Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaper › Journal article › Research › peer-review
Behind the Organic Veil : Assessing the Impact of Chemical Deflocculation on Organic Content Reduction and Lacustrine Arcellinida (Testate Amoebae) Analysis. / Nasser, Nawaf A.; Gregory, Braden R.B.; Steele, Riley E.; Patterson, R. Timothy; Galloway, Jennifer M.
In: Microbial Ecology, Vol. 79, No. 2, 2020, p. 443-458.Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaper › Journal article › Research › peer-review
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TY - JOUR
T1 - Behind the Organic Veil
T2 - Assessing the Impact of Chemical Deflocculation on Organic Content Reduction and Lacustrine Arcellinida (Testate Amoebae) Analysis
AU - Nasser, Nawaf A.
AU - Gregory, Braden R.B.
AU - Steele, Riley E.
AU - Patterson, R. Timothy
AU - Galloway, Jennifer M.
PY - 2020
Y1 - 2020
N2 - Arcellinida (testate lobose amoebae) are widely used as bio-indicators of lacustrine environmental change. Too much obscuring organic material in a gridded wet Petri dish preparation makes it difficult to observe all specimens present and slows quantification as the organic material has to be carefully worked through with a dissection probe. Chemical deflocculation using soda ash (Na2CO3·H2O), potassium hydroxide (KOH), or sodium hexametaphosphate ((NaPO3)6) has previously been shown to disaggregate and reduce organic content in lake sediments, but to date, no attempt has been made to comparatively evaluate the efficiency of these deflocculants in disaggregating organic content and their impact on Arcellinida analysis in lacustrine sediments. Here, we assess the effectiveness of soda ash, potassium hydroxide, and sodium hexametaphosphate treatments on removing organic content and the impact of those digestions on Arcellinida preservation in 126 sample aliquots subdivided from three sediment samples (YK-20, YK-25, and YK-57) collected from three lakes near Yellowknife, Northwest Territories, Canada. Following treatment, cluster analysis and Bray-Curtis dissimilarity matrix (BCDM) were utilized to determine whether treatments resulted in dissolution-driven changes in Arcellinida assemblage composition. Observed Arcellinida tests in aliquots increased drastically after treatment of organic-rich samples (47.5–452.7% in organic-rich aliquots and by 14.8% in aliquots with less organic matter). The BCDM results revealed that treatment with 5% KOH resulted in the highest reduction in observed organic content without significantly affecting Arcellinida assemblage structure, while soda ash and sodium hexametaphosphate treatments resulted in marginal organic matter reduction and caused severe damage to the arcellinidan tests.
AB - Arcellinida (testate lobose amoebae) are widely used as bio-indicators of lacustrine environmental change. Too much obscuring organic material in a gridded wet Petri dish preparation makes it difficult to observe all specimens present and slows quantification as the organic material has to be carefully worked through with a dissection probe. Chemical deflocculation using soda ash (Na2CO3·H2O), potassium hydroxide (KOH), or sodium hexametaphosphate ((NaPO3)6) has previously been shown to disaggregate and reduce organic content in lake sediments, but to date, no attempt has been made to comparatively evaluate the efficiency of these deflocculants in disaggregating organic content and their impact on Arcellinida analysis in lacustrine sediments. Here, we assess the effectiveness of soda ash, potassium hydroxide, and sodium hexametaphosphate treatments on removing organic content and the impact of those digestions on Arcellinida preservation in 126 sample aliquots subdivided from three sediment samples (YK-20, YK-25, and YK-57) collected from three lakes near Yellowknife, Northwest Territories, Canada. Following treatment, cluster analysis and Bray-Curtis dissimilarity matrix (BCDM) were utilized to determine whether treatments resulted in dissolution-driven changes in Arcellinida assemblage composition. Observed Arcellinida tests in aliquots increased drastically after treatment of organic-rich samples (47.5–452.7% in organic-rich aliquots and by 14.8% in aliquots with less organic matter). The BCDM results revealed that treatment with 5% KOH resulted in the highest reduction in observed organic content without significantly affecting Arcellinida assemblage structure, while soda ash and sodium hexametaphosphate treatments resulted in marginal organic matter reduction and caused severe damage to the arcellinidan tests.
KW - Arcellinida
KW - Arcellinidan analysis
KW - Chemical treatment
KW - Lake sediments
KW - Organic content
KW - Sample preparation methods
UR - http://www.scopus.com/inward/record.url?scp=85071172131&partnerID=8YFLogxK
U2 - 10.1007/s00248-019-01429-0
DO - 10.1007/s00248-019-01429-0
M3 - Journal article
C2 - 31432244
AN - SCOPUS:85071172131
VL - 79
SP - 443
EP - 458
JO - Microbial Ecology
JF - Microbial Ecology
SN - 0095-3628
IS - 2
ER -