Nitrogen Metabolism in <i>Paramecium aurelia</i>

Soldo, A. T.; Wagtendonk, W. J. Van

doi:10.1111/j.1550-7408.1961.tb01179.x

Cited by 37 publications

(4 citation statements)

References 51 publications

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“…Paramecium is an ammonotelic organism; it does not synthesize urea [50] and, like mammals, it lacks urease. It is generally believed that aquatic organisms smaller than a micrometer in diameter rid themselves of the toxic excretory product ammonia by simple diffusion of the compound into the aqueous milieu.…”

Section: Discussionmentioning

confidence: 99%

The Occurrence of Biogenic Calcian Struvite, (Mg, Ca)NH₄PO₄.6H₂O, as Intracellular Crystals inParamecium

Grover¹,

Rope

Kaneshiro

1997

J Eukaryotic Microbiology

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ABSTRACT. Intracellular crystals are conspicuous refractile “inclusion bodies” commonly found in many protozoans, but very few have been identified mineralogically. We have isolated crystals from axenically grown mass cultures of Paramecium tetraurelia, and purified them using differential centrifugation. The crystals’ structure and chemistry were analyzed using x‐ray powder diffraction and energy‐dispersive electron microprobe techniques. The morphology was studied by means of scanning electron microscopy. The crystals were identified as the orthorhombic mineral, calcian struvite, (Mg, Ca)NH4PO4.6H2O. Struvite from P. tetraurelia exhibited a variety of crystal habits, including hemimorphic forms, epitactic overgrowths and several types of twins. A linear correlation between computed hydration number and Mg content suggests that the crystal composition may reflect the range of conditions under which struvite nucleation and growth occur. The mineral struvite also occurs in association with guano and other rich organic products, and can be biologically induced to precipitate extracellularly. Extracellular struvite has been well characterized in pathogenic calculi (kidney stones) of humans and cats, where precipitation is enhanced by bacterial urease activity that produces ammonia in the urinary tract. This is the first study demonstrating that struvite is also biologically controlled to form as an intracellular mineral. These crystals may have formed within lipid‐rich, membrane‐bound vesicles in Paramecium.

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Section: Discussionmentioning

confidence: 99%

The Occurrence of Biogenic Calcian Struvite, (Mg, Ca)NH₄PO₄.6H₂O, as Intracellular Crystals inParamecium

Grover¹,

Rope

Kaneshiro

1997

J Eukaryotic Microbiology

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“…Cytoplasmic inclusions composed mainly of hypoxanthine and guanine were isolated from the marine hymenostone ciliate Parauronema acutum (Soldo et al 1978). Guanine, hypoxanthine, adenine and dihydrouracil were excreted from freshwater ciliates, such as species of Paramecium (Soldo & Van Wagtendonk 1961). Berman et al (1987) observed the release of ATP in 'reconstituted' seawater cultures containing bacteria, pico-phytoplankton and heterotrophic flagellates.…”

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confidence: 99%

Dissolved organic nitrogen: a dynamic participant in aquatic ecosystems

Berman¹,

Bronk²

2003

Aquat. Microb. Ecol.

528

344

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In both marine and freshwaters, the concentration of dissolved organic nitrogen (DON) frequently exceeds that of dissolved inorganic nitrogen (DIN), including ammonium, nitrate, and nitrite. Recent evidence indicates that many organic N compounds are released into the DON pool and taken up from this pool by planktonic microbiota on timescales of hours to days. This observation suggests that many components of the DON pool can play an active role in supplying N nutrition directly or indirectly to phytoplankton and bacteria and, in so doing, may affect the species composition of the ambient microbial assemblage. Here we present an overview of the state of knowledge of DON pools in aquatic environments, focused mainly on data gathered in the last decade. We review information on DON concentrations in freshwater and marine systems, analytical methods for the determination of DON, and the biotic and abiotic sources and sinks of DON. More detailed discussion addresses specific components of the DON pool: urea, dissolved combined and free amino acids, proteins, nucleic acids, amino sugars, and humic substances. The DON pool in natural waters is not inert and can be an important sink and source for N. There is a need for greater appreciation and understanding of the potential role of DON as a dynamic participant in the nitrogen cycle within aquatic ecosystems, particularly in freshwater environments.KEY WORDS: Dissolved organic nitrogen · Phytoplankton · Bacteria · N nutrition · N cycling · Marine/freshwater ecosystems Resale or republication not permitted without written consent of the publisherAquat Microb Ecol 31: 2003 ranged from 3.5 to 10.4 µM N. Such observations are not consistent with the perception of a DON pool composed entirely of recalcitrant compounds.Subsequent to the comprehensive and detailed review of Antia et al. (1991), some salient new features of N flux into and out of DON pools have become evident. These imply that many DON compounds are cycled more rapidly in aquatic environments than previously recognized. We now know that DON may be released from actively growing phytoplankton, sometimes in appreciable quantities (Bronk et al. 1994, Bronk & Ward 1999, Diaz & Raimbault 2000, possibly via viral lysis or autolysis of bacteria (Fuhrman 1999) and algae (Gobler et al. 1997, Agusti et al. 1998, that elevated concentrations of DON are common in blooms of Trichodesmium, the primary N 2 fixer in the ocean (Capone et al. 1994, Glibert & Bronk 1994, Vidal et al. 1999, and that atmospheric inputs of DON to the oceans can be substantial (Cornell et al. 1995.Sinks for DON have also been studied in more detail over the last decade. Algae (Lewitus et al. 2000), cyanobacteria (Berman 2001), bacteria (Antia et al. 1991, archaebacteria (Ouverney & Fuhrman 2000) and perhaps even protists (Tranvik et al. 1993) have been shown to exploit various components of the DON pool either directly or after bacterial degradation. The potential of photochemical modification or degradation of DON constituents ha...

