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In-Field Implementation of a Recombinant Factor C Assay for the Detection of Lipopolysaccharide as a Biomarker of Extant Life within Glacial Environments.

Barnett MJ, Wadham JL, Jackson M, Cullen DC - Biosensors (Basel) (2012)

Bottom Line: In situ or in-field detection and characterisation of microbial communities is becoming recognised as an important approach to improve our understanding of such communities.Within this context we demonstrate, for the first time, the ability to detect Gram-negative bacteria in glacial field-environments (including subglacial environments) via the detection of lipopolysaccharide (LPS); an important component of Gram-negative bacterial cell walls.Sixteen of these samples returned positive LPS detection.

View Article: PubMed Central - PubMed

Affiliation: Cranfield Health, Vincent Building, Cranfield University, Cranfield, Bedfordshire, MK43 0AL, UK. m.barnett.s06@gmail.com.

ABSTRACT
The discovery over the past two decades of viable microbial communities within glaciers has promoted interest in the role of glaciers and ice sheets (the cryosphere) as contributors to subglacial erosion, global biodiversity, and in regulating global biogeochemical cycles. In situ or in-field detection and characterisation of microbial communities is becoming recognised as an important approach to improve our understanding of such communities. Within this context we demonstrate, for the first time, the ability to detect Gram-negative bacteria in glacial field-environments (including subglacial environments) via the detection of lipopolysaccharide (LPS); an important component of Gram-negative bacterial cell walls. In-field measurements were performed using the recently commercialised PyroGene® recombinant Factor C (rFC) endotoxin detection system and used in conjunction with a handheld fluorometer to measure the fluorescent endpoint of the assay. Twenty-seven glacial samples were collected from the surface, bed and terminus of a low-biomass Arctic valley glacier (Engabreen, Northern Norway), and were analysed in a field laboratory using the rFC assay. Sixteen of these samples returned positive LPS detection. This work demonstrates that LPS detection via rFC assay is a viable in-field method and is expected to be a useful proxy for microbial cell concentrations in low biomass environments.

No MeSH data available.


Related in: MedlinePlus

Map of Engabreen area with locations of the subaerial stream sampling sites and water access tunnels (black lines). EN—englacial stream; FO—forest stream; SL—shrubland stream and Engabrevatnet is the proglacial lake. The proglacial stream sample in 2008 was in the position same as EN (2009), the snow samples were collected from near the shrubland stream site, and the basal ice samples were collected from the research shaft (RS). The outline of the glacier is from 1995, but similar to November 2008 and March 2009.
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f1-biosensors-02-00083: Map of Engabreen area with locations of the subaerial stream sampling sites and water access tunnels (black lines). EN—englacial stream; FO—forest stream; SL—shrubland stream and Engabrevatnet is the proglacial lake. The proglacial stream sample in 2008 was in the position same as EN (2009), the snow samples were collected from near the shrubland stream site, and the basal ice samples were collected from the research shaft (RS). The outline of the glacier is from 1995, but similar to November 2008 and March 2009.

Mentions: Sediment, ice and meltwater samples were collected from the glacier snout and proglacial plain (subaerial samples), and subglacial environments (via the Svartisen Subglacial Laboratory), and were collected on different days during three one-week-long field campaigns from 19-27 November 2007, 19-26 November 2008 and 18-27 March 2009. In November 2008 and March 2009 a systematic sampling strategy was applied to collect equivalent samples, as far as practical, from both field campaigns. In November 2008 and March 2009 the samples clustered into three sample locations: subglacial meltwater collected from bedrock tunnels directly beneath the glacier; basal ice samples from the ice cave; and subaerial samples i.e., external to the Svartisen Subglacial Laboratory and tunnels (Figure 1). The subglacial meltwater samples (coded MW 1 to 5) were collected from different locations along a ∼600 m tunnel (the Spiral Tunnel and Stream), sites MW 1 and 2 were under the centre of the glacier and site MW 5 was the closest to the glacier margin. The samples were collected from subglacial inlets in the tunnel roof (sites MW 1, 2 and 3) and from fast flowing portions of the meltwater stream (sites MW 4 and 5). Site MW 5 was at the confluence of an additional subglacial meltwater stream and associated tunnel close to the research shaft (RS in Figure 1). The Spiral Tunnel consists of purely subglacial meltwater and the additional stream mainly drains snowmelt and/or rainwater. Basal ice samples (coded BI 1 to 6) were collected along a transect, from ice in contact with bedrock into glacial ice, where the total perpendicular distance from the bedrock contact to the furthest bulk ice sample was ∼5 m. BI 1 to 3 were debris rich ice samples, where BI 1 was in contact with the bedrock and BI 3 was near the contact with the glacial ice. BI 3 to 6 were glacial ice (or sediment poor ice), where BI 4 was near the contact with debris rich ice and BI 6 was furthest from the contact. The external samples consisted of snow, and water from englacial, proglacial, and forest streams (locations in Figure 1).


