Effects of the cultivation of genetically modified Bt crops on nontarget soil organisms - Microbial Ecology in Sustainable Agroecosystems - page 165

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

Culturable functional
groups (nitrogen-
fixing, inorganic
phosphate-dissolving,
and potassium-
dissolving bacteria)

Culturing
technique

Field Rhizosphere soils of Bt

(SGK321 and
Nu-COTN99B) and
non- Bt cotton
(SHIYUAN321)
Addition of purified Bt
protein

Cry1Ac Lower numbers of

culturable functional
groups of bacteria in
soil with Bt cotton
Nu-COTN99B versus
non- Bt cotton
throughout most of
the growing season;
nitrogen-fixing
bacteria reduced in
soil amended with
more than 500 ng/g
purified Bt protein

Rui et al.
(2005)

Microbial community
structure

PLFA
CLPP

Field Soil cultivated with Bt

(MEB307 Bt ) and
non- Bt maize isoline
(Monumental)

Cry1Ab No difference in

microbial community
structure between Bt
and non- Bt soil

Griffiths et al.
(2005)

Functional diversity of
microbial communities
as determined by
enzyme activity
(urease, phosphatase,
dehydrogenase,
phenol oxidase, and
protease)

Enzyme assays
Biolog

Greenhouse Rhizosphere soil

cultivated with Bt
(Sukang-103) and
non- Bt (Sumian-12)
cotton
Soil amended with
biomass of Bt and
non- Bt cotton

Cry1Ac No negative effect of

cultivation with or
amendment with Bt
cotton on enzyme
activity, functional
diversity of microbial
community, or species
richness

Shen et al.
(2006)

Soil microbial
community

PLFA Greenhouse Soil cultivated with Bt

(Event MON810) and
non- Bt (Monumental)
maize collected from
field sites

Cry1Ab No effect of Bt soil on

soil microbial
community

Griffiths et al.
(2006)

(continued)