Substrate induced respiration in soil amended with different amino acid isomers

Hopkins, D. W.; Ferguson, Keith

doi:10.1016/0929-1393(94)90025-6

Cited by 48 publications

(22 citation statements)

References 9 publications

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“…This incubation experiment was conducted in triplicate, with three chambers containing no soil and three chambers each with soil amended with fresh plant material, post-harvest residues, surface residues, or buried residues. Mineralization of C was estimated from CO 2 production measured at 7, 14, 28, 56 and 84 d of incubation by gas chromatography (thermal conductivity detector) of samples of the head space gas, as described by Hopkins and Ferguson (1994). Immediately after each CO 2 determination, a 0.5-g (fresh wt) sample of soil was removed from each incubation chamber and frozen at -20°C.…”

Section: Decomposition Of Maize Leaf Materials and Persistence Of δ-Enmentioning

confidence: 99%

Decomposition of residues and loss of the δ-endotoxin from transgenic (Bt) corn (Zea mays L.) in soil

Hopkins

Gregorich

2005

Can. J. Soil. Sci.

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. 2005. Decomposition of residues and loss of the δ-endotoxin from transgenic (Bt) corn (Zea mays L.) in soil. Can. J. Soil Sci. 85: 19-26. Corn and other crops genetically modified to express the insecticidal δ-endotoxin from Bacillus thuringiensis (Bt) are grown widely across north America. Studies have shown that the δ-endotoxin can be stabilised on soil colloids where its activity is retained, but reports of direct ecological effects of the δ-endotoxin on soil processes are limited. We have determined the concentrations of the δ-endotoxin in organic residues from Bt-corn plants at increasing stages of ageing and decay, and the subsequent decomposition in soil of these residues and the δ-endotoxin in them. The δ-endotoxin concentrations declined from 6.8 µg g -1 in the fresh plant material, to 0.82 µg g -1 in the post-harvest residues collected in the fall, and to 0.026 µg g -1 in the residues collected from soil surface the following spring. The concentration of δ-endotoxin in buried residues collected in the spring was not significantly different from zero. When incubated in soil in the laboratory over 84 d, the δ-endotoxin decomposed more rapidly than bulk plant C by factors of 1.85 for the fresh plant materials and 3.21 for the post-harvest residues. Within 14 d of incubation, the δ-endotoxin concentration in the residues collected at the soil surface was below the limit of detection. We contrasted the laboratory decomposition data with data from a field experiment to estimate the period that the δ-endotoxin in corn residues may survive in the field. Based on estimates derived from this comparison, we predict that following an October harvest in eastern Ontario the δ-endotoxin would fall below the detection threshold during November for post-harvest residues. Since stabilisation of the δ-endotoxin on soil colloids depends on it surviving (i.e., not being decomposed) for long enough to be released from the plant residue matrix and come into proximity with colloid surfaces, the rapid decay of the δ-endotoxin suggests that only a small fraction of the δ-endotoxin from post-harvest residues persists long enough to become stabilised in the field. Des études ont montré que la δ-endotoxine se stabilise sur les colloïdes du sol et garde son activité, mais on sait peu de choses au sujet de son incidence écologique sur les processus du sol. Les auteurs ont établi la concentration de δ-endotoxine dans les résidus organiques de plants de maïs Bt à différents stades de vieillissement et de pourrissement ainsi que la décomposition subséquente de ces résidus et de la δ-endotoxine dans le sol. La concentration de δ-endotoxine passe de 6,8 µg par gramme dans les tissus végétaux frais à 0,82 µg par gramme dans les résidus post-messianiques recueillis à l'automne puis à 0,026 µg par gramme dans ceux prélevés à la surface du sol le printemps suivant. La concentration de δ-endotoxine dans les résidus enfouis, prélevés au printemps, ne diffère pas significativement de zéro. Incubée pendant 84 jours dans le sol en laboratoire, ...

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Section: Decomposition Of Maize Leaf Materials and Persistence Of δ-Enmentioning

confidence: 99%

Decomposition of residues and loss of the δ-endotoxin from transgenic (Bt) corn (Zea mays L.) in soil

Hopkins

Gregorich

2005

Can. J. Soil. Sci.

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“…When protein decomposition rates are low, many proteinaceous amino acids undergo slow abiotic racemization, which can lead to concentrations of D-amino acids in soil organic matter as high as 70% of that of the corresponding L-enantiomer (Amelung and others 2006;Wischern and others 2004). Studies by Hopkins and others (1994) and Jones and others (2005b) have investigated the concept that D-enantiomeric amino acids may be only available to bacteria, as tentatively suggested by Hopkins and Ferguson (1994). Whilst the idea of a bacterial-only pool of D-enantiomeric amino acids has been questioned, to our knowledge, no widespread work has been carried out to assess the utilization of D-enantiomeric oligopeptides by soil microorganisms.…”

Section: Introductionmentioning

confidence: 99%

“…First, we hypothesized that potential N acquisition by soil microorganisms from peptides is universally faster than that from FAAs across soils of different ecosystems and climatic zones. Second, given the tentative supposition that D-enantiomeric AA-N is only utilized by bacteria (Hopkins and Ferguson 1994) or at the very least its utilization has been shown to be varied across soils (Hopkins and others 1994); we hypothesized that L-enantiomeric-AA-and peptidic-N has the potential to contribute more N uptake across all regions at all chain lengths than D-enantiomeric moieties. More specifically, we hypothesized that the uptake of L-enantiomeric N would remain unaffected by variation in soil microbial structure between different soil types.…”

Section: Introductionmentioning

confidence: 99%

Oligopeptides Represent a Preferred Source of Organic N Uptake: A Global Phenomenon?

et al. 2012

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Over the past 20 years, our understanding of soil nitrogen (N) cycling has changed with evidence that amino acids are major substrates for both soil microorganisms and plants. However, the recent discovery that plants and microorganisms can directly utilize small peptides in soil needs to be evaluated for its ecological significance, because peptides are released earlier in protein decomposition and thus would provide significant competitive advantage to any organism that can use them directly. We tested whether soil microorganisms took up peptides faster than amino acids across a broad range of ecosystems. We show that L-enantiomeric-peptidic-N is taken up significantly faster than the equivalent monomer, and that this is universal across soils from different ecosystems, with distinct microbial communities. Peptides may have an unrecognized, global, importance in the terrestrial N cycle, providing N to soil microorganisms at an earlier stage of decomposition than previously acknowledged.

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“…was around 1.5 % of the total amino acid pool (Vranova et al 2012). Research studies have demonstrated that plants can absorb D-AAs from soil through plant roots (Hopkins and Ferguson 1994;Svennerstam et al 2007). …”

Section: D-aas In Plants and Animalsmentioning

confidence: 99%

Distribution, industrial applications, and enzymatic synthesis of d-amino acids

Gao

Ma²,

Zhu

2015

Appl Microbiol Biotechnol

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D-Amino acids exist widely in microbes, plants, animals, and food and can be applied in pharmaceutical, food, and cosmetics. Because of their widespread applications in industry, D-amino acids have recently received more and more attention. Enzymes including D-hydantoinase, N-acyl-D-amino acid amidohydrolase, D-amino acid amidase, D-aminopeptidase, D-peptidase, L-amino acid oxidase, D-amino acid aminotransferase, and D-amino acid dehydrogenase can be used for D-amino acids synthesis by kinetic resolution or asymmetric amination. In this review, the distribution, industrial applications, and enzymatic synthesis methods are summarized. And, among all the current enzymatic methods, D-amino acid dehydrogenase method not only produces D-amino acid by a one-step reaction but also takes environment and atom economics into consideration; therefore, it is deserved to be paid more attention.

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Substrate induced respiration in soil amended with different amino acid isomers

Cited by 48 publications

References 9 publications

Decomposition of residues and loss of the δ-endotoxin from transgenic (Bt) corn (Zea mays L.) in soil

Decomposition of residues and loss of the δ-endotoxin from transgenic (Bt) corn (Zea mays L.) in soil

Oligopeptides Represent a Preferred Source of Organic N Uptake: A Global Phenomenon?

Distribution, industrial applications, and enzymatic synthesis of d-amino acids

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