scholarly journals High Rate of Uptake of Organic Nitrogen Compounds by Prochlorococcus Cyanobacteria as a Key to Their Dominance in Oligotrophic Oceanic Waters

2003 ◽  
Vol 69 (2) ◽  
pp. 1299-1304 ◽  
Author(s):  
Mikhail V. Zubkov ◽  
Bernhard M. Fuchs ◽  
Glen A. Tarran ◽  
Peter H. Burkill ◽  
Rudolf Amann
Keyword(s):  
Amino Acids ◽  
Arabian Sea ◽  
Organic Nitrogen ◽  
Direct Evidence ◽  
Microbial Loop ◽  
High Rate ◽  
Marine Cyanobacteria ◽  
Nitrogen Compounds ◽  
Flow Sorting

ABSTRACT Direct evidence that marine cyanobacteria take up organic nitrogen compounds in situ at high rates is reported. About 33% of the total bacterioplankton turnover of amino acids, determined with a representative [35S]methionine precursor and flow sorting, can be assigned to Prochlorococcus spp. and 3% can be assigned to Synechococcus spp. in the oligotrophic and mesotrophic parts of the Arabian Sea, respectively. This finding may provide a mechanism for Prochlorococcus' competitive dominance over both strictly autotrophic algae and other bacteria in oligotrophic regions sustained by nutrient remineralization via a microbial loop.

The autotrophic nutrition of symbiotic marine coelenterates with special reference to hermatypic corals. I. Movement of photosynthetic products between the symbionts

1971 ◽  
Vol 178 (1050) ◽  
pp. 111-129 ◽  
Keyword(s):  
Amino Acids ◽  
Organic Nitrogen ◽  
Sea Water ◽  
Nitrogen Compounds ◽  
Organic Substances ◽  
Low Concentrations ◽  
Steady Rate ◽  
Hermatypic Corals ◽  
Photosynthetic Products ◽  
Related Compounds

When symbiotic coelenterates, especially hermatypic corals, were incubated in the light in sea water containing NaH 14 CO 3 , small quantities of fixed 14 C were released from the tissues at a steady rate over 4 h. The rate of release was greatly increased in the presence of glycerol, glucose and alanine; the additional 14 C released was in the same substance as that added to the medium. The following related compounds had little or no effect on 14 C release : ethylene glycol, sorbose, fructose, glucosamine, glycine, proline, serine and glutamic acid. Such results have been previously reported in other symbiotic systems, and the substances causing the specific release of fixed 14 C are believed to be those which move from the autotrophic to the heterotrophic symbiont. This belief is supported here by previous observations that glycerol, glucose and alanine are among the most important organic substances released by freshly isolated zooxanthellae. Ammonium chloride increased the amount of fixed 14 C released by corals into alanine media, possibly due to conversion of ammonia to amino acids by zooxanthellae. Appreciable release of 14 C fixed in the dark also occurred into alanine solutions. These results suggest possible roles of zooxanthellae in supplying organic nitrogen compounds to the host cell at night as well as during the day. The involvement of zooxanthellae in ‘recycling’ nitrogen compounds within the association may help to explain the success of corals in seas poor in nutrients. There was substantial utilization of external glycerol and glucose when supplied at either high or low concentrations. Corals may well be able to utilize some of the small amounts of organic matter dissolved in sea water in the natural environment.

ASSIMILATE DISTRIBUTION AND UTILIZATION IN MAIZE

1978 ◽  
Vol 58 (3) ◽  
pp. 719-730 ◽  
Author(s):  
N. A. FAIREY ◽  
T. B. DAYNARD
Keyword(s):  
Amino Acids ◽  
Free Amino Acids ◽  
Free Amino ◽  
Organic Nitrogen ◽  
Initial Rate ◽  
Nitrogen Compounds ◽  
Stem Tissue ◽  
Crop Canopy ◽  
The Third ◽  
Structural Carbohydrate

The dynamics of distribution and utilization of assimilates from three leaf positions, i.e. the ear leaf (0) and the third leaves above (+3) and below (−3) the ear leaf, in a maize canopy were determined for plants labelled with 14CO2 at 10 days after silk emergence. The initial rate of translocation of assimilates (principally sugars) from leaf blades increased with the height of the leaf in the crop canopy. However, by 21 days after labelling no differences in 14C retention among leaf positions were evident. Sugars from source leaves were gradually utilized in the synthesis of starch and residual matter (principally protein and structural carbohydrate) as they were distributed throughout the plant. Carbon incorporated by the −3 leaf was recovered in free amino acids plus amides and organic acids to a greater extent than that incorporated by the +3 or 0 leaves. Temporary storage of sugars in stem tissue was evident for all three labelled-leaf treatments; the sugars were ultimately used in the synthesis of starch, lipid plus pigment and residual matter of kernels. Some carbon incorporated by lower leaves appeared to be cycled through the root system, possibly being returned to the shoot in organic nitrogen compounds.

