Bt genes occur in
Bacillus thuringenesis
Escherichia coli
Agrobacterium tumefaciens
Rhizobium
Bacillus thuringenesis (Bt) is a species of bacteria that lives in the soil. It makes proteins that are toxic to some insects when eaten, but not others.
Bacillus thuringenesis is a gram positive . Soil dwelling bacterium ,commonly used as biological pesticide