Effects of the cultivation of genetically modified Bt crops on nontarget soil organisms - Microbial Ecology in Sustainable Agroecosystems - page 167

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

Enzyme activities
(urease, acid
phosphomonoesterase,
arylsulfatase,
invertase, cellulase)
and Bt protein
persistence in soil

ELISA to quantify
Bt protein
Enzyme activity
tests

Laboratory Field collected soil

amended with leaves
and stems of Bt cotton
( Bt -GK and Bt -ZK)
and a non- Bt isoline
(non- Bt ZM)

Cry1Ac Bt cotton stems and

leaves had a positive
effect on urease, acid
phosphomonoesterase,
invertase, and cellulase
activities, but a
negative effect on
arylsulfatase activity;
after 56 days, Bt
protein detected in soil
with 41% and 60% of
the introduced
amounts remaining
from Bt -ZK and Bt -GK,
respectively

Sun et al.
(2007)

Microbial diversity
(total culturable,
gram-negative,
chitin-utilizing,
cellulose-utilizing,
ammonium- and
nitrite-oxidizing, and
nitrate-reducing and
denitrifying
organisms), enzyme
activities
(arylsulfatase, acid and
alkaline phosphatases,
dehydrogenases, and
proteases)

Dilution plating
Most probable
number (MPN)
counts
DGGE
Enzyme assays

Field Soil cultivated with Bt

(Bt 11, MON810,
MON863) and non- Bt
maize

Cry1Ab
Cry3Bb1

No consistent
differences in
microbial diversity or
enzyme activities

Icoz et al.
(2008)

(continued)