title: Allelopathic activity among Cyanobacteria and microalgae isolated from Florida freshwater habitats.
abstract: We evaluated allelopathic interactions between strains of Cyanobacteria and green algae isolated from south and central Florida. Allelopathy, including inhibition or stimulation of growth, was assessed by cocultivation of each of the isolated strains, as well as by evaluation of extracts prepared from the isolates. All of the strains of Cyanobacteria, and four of the six isolates of green algae, showed some allelopathic activity (i.e. inhibition or stimulation of the growth of other strains). Of these, the most pronounced activity was observed for the cyanobacterial isolate Fischerella sp. strain 52-1. In the cocultivation experiments this cyanobacterium inhibited the growth of all tested green algae and Cyanobacteria. The crude lipophilic extracts from Fischerella sp. strain 52-1 isolated from both the biomass and the culture liquid inhibited photosynthesis of the green alga Chlamydomonas sp. in a concentration- and time-dependent manner and caused extensive loss of ultrastructural cell organization. Preliminary chemical characterization of compounds extracted from Fischerella sp. strain 52-1 indicated the presence of indole alkaloids, and further characterization has confirmed that these compounds belong to the hapalindoles previously isolated from other species of Fischerella and related genera. Further chemical characterization of these compounds, and further investigation of their apparent role in allelopathy is ongoing.
authors.affiliation: Department of Biological Sciences, Florida International University, Miami, FL 33199, USA. gantarm@fiu.edu
authors.forename: Miroslav
authors.initials: M
authors.lastname: Gantar
authors.forename: John P
authors.initials: JP
authors.lastname: Berry
authors.forename: Serge
authors.initials: S
authors.lastname: Thomas
authors.forename: Minglei
authors.initials: M
authors.lastname: Wang
authors.forename: Roberto
authors.initials: R
authors.lastname: Perez
authors.forename: Kathleen S
authors.initials: KS
authors.lastname: Rein
mesh_terms: D000898:Antibiosis; D000460:Chlorophyta / Q000187:drug effects / Q000254:growth & development* / Q000648:ultrastructure; D018920:Coculture Techniques; D017077:Culture Media, Conditioned / Q000737:chemistry; D000458:Cyanobacteria / Q000145:classification / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D017753:Ecosystem; D005431:Florida; D005618:Fresh Water / Q000382:microbiology*; D026121:Indole Alkaloids / Q000302:isolation & purification / Q000378:metabolism* / Q000494:pharmacology; D010788:Photosynthesis / Q000187:drug effects
chemical_list: D017077:Culture Media, Conditioned; D026121:Indole Alkaloids