Effects of Tubificid Worms on Denitrification and Nitrification in Stream Sediment

1980 ◽  
Vol 37 (4) ◽  
pp. 656-663 ◽  
Author(s):  
Lakeram Chatarpaul ◽  
John B. Robinson ◽  
Narinder K. Kaushik
Keyword(s):  
Organic Matter ◽  
Nitrogen Cycling ◽  
Stream Sediment ◽  
Tubifex Tubifex ◽  
Gut Contents ◽  
Distilled Water ◽  
Nitrate N ◽  
Limnodrilus Hoffmeisteri ◽  
Transformation Processes ◽  
Tubificid Worms

Labeled nitrate-N in the form of K15NO3 was used to determine the effects of the tubificid oligochaetes, Tubifex tubifex and Limnodrilus hoffmeisteri, on the N transformation processes in stream sediment contained in laboratory columns. Denitrification and nitrification occurred simultaneously and were enhanced significantly in the presence of the worms. The denitrification rate over 48 d at 15 °C in the sediment that contained the worms was 90 mg N/m2∙d−1; the simultaneous rate of nitrification was 69 mg N/m2∙d−1. The corresponding rates for denitrification and nitrification in sediment without worms were 50 mg N/m2∙d−1 and 29 mg N/m2∙d−1. The rate of CO2 evolution from sediment containing worms and overlain with nitrate-N solution was about 21% greater than that of sediment with worms overlain with distilled water. It was concluded from experiments using chloride as tracer that denitrification could be enhanced by the worms at least in part as a result of accelerated movement of nitrate-N into the sediment. However, when a column of glass beads was used as substrate for worms, and with no organic matter present, the concentration of nitrate in an overlying solution declined at an appreciable rate. This suggested that denitrification occurred in or on the worms, a possibility supported by the observation that denitrifying bacteria could be isolated from both the exterior and the gut contents of the worms.Key words: tubificid worms, stream nutrient cycling, denitrification, nitrogen cycling

Role of Tubificid Worms on Nitrogen Transformations in Stream Sediment

1979 ◽  
Vol 36 (6) ◽  
pp. 673-678 ◽  
Author(s):  
L. Chatarpaul ◽  
J. B. Robinson ◽  
N. K. Kaushik
Keyword(s):  
Initial Period ◽  
Organic Content ◽  
Stream Sediment ◽  
Tubifex Tubifex ◽  
Nitrogen Transformations ◽  
Nitrate N ◽  
Limnodrilus Hoffmeisteri ◽  
Significant Difference ◽  
Tubificid Worms

Sediments obtained from Swifts Brook were highly organic whereas those from Canagagigue Creek were coarse-textured with relatively little organic content. Columns of sediment were overlain with continuously aerated 10 mg/L nitrate-N solution or distilled water. When columns of Canagagigue sediment with tubificid worms (Tubifex tubifex and Limnodrilus hoffmeisteri) were incubated for 33 d they lost nitrate-N at a significantly higher rate (P < 0.01) than did columns without worms. Following the initial period of nitrate disappearance (resulting from denitrification in the sediment) nitrate-N increased again, this increase being greatest in the presence of worms. The increasing concentration of nitrate-N probably resulted from nitrification which was masked early in the experiment by rapid denitrification. In columns with Swifts Brook sediment, added nitrate disappeared rapidly but no significant difference was observed between the columns with worms and those without; nitrate-N concentration was never observed to increase. Possibly both nitrification and denitrification are also enhanced here by the presence of tubificids but the effects are masked. Key words: tubificids, denitrification, nitrification, stream sediment, nitrate, ammonium, fecal pellets

scholarly journals Checklist of Aquatic Oligochaetes Species in Tigris–Euphrates River basin

2014 ◽  
Vol 11 (3) ◽  
pp. 1397-1404 ◽  
Author(s):  
Baghdad Science Journal
Keyword(s):  
Single Species ◽  
Abundant Species ◽  
Tubifex Tubifex ◽  
Euphrates River ◽  
Tigris River ◽  
Limnodrilus Hoffmeisteri ◽  
Frequent Species ◽  
Aquatic Oligochaetes ◽  
Stylaria Lacustris ◽  
Tubificid Worms

