Primary Production Of Organic Matter Research Articles

Characterization of the particulate protein in Pacific surface waters

We investigated molecular characteristics of particulate proteins in Pacific surface waters using two-dimensional electrophoresis (2DE). Most proteinaceous materials estimated by dye-binding methods were characterized by the 2DE unresolved acidic materials with a broad range of molecular mass and the 2DE unresolved low molecular mass materials with a broad range of isoelectric point. The 2DE unresolved acidic and low molecular mass materials were considered to comprise peptides conjugated with acidic saccharides and degradation products (peptides) of proteins, respectively, which indicates that almost all proteins in living organisms failed to survive in detrital particulate organic matter (POM). Nevertheless, 23 discrete proteins were distinguished by the 2DE. Electrophoretic patterns of the discrete proteins indicated that they were a component of detrital POM. Three discrete proteins were subjected to N terminal amino acid sequence analysis. Two proteins out of three could not be determined because their N termini were blocked, and one protein was determined from the N terminus to the ninth amino acid residue. A homology search revealed that the N terminal amino acid sequence of the protein agreed completely with that of 70 kDa heat shock protein (HSP70) derived from photosynthetic organisms. HSP70 is a major member of the molecular chaperones that protect or repair proteins from damage under conditions of environmental stress. The occurrence of HSP70 in this study demonstrated that phytoplankton were able to induce the molecular chaperone(s). Clarification of factor(s) controlling induction of chaperones will enable us to assess the actual environmental stress on phytoplankton at the biomolecular level. The particulate organic matter (POM) in surface water is a complex mixture of living biomass and nonliving detritus. The contribution of living biomass to the bulk POM is generally 1 order of magnitude lower than that of detrital organic matter (e.g., Volkman and Tanoue 2002). The particulate combined amino acids (PCAA) are the largest identified fraction in surface POM (e.g., Wakeham et al. 1997), and dye-binding colorimetric methods demonstrated that proteinaceous materials were a major component of POM (Setchell 1981; Long and Azam 1996). Phytoplankton is a primary producer of organic matter in the sea, and most combined amino acids in phytoplankton are in the form of proteins. However, heterotrophic processing may convert cellular proteins of phytoplankton to other forms before its incorporation into detrital pool. At present the chemical nature of the detrital combined amino acids and proteinaceous materials is not well documented, and the processes by which organic matter produced by phytoplankton is transferred to detrital POM are not clear. The characterization of proteinaceous materials in POM at the molecular level is 1

Diagenesis of Neogene diatoms and their importance as a source of petroleum in Japan

Abstract Various siliceous rocks are found in the Ohdoji, Akaishi and Maido Formations from the western Aomori basin, and the Yotsuzawa and Wadagawa Formations from the eastern Aomori basin of northern Honshu, Japan. These rocks are classified into diatomite, siliceous shale and chert.Diatomite is composed of abundant amorphous silica and has porosity between 50 and 65%. Siliceous shale is composed of a large amount of quartz, and has porosity ranging from 25 to 35%. Chert is chiefly composed of cristobalite or quartz, and has porosity between 20 to 30%.Average contents of total organic carbon, S1 and S2 generally increase from argillaceous rocks → diatomites → siliceous shales → cherts. Maturation of organic matter in these rocks is generally lower than that in average source rocks. Diatoms, which appeared in the late Cretaceous and became increasingly important in the Miocene, are the principal primary producers of organic matter in the marine environment during the Cenozoic. Excellent organic components and higher biological productivity show that diatoms might be the most important source of petroleum during the Neogene in Japan.Proteins, carbohydrates and lipids in diatoms have been transformed into fulvic acids, humic acids and humin by polycondensation and polymerization. Later, these humin materials could be changed into insoluble kerogen under the effect of mild temperature and pressure. A part of the lipids would transform to geochemical fossils (biomarkers). Amorphous silica in cells of diatoms would change to low‐cristobalite and low‐quartz by the increase of geothermal temperature.

