Abstract
Extracellular polymeric substances (EPS) is a generic term often applied to high molecular weight polymers implicated in the biostabilisation of natural sediments. Quantitative analysis of in situ EPS production rates and sediment contents has usually involved extraction of EPS in saline media prior to precipitation in alcohol and quantification against a glucose standard (phenol-sulphuric acid assay). Extracted and synthetic EPS has also been used to create engineered sediments for erosion experiments. This study investigated two steps in the EPS extraction procedure, saline extraction and alcohol precipitation. Comparisons of the effects of different extracted polymers were made in sediment erosion experiments using engineered sediments. Sediment EPS content decreased as the salinity of the extractant increased, with highest values obtained for extraction in fresh water. Potential errors were observed in the quantification of the soluble colloidal polymer fraction when divided into EPS and lower molecular weight polymers (LMW) as used in many studies. In erosion studies, 15 mg kg(-1) of alcohol (IMS) extracted EPS polymer (in 5 g kg(-1) IMS precipitate, equivalent to approximately 5g salt kg(-1) sediment dry weight) decreased the erosion threshold of cohesive sediments whereas 30 mg kg(-1) (in 10 g kg(-1) IMS precipitate, approximately 10 g salt kg(-1) sediment dry weight) had no effect compared to controls. This could be due to the influence of EPS on water content: low levels of EPS did not bind but prevented desiccation, lowering sediment stability against controls. At higher EPS content, binding effects balanced water content effects. Salt alone (at 10 g kg(-1)) slightly increased the erosion threshold after a 6-h desiccation period. In comparison, carbohydrates produced without alcohol precipitation (rotary evaporation) increased the erosion threshold at both 0.5 and 1.0 g EPS kg(-1) dry weight of sediment. It was concluded that the role of microphytobenthic polymers in biostabilisation of sediments is best determined through the study of natural intact sediment samples. (C) 2004 Elsevier Ltd. All rights reserved.
| Original language | English |
|---|---|
| Pages (from-to) | 1623-1635 |
| Number of pages | 13 |
| Journal | Continental Shelf Research |
| Volume | 24 |
| Issue number | 15 |
| Early online date | 20 Aug 2004 |
| DOIs | |
| Publication status | Published - Oct 2004 |
Keywords
- EPS
- extraction
- quantification
- sediment erosion
- intertidal sediments
- epipelic diatoms
- benthic diatoms
- exopolymer production
- microphytobenthos
- dynamics
- erodibility
- stabilization
- stability
- biology
Cite this
Extracellular polymeric substances : quantification and use in erosion experiments. / Perkins, R. G.; Paterson, D. M.; Sun, Hongyue; Watson, John; Player, Michael Antony.
In: Continental Shelf Research, Vol. 24, No. 15, 10.2004, p. 1623-1635.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Extracellular polymeric substances
T2 - quantification and use in erosion experiments
AU - Perkins, R. G.
AU - Paterson, D. M.
AU - Sun, Hongyue
AU - Watson, John
AU - Player, Michael Antony
PY - 2004/10
Y1 - 2004/10
N2 - Extracellular polymeric substances (EPS) is a generic term often applied to high molecular weight polymers implicated in the biostabilisation of natural sediments. Quantitative analysis of in situ EPS production rates and sediment contents has usually involved extraction of EPS in saline media prior to precipitation in alcohol and quantification against a glucose standard (phenol-sulphuric acid assay). Extracted and synthetic EPS has also been used to create engineered sediments for erosion experiments. This study investigated two steps in the EPS extraction procedure, saline extraction and alcohol precipitation. Comparisons of the effects of different extracted polymers were made in sediment erosion experiments using engineered sediments. Sediment EPS content decreased as the salinity of the extractant increased, with highest values obtained for extraction in fresh water. Potential errors were observed in the quantification of the soluble colloidal polymer fraction when divided into EPS and lower molecular weight polymers (LMW) as used in many studies. In erosion studies, 15 mg kg(-1) of alcohol (IMS) extracted EPS polymer (in 5 g kg(-1) IMS precipitate, equivalent to approximately 5g salt kg(-1) sediment dry weight) decreased the erosion threshold of cohesive sediments whereas 30 mg kg(-1) (in 10 g kg(-1) IMS precipitate, approximately 10 g salt kg(-1) sediment dry weight) had no effect compared to controls. This could be due to the influence of EPS on water content: low levels of EPS did not bind but prevented desiccation, lowering sediment stability against controls. At higher EPS content, binding effects balanced water content effects. Salt alone (at 10 g kg(-1)) slightly increased the erosion threshold after a 6-h desiccation period. In comparison, carbohydrates produced without alcohol precipitation (rotary evaporation) increased the erosion threshold at both 0.5 and 1.0 g EPS kg(-1) dry weight of sediment. It was concluded that the role of microphytobenthic polymers in biostabilisation of sediments is best determined through the study of natural intact sediment samples. (C) 2004 Elsevier Ltd. All rights reserved.
AB - Extracellular polymeric substances (EPS) is a generic term often applied to high molecular weight polymers implicated in the biostabilisation of natural sediments. Quantitative analysis of in situ EPS production rates and sediment contents has usually involved extraction of EPS in saline media prior to precipitation in alcohol and quantification against a glucose standard (phenol-sulphuric acid assay). Extracted and synthetic EPS has also been used to create engineered sediments for erosion experiments. This study investigated two steps in the EPS extraction procedure, saline extraction and alcohol precipitation. Comparisons of the effects of different extracted polymers were made in sediment erosion experiments using engineered sediments. Sediment EPS content decreased as the salinity of the extractant increased, with highest values obtained for extraction in fresh water. Potential errors were observed in the quantification of the soluble colloidal polymer fraction when divided into EPS and lower molecular weight polymers (LMW) as used in many studies. In erosion studies, 15 mg kg(-1) of alcohol (IMS) extracted EPS polymer (in 5 g kg(-1) IMS precipitate, equivalent to approximately 5g salt kg(-1) sediment dry weight) decreased the erosion threshold of cohesive sediments whereas 30 mg kg(-1) (in 10 g kg(-1) IMS precipitate, approximately 10 g salt kg(-1) sediment dry weight) had no effect compared to controls. This could be due to the influence of EPS on water content: low levels of EPS did not bind but prevented desiccation, lowering sediment stability against controls. At higher EPS content, binding effects balanced water content effects. Salt alone (at 10 g kg(-1)) slightly increased the erosion threshold after a 6-h desiccation period. In comparison, carbohydrates produced without alcohol precipitation (rotary evaporation) increased the erosion threshold at both 0.5 and 1.0 g EPS kg(-1) dry weight of sediment. It was concluded that the role of microphytobenthic polymers in biostabilisation of sediments is best determined through the study of natural intact sediment samples. (C) 2004 Elsevier Ltd. All rights reserved.
KW - EPS
KW - extraction
KW - quantification
KW - sediment erosion
KW - intertidal sediments
KW - epipelic diatoms
KW - benthic diatoms
KW - exopolymer production
KW - microphytobenthos
KW - dynamics
KW - erodibility
KW - stabilization
KW - stability
KW - biology
U2 - 10.1016/j.csr.2004.06.001
DO - 10.1016/j.csr.2004.06.001
M3 - Article
VL - 24
SP - 1623
EP - 1635
JO - Continental Shelf Research
JF - Continental Shelf Research
SN - 0278-4343
IS - 15
ER -