Additionally, recent work in model systems of surface growth has shown that motility on agar plate surfaces, swarming, CDK inhibitor twitching, gliding, and swimming, is strongly affected by the plate environment [13]. Swarming as an agar plate physiology has been studied for many years in Proteus species, which grow and swarm very find more rapidly in culture [14]. It has also been studied in several other model systems, such as Bacillus subtilis [15], Serratia liquifaciens [16], Pseudomonas aeruginosa [17],

and several other pathogenic and environmental isolates (for review see [18]). Swarming motility is intimately involved in the virulence of many important pathogens [19], but is also a standard physiological response to environmental conditions [20]. Interestingly, although swarming motility in particular is observed in a wide array of microorganisms, the effect of nutrient sources on swarming has only been studied in a few systems. Carbon sources associated with swarming were identified in Salmonella species, showing that different strains responded to different

nutrient classes [21]. In P. aeruginosa, certain amino acids can stimulate swarming motility [22]. Carbon source dependence in P. aeruginosa has only been examined under a few circumstances, showing that P. aeruginosa does not swarm Fosbretabulin on succinate in FAB medium [22, 23]. This work also addressed the role of nutrients in the physiology of flow cell biofilms, suggesting that surface roughness is related to nutrient sources. Based on other work, it has been suggested that salt concentration also plays a role [24], probably by altering the water availability Carbachol at the agar surface. Surface wetting has been observed to impact swarming in Salmonella, with flagella playing roles in wetness detection and motility through the activity of FlgM [25]. Over the past decade, the study of microbial biofilms has grown exponentially (for review see [26, 27]). The biofilm lifestyle

is now universally acknowledged as the dominant form of microbial growth in the environment, ranging from desert crusts to biofilms on hospital catheters [27]. Several model systems have been utilized to examine the genetics of biofilm formation, and the gram-negative Pseudomonas aeruginosa has become a particularly well studied system. The study of this and other model biofilms has made clear some of the salient features of this lifestyle, such as attachment, growth, maturation, and detachment [28–30]. Other microorganisms have also been extensively studied, but most of the effort has understandably focused on biofilms of medical interest, such as urinary tract pathogens [31], dental or periodontal disease associated bacteria [32], enteric pathogens [33], and gram positive cocci associated with catheter and nosocomial wound infections [34, 35].