title: Simultaneous cultivation of Spirulina platensis and the toxigenic cyanobacteria Microcystis aeruginosa.
abstract: Mangueira Lagoon, located in the extreme south of Brazil, has water with physicochemical characteristics such as alkaline pH and carbonate levels propitious for the growth of the cyanobacterium Spirulina platensis. Previously published studies have shown that Mangueira Lagoon water supplemented with small quantities of carbon and nitrogen is suitable for S. platensis cultivation and can significantly reduce production costs. We studied mixed cultures of Spirulina platensis and the toxic cyanobacterium Microcystis aeruginosa using a 2(3) factorial design in which the three factors were the initial biomass concentration of S. platensis and M. aeruginosa and the type of culture medium (100% Zarrouk's medium or 80% Mangueira Lagoon water plus 20% Zarrouk's medium). The highest S. platensis maximum specific growth rate (mu(max)) occurred in the culture with the highest M. aeruginosa biomass concentration and when undiluted culture medium was used (micro(max) = 0.283 d(-1)). The highest M. aeruginosa specific death rate (k) was obtained in the presence of S. platensis (k = 0.555 d(-1)) and was independent of the initial M. aeruginosa biomass concentration and culture medium, demonstrating that S. platensis cultures are not susceptible to contamination by M. aeruginosa. The culture medium had no significant influence (p > 0.05) on S. platensis micro(max) values, indicating that production costs could be reduced by using a medium consisting of 80% Mangueira Lagoon water plus 20% Zarrouk's medium.
authors.affiliation: Laboratório de Engenharia Bioquímica, Departamento de Química, Fundação Universidade Federal do Rio Grande, Caixa Postal 474, CEP 96201-900, Rio Grande, RS, Brazil. dqmjorge@furg.br
authors.forename: Jorge Alberto Vieira
authors.initials: JA
authors.lastname: Costa
authors.forename: Michele Greque
authors.initials: MG
authors.lastname: de Morais
authors.forename: Francieli
authors.initials: F
authors.lastname: Dalcanton
authors.forename: Carolina da Cruz
authors.initials: Cda C
authors.lastname: Reichert
authors.forename: Andrei José
authors.initials: AJ
authors.lastname: Durante
mesh_terms: D018533:Biomass; D001938:Brazil; D002980:Climate; D003470:Culture Media; D000458:Cyanobacteria / Q000254:growth & development*; D007700:Kinetics; D046931:Microcystis / Q000254:growth & development*; D014871:Water Microbiology
chemical_list: D003470:Culture Media