment, where ¹³C-depleted leaf litter was incubated on a ¹³C-enriched soil. The aim of our study was to identify the soil compounds where the C derived from three different litter species is retained. Three ¹³C-depleted leaf litter (Liquidambar styraciflua L., Cercis canadensis L. and Pinus taeda L., δ¹³C_vsPDB ≈ ?43‰), differing in their degradability, were incubated on a C4 soil (δ¹³C_vsPDB ≈ ?18‰) under laboratory-controlled conditions for 8 months. At harvest, compound-specific isotope analyses were performed on different classes of soil compounds [i.e. phospholipids fatty acids (PLFAs), n-alkanes and soil pyrolysis products]. Linoleic acid (PLFA 18:2ω6,9) was found to be very depleted in ¹³C (δ¹³C_vsPDB ≈ from ?38 to ?42‰) compared to all other PLFAs (δ¹³C_vsPDB ≈ from ?14 to ?35‰). Because of this, fungi were identified as the first among microbes to use the litter as source of C. Among n-alkanes, long-chain (C27–C31) n-alkanes were the only to have a depleted δ¹³C. This is an indication that not all of the C derived from litter in the soil was transformed by microbes. The depletion in ¹³C was also found in different classes of pyrolysis products, suggesting that the litter-derived C is incorporated in less or more chemically stable compounds, even only after 8 months decomposition.     

Effects of grazing by deposit feeders on biogenic hydrocarbons in coral-reef surface sediments

The Fraction I hydrocarbons (containing alkanes, some alkenes, cyclo-alkanes or-alkenes) in the top 2 cm of sediment, in two species of deposit feeders (the holothurian Holothuria atra and the gastropod Strombus luhuanus), and in their feces were analyzed. Collections were made at Heron Island in December, 1982, and analyses were completed in January 1983. On the basis of their relative concentrations in whole samples, and in the lipid fractions of sediment and animal tissue, the Fraction I hydrocarbons were placed in three categories. Some compounds give evidence of passive movement from a high concentration in sediment lipid into an area of lower concentration in animal lipid fractions. Others may be selectively excreted and/or degraded by animals; while still others appear to be selectively accumulated and/or produced in animal tissue. The relatively short-chain n-alkanes, mono-olefins and C₂₅ cyclo-alkanes or alkenes in sediment and feces showed a net loss from sediment on its passage through the animals, whereas C₂₂ to C₃₂ n-alkanes, showed a net production in the guts of the animals and contributed to the pool of these compounds in sediments. About 40 to 55% of the group of short-chain n-alkanes, mono-olefins and C₂₅ cyclo-alkanes or alkenes in sediment are converted into long-chain n-alkanes as the sediment passes through the guts of H. atra and S. luhuanus. H. atra remove about 0.2% of the standing pool of short-chain n-alkanes, mono-olefins and C₂₅ cyclo-alkanes or alkenes in an average square-metre of sediment, of 2 cm depth, per day, and they contribute an amount of n-C₂₂ to n-C₃₂ alkanes equal to about 1.1% of the standing pool of these compounds.     

Investigation of the sources of aliphatic hydrocarbons in the mussel Mytilus edulis from north sea oil production platforms by Capillary glc and CGCMS†

Aliphatic hydrocarbons isolated from mussels collected over a 20 month period from three North Sea Forties field oil production platforms have been examined by capillary gas chromatography and gas chromatography‐mass spectrometry.

The biological hydrocarbons consist predominantly (300–700 μh g^‐1 lipid) of C₃₁ and C₃₃ n‐alkenes with 2, 3 and 4 double bonds probably derived from a dietary intake of Emiliania huxleyi, a microscopic coccolithophorid alga. In some of the mussels C₁₈, C₂₀ and C₂₂ n‐alkanes are present in unusually high abundance compared to their odd carbon number homologues. Possible reasons for this distribution are discussed.

The concentrations of fossil fuel hydrocarbons (mainly unresolved complex mixtures) in the mussels ranged from 330 to 5,298 μg g^‐1 of lipid. No significant increase in values was detected two months after the start of discharge of treated Forties production water from the Forties D platform.

