title: Facilitation as Attenuating of Environmental Stress among Structured Microbial Populations.
abstract: There is currently an intense debate in microbial societies on whether evolution in complex communities is driven by competition or cooperation. Since Darwin, competition for scarce food resources has been considered the main ecological interaction shaping population dynamics and community structure both in vivo and in vitro. However, facilitation may be widespread across several animal and plant species. This could also be true in microbial strains growing under environmental stress. Pure and mixed strains of Serratia marcescens and Candida rugosa were grown in mineral culture media containing phenol. Growth rates were estimated as the angular coefficients computed from linearized growth curves. Fitness index was estimated as the quotient between growth rates computed for lineages grown in isolation and in mixed cultures. The growth rates were significantly higher in associated cultures than in pure cultures and fitness index was greater than 1 for both microbial species showing that the interaction between Serratia marcescens and Candida rugosa yielded more efficient phenol utilization by both lineages. This result corroborates the hypothesis that facilitation between microbial strains can increase their fitness and performance in environmental bioremediation.
authors.affiliation: Laboratory of Environmental Microbiology, Department of Biology, Sciences Center, Federal University of Ceará, Pici Campus, Block 909, 60455-760 Fortaleza, CE, Brazil.
authors.forename: Suzana Cláudia Silveira
authors.identifier: 0000-0002-8353-7190
authors.initials: SC
authors.lastname: Martins
authors.affiliation: Sea Sciences Institute, Federal University of Ceará, 60165-081 Fortaleza, CE, Brazil.
authors.forename: Sandra Tédde
authors.initials: ST
authors.lastname: Santaella
authors.affiliation: Laboratory of Environmental Microbiology, Department of Biology, Sciences Center, Federal University of Ceará, Pici Campus, Block 909, 60455-760 Fortaleza, CE, Brazil.
authors.forename: Claudia Miranda
authors.initials: CM
authors.lastname: Martins
authors.affiliation: Graduate Program of Ecology and Natural Resources, Department of Biology, Sciences Center, Federal University of Ceará, 60455-760 Fortaleza, CE, Brazil.
authors.forename: Rogério Parentoni
authors.initials: RP
authors.lastname: Martins
mesh_terms: D002175:Candida / Q000187:drug effects / Q000254:growth & development / Q000502:physiology*; D004777:Environment; D019800:Phenol / Q000494:pharmacology; D011140:Polyurethanes / Q000494:pharmacology; D012705:Serratia / Q000187:drug effects / Q000254:growth & development / Q000502:physiology*
chemical_list: D011140:Polyurethanes; D019800:Phenol; C028279:polyurethane foam