Protozoan predation in soil slurries compromises determination of contaminant mineralization potential

Nora Badawi; Anders R.  Johnsen; Kristian Koefoed Brandt; Jan Sørensen; Jens Aamand

doi:10.1016/j.envpol.2012.06.013

Protozoan predation in soil slurries compromises determination of contaminant mineralization potential

Nora Badawi, Anders R. Johnsen, Kristian Koefoed Brandt, Jan Sørensen, Jens Aamand

6 Citations (Scopus)

Abstract

Soil suspensions (slurries) are commonly used to estimate the potential of soil microbial communities to mineralize organic contaminants. The preparation of soil slurries disrupts soil structure, however, potentially affecting both the bacterial populations and their protozoan predators. We studied the importance of this "slurry effect" on mineralization of the herbicide 2-methyl-4-chlorophenoxyacetic acid (MCPA, ¹⁴C-labelled), focussing on the effects of protozoan predation. Mineralization of MCPA was studied in "intact" soil and soil slurries differing in soil:water ratio, both in the presence and absence of the protozoan activity inhibitor cycloheximide. Protozoan predation inhibited mineralization in dense slurry of subsoil (soil:water ratio 1:3), but only in the most dilute slurry of topsoil (soil:water ratio 1:100). Our results demonstrate that protozoan predation in soil slurries may compromise quantification of contaminant mineralization potential, especially when the initial density of degrader bacteria is low and their growth is controlled by predation during the incubation period.

Original language	English
Journal	Environmental Pollution
Volume	170
Pages (from-to)	32-38
Number of pages	7
ISSN	0269-7491
DOIs	https://doi.org/10.1016/j.envpol.2012.06.013
Publication status	Published - Nov 2012

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@article{0800d3ec0a7542fdb92d173caeaa5eba,

title = "Protozoan predation in soil slurries compromises determination of contaminant mineralization potential",

abstract = "Soil suspensions (slurries) are commonly used to estimate the potential of soil microbial communities to mineralize organic contaminants. The preparation of soil slurries disrupts soil structure, however, potentially affecting both the bacterial populations and their protozoan predators. We studied the importance of this {"}slurry effect{"} on mineralization of the herbicide 2-methyl-4-chlorophenoxyacetic acid (MCPA, 14C-labelled), focussing on the effects of protozoan predation. Mineralization of MCPA was studied in {"}intact{"} soil and soil slurries differing in soil:water ratio, both in the presence and absence of the protozoan activity inhibitor cycloheximide. Protozoan predation inhibited mineralization in dense slurry of subsoil (soil:water ratio 1:3), but only in the most dilute slurry of topsoil (soil:water ratio 1:100). Our results demonstrate that protozoan predation in soil slurries may compromise quantification of contaminant mineralization potential, especially when the initial density of degrader bacteria is low and their growth is controlled by predation during the incubation period.",

author = "Nora Badawi and Johnsen, {Anders R.} and Brandt, {Kristian Koefoed} and Jan S{\o}rensen and Jens Aamand",

year = "2012",

month = nov,

doi = "10.1016/j.envpol.2012.06.013",

language = "English",

volume = "170",

pages = "32--38",

journal = "Environmental Pollution",

issn = "0269-7491",

publisher = "Pergamon Press",

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TY - JOUR

T1 - Protozoan predation in soil slurries compromises determination of contaminant mineralization potential

AU - Badawi, Nora

AU - Johnsen, Anders R.

AU - Brandt, Kristian Koefoed

AU - Sørensen, Jan

AU - Aamand, Jens

PY - 2012/11

Y1 - 2012/11

N2 - Soil suspensions (slurries) are commonly used to estimate the potential of soil microbial communities to mineralize organic contaminants. The preparation of soil slurries disrupts soil structure, however, potentially affecting both the bacterial populations and their protozoan predators. We studied the importance of this "slurry effect" on mineralization of the herbicide 2-methyl-4-chlorophenoxyacetic acid (MCPA, 14C-labelled), focussing on the effects of protozoan predation. Mineralization of MCPA was studied in "intact" soil and soil slurries differing in soil:water ratio, both in the presence and absence of the protozoan activity inhibitor cycloheximide. Protozoan predation inhibited mineralization in dense slurry of subsoil (soil:water ratio 1:3), but only in the most dilute slurry of topsoil (soil:water ratio 1:100). Our results demonstrate that protozoan predation in soil slurries may compromise quantification of contaminant mineralization potential, especially when the initial density of degrader bacteria is low and their growth is controlled by predation during the incubation period.

AB - Soil suspensions (slurries) are commonly used to estimate the potential of soil microbial communities to mineralize organic contaminants. The preparation of soil slurries disrupts soil structure, however, potentially affecting both the bacterial populations and their protozoan predators. We studied the importance of this "slurry effect" on mineralization of the herbicide 2-methyl-4-chlorophenoxyacetic acid (MCPA, 14C-labelled), focussing on the effects of protozoan predation. Mineralization of MCPA was studied in "intact" soil and soil slurries differing in soil:water ratio, both in the presence and absence of the protozoan activity inhibitor cycloheximide. Protozoan predation inhibited mineralization in dense slurry of subsoil (soil:water ratio 1:3), but only in the most dilute slurry of topsoil (soil:water ratio 1:100). Our results demonstrate that protozoan predation in soil slurries may compromise quantification of contaminant mineralization potential, especially when the initial density of degrader bacteria is low and their growth is controlled by predation during the incubation period.

U2 - 10.1016/j.envpol.2012.06.013

DO - 10.1016/j.envpol.2012.06.013

M3 - Journal article

C2 - 22763328

SN - 0269-7491

VL - 170

SP - 32

EP - 38

JO - Environmental Pollution

JF - Environmental Pollution

ER -

Protozoan predation in soil slurries compromises determination of contaminant mineralization potential

Abstract

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