Effects of the cultivation of genetically modified Bt crops on nontarget soil organisms - Microbial Ecology in Sustainable Agroecosystems - page 168

Table 8.3 Summary of Effects of Cultivation of Bt Crops or Amendment with Bt Proteins on Soil Bacteria (continued)
Organism/activity
tested

Bt crop plant/
experimental variable

Methodology Study location Protein Effect on bacteria Source

Rhizosphere microbial
community
composition
Soil enzyme activities
(phosphatase activity,
dehydrogenase
activity, respiration,
and methanogenesis)

T-RFLP
DGGE

Field Bt rice, non- Bt rice, and

non- Bt rice treated
with the insecticide
Triazophos

Cry1Ab No negative effect of

Bt rice on microbial
community structure
or soil enzyme
activities in the
rhizosphere

Liu et al.
(2008)

Aerobic bacteria,
enzyme activity
(dehydrogenase and
nitrogenase enzymes),
and ATP content

Culturing
techniques

Field Rhizosphere and

nonrhizosphere soil
cultivated with Bt
(Events 176 and
MON810) and non- Bt
maize

Cry1Ab No negative effect of

Bt cultivar

Oliveira et al.
(2008)

Rhizosphere bacteria Culturing

techniques

Field Soil with Bt and non- Bt

cotton

Cry1A,
CpTI

No negative effect of
Bt cotton on
rhizosphere bacteria

Hu et al.
(2009)

Microbial
decomposition rates as
determined by
ash-free mass
remaining (AFMR),
total carbon (TC) and
total nitrogen (TN)
content after
decomposition, and
cellulose and lignin
contents of the original
rice residues

AFMR:
calculation of
ash weight
TC and TN:
combustion in
an element
autoanalyzer

Field Litterbags containing

roots or straw from Bt
(KMD) and non- Bt
( XiuShui 11) rice

Cry1Ab Bt rice roots

decomposed faster
than non- Bt rice roots
in buried litterbags in
the first 200 days
No difference in
decomposition rate
between Bt and
non- Bt rice straw
buried in litterbags

Wu et al.
(2009)

(continued)