In-Field Implementation of a Recombinant Factor C Assay for the Detection of Lipopolysaccharide as a Biomarker of Extant Life within Glacial Environments.

Barnett MJ, Wadham JL, Jackson M, Cullen DC - Biosensors (Basel) (2012)

Map of Engabreen area with locations of the subaerial stream sampling sites and water access tunnels (black lines). EN—englacial stream; FO—forest stream; SL—shrubland stream and Engabrevatnet is the proglacial lake. The proglacial stream sample in 2008 was in the position same as EN (2009), the snow samples were collected from near the shrubland stream site, and the basal ice samples were collected from the research shaft (RS). The outline of the glacier is from 1995, but similar to November 2008 and March 2009.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4263545&req=5

f1-biosensors-02-00083: Map of Engabreen area with locations of the subaerial stream sampling sites and water access tunnels (black lines). EN—englacial stream; FO—forest stream; SL—shrubland stream and Engabrevatnet is the proglacial lake. The proglacial stream sample in 2008 was in the position same as EN (2009), the snow samples were collected from near the shrubland stream site, and the basal ice samples were collected from the research shaft (RS). The outline of the glacier is from 1995, but similar to November 2008 and March 2009.
Mentions: Sediment, ice and meltwater samples were collected from the glacier snout and proglacial plain (subaerial samples), and subglacial environments (via the Svartisen Subglacial Laboratory), and were collected on different days during three one-week-long field campaigns from 19-27 November 2007, 19-26 November 2008 and 18-27 March 2009. In November 2008 and March 2009 a systematic sampling strategy was applied to collect equivalent samples, as far as practical, from both field campaigns. In November 2008 and March 2009 the samples clustered into three sample locations: subglacial meltwater collected from bedrock tunnels directly beneath the glacier; basal ice samples from the ice cave; and subaerial samples i.e., external to the Svartisen Subglacial Laboratory and tunnels (Figure 1). The subglacial meltwater samples (coded MW 1 to 5) were collected from different locations along a ∼600 m tunnel (the Spiral Tunnel and Stream), sites MW 1 and 2 were under the centre of the glacier and site MW 5 was the closest to the glacier margin. The samples were collected from subglacial inlets in the tunnel roof (sites MW 1, 2 and 3) and from fast flowing portions of the meltwater stream (sites MW 4 and 5). Site MW 5 was at the confluence of an additional subglacial meltwater stream and associated tunnel close to the research shaft (RS in Figure 1). The Spiral Tunnel consists of purely subglacial meltwater and the additional stream mainly drains snowmelt and/or rainwater. Basal ice samples (coded BI 1 to 6) were collected along a transect, from ice in contact with bedrock into glacial ice, where the total perpendicular distance from the bedrock contact to the furthest bulk ice sample was ∼5 m. BI 1 to 3 were debris rich ice samples, where BI 1 was in contact with the bedrock and BI 3 was near the contact with the glacial ice. BI 3 to 6 were glacial ice (or sediment poor ice), where BI 4 was near the contact with debris rich ice and BI 6 was furthest from the contact. The external samples consisted of snow, and water from englacial, proglacial, and forest streams (locations in Figure 1).

Bottom Line: In situ or in-field detection and characterisation of microbial communities is becoming recognised as an important approach to improve our understanding of such communities.Within this context we demonstrate, for the first time, the ability to detect Gram-negative bacteria in glacial field-environments (including subglacial environments) via the detection of lipopolysaccharide (LPS); an important component of Gram-negative bacterial cell walls.Sixteen of these samples returned positive LPS detection.

View Article: PubMed Central - PubMed

Affiliation: Cranfield Health, Vincent Building, Cranfield University, Cranfield, Bedfordshire, MK43 0AL, UK. m.barnett.s06@gmail.com.

ABSTRACT
The discovery over the past two decades of viable microbial communities within glaciers has promoted interest in the role of glaciers and ice sheets (the cryosphere) as contributors to subglacial erosion, global biodiversity, and in regulating global biogeochemical cycles. In situ or in-field detection and characterisation of microbial communities is becoming recognised as an important approach to improve our understanding of such communities. Within this context we demonstrate, for the first time, the ability to detect Gram-negative bacteria in glacial field-environments (including subglacial environments) via the detection of lipopolysaccharide (LPS); an important component of Gram-negative bacterial cell walls. In-field measurements were performed using the recently commercialised PyroGene® recombinant Factor C (rFC) endotoxin detection system and used in conjunction with a handheld fluorometer to measure the fluorescent endpoint of the assay. Twenty-seven glacial samples were collected from the surface, bed and terminus of a low-biomass Arctic valley glacier (Engabreen, Northern Norway), and were analysed in a field laboratory using the rFC assay. Sixteen of these samples returned positive LPS detection. This work demonstrates that LPS detection via rFC assay is a viable in-field method and is expected to be a useful proxy for microbial cell concentrations in low biomass environments.

No MeSH data available.


Related in: MedlinePlus