General:

* Living

* Organic

* Biological

* Biotic (this is a synonym for itself, but often used interchangeably)

More specific:

* Flora and fauna (when referring to plants and animals)

* Biota (the sum of all living organisms in a specific area)

* Living organisms

* Biological components

* Ecosystem components (when referring to a specific ecological context)

The best synonym will depend on the specific situation you are using it in.