Brenda is a comprehensive enzyme information system.

Entrze is National Center for Biotechnology information (NCBI) 's life sciences search engine.

Public Library of Science is a freely available scientific and medical literature site made by scientists and physicians.

Microbes info  is an internet gateway portal designed to bring useful and interesting microbiology informational resources to all interested. Microbes.info is a firm starting point for finding information concerning Microbiology.