Cyanobacterial populations that build ‘kopara’ microbial mats in Rangiroa, Tuamotu Archipelago, French Polynesia

Abstract

Cyanobacterial populations, the primary producers and builders of 'kopara' microbial mats were studied in four selected ponds along the rim of the Rangiroa Atoll, French Polynesia using a polyphasic approach. Seven isolates were maintained in uni-cyanobacterial cultures, characterized morphotypically and phylogenetically by evaluating sequences of the 16S rRNA gene of about 620 base pairs in length. Cyanobacteria in natural populations were analyzed microscopically, characterized morphotypically, and compared with cultured strains. Three of the isolates were identified in the field samples: Lyngbya aestuarii, Johannesbaptistia pellucida and Chroococcus submarinus were present in the mats only as minor components, whereas the species of Schizothrix that dominated the mat community could not be cultured. The sequence of Johannesbaptistia pellucida is published for the first time. The phylogenetic and taxonomic relations are discussed on the basis of a reconstructed phylogenetic tree in relation to morphotypic characters. Sequences of Kopara isolates plot separately from those cultured from the lagoon of the neighbouring atoll Tikehau, indicating a narrow niche differentiation of benthic cyanobacterial taxa. The results support the application of a polyphasic approach to characterization, ecology and diversity of cyanobacteria.

Factors influencing microbial mat composition, distribution and dinitrogen fixation in three western Indian Ocean coral reefs

“…They occur as stratified multi-species microbial mats (Stal, 2002), as persistent, horizontally spreading coatings over tidal mud flats (Abed et al, 2008), and as rapidly growing subtidal unicyanobacterial structures or mini-blooms (Abed et al, 2003a). Cyanobacteria-dominated mats and colonies are abundant in coral reef ecosystems, as has been shown for atolls (Webb et al, 1975;Charpy-Roubaud et al, 2001;Charpy-Roubaud & Larkum, 2005;Richert et al, 2006), the Great Barrier Reef (Larkum, 1988;Larkum et al, 1988), the Eilat reef, Israel (Shashar et al, 1994), the Kabira reef, Ishigaki, Japan (Kayanne et al, 2005), reefs near Zanzibar (Bauer et al, 2008), the lagoon of New Caledonia (Charpy et al, 2007), and the shallow lagoons of Okinawa and La Re´union . Cyanobacteriadominated benthic structures are also associated with carbonate precipitation (e.g.…”

Cyanobacterial Contribution to Travertine Deposition in the Hoyoux River System, Belgium

“…Past experiences have documented the prevalence of opportunistic organisms favoured by standard culture media at the expense of the field populations that are often adapted to nutrient-deprived extreme life conditions [61] and often do not grow at all in synthetic media [62].…”

Cyanobacterial Taxonomy: Current Problems and Prospects for the Integration of Traditional and Molecular Approaches

“…Examples of such molecular studies are analyses of halophilic vegetation from coastal regions of California (Garcia-Pichel et al 1998), extreme habitats in Antarctica (Moorhead and Priscu 1998;Nadeau et al 2001) and planktic communities (Lyra et al 2001). Examples of detailed studies based on the precise phenotype analyses are Richert et al (2006) Island in Antarctica, and Komárek and Komárková-Legnerová (2007) from alkaline marshes in Belize, Central America (Fig. 13).…”