To determine the pollutant hydrocarbon sources, the sterane and terpane distributions of hydrocarbon fractions isolated from the mussels and from a number of fossil fuels, including Forties crude oil, were examined by mass fragmentography. The steranes in the mussels from the Forties C and D platforms contained higher proportions of regular 14α(H), 17α(H) components than Forties oil in which the steranes were mainly 13ß(H), 17α(H) diasteranes. In addition, the terpane distributions of the mussel fractions differed markedly from that of Forties crude oil, particularly in the relative abundance of diterpanes to triterpanes, which was higher in the mussel fractions than in the oil, and in the absence of 17α(H), 18α(H), 21ß(H)‐18, 30‐bisnorhopane, a known component of Forties crude. Furthermore, the ratio of C₂₉ to C₃₀ triterpanes was greater than unity in the mussels but much less than unity in the Forties oil. These data preclude Forties or other similar North Sea crudes as the major source of pollutant aliphatic hydrocarbons in the mussels. The relative concentrations and distributions of steranes and triterpanes suggest that the most likely source of pollutants is a Middle Eastern based oil derived either from rig activities, or from background pollution in the North Sea. The low concentration of ≥ C₂₇ steranes in the more polluted mussels (e.g. Forties B; UCM > 200 ppm dry wt.) suggests that gas oils used on the platforms may be the major source of petrogenic hydrocarbons in these samples.     

Evidence for n-alkane consumption and oxidation by filamentous cyanobacteria from oil-contaminated coasts of the Arabian Gulf

Microcoleus chthonoplastes and Phormidium corium were isolated from microbial mats covering all sediments along the Arabian Gulf coasts. These isolates could consume and oxidise n-alkanes. The establishment of axenic cultures faced the problem that with progressive axenity the cyanobacterial growth seemed to cease. The associated organotrophic bacteria, Rhodococcus rhodochrous, Arthrobacter nicotianae, Pseudomonas sp. and Bacillus sp., could utilize n-alkanes. The total number of these organotrophs was about 2×10⁶ cells g⁻¹ fresh culture, and R. rhodochrous was the most dominant. In order to test the potential of cyanobacteria for n-alkane consumption, experiments were constructed to rule out the role of the associated organotrophic bacteria. Aliquots, 0.5 g fresh cyanobacterial samples, each containing about 1×10⁶ organotrophic bacterial cells (≡0.001 mg fresh bacteria) were incubated in inorganic medium aliquots supplied with an n-alkane. The same was repeated using 1.0×10⁶ cells each of the four organotrophic bacteria instead of the cyanobacterial samples. The nonaxenic cyanobacterial samples consumed up to 60% of the available alkane, whereas no detectable consumption was measured in any of the pure organotrophic bacterial cultures. For all organotrophic bacteria, the numbers had to be increased ten-thousand times in order that detectable alkane consumption might become measurable. The fatty acids resulting from the n-alkane oxidation were found incorporated in cell lipid classes characteristic of cyanobacteria, namely in galactolipids and sulfolipids. These results may imply that the two test cyanobacteria contribute directly to n- alkane uptake and oxidation. Received: 6 May 1997 / Accepted: 2 October 1997     

Particulate and semivolatile associated aliphatic hydrocarbon exhaust emission from heavy duty diesel vehicles

The exhaust emissions from two heavy duty diesel vehicles running on eight different fuel compositions were investigated regarding their content of high molecular weight (≥ C₁₂) aliphatic/ olefinic hydrocarbons. It was concluded that the emitted amount of semi‐volatile associated aliphatic hydrocarbons (range C₁₂‐C₂₂) depend on the fuel used in the engines and that these emissions mainly consisted of uncombusted fuel components. It was also found that uncombusted engine lubrication oil was the main constituent of the emitted particulate associated aliphatic hydrocarbons (C₁₇‐C₄₀). These constituted between 58% and 95% of the total emissions of the high molecular weight aliphatic compounds. Emission factors for the total of high molecular aliphatic hydrocarbons (C₁₂‐C₄₀) were demonstrated to be in the range of 15–100 mg/km. Some individual aliphatic hydrocarbons with cocarcinogenic effects were identified and quantified in both particulate and semi‐volatile phases of the exhaust. Multivariate data analysis was used to investigate the relationship between fuel parameters and emission of semi‐volatile aliphatic emission.     