scholarly journals Opportunistic bacteria with reduced genomes are effective competitors for organic nitrogen compounds in coastal dinoflagellate blooms

Microbiome ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Yu Han ◽  
Nianzhi Jiao ◽  
Yao Zhang ◽  
Fan Zhang ◽  
Chen He ◽  
...  
Keyword(s):  
Amino Acids ◽  
Organic Matter ◽  
Stationary Phase ◽  
Organic Nitrogen ◽  
Heterotrophic Bacteria ◽  
Significant Proportion ◽  
Gc Content ◽  
Nitrogen Compounds ◽  
Opportunistic Bacteria ◽  
Nucleotides And Nucleosides

Abstract Background Phytoplankton blooms are frequent events in coastal areas and increase the production of organic matter that initially shapes the growth of opportunistic heterotrophic bacteria. However, it is unclear how these opportunists are involved in the transformation of dissolved organic matter (DOM) when blooms occur and the subsequent impacts on biogeochemical cycles. Results We used a combination of genomic, proteomic, and metabolomic approaches to study bacterial diversity, genome traits, and metabolic responses to assess the source and lability of DOM in a spring coastal bloom of Akashiwo sanguinea. We identified molecules that significantly increased during bloom development, predominantly belonging to amino acids, dipeptides, lipids, nucleotides, and nucleosides. The opportunistic members of the bacterial genera Polaribacter, Lentibacter, and Litoricola represented a significant proportion of the free-living and particle-associated bacterial assemblages during the stationary phase of the bloom. Polaribacter marinivivus, Lentibacter algarum, and Litoricola marina were isolated and their genomes exhibited streamlining characterized by small genome size and low GC content and non-coding densities, as well as a smaller number of transporters and peptidases compared to closely related species. However, the core proteomes identified house-keeping functions, such as various substrate transporters, peptidases, motility, chemotaxis, and antioxidants, in response to bloom-derived DOM. We observed a unique metabolic signature for the three species in the utilization of multiple dissolved organic nitrogen compounds. The metabolomic data showed that amino acids and dipeptides (such as isoleucine and proline) were preferentially taken up by P. marinivivus and L. algarum, whereas nucleotides and nucleosides (such as adenosine and purine) were preferentially selected by L. marina. Conclusions The results suggest that the enriched DOM in stationary phase of phytoplankton bloom is a result of ammonium depletion. This environment drives genomic streamlining of opportunistic bacteria to exploit their preferred nitrogen-containing compounds and maintain nutrient cycling.

scholarly journals A multiproxy approach to understanding the "enhanced" flux of organic matter through the oxygen-deficient waters of the Arabian Sea

2016 ◽  
Vol 13 (7) ◽  
pp. 2077-2092 ◽  
Author(s):  
Richard G. Keil ◽  
Jacquelyn A. Neibauer ◽  
Christina Biladeau ◽  
Kelsey van der Elst ◽  
Allan H. Devol
Keyword(s):  
Organic Matter ◽  
Arabian Sea ◽  
Direct Evidence ◽  
Microbial Loop ◽  
Oxygen Effect ◽  
Oxygen Effects ◽  
Incubation Experiments ◽  
Refractory Organic Matter ◽  
Zooplankton Dynamics ◽  
Organic Carbon Fluxes

Abstract. Free-drifting sediment net traps were deployed 14 times at depths between 80 and 500 m for 1–3 days each during the late monsoon–intermonsoon transition in the central Arabian Sea. Two locations (19.5 and 15.5° N) were within the permanently oxygen-deficient zone (ODZ), and a third (11° N) had a shallow and thin oxygen minimum. The secondary nitrite maximum, which serves as a tracer of the ODZ, thinned from ∼ 250 m thick at stations 19.5 and 15.5° N to ∼ 50 m thick at station 11° N. Overall, organic carbon fluxes ranged from 13.2 g m2 yr−1 at 80 m to a minimum of 1.1 g m2 yr−1 at 500 m. Fluxes at the more oxygenated 11° N station attenuate faster than within the permanent ODZ. Martin curve attenuation coefficients for 19.5 and 15.5° N are respectively 0.59 and 0.63 and for 11° N it is 0.98. At least six potential mechanisms might explain why particles sinking through the ODZ are more effectively transferred to depth: (M1) oxygen effects, (M2) microbial loop efficiencies and chemoautotrophy, (M3) changes in zooplankton dynamics, (M4) additions of ballast that might sorb and protect organic matter from decay (M4a) or change sinking speeds (M4b), (M5) inputs of refractory organic matter and (M6) temperature effects. These mechanisms are intertwined, and they were explored using a combination of mineral (XPS) and organic matter characterizations of the sinking material, shipboard incubation experiments, and evaluations of existing literature. Direct evidence was found supporting an oxygen effect and/or changes in the efficiency of the microbial loop including the addition of chemoautotrophic carbon to the sinking flux in the upper 500 m. Less direct evidence was found for the other potential mechanisms. A simple conceptual model consistent with our and other recent data suggests that the upper ODZ microbial community determines the initial flux attenuation, and that zooplankton and sinking speed become more important deeper in the water column. The exact interplay between the various mechanisms remains to be further evaluated.

