Bacterial utilization of dissolved free amino acids, dissolved combined amino acids and ammonium in the Delaware Bay estuary:effects of carbon and nitrogen limitation

Middelboe, Mathias; Nh, Borch; Dl, Kirchman

doi:10.3354/meps128109

Cited by 89 publications

(84 citation statements)

References 7 publications

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“…Like in previous studies, we could show that aminopeptidase activity and uptake of the resulting DFAA seem to be uncoupled (Karner and Herndl, 1992;Smith et al, 1992;Middelboe et al, 1995). This may suggest that peptidases expressed by the community have the potential to saturate bacterial uptake systems in the presence of high amounts of peptides and proteins susceptible to enzyme attack.…”

Section: Discussionsupporting

confidence: 49%

Links between bacterial production, amino-acid utilization and community composition in productive lakes

et al. 2007

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Influence of distribution and abundance of bacterial taxa on ecosystem function are poorly understood for natural microbial communities. We related 16S rRNA-based terminal restriction fragment length polymorphism to bacterial production and arginine uptake kinetics to test if functional features of bacterioplankton in four lakes could be predicted from community composition. Maximum arginine uptake rate (arginine V max ) ranged from 10% to 100% of bacterial production. Owing to high growth efficiencies on arginine (63-77%), the bacterial community could potentially saturate its carbon demand using this single organic substrate, for example, during sudden surges of free amino acids. However, due to low in situ concentrations of arginine in these lakes (o0.9 lg l À1 ), actual uptake rates at ambient concentrations rarely exceeded 10% of V max . Bacterial production and arginine V max could be predicted from a subset of bacterial ribotypes, tentatively affiliated with several bacterial divisions (Cyanobacteria, Actinobacteria, Bacteroidetes and Proteobacteria). Multivariate statistical analysis indicates that there were both highly important and less important ribotypes for the prediction of bacterial production and arginine V max . These populations were either negatively or positively related to the respective functional feature, indicating contrasting ecological roles. Our study provides a statistically robust demonstration that, apart from environmental conditions, patterns in bacterial community composition can also be used to predict lake ecosystem function.

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Section: Discussionsupporting

confidence: 49%

Links between bacterial production, amino-acid utilization and community composition in productive lakes

et al. 2007

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“…From our experimental design, we cannot distinguish between the different release mechanisms. Middelboe et al (1995b) report an increase of aminopeptidase activities of attached bacteria during the progression of a diatom bloom in a eutrophic lake to up to 75% of the total, implying that bacterially mediated amino acid release was of high significance. In mesotrophic Lake Constance, however, release of amino acids by aggregate-associated bacteria presumably was less important, even though Grossart and Simon (1998) report that aminopeptidase activity on lake snow was substantially enhanced during the clear-water phase and the blooms in spring and fall.…”

Section: Discussionmentioning

confidence: 99%

“…At two instances, however-in the late spring bloom and in the clear-water phase, when bacterial production rates were low-release in this fraction was substantial. There is evidence that bacteria release DCAAs during growth and in the late stationary phase (Simon and Rosenstock 1992;Rosenstock and Simon 1993;Kroer et al 1994;Middelboe et al 1995a), but phageinduced mortality could also have caused release of protein (Fuhrman 1992). DFAAs may be the product of the activity of extracellular proteases, which are released by zooplankton activity (Bochdansky et al 1995).…”

Section: Discussionmentioning

confidence: 99%

“…5F). At these situations, the hydrolytic activity of attached bacteria presumably was important in dissolving senescent algal material (Middelboe et al 1995b).…”

Section: Discussionmentioning

confidence: 99%

“…Much is known about the turnover of dissolved free amino acids (DFAAs) and their significance for the growth of heterotrophic bacteria (e.g., Jørgensen 1987;Simon and Rosenstock 1992). Several studies found that DFAAs and ammonium are the primary N sources for bacteria (Keil and Kirchman 1991;Jørgensen et al 1993;Middelboe et al 1995a), whereas others showed that dissolved combined amino acids (DCAAs) are of similar or even higher significance for the growth of bacterioplankton (Coffin 1989;Rosenstock and Simon 1993;Kroer et al 1994). The DCAA pool is chemically complex and is composed of various types of combined amino acids, including oligo-and polypeptides, protein, and amino acids bound to humic substances (Keil and Kirchman 1993;Hubberten et al 1994).…”

Section: Acknowledgmentsmentioning

confidence: 99%

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Sources and sinks of dissolved free amino acids and protein in a large and deep mesotrophic lake

Rosenstock

Simon

2001

Limnology & Oceanography

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We studied the microbial cycling of dissolved free amino acids (DFAAs) and protein in mesotrophic Lake Constance, Germany, by examining their release by phytoplankton and various heterotrophic organisms and incorporation by heterotrophic bacterioplankton. Release processes of both substrate classes, measured by an isotope dilution approach, comprised, as an annual mean, 15% of primary production and as much as 64% during the clearwater phase. DFAAs accounted for ϳ70% of total release during the spring bloom, in the early phase predominantly as photosynthetic extracellular products of rapidly growing algae and toward the end as a result of copepod grazing. Thereafter, during the clear-water phase, when daphnids were most abundant, release was dominated by protein. At this time, and again in late summer, lysis of grazing-damaged and senescent algae, including as well the hydrolytic activity of attached bacteria was one of the most important sources of protein. Rotifers, protozoans, and release processes in the fraction Ͻ1 m were minor sources of DFAA ϩ protein. Concentrations of dissolved combined amino acids (DCAAs) and protein ranged between 750-1,900 and 1-280 nM, respectively, and peaked during phytoplankton blooms in spring and summer. As an annual mean, concentrations of labile protein constituted 8% of DCAAs, and the ratio of DFAAs to DCAAs was 0.16. About 50% of the DCAAs occurred in the molecular weight fraction between DFAA and 3 kDa and 30% in that Ͼ30 kDa. Concentrations of DCAAs Ͼ3 kDa were closely correlated to chlorophyll a, suggesting their phytoplankton origin and thus a ready availability. Protein was the preferred bacterial substrate. As an annual mean, its incorporation supported 45% of bacterial biomass production, compared with 13% by DFAAs. During winter and spring, when DFAA concentrations were highest, DFAA incorporation constituted up to 40% of bacterial production. Annually, the sum of DFAA ϩ protein supported 58% and 80% of the bacterial C and N demand, respectively, indicating that they were the most important bacterial C and N sources.

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Effect on water quality, growth performance and economics of giant freshwater prawn, Macrobrachium rosenbergii with partial feed in biofloc system

Islam

Bir

et al. 2023

Aquaculture Fish & Fisheries

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The aim of the present study was to evaluate the water quality, growth performance, body composition, length–weight relationship, condition factors and benefit–cost analysis of giant freshwater prawn (Macrobrachium rosenbergii) cultured with biofloc system in pond conditions. The experiment was conducted in twelve (12) experimental ponds, each measuring 240 m2. The control group was cultured without any biofloc (T1), and biofloc‐based three treatments were biofloc with 100% feed (T2), biofloc with 90% feed (T3) and biofloc with 80% feed (T4). The biofloc‐based treatments showed significantly higher floc volume, total suspended solids, total heterotrophic bacteria and plankton density than the control (p < 0.05). All the growth parameters were significantly higher in biofloc‐based treatments (T2, T3 and T4) than in the control (T1). The lowest feed conversion ratio was found lowest in T4 (1.40 ± 0.02) and highest in T1 (2.13 ± 0.04), which was significantly different among the treatments (p < 0.05). The significantly highest production was obtained 939.02 ± 6.61 kg/ha in T2, and the lowest was 779.67 ± 7.50 kg/ha in T1. The length–weight relationship indicated positive allometric growth in all treatments. The condition factor ranged from 0.95 to 1.07, showing that the prawns were in good health throughout all treatments. The results of the present study indicated that M. rosenbergii can adapt to a biofloc‐based aquaculture system, and the conventional feeding rations can be reduced up to 20% without affecting the growth and production.

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Bacterial utilization of dissolved free amino acids, dissolved combined amino acids and ammonium in the Delaware Bay estuary:effects of carbon and nitrogen limitation

Cited by 89 publications

References 7 publications

Links between bacterial production, amino-acid utilization and community composition in productive lakes

Links between bacterial production, amino-acid utilization and community composition in productive lakes

Sources and sinks of dissolved free amino acids and protein in a large and deep mesotrophic lake

Effect on water quality, growth performance and economics of giant freshwater prawn, Macrobrachium rosenbergii with partial feed in biofloc system

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