Neogene diatoms as the important source of petroleum in Japan

Major oil and gas fields in Japan are located in the area extending from central Hokkaido through northeast Honshu. Most productive horizons are generally found in the late Middle Miocene (approximately 12-10 Ma) Onnagawa Formation of the Akita basin and equivalent formations of other basins. These formations are composed mainly of chert, siliceous shale, diatomite, mudstone, marlite, and acidic pyroclastic rocks. Source rock potentials by Rock Eval analyses in the Miocene Ohdoji and Wadagawa Formations from the Aomori basin, equivalent to the Onnagawa Formation, show the highest values as compared with other formations in the basin. Average contents of TOC, S 1, and S 2 generally increase from argillaceous rocks→diatomites→siliceous shales→cherts. Organic matter in siliceous shales belongs to type I, in argillaceous rocks to type III, and in diatomites and cherts to intermediate types between II and III. Maturation of organic matter in these rocks in generally lower than that in average source rocks. Besides n-alkanes and aromatics, many unknown components were found in the hydrocarbons produced from kerogen by pyrolysis gas chromatography. They are probably related to naphthenes and alkylbenzenes. Based on the relative amounts of aromatics (toluene + p-xylene), light n-alkanes (C 8–C 10), and heavy n-alkanes (C 11–C 20), these rocks are classified into three groups. They are light n-alkanes and aromatics-common (mainly cherts), heavy n-alkanes-rich and aromatics-poor (chiefly siliceous shales), and light n-alkanes-poor and aromatics-rich (mainly diatomites) groups. Compositional ratios among stigmastane, ergostane, and cholestane of steranes determined by gas chromatography/mass spectrometry on bitumen may indicate that the type of organic matter is of open marine origin. Chemical indicators of maturity, e.g., the composition of saturated hydrocarbons such as CPI and isomerization of steranes and triterpanes, may support the poorly biogeochemical transformation of organic matter into petroleum. Diatoms, which appeared in the Late Cretaceous and became increasingly important in the Miocene, are the principal primary producers of organic matter in the marine environment during the Cenozoic. Excellent organic components and higher biological productivity show that diatoms might be the most important sources of petroleum during the Neogene in Japan.

Importance of Neogene Siliceous Rocks as the Source of Petroleum in Japan

Abstract Major oil and gas fields in Japan are located in the area from the central Hokkaido through northeast Honshu. Most productive horizons are generally found in formations of the late Middle Miocene (approximately 12-10 Ma) Onnagawa provincial stage of Japan. These formations are composed mainly of hard mudstone, siliceous shale, diatomaceous mudstone, marlite, and acidic pyroclastic rocks. Source rock potentials in argillaceous rocks of the Miocene Ohdoji Formation in Aomori, the Onnagawa Formation in Akita, and the Lower Teradomari Formation in Niigata show the highest values as compared with other formations in these areas. Average contents of organic carbon and hydrocarbons of siliceous sediments such as diato-mite, siliceous shale, and chert in the Aomori basin indicate the higher values as compared with other argillaceous sediments. Diatoms, which appeared in the late Cretaceous, are the principal primary producers of organic matter in the marine environment during the Cenozoic. Organic components and biological productivity show that diatoms have been the most important source of petroleum during the Neogene in Japan.

Coastal ecosystem dynamics: Relevance of benthic processes

It is believed that the ecological balance and productivity of marine coastal environments are directly related to nutrient supplies from various sources including riverine-estuarine-coastal exchange, upwelling, precipitation, nitrogen fixation, and nutrient regeneration. In south Texas coastal waters, where phytoplankton productivity is comparable to other high productive coastal areas, many nutrient sources are suspected, but are not equally important in supplying sufficient nutrients to drive coastal production dynamics. Nitrogen regeneration from the benthos is implicated from a 2.5-y study of the nutrient cycling processes important in contributing to production levels in these waters. Sediments of the south Texas coastal habitat appear to exhibit a sensitive coupling with overlying waters, where a strong negative correlation exists between the random periodicity of external supplies of ‘new’ nitrogen to the coastal system and the rate at which nitrogen is recycled by sediments. This pattern buffers these waters against extended periods of low input of nutrients from external sources. The development of a conceptual scheme for nutrient cycling in this coastal habitat has provided a more holistic framework from which we can derive an objective assessment of the importance of mechanisms in the system. All data collected so far suggest that the primary production of organic matter and passage through the benthic habitat of these coastal waters is an important pattern responsible for the continued maintenance of productivity in the south Texas coastal ecosystem.