Glycolate metabolism by Pseudomonas sp., strain S227, isolated from a coastal marine sediment

Glycolate excreted by phytoplankton is a potentially important nutrient for bacteria in coastal and estuarine environments. The metabolism of glycolate by Pseudomonas sp., strain S227, originally isolated from the New York Bight Apex, has been studied. The specific growth rate for this strain on glycolate is 0.156 doublings h^-1. The apparent V_max and K_m for glycolate uptake are 83.6 nmol min^-1 mg cell protein^-1 and 7.4x10^-8 M, respectively. The preferential respiration of the carboxyl carbon (C-1) and the incroporation of the hydroxymethyl carbon (C-2) suggest that the glycerate pathway is used for growth on glycolate. Alternatively, another pathway can be utilized which results in the complete catabolism of glycolate. Glycolate and lactate metabolism are also closely linked either by a common metabolic pathway or a common transport system other than the monocarboxylate transport system. The magnesium ion concentration is also important in glycolate metabolism. The characteristics of glycolate metabolism observed in Pseudomonas sp., strain S227, are advantageous in coastal and estuarine environments where glycolate production is intermittent, and the concentrations are low.     

Very long-chain aliphatic hydrocarbons in lipids of mussels (Mytilus edulis) suspended in the water column near petroleum operations off Sable Island,Nova Scotia,Canada

Mussels (Mytilus edulis) suspended in the water column in 1994 and 1995 for the monitoring of oil drilling operations off Sable Island, Nova Scotia were examined for hydrocarbon profiles, particularly aliphatic hydrocarbons. A spring bloom of phytoplankton occurred during the 90-d suspension period in 1995. Hydrocarbons isolated from the 1995 suspended mussels showed very high concentrations of both biogenic hydrocarbons and very long-chain n-alkanes from C₂₀ to C₃₂, initially thought to be petrogenic. Both types of hydrocarbons were either not detected or were only present in trace amounts in the mussels suspended in 1994 at similar sites. The biogenic hydrocarbons in the 1995 mussels were apparently of planktonic origin, from the spring bloom, and were dominated by heneicosahexaene (21:6), followed by pristance, heptadecane, and varions monounsaturated and polyunsaturated phytenes, heptadecenes, nonadecenes and heneicosenes. They could be readily hydrogenated to yield the basic alkanes. The 1995 mussels suspended within 1 km from the oil well platform were probably slightly tainted by petrogenic hydrocarbons, as evidenced by the detection of phytane and high concentrations of total aliphatic hydrocarbons, whereas the mussels suspended 10 km from the platform showed only high concentrations of biogenic hydrocarbons and the novel long-chain n-alkanes. The occurrence of an unusual phytoplankton bloom during the suspension period severely interfered with the petroleum monitoring role of mussels by altering the mussel hydrocrbon profiles through the accumulation into and probably selective depuration of xenobiotic hydrocarbons from the mussel, tissues.J. Parsons (deceased)     

Dibenzofuran: Bakterielle Mineralisierung

The degradation of uniformly¹⁴C-labelled dibenzofuran (DBF) by the strainPseudomonas sp HH 69 and a consortium consisting of the DBF-degrading Pseudomonas strain NRM and an accompanying Nocardia-like strain NRH, was monitored in liquid-batch cultures and in different soil samples. Experiments involving the strain and a consortium in aereated liquid cultures (batch process) showed that DBF was utilized as a source of energy and carbon. Thereby, more than 65% of DBF is rapidly converted to CO₂, about 20% to biomass and only about 10% to slow-degrading intermediate metabolites, respectively. The same microorganisms also exhibited comparable degrees of degradation efficiency in various types of soils contaminated with DBF. For instance, DBF, uniformly distributed in sterile soil samples, in concentrations between 0.2 to 200 ppm, was converted to CO₂, within 10 days, to the extent of about 75% by the strainPseudomonas sp. HH 69.     

Evidence for covalently bonded chlorine–fullerene formed by ozonation and chlorination at room temperature