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“…(9) presented pertinent and workable general considerations on the subject; imbalances in culture media could be detected effectively after Hutner ( 10) explained the "accordion" design. Other papers (not exclusively physiological) which support the point are the following: Loefer & Scherbaum( 1 5 ) , Soldo & van Wagtendonk (28), Seaman(26), Allen( l ) , Shaw & Williams (27), Guttman & Friedman( 5). Those investigations were concerned with details ranging from amino-acid composition to genomic exclusion and pharmacological models.…”

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confidence: 95%

Cultivation of the Peritrich Telotrochidium henneguyi in Axenic and Non‐Axenic Media*

Finley

McLaughlin

1965

The Journal of Protozoology

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SYNOPSIS. Telotrochidium henneguyi was cultured axenically. The major nutrients in medium T‐3 were liver extract (1:20 National Biochemicals Co.), hydrolyzed yeast nucleic acid, glucose, and dl‐β‐hydroxybutyric acid; these were fortified with phosphate buffer, EDTA, and penicillin. The supplements were: 18 amino acids, 7 vitamins, 10 salts supplying trace‐metals; uridylic, cytidylic, guanylic, and adenylic acids; thymidine‐5‐diphosphate, nicotinamide mononucleotide, and choline. Optimum conditions for axenic cultivation were obtained with phosphate buffer 2 × 10−1M, penicillin 5,000 U.S.P. units/ml, 23°C, pH 6.8. A monoxenic maintenance medium (“T‐broth”) allowed prolific growth and produced trxmendous populations. It was composed of Bacillus cereus in an aqueous broth‐concoction of Proteose‐peptone, Cerophyl, and wheat kernels. Axenic T‐3 medium supported serial subculture; yields of peritrichs were comparable to those in T‐broth. Axenic yields were poorer in medium lacking the T‐3 supplemenits but containing the major nutrients fortified with acid‐hydrolyzed gelatin, serine, riboflavin, EDTA, CaCL, FeCI3, KCI, MgSO4·7 H2O, phosphate buffer, and penicillin. For rapid axenination, excystment was induced by vibrating encysted peritrichs ∼ 30 sec in a Vortex Jr. mixer. Freshly excysted animals were washed by centrifugation. A salt solution, not distilled water, was used for washing inoculants. Inocula consisting of 1 × 103 or more animals were obtained by conventional centrifuge methods. Extension of this investigation to construction of a chemically defined medium is discussed.

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Nitrogen Metabolism in Paramecium aurelia

Cited by 37 publications

References 51 publications

The Occurrence of Biogenic Calcian Struvite, (Mg, Ca)NH₄PO₄.6H₂O, as Intracellular Crystals inParamecium

The Occurrence of Biogenic Calcian Struvite, (Mg, Ca)NH₄PO₄.6H₂O, as Intracellular Crystals inParamecium

Dissolved organic nitrogen: a dynamic participant in aquatic ecosystems

Cultivation of the Peritrich Telotrochidium henneguyi in Axenic and Non‐Axenic Media*

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Nitrogen Metabolism in Paramecium aurelia

Cited by 37 publications

References 51 publications

The Occurrence of Biogenic Calcian Struvite, (Mg, Ca)NH4PO4.6H2O, as Intracellular Crystals inParamecium

The Occurrence of Biogenic Calcian Struvite, (Mg, Ca)NH4PO4.6H2O, as Intracellular Crystals inParamecium

Dissolved organic nitrogen: a dynamic participant in aquatic ecosystems

Cultivation of the Peritrich Telotrochidium henneguyi in Axenic and Non‐Axenic Media*

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The Occurrence of Biogenic Calcian Struvite, (Mg, Ca)NH₄PO₄.6H₂O, as Intracellular Crystals inParamecium

The Occurrence of Biogenic Calcian Struvite, (Mg, Ca)NH₄PO₄.6H₂O, as Intracellular Crystals inParamecium