Studies on soil organic matter: Part I. The chemical nature of soil organic nitrogen

1949 ◽  
Vol 39 (2) ◽  
pp. 183-193 ◽  
Author(s):  
J. M. Bremner
Keyword(s):  
Amino Acids ◽  
Acid Hydrolysis ◽  
Total Nitrogen ◽  
Organic Nitrogen ◽  
Chemical Nature ◽  
Nitrogen Compounds ◽  
Soil Organic Nitrogen ◽  
Reducing Conditions ◽  
Nitrogen Contents ◽  
Hydrolysis Of

1. The acid hydrolysis of six soils with nitrogen contents ranging from 0·1 to 2·38% has been studied by determining the amounts of ammonia-, humin- and α-amino-N present in the soil hydrolysates after various periods of hydrolysis.2. Under the conditions of hydrolysis employed (3 ml. of 6N-HCl/g. soil) the period required for maximum liberation of amino-acids from the soils was about 12 hr. 24·2–37·1% of the total-nitrogen of the soils examined was liberated as α-amino-N in this period. Further hydrolysis led to destruction of amino-acids. Similar amounts of α-amino-N were liberated by hydrolysis of the soils with alkali (5N-NaOH).3. From 69 to 87% of the total-nitrogen of the soils was brought into solution by acid hydrolysis; the amount dissolved by hydrolysing with alkali or with alkali under reducing conditions (alkalistannite) was not significantly different. It is concluded that most of the insoluble-nitrogen found after acid hydrolysis is not derived from protein material, and it is suggested that some of this nitrogen is in the form of heterocyclic nitrogen compounds.

scholarly journals Xylem sap nitrogen compounds of some Crotalaria species

1999 ◽  
Vol 56 (3) ◽  
pp. 733-737 ◽  
Author(s):  
Angela Pierre Vitória ◽  
Ladaslav Sodek
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Composition ◽  
Acid Composition ◽  
Organic Nitrogen ◽  
General Pattern ◽  
Xylem Sap ◽  
Nitrogen Compounds ◽  
Legume Species ◽  
Major Amino Acid

Thirteen species of Crotalaria were analysed for nitrogen compounds in the xylem root bleeding sap. Amino acids were the main form of organic nitrogen found, but only traces of ureides were present. Of the four species analysed for amino acid composition, asparagine was found to be the major amino acid, accounting for over 68% of the nitrogen transported. No striking deviations from this general pattern was found between species, between vegetative and floral stages of development, or between nodulated and non-nodulated plants. It was concluded that the Crotalaria species studied here have an asparagine-based nitrogen metabolism, consistent with many other non-ureide-producing legume species.

NUTRITIONAL FACTORS RELATING TO GROWTH AND OXYTETRACYCLINE FORMATION BY STREPTOMYCES RIMOSUS

1964 ◽  
Vol 10 (3) ◽  
pp. 389-395 ◽  
Author(s):  
Walter A. Zygmunt
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Organic Nitrogen ◽  
Antibiotic Production ◽  
Synthetic Medium ◽  
Nitrogen Compounds ◽  
Streptomyces Rimosus ◽  
Nutritional Factors ◽  
Amino Acid Utilization ◽  
Different Strains

The effects of a variety of nitrogen compounds, mainly amino acids, on oxytetracycline formation and growth were studied in Streptomyces rimosus. Of the amino acids, N-acetyl-DL-alanine and N-acetylglycine supported the highest antibiotic yields. No correlation was evident between the capacity of an amino acid to support growth or stimulate antibiotic formation. Likewise, other adjuncts that stimulated growth did not necessarily enhance antibiotic production. Nutritional differences based on amino acid utilization and antibiotic synthesis using alanine and aspartic acid isomers existed among different strains of S. rimosus. In addition, a synthetic medium was developed that gives excellent antibiotic production though organic nitrogen is omitted.

scholarly journals THE OCCURRENCE OF AMINO ACIDS AND OTHER ORGANIC NITROGEN COMPOUNDS IN LAKE WATER

1925 ◽  
Vol 63 (2) ◽  
pp. 287-295
Author(s):  
W.H. Peterson ◽  
E.B. Fred ◽  
B.P. Domogalla
Keyword(s):  
Amino Acids ◽  
Lake Water ◽  
Organic Nitrogen ◽  
Nitrogen Compounds
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