This article reports for the first time that fullerene (nC₆₀) can form chlorinated disinfection by-products in aqueous systems at ambient temperature. The ability of nC₆₀ to form colloidal suspensions in aqueous media increases the chance that these particles will migrate in the environment and then in drinking water supply systems. Since nC₆₀ is not completely removed by conventional water treatment, any residual nC₆₀ is likely to be oxidized during disinfection process. While the ozonation of nC₆₀ has been studied, little is known about the reaction between nC₆₀ and chlorine. To address this issue, we subjected aqueous nC₆₀ suspensions to chlorination and sequential ozonation/chlorination at ozone dosages of 4.5, 10, 15 and 24 mg O₃/mg nC₆₀. The morphology and physicochemical properties of oxidized nC₆₀ aggregates were evaluated by scanning electron microscopy, transmission electron microscopy, UV–visible absorption spectroscopy and X-ray photoelectron spectroscopy (XPS). We found that while the particles in the as-prepared nC₆₀ were predominantly spheres, the ozonation of nC₆₀ resulted in the formation of irregularly shaped aggregates. The concentration of atomic carbon found by XPS in the nC₆₀ samples decreased from 92 % for the as-prepared nC₆₀ to 50 % for the aggregates ozonated at 24 mg O₃/mg nC₆₀ and then chlorinated at 68 mg Cl₂/L and allowed to react for 100 min. The presence of Cl atoms covalently bonded to C atoms was confirmed by XPS peaks corresponding to a binding energy (E _b) of 200.1–202.4 eV. This demonstrates the need to better assess and monitor the formation of potentially toxic chlorinated disinfection by-products from carbon nanomaterials during water treatment.     

Strengthening effects of ammonia nitrogen on the harmless biological treatment of oily sludge

To improve the efficiency of oil degradation and strengthen the harmless treatment of oily sludge, three dominant strains identified as Chryseomicrobium sp. YL2, Gordonia sp. YL3 and Acinetobacter sp. YL5 were isolated from soil near a refinery, and the effects on the bioremediation of the oily sludge from the refinery were investigated. The results showed that the efficiency of oil degradation increased by 31.5% compared with the control when the dominant strains were added to the treatment of oily sludge. Furthermore, the dominant strains could use oil as a carbon source for heterotrophic nitrification–aerobic denitrification. The addition of ammonia nitrogen resulted in a large number of remaining microbes and heightened dehydrogenase activity in the oily sludge, further accelerating oil degradation, mainly for C₁₁ to C₂₅ saturated hydrocarbons, and the oil degradation efficiency increased by 40.8%. After 120 days of bioremediation, the biotoxicity of oily sludge, which was expressed by the equivalent phenol concentration, decreased by 40.0% compared with that of the control, indicating that the addition of ammonia nitrogen enhanced the biodegradation of oil. This method can be used to strengthen the harmless treatment of oily sludge in practical engineering applications.     

Biosorption and biotransformation of crystal violet by Aeromonas hydrophila DN322p

DN322p, an offspring of Aeromonas hydrophila DN322, has the capacity to adsorb and decolorize triphenylmethane dyes in wastewater simultaneously. As a common triphenylmethane dye, crystal violet (CV) was chosen to test the decolorization characteristics of DN322p. Within 0.5 h, the strain DN322p adsorbed a large amount of CV, producing a deep-colored cell pellet and colorless supernatant. The colors of the cell pellet and supernatant lightened over time. The supernatant and dichloromethane extract of the cell pellet both showed conspicuous CV and leuco CV (LCV) characteristic absorbance peaks at 590 nm and 260 nm, respectively, in the UV-vis spectral analysis. This finding indicated that the DN322p cells can adsorb the two dyes. A 99% (w/w) decolorization rate was achieved within 2.5 h with shaking at 30°C for 50 mg CV·L^?1. High Performance Liquid Chromatography (HPLC) analysis of the dichloromethane extract of the supernatant and cell pellet confirmed that CV was mainly converted into its leuco form. Dead cells had a similar adsorption capacity with living cells. About 90% of CV in the dye solution (50 mg·L^?1) was removed by autoclaved cells with an optical delnsity at 600 nm (OD₆₀₀) above 1.0.     

Adsorption of fluoride on clay minerals and their mechanisms using X-ray photoelectron spectroscopy

This research investigates the adsorption mechanisms of fluoride (F) on four clay minerals (kaolinite, montmorillonite, chlorite, and illite) under different F^? concentrations and reaction times by probing their fluoride superficial layer binding energies and element compositions using X-ray photoelectron spectroscopy (XPS). At high F^? concentrations (C ₀ = 5?C1000 mg·L^?1), the amount of F^? adsorbed (Q _F), amount of hydroxide released by clay minerals, solution F^? concentration, and the pH increase with increasing C ₀. The increases are remarkable at C ₀>50 mg·L^?1. The QF increases significantly by continuously modifying the pH level. At C ₀<5?C100 mg·L^?1, clay minerals adsorb H⁺ to protonate aluminum-bound surface-active hydroxyl sites in the superficial layers and induce F^? binding. As the C ₀ increases, F^?, along with other cations, is adsorbed to form a quasi-cryolite structure. At C ₀>100 mg·L^?1, new minerals precipitate and the product depends on the critical Al³⁺ concentration. At [Al³⁺]>10^?11.94 mol·L^?1, cryolite forms, while at [Al³⁺]<10^?11.94 mol·L^?1, AlF₃ is formed. At low C ₀ (0.3?C1.5 mg·L^?1), proton transfer occurs, and the F^? adsorption capabilities of the clay minerals increase with time.     