The residence time of particulate organic carbon in the surface layer of the ocean

Part of the primary production of organic matter in the open ocean is driven by regenerated nutrients and part by the transport of nutrients from the water below the euphotic zone. If we consider time and space scales sufficiently large, it is clear that the upward transport of nitrate from below and the resulting new production must be equivalent to the downward transport of nitrogen in the sinking organic particles. We hypothesize that new production and sinking are coupled and that is possible to calculate the residence time of organic particles and their recycling time via consumption and decomposition in the surface layer. Comparison of new production and the sinking flux of particulate organic carbon (POC) measured with sediment traps is consistent with this hypothesis. A study in the Southern California Bight showed variations in τ POC from 3 to >100 days between seasons and years while the recycling time of POC in the surface layer was fairly uniform at about 11 days.

The Gulf of St. Lawrence and the Baltic Sea: a comparison of two organic systems

The Gulf of St. Lawrence and the Baltic Sea hold comparable quantities of water (though not of salts) and draw fresh water from a comparable area, but because of a tenfold difference in water exchange with the ocean, the residence time of water in the Gulf is 200–500 days, in the Baltic some 20 years. Annual primary production of organic matter is comparable in the two systems (35–50 × 10 6 tonnes yr −1), little of which leaves the Baltic, whereas export from the Gulf is substantial. The consequences of this are greater depletion of oxygen in the deeper waters and accumulation of organic matter in the sediments of the Baltic as compared to the Gulf of St. Lawrence.

Phosphorus in primary aquatic plants

As with other organisms, phosphorus is an essential element for aquatic plants. It is a component of molecules such as the nucleic acids and adenosine triphosphate (ATP) involved in the vital processes of enzyme synthesis and energy transfer and its compounds play a basic role in the mechanisms of photosynthesis by which these plants act as the primary producers of organic matter in aquatic environments. In the plant it is about eighth in order of abundance among the elements whereas in cosmic abundance it lies fifteenth and among the nutrient elements dissolved in natural waters it is often in relatively shortest supply. These facts lead to the conclusion that the concentration of available phosphorus compounds controls the growth of plants in aquatic habitats. This generalization has a certain validity, as Vollenweider (1968), for example, has shown, but because of the complexities in the utilization and metabolism of phosphorus by plants apparent exceptions are frequent and those who have sought to controvert it have had no difficulty in finding data to support their case (see Schindler, 1971).In this review attention will be concentrated on the relations of algal growth to phosphorus supply. This seems justified because not only are algae the predominant plants in aquatic habitats but little research appears to have been carried out specifically on phosphorus uptake and metabolism in higher aquatic plants. Presumably the latter are generally similar to terrestrial flowering plants in their relations to phosphorus and the information given in works on plant physiology applies. No attempt can be made to review completely the literature on the phosphorus metabolism of algae. For further references the reviews of Kuhl (1962, 1968) should be consulted.

Biochemical activity of micro-organisms isolated from various regions of the World Ocean.

SUMMARY: There were found considerably fewer biochemically active microorganisms among heterotrophs inhabiting the equatorial-tropical zone of the World Ocean than in the high latitude area. Many micro-organisms with many-sided enzymic activities were present in the microbial population of the near-polar area, determining more profound transformations of organic matter in the waters of these areas as compared with the tropical area and consequently an increased concentration of biogenic substances. It is suggested that there is a unique exchange between the areas of low latitudes and those of high latitudes in the World Ocean. Currents driving equatorial-tropical waters to the north and south carry with them organic matter, chiefly allochthonous in origin; this material is more completely decomposed by the microbial species which inhabit high latitudes. The liberated biogenic substances are carried by currents into the depths of other geographic areas, thus increasing the reserve of substances taking part in the primary production of organic matter in these areas of the World Ocean.