Why must genetically altered bacteria be grown in a carefully controlled environment?

Genetically modified organisms (GMOs) are widely used in research and for making pharmaceuticals and other products. However, use of genetically modified bacteria outside of the lab has been limited by concerns that they—and the sometimes novel genes they carry—could escape into the wild.

Scientists have attempted to solve this problem in a variety of ways, including the creation of bacteria that depend on nutrients they can’t make themselves. But these bacteria might survive in the wild by receiving those nutrients from natural organisms.

Not only have GMO crops not improved yields, they have vastly increased the use of glyphosate, the active ingredient in Monsanto's Roundup herbicide. ... The explosion in glyphosate use is not only bad for farmers' health, it's also bad for the environment, especially for certain birds, insects and other wildlife.

Genetic Contamination/Interbreeding

Introduced GMOs may interbreed with the wild-type or sexually compatible relatives. The novel trait may disappear in wild types unless it confers a selective advantage to the recipient. However, tolerance abilities of wild types may also develop, thus altering the native species’ ecological relationship and behaviour.

cells use diffusion to get substances in and out of themselves. that diffusion will occur across the cell membrane or the outer covering of the cell. because we are talking about the surface of the cell, surface area and volume are  important factors here. as a cell increases in size, its surface area and volume increase as well.  we call that the surface area to volume ratio (sa: vol).  but the catch is that  volume increases at a greater rate than surface  area. in other words, as a cell gets bigger, the sa: vol gets smaller. so a really small cell like bacteria is mostly cell membrane (surface) with very little contents (volume). a really big cell like an egg, is mostly insides with a super thin membrane. so what ends up happening is that the cell cannot efficiently diffuse all of the stuff it needs in/out to survive. therefore cell size is limited to about 100mm. so how do we make organisms bigger than 100mm? cells divide! by dividing and becoming multicellular, organisms are able to grow!   check out the diagrams i attached to see the effect of sa: vol. i hope this ! good luck!