Morphological and Genetic Evidence that the Cyanobacterium Lyngbya wollei (Farlow ex Gomont) Speziale and Dyck Encompasses at Least Two Species

Abstract

Dense blooms of the cyanobacterium Lyngbya wollei are increasingly responsible for declining water quality and habitat degradation in numerous springs, rivers, and reservoirs. This research represents the first molecular phylogenetic analysis of L. wollei in comparison with the traditional morphological characterization of this species. Specimens were collected from several springs in Florida and a reservoir in North Carolina. Segments of the small-subunit (SSU) rRNA and nifH genes were PCR amplified, cloned, and sequenced. The phylogenetic analysis of the SSU rRNA gene revealed sequences that fell into three distinct subclusters, each with >97% sequence similarity. These were designated operational taxonomic unit 1 (OTU1), OTU2, and OTU3. Similarly, the nifH sequences fell into three distinct subclusters named S1, S2, and S3. When either bulk samples or individual filaments were analyzed, we recovered OTU1 with S1, OTU2 with S2, and OTU3 with S3. The coherence between the three SSU rRNA gene and nifH subclusters was consistent with genetically distinct strains or species. Cells associated with subclusters OTU3 and S3 were significantly wider and longer than those associated with other subclusters. The combined molecular and morphological data indicate that the species commonly identified as L. wollei in the literature represents two or possibly more species. Springs containing OTU3 and S3 demonstrated lower ion concentrations than other collection sites. Geographical locations of Lyngbya subclusters did not correlate with residual dissolved inorganic nitrogen or phosphorus concentrations. This study emphasizes the need to complement traditional identification with molecular characterization to more definitively detect and characterize harmful cyanobacterial species or strains.

Molecular identification, typing and traceability of cyanobacteria from freshwater reservoirