Growth Rates of Marine Bacterial Isolates on Particulate Organic Substrates Solubilized by Freely Released Extracellular Enzymes

Vetter, Y.A.; Deming, Jody W.

doi:10.1007/s002489900133

Cited by 50 publications

(34 citation statements)

References 29 publications

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“…Vetter & Deming (1999) reported that released bacterial EE could produce sufficient hydrolysate from POC to support growth in the absence of any other significant source of DOC and without direct contact between the cell and particulate substrate. These empirical results obtained by Vetter & Deming (1999) support the model-based predictions formulated in an earlier paper (Vetter et al 1998), suggesting that dissolved EE are advantageous when bacteria are attached to particles and when the substrate is within a well-defined distance from the enzyme source.…”

Section: Discussionmentioning

confidence: 99%

“…The release of EE into particles by particle-associated prokaryotes might help in maintaining relatively high metabolic activity as compared to their free-living counterparts. In fact, bacterial foraging theory suggests that independent of possible assemblage differences, individual bacteria may produce more EE in diffusionally constrained space such as particle aggregates, where the return of hydrolysate is potentially high (Vetter et al 1998) or, when confronted with polymeric organic matter (Chrost 1991, Vetter & Deming 1999. Moreover, Allison (2005) argued that microbes releasing EE have a competitive advantage over other microbes in environments with low rates of enzyme diffusion, such as sediments or particles.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

High dissolved extracellular enzymatic activity in the deep central Atlantic Ocean

Baltar¹,

Arı́stegui²,

Gasol³

et al. 2010

Aquat. Microb. Ecol.

104

120

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The distribution of prokaryotic abundance (PA), prokaryotic heterotrophic production (PHP), and suspended particulate organic material (POM), as well as total and dissolved (operationally defined as passing through 0.2 µm pore size filters) potential extracellular enzymatic activities (EEA; α-and β-glucosidase [AGase and BGase], leucine aminopeptidase [LAPase], and alkaline phosphatase [APase]) were determined in the meso-and bathypelagic waters of the (sub)tropical Atlantic along an eastern zonal transatlantic transect and a western N-S transect. Significant differences between both transects were found for POM concentration but not for PA, PHP (except in the subsurface and oxygen minimum layer), and dissolved and total EEA. PHP decreased by 3 orders of magnitude from the lower euphotic zone to bathypelagic waters, while PA and cell-specific PHP decreased only by 1 and 2 orders of magnitude, respectively. The proportion of the dissolved to the total EEA was high in the dark ocean for all the enzymes, ranging from 54 to 100, 56 to 100, 65 to 100 and 57 to 97% for AGase, BGase, LAPase and APase, respectively. The kinetic parameters (V max and K m ) of both the dissolved and total fractions of LAPase and APase were very similar throughout the water column, suggesting a similar origin for both dissolved and particulate EEA. Significant correlations of both dissolved and total EEA were found with prokaryotic metabolism and the POM pool. Based on the previous notion that the fraction of dissolved EEA is higher in particle-attached than in free-living microbes, our results suggest that microbial activity in the dark ocean occurs mainly on colloidal and particulate material. This is in agreement with recent genomic evidence. However, these colloidal and particulate materials are prone to disruption during the sampling process. Hence, more selective sampling techniques are needed to specifically collect these deep-water aggregates that probably represent hotspots of microbial activity in the deep ocean.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

High dissolved extracellular enzymatic activity in the deep central Atlantic Ocean

Baltar¹,

Arı́stegui²,

Gasol³

et al. 2010

Aquat. Microb. Ecol.

104

120

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show abstract

“…Laboratory experiments show that pure cultures of marine bacteria release enzymes into the surrounding media (Vetter and Deming, 1999;Alderkamp et al, 2007). High levels of dissolved endopeptidase activity in coastal seawater (Obayashi and Suzuki, 2008) also underscore the importance of cell-free enzymes in the ocean.…”

Section: Discussionmentioning

confidence: 99%

Changes in the spectrum and rates of extracellular enzyme activities in seawater following aggregate formation

2010

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Abstract. Marine snow aggregates are heavily colonized by heterotrophic microorganisms that express high levels of hydrolytic activities, making aggregates hotspots for carbon remineralization in the ocean. To assess how aggregate formation influences the ability of seawater microbial communities to access organic carbon, we compared hydrolysis rates of six polysaccharides in coastal seawater after aggregates had been formed (via incubation on a roller table) with hydrolysis rates in seawater from the same site that had not incubated on a roller table (referred to as whole seawater). Hydrolysis rates in the aggregates themselves were up to three orders of magnitude higher on a volume basis than in whole seawater. The enhancement of enzyme activity in aggregates relative to whole seawater differed by substrate, suggesting that the enhancement was under cellular control, rather than due to factors such as lysis or grazing. A comparison of hydrolysis rates in whole seawater with those in aggregatefree seawater, i.e. the fraction of water from the roller bottles that did not contain aggregates, demonstrated a nuanced microbial response to aggregate formation. Activities of laminarinase and xylanase enzymes in aggregate-free seawater were higher than in whole seawater, while activities of chondroitin, fucoidan, and arabinogalactan hydrolyzing enzymes were lower than in whole seawater. These data suggest that aggregate formation enhanced production of laminarinase and xylanase enzymes, and the enhancement also affected the surrounding seawater. Decreased activities of chondroitin, fucoidan, and arabinoglactan-hydrolyzing enzymes in aggregate-free seawaters relative to whole seawater are likely due to shifts in enzyme production by the aggregateCorrespondence to: K. Ziervogel (ziervoge@email.unc.edu) associated community, coupled with the effects of enzyme degradation. Enhanced activities of laminarin-and xylanhydrolyzing enzymes in aggregate-free seawater were due at least in part to cell-free enzymes. Measurements of enzyme lifetime using commercial enzymes suggest that hydrolytic cell-free enzymes may be active over timescales of days to weeks. Considering water residence times of up to 10 days in the investigation area (Apalachicola Bay), enzymes released from aggregates may be active over timescales long enough to affect carbon cycling in the Bay as well as in the adjacent Gulf of Mexico. Aggregate formation may thus be an important mechanism shaping the spectrum of enzymes active in the ocean, stimulating production of cell-free enzymes and leading to spatial and temporal decoupling of enzyme activity from the microorganisms that produced them.

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“…Thus, presence of cellulolytic and hemi-cellulolytic bacteria in one particular region and their absence in other region should indicated presence of wide-ranging organic matter in each region (Khanderparker et al, 2011). Previous research has also put forth a widely accepted concept that hydrolytic enzymes are induced by presence of polymeric substrates (Chrost, 1991;Vetter and Deming, 1999). It was observed that the genus Bacillus and Vibrio were the dominant hemicellulase and cellulase producers in both the estuaries.…”

Section: Api 20e* Strains Onpg Adh Odc Cit Ure Tda Ind Vp Gel Glu Manmentioning

confidence: 99%

Starvation Conditions Effects on Carbohydrate Metabolism of Marine Bacteria

Bour¹

2012

Carbohydrates - Comprehensive Studies on Glycobiology and Glycotechnology

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Growth Rates of Marine Bacterial Isolates on Particulate Organic Substrates Solubilized by Freely Released Extracellular Enzymes

Cited by 50 publications

References 29 publications

High dissolved extracellular enzymatic activity in the deep central Atlantic Ocean

High dissolved extracellular enzymatic activity in the deep central Atlantic Ocean

Changes in the spectrum and rates of extracellular enzyme activities in seawater following aggregate formation

Starvation Conditions Effects on Carbohydrate Metabolism of Marine Bacteria

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