"I researched different types of construction methods involving pile systems and realised that injection piles could probably be used to get the bacteria down into the sand - a procedure that would be analogous to using an oversized 3D printer, solidifying parts of the dune as needed. The piles would be pushed through the dune surface and a first layer of bacteria spread out, solidifying an initial surface within the dune. They would then be pulled up, creating almost any conceivable (structurally sound) surface along their way, with the loose sand acting as a jig before being excavated to create the necessary voids."
That is a fascinating hack of the real world. I could see this being readily applicable to construction in desert climates; my first question would be about the water budget necessary to support the biological glue.
There are multiple well understood ways of limiting the effects of biological activity. It's not like compost heaps or breweries have eaten civilization yet.
"I researched different types of construction methods involving pile systems and realised that injection piles could probably be used to get the bacteria down into the sand - a procedure that would be analogous to using an oversized 3D printer, solidifying parts of the dune as needed. The piles would be pushed through the dune surface and a first layer of bacteria spread out, solidifying an initial surface within the dune. They would then be pulled up, creating almost any conceivable (structurally sound) surface along their way, with the loose sand acting as a jig before being excavated to create the necessary voids."