When they were talking about developing microbes that could excrete insulating materials, they said existing biofilms are sugar-based and wouldn't be able to ho

When they were talking about developing microbes that could excrete insulating materials, they said existing biofilms are sugar-based and wouldn't be able to hold in enough/heat water. So I started thinking about what if they could excrete minerals or metals. Then I was thinking about the challenges of expanding a protected inside area without exposing it to the outside. And about how much material would be needed. Which led me to thinking of covering individual microbes with metal. And now I have this picture in my head of a little microbe walking around in a armor.