Network 1 represents those genes included in the stress and virulence thematic microarray that were up(down)-regulated in response to several environmental stresses and anoxic condition. The bi-partite network connects genes with environmental conditions and regulation pattern. Node colors represent the modules, i.e. highly connected groups of nodes, detected in this network. Gene names added only for highly connected nodes, i.e. hubs with between 4 and 8 links as described in Table S2. The 5 selected hubs to carry out mutations are in blue font and underlined in red.