Geochemical and ecological significance of soil lipids under Rhododendron ponticum stands

The bio-geographical significance of Rhododendron ponticum spp. baeticum (Ericaceae) as a relict species is well recognized. However, out of its native habitat it is an invasive exotic considered a major threat to natural ecosystems in areas of Atlantic Western Europe. The studies on the impact of Rhododendron influence on soil organic matter composition and associated ecological implications, i.e. presence of bioactive compounds with ecological significance, are limited. This work describes the soil lipid assemblage in three sites under Rhododendron stands and adjacent sites with deciduous oak (Quercus canariensis), both in their native habitats in Southern Spain (Sierra de Luna, Cádiz). The results are discussed in terms of organic matter dynamics and the presence of molecules that may be associated with Rhododendron invasive success. The soils are acid Xerochrepts formed on siliceous sands. Composite soil samples were taken at two depths (0?C10?cm and 10?C20?cm) and soxhlet extracted with a dichloromethane-methanol mixture (3:1). Soil lipid assemblage was studied by GC/MS after fractionation and appropriate derivatization of extracts. The qualitative chemical composition of soil extractable lipids under Rhododendron is reported here for the first time. Our results show that soil n-alkane and fatty acid distributions are compatible with an input from plant epicuticular waxes, as well as with the occurrence of selective preservation of long-chain fatty acids with depth. The pattern of short-chain n-alkanes found in surface samples indicates an anthropogenic contamination threat from nearby industrialized areas of ??Campo de Gibraltar??. The presence of branched iso and anteiso C₁₅ and C₁₇, ??-hydroxy fatty acids and the sterol brassicasterol points to high microbial soil activity. Finally, the pentacyclic triterpenes taraxerone and taraxerol were detected in soils with Rhododendron but not with Quercus. These are known bio-active plant compounds and could be related with the effectiveness of Rhododendron as an invasive exotic species.     

Hydrocarbons characterization in coastal sediments of the Argentine Patagonia using the nuclear magnetic resonance (NMR) spectroscopy

Hydrocarbons in Patagonian sediments were analyzed to evaluate their biogenic or petrogenic origins. Structural determination by ¹H-NMR spectrometry and principal component analysis (PCA) show that the first two principal components accounted for more than 75.7% of the variance. The results indicate that biogenic hydrocarbons have mainly linear hydrocarbon chains and polar groups (high H₂, H₄, H₅, and H_COOH), while petrogenic hydrocarbons show more branched chains and mainly mono-aromatic components, e.g., crude oil (high H₁, H_1A, and H₃) or mainly poly-aromatic components (high H₄, and H_2A) in weathering oil.     

Application of an odd/even predominance of n-alkanes in oil–source rock correlation: taking the lower Paleozoic strata of the Tarim Basin as an example

The composition and distribution of n-alkanes carbon numbers reflect the source of kerogenic organic matter, sedimentary environment, and maturity of the rocks. The comparison results of the n-alkanes GC (gas chromatography) chromatograms in the Tazhong Low Uplift show that the n-alkanes of the source rocks in Upper Ordovician display an odd carbon number predominance. At the same time, Cambrian–Lower Ordovician exhibit an even carbon number predominance. The correlation between oil and source rock illustrates that crude oils in the fields of well TZ10-12 and well TZ24 stem from the Upper Ordovician source rocks. The origins of the crude oils in the fields of well TZ161-162 and well TZ45 are Cambrian–Lower Ordovician. The strata corresponding to the crude oils with odd/even carbon number predominance match the oil–source rock correlation. Thus, the characteristics of odd/even carbon number predominance in n-alkane compounds are effective for oil–source rock correlation in the Tazhong Low Uplift, Tarim Basin.     

