Maybe Tier- und Freizeitpark Thüle for Ring-Tailed lemurs or Serengetipark Hodenhagen for at least Ring-Tailed lemurs and maybe some other lemurs (can't remember since I couldn't use them because of covid...). They are both around 1 hour from Bremen and have at least one walk-through.
I could list more but maybe could specify what you mean with "near" Bremen