scholarly journals Seasonal variation in sedimentary amino acids and the association of organic matter with mineral surfaces in a sandy eelgrass meadow

2002 ◽  
Vol 227 ◽  
pp. 275-280 ◽  
Author(s):  
BAS Van Mooy ◽  
RG Keil
2021 ◽  
Vol 230 ◽  
pp. 103931
Author(s):  
Jin-E Wei ◽  
Yan Chen ◽  
Jian Wang ◽  
Shi-Bo Yan ◽  
Hong-Hai Zhang ◽  
...  

Life ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 32
Author(s):  
Walaa Elmasry ◽  
Yoko Kebukawa ◽  
Kensei Kobayashi

The extraterrestrial delivery of organics to primitive Earth has been supported by many laboratory and space experiments. Minerals played an important role in the evolution of meteoritic organic matter. In this study, we simulated aqueous alteration in small bodies by using a solution mixture of H2CO and NH3 in the presence of water at 150 °C under different heating durations, which produced amino acids after acid hydrolysis. Moreover, minerals were added to the previous mixture to examine their catalyzing/inhibiting impact on amino acid formation. Without minerals, glycine was the dominant amino acid obtained at 1 d of the heating experiment, while alanine and β-alanine increased significantly and became dominant after 3 to 7 d. Minerals enhanced the yield of amino acids at short heating duration (1 d); however, they induced their decomposition at longer heating duration (7 d). Additionally, montmorillonite enhanced amino acid production at 1 d, while olivine and serpentine enhanced production at 3 d. Molecular weight distribution in the whole of the products obtained by gel chromatography showed that minerals enhanced both decomposition and combination of molecules. Our results indicate that minerals affected the formation of amino acids in aqueous environments in small Solar System bodies and that the amino acids could have different response behaviors according to different minerals.


2016 ◽  
Vol 283 (1839) ◽  
pp. 20160996 ◽  
Author(s):  
Noboru Katayama ◽  
Kobayashi Makoto ◽  
Osamu Kishida

Conventional food-web theory assumes that nutrients from dissolved organic matter are transferred to aquatic vertebrates via long nutrient pathways involving multiple eukaryotic species as intermediary nutrient transporters. Here, using larvae of the salamander Hynobius retardatus as a model system, we provide experimental evidence of a shortcut nutrient pathway by showing that H. retardatus larvae can use dissolved amino acids for their growth without eukaryotic mediation. First, to explore which amino acids can promote larval growth, we kept individual salamander larvae in one of eight different high-concentration amino acid solutions, or in control water from which all other eukaryotic organisms had been removed. We thus identified five amino acids (lysine, threonine, serine, phenylalanine, and tyrosine) as having the potential to promote larval growth. Next, using 15 N-labelled amino acid solutions, we demonstrated that nitrogen from dissolved amino acids was found in larval tissues. These results suggest that salamander larvae can take up dissolved amino acids from environmental water to use as an energy source or a growth-promoting factor. Thus, aquatic vertebrates as well as aquatic invertebrates may be able to use dissolved organic matter as a nutrient source.


Author(s):  
Jinyi Qin ◽  
Rui Zhang ◽  
Ruiwen Yang ◽  
Jiao Fang ◽  
Yu Zhang ◽  
...  

Abstract Sewage sludge was subjected to hydrothermal fueling (HTF) (330 °C for 40 min), obtaining hydrochar at 13.5 MJ kg−1. The higher heating value (HHV) of the raw sludge was related to its fatty acid content. The results showed that although the higher heating value (HHV) of the raw sludge was related to its fatty acid content, with the intensification of HTF, the increase in aliphatic/cyclic amino acids determined the production of HHV in the hydrochar. In order to increase the content of fatty acids and amino acids, the sludge was fermented. However, the Bacteroidetes consumed the organic matter too early, which was detrimental to the production of HHV. Therefore, appropriate sludge fermentation is recommended to restrict excessive Bacteroidetes proliferation, decompose lipids to saturated fatty acids, and convert proteins to aliphatic/cyclic amino acids to increase the efficiency of converting sludge to fuel.


1972 ◽  
Vol 27 (1) ◽  
pp. 39-50 ◽  
Author(s):  
J. C. Macrae ◽  
M. J. Ulyatt ◽  
P. D. Pearce ◽  
Jane Hendtlass

1. In two experiments, sheep prepared with a rumen cannula and with re-entrant cannulas in the duodenum and ileum were continuously fed on diets of dried grass, dried grass plus formalin-treated casein, or dried grass plus untreated casein. Paper impregnated with chromic oxide was given once daily via the rumen fistula.2. In ten 24 h collections of digesta entering the duodenum and eleven 24 h collections of digesta reaching the ileum of sheep given dried grass, there were highly significant correlations between the 24 h flows of Cr marker and the corresponding flows of dry matter, organic matter, nitrogen, gross energy, hemicellulose and cellulose (P < 0.01) at both sites.3. Daily amounts of non-ammonia N and of individual amino acids entering and leaving the small intestine and of total N excreted in faeces and urine are given.4. Net retention of supplementary N was 36% when the supplement was administered as formalin-treated casein, but only 17% when it was administered as untreated casein.5. Formalin treatment of casein significantly increased the daily amounts of non-ammonia N entering the small intestine (P < 0.01) and the amounts of non-ammonia N apparently absorbed therein (P < 0.05).6. Apparent absorption of amino acids from the small intestine was significantly greater (P < 0.05) with treated casein than with untreated casein. There were relative increases in the small amounts of several free amino acids measured, including taurine, in the ileal digesta of sheep receiving the treated casein supplement.


1960 ◽  
Vol 15 (1) ◽  
pp. 121-124 ◽  
Author(s):  
Henry B. Hale ◽  
James P. Ellis ◽  
Donald D. Van Fossan

Amino acid excretion was studied in young, healthy men during summer, fall and winter months in a southwestern U. S. location. Both untimed and timed urine samples were employed. The amino acids determined were alanine, arginine, cysteine, glutamic acid, glutamine, glycine, histidine, lysine, methyl histidine, serine, threonine and valine. Supplemental determinations included urine volume, creatinine, uric acid, urea, sodium and potassium. Using untimed urine samples and expressing values as ratios with creatinine, significant seasonal variation was found for alanine, arginine, cysteine, glutamic acid, glycine, lysine and serine. Submitted on April 11, 1959


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