Biogeochemistry of aromatic hydrocarbons in the benthos of microcosms†

Investigations into the fate of petroleum compounds in the marine environment were carried out using experimental microcosms of two sizes and designs. Aromatic hydrocarbons or No. 2 fuel oil were spiked to the water of a 13 m³ continuous flow system and to a 2281 recycled flow system. The transport and alteration of this oil was traced in the sediment and benthic organisms (Glycera americana, Crepidula sp., and Nephtys incisa) of these microcosms. Measurable contamination was found in both sample types. The aromatic hydrocarbon distribution, including relative isomeric distribution (e.g., C₂‐phenanthrenes) was found to be different in sediment and in organisms from that which was originally introduced to the experimental microcosm. Differences in isomer distribution between Glycera and Crepidula were also detected. Based on the experimental data: molecular weight and specific isomeric form, biochemical processes, solubility, and particle adsorption/desorption influence the fate of petroleum compounds in benthic ecosystems.     

New denitrifying bacteria isolated from Red Sea sediments

Sediments of various newly discovered deeps in the Red Sea were analyzed for the occurrence of denitrifying bacteria. The samples were collected in 1972 during the Valdivia cruises. Among the 27 different samples investigated, 17 revealed both coccoid and rod-shaped bacteria when enriched in complex nutrient broth (with 10% NaCl). Denitrifiers were recorded abundantly in the sediments, their population decreasing from some 10⁶/g in the surface material to only a few in the subsediment. A total of 16 pure cultures of denitrifying bacteria were isolated from the Suakin-and Thetis-deeps and studied morphologically, physiologically and biochemically. Genetics (molar percentage of guanine plus cytosine, % GC) and numerical taxonomy were included to reveal relationships and improve taxonomic classification. Fifteen isolates were described as Gram-negative, aerobic and facultative anaerobic (with NO ₃ ^- as H⁺-acceptor), polarly flagellated rods (Pseudomonas spp.); one was an inmotile, Gram-positive, facultative anaerobic coccus. None of the 15 Pseudomonas-isolates could be identified with one of the denitrifying species so far described and recognized. The strains should be regarded as hitherto undescribed denitrifying marine bacteria.Supported by the Bundesministerium für Forschung und Technologie, Bonn, Germany (FRG).     

Ecological significance of salp fecal pellets collected by sediment traps in the eastern North Pacific

Five sediment traps were moored at depths of 740, 940, 1 440, 3 440 and 4 240 m for 7 d in December 1982 at Station 5 in the eastern North Pacific about 400 km from San Francisco. Dark green sinking particles enclosed in tough membrane consisted of mostly coccolithophores with some diatoms, dinoflagellates and chrysophytes. The average size of the particles was 10x5x2 mm. These characteristics indicate that the particles were fecal pellets of salp inhabiting the surface waters. Vertical fluxes of the organic carbon and nitrogen through sinking of the salp fecal pellets ranged from 6.7 to 23 mgC m^-2 d^-1 and from 0.88 to 3.2 mgN m^-2 d^-1, respectively. These values were several times higher than those determined in other oceanic areas by sediment trap experiments. Hydrocarbons consisting of short-chain n-alkanes (n-C₁₅-C₂₀) with n-C₁₇, the most predominant component, heneicosa-hexaene (n-C_21:6), br-C₂₅ alkenes and long-chain n-alkanes (n-C₂₁-C₃₀), without any odd or even carbon number predominance, were found from five depths. The presence of short-chain n-alkanes and n-C_21:6 indicated that phytoplankton in the surface waters was a primary source of organic matter in the sinking particles. Two isomers of br-C_25:3 and br-C_25:4 alkenes found in these particles also indicated that br-C₂₅ alkenes were the important biological marker of fecal pellet of zooplankton. The distribution pattern of the long-chain n-alkanes suggested that the sinking particles may be affected by bacteria to some extent. Fatty acids of the sinking particles were separated into free, triglyceride and wax ester fractions consisting of mono- and poly-unsaturated, and saturated fatty acids, with a range from C₁₄ to C₃₀. Concentrations of mono- and poly-unsaturated fatty acids decreased more rapidly toward the deep than those of saturated fatty acids, which cause low ratios of mono- and poly-unsaturated fatty acids/saturated fatty acids. This indicates that unsaturated fatty acids were more rapidly decayed by marine microbes than saturated fatty acids in the deep water, despite the fact that a significant amount of unsaturated fatty acids still remained in the sinking particles collected from the deep waters. Our results revealed that the salp fecal pellet plays an important role in supplying foods to organisms in intermediate and deep seas.