A total of 60 species of aquatic oligochaetes were identified in different sites within Tigris-Euphrates basin / Iraq, including River Tigris, River Euphrates, Southern marshes ( Al-Haweiza , Al-Hammar and Al-Chebaiesh ) , Shutt Al-Germa, and Shatt Al-Arab. In River Euphrates 39 species were identified, 40 species from River Tigris and 32 species from Shatt-Al-Arab and southern marshes.The identified species were classified as four species of Family Aeolosomatidae, 54 species of Naididae ( 31 Naidinae , 8 Pristininae and 15 Tubificid worms), one species of each of Lumbriculidae ( Lumbriculus variegates ) and Lumbricidae ( Eiseiella tetraedra). Among Aeolosomatidae , Aelosoma aquaternarium, A. Liedyi, A. variegatum and A. hemprichi, in which, A. variegatum was the most frequent species, found in Euphrates river. Naidinae community were represented by five species of genus Chaetogaster, two species of each of Paranais, Slavina, & Stylaria, four species of Allonais , and seven species of each of Dero and Nais, in addition to Stephensoniana trivandrana, Specaria josinae and Ophidonais serpentina. Nais variabilis was the most abundant and frequent species in River Tigris while Stylaria lacustris & Ophidonais serpentina are abundant in River Euphrates . Species of Pristininae were representative by four species of genus Pristina and three species of genus pristinella, among them Priatina longiseta is the most abundant species.Tubificid worms, Branchuira sowerbyi and Limnodrilus hoffmeisteri were the most frequent and abundant species in the surface sediments of Iraqi waters. Beside L. hoffmeisteri , other five species of Limnodrilus, two species of Potomothrix, and a single species of Tubifex tubifex , Embolocephalus velutinus, Aulodrilus piguetia, Psammoryctides moravicus and Rhyacodrilus coccineus were recorded.

scholarly journals Effect of Plant Growth Regulators on Protease Activity in Forest Floor of Norway Spruce Stand

Forests ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 665
Author(s):  
Ladislav Holik ◽  
Jiří Volánek ◽  
Valerie Vranová
Keyword(s):  
Organic Matter ◽  
Proteolytic Activity ◽  
Protease Activity ◽  
Forest Floor ◽  
Soil Microbial Activity ◽  
Inhibitory Effects ◽  
Chlorocholine Chloride ◽  
Soil Microbial ◽  
Native Soil ◽  
Transformation Processes

Soil proteases are involved in organic matter transformation processes and, thus, influence ecosystem nutrient turnovers. Phytohormones, similarly to proteases, are synthesized and secreted into soil by fungi and microorganisms, and regulate plant rhizosphere activity. The aim of this study was to determine the effect of auxins, cytokinins, ethephon, and chlorocholine chloride on spruce forest floor protease activity. It was concluded that the presence of auxins stimulated native proteolytic activity, specifically synthetic auxin 2-naphthoxyacetic acid (16% increase at added quantity of 5 μg) and naturally occurring indole-3-acetic acid (18%, 5 μg). On the contrary, cytokinins, ethephon and chlorocholine chloride inhibited native soil protease activity, where ethephon (36% decrease at 50 μg) and chlorocholine chloride (34%, 100 μg) showed the highest inhibitory effects. It was concluded that negative phytohormonal effects on native proteolytic activity may slow down organic matter decomposition rates and hence complicate plant nutrition. The study enhances the understanding of rhizosphere exudate effects on soil microbial activity and soil nitrogen cycle.

scholarly journals 18S rRNA gene sequences of leptocephalus gut contents, particulate organic matter, and biological oceanographic conditions in the western North Pacific

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tsuyoshi Watanabe ◽  
Satoshi Nagai ◽  
Yoko Kawakami ◽  
Taiga Asakura ◽  
Jun Kikuchi ◽  
...  
Keyword(s):  
Organic Matter ◽  
Particulate Organic Matter ◽  
North Pacific ◽  
Western North Pacific ◽  
18S Rrna ◽  
18S Rrna Gene ◽  
Gut Contents ◽  
Rrna Gene ◽  
Marine Snow ◽  
Chlorophyll Maximum

AbstractEel larvae apparently feed on marine snow, but many aspects of their feeding ecology remain unknown. The eukaryotic 18S rRNA gene sequence compositions in the gut contents of four taxa of anguilliform eel larvae were compared with the sequence compositions of vertically sampled seawater particulate organic matter (POM) in the oligotrophic western North Pacific Ocean. Both gut contents and POM were mainly composed of dinoflagellates as well as other phytoplankton (cryptophytes and diatoms) and zooplankton (ciliophoran and copepod) sequences. Gut contents also contained cryptophyte and ciliophoran genera and a few other taxa. Dinoflagellates (family Gymnodiniaceae) may be an important food source and these phytoplankton were predominant in gut contents and POM as evidenced by DNA analysis and phytoplankton cell counting. The compositions of the gut contents were not specific to the species of eel larvae or the different sampling areas, and they were most similar to POM at the chlorophyll maximum in the upper part of the thermocline (mean depth: 112 m). Our results are consistent with eel larvae feeding on marine snow at a low trophic level, and feeding may frequently occur in the chlorophyll maximum in the western North Pacific.

scholarly journals Factors Affecting Microbial Formation of Nitrate-Nitrogen in Soil and Their Effects on Fertilizer Nitrogen Use Efficiency

2001 ◽  
Vol 1 ◽  
pp. 122-129 ◽  
Author(s):  
Alan Olness ◽  
Dian Lopez ◽  
David Archer ◽  
Jason Cordes ◽  
Colin Sweeney ◽  
...  
Keyword(s):  
Organic Matter ◽  
Decision Aid ◽  
Pore Space ◽  
Organic Matter Content ◽  
Clay Content ◽  
Matter Content ◽  
N Fertilizer ◽  
Nitrate N ◽  
Soil Clay ◽  
Soil Clay Content

Mineralization of soil organic matter is governed by predictable factors with nitrate-N as the end product. Crop production interrupts the natural balance, accelerates mineralization of N, and elevates levels of nitrate-N in soil. Six factors determine nitrate-N levels in soils: soil clay content, bulk density, organic matter content, pH, temperature, and rainfall. Maximal rates of N mineralization require an optimal level of air-filled pore space. Optimal air-filled pore space depends on soil clay content, soil organic matter content, soil bulk density, and rainfall. Pore space is partitioned into water- and air-filled space. A maximal rate of nitrate formation occurs at a pH of 6.7 and rather modest mineralization rates occur at pH 5.0 and 8.0. Predictions of the soil nitrate-N concentrations with a relative precision of 1 to 4 μg N g–1of soil were obtained with a computerized N fertilizer decision aid. Grain yields obtained using the N fertilizer decision aid were not measurably different from those using adjacent farmer practices, but N fertilizer use was reduced by >10%. Predicting mineralization in this manner allows optimal N applications to be determined for site-specific soil and weather conditions.

scholarly journals EFFECT OF FOLIAR APPLICATION OF ORGANIC EXTRACT AND HAMIC ACID APPLICATION ON STRAWBERY PRODACTION

2016 ◽  
Vol 47 (3) ◽  
Author(s):  
AL- Karawi & Al-Rawi
Keyword(s):  
Organic Matter ◽  
Humic Acid ◽  
Foliar Application ◽  
Fruit Weight ◽  
Distilled Water ◽  
College Of Agriculture ◽  
Organic Extract ◽  
Four Levels ◽  
Effect On Yield ◽  
Spraying Plants

This study was carried out in greenhouse Date to palm Research units, College of Agriculture, University of Baghdad ( Abu Ghraib ) , seasons 2013 and 2014 to investigate the effect of foliar application organic matter extract and humic acid and their interactions on yield of strawberry plants . The study include 12 treatments , to spray strawberry's plant with four levels of organic matter spray included distilled water only (T0) , (1) volume of organic matter extract to volume of distilled water ( 1:1)  (T1) , (2) volume of organic matter extract to volume of distilled water (2:1 ) (T2 ) and (3) volume of organic matter extract volume of distilled water (3:1) (T3), the second factor was three concentrations of humifert-ultra , 0( H0 ) , 2.5 ml.L-1 ( H2.5) and 5 ml.L-1  ( H5 ) to the soil . Factorial Experiment carried out according to RCBD with  three replications , averages compared by LSD test at the level of 5% probability. Results that have been obtained is that spraying plants extract organic matter led to a significant increase in the number of flowers and the percentage of the contract and the number of fruits and had no significant effect on yield of plant. addition of humic acid led to a significant increase in the number of flowers and the percentage of fruit set and the number of fruits and fruit weight and yield of plant .

scholarly journals Feeding habits of Chironomid larvae (Insecta: Diptera) from a stream in the Floresta da Tijuca, Rio de Janeiro, Brazil

2003 ◽  
Vol 63 (2) ◽  
pp. 269-281 ◽  
Author(s):  
A. L. Henriques-Oliveira ◽  
J. L. Nessimian ◽  
L. F. M. Dorvillé
Keyword(s):  
Organic Matter ◽  
Particulate Organic Matter ◽  
Rio De Janeiro ◽  
Feeding Habits ◽  
Gut Contents ◽  
Chironomid Larvae ◽  
Main Food ◽  
Animal Remains ◽  
Aquatic Food ◽  
Main Food Source

Chironomids larvae are frequently one of the most abundant and diverse groups of insects in several kinds of aquatic environments. Also, they play a major role in the aquatic food webs, representing a major link among producers and secondary consumers. This work investigates the feeding behavior of the chironomid larvae present in the Rio da Fazenda, situated in the Parque Nacional da Tijuca, Rio de Janeiro, Brazil, between August 1994 and May 1995. Algae, fungi, pollen, leaf and wood fragments, animal remains, detritus and silt were the main gut contents found in the larvae studied. The main food item ingested by the larvae was detritus, except for the Stenochironomus whose main food source was leaf and wood fragments. Tanypodinae exhibited a large quantity of animal remains of several kinds in the diet. During the period studied it was observed that the diet of 16 genera (out of 24 studied) varied. Tanypodinae had mainly coarse particulate organic matter (> 1 mm) in the gut contents, while Chironominae and Orthocladiinae had fine particulate organic matter (< 1 mm).

INFLUENCE OF ORGANIC MATTER ON THE GERMICIDAL EFFICIENCY OF QUATERNARY AMMONIUM AND HYPOCHLORITE COMPOUNDS

1948 ◽  
Vol 26f (2) ◽  
pp. 91-104 ◽  
Author(s):  
C. K. Johns
Keyword(s):  
Staphylococcus Aureus ◽  
Organic Matter ◽  
Quaternary Ammonium ◽  
Tap Water ◽  
Skim Milk ◽  
Distilled Water ◽  
Water Solutions ◽  
E Coli ◽  
Test Organisms ◽  
High Concentrations

Using Staphylococcus aureus and Eschericha coli as test organisms, the influence of various concentrations of skim milk on the germicidal potency of Roccal and of Dalglish hypochlorite solutions was studied. Both germicides retained their activity in the presence of unexpectedly high concentrations of skim milk, especially against S. aureus. Small concentrations frequently showed a slight potentiating effect in both laboratory and plant tests. The effectiveness of the hypochlorite fell off sharply beyond a certain concentration, while that of Roccal declined more gradually. Solutions of Roccal prepared with tap water were decidedly less active against E. coli than those prepared with distilled water. With the hypochlorite, tap water solutions were equally effective. Against S. aureus, a similar difference was noted although to a lesser extent. Added skim milk depressed the germicidal action of tap water solutions of Roccal to a greater extent than for distilled water solutions, while for the hypochlorite the reverse held true.

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