Sorbti Diaper
Sorbit is a fully biodegradable diaper made out of bacterial cellulose grown from citrus agricultural waste. The material is soft, water-repellant on the outside, and absorbent on the inside.

There is a story in Co.Design about using bacteria in home design featuring a project from UC Davis students.  See "The next big home design trend? Bacteria" by Katherine Schwab. The article discusses multiple projects including one on biodegradable diapers from UC Davis:

Parents would probably be alarmed at the thought of more bacteria near where their baby sleeps. But a team of students from UC Davis has created a fully biodegradable diaper made from citrus waste that has been transformed into bacterial cellulose–which feels a bit like plastic, but you can toss it in the garden when you’re done. There’s also an absorbent layer of Aerogel that the students grew using the bacterial cellulose to soak up any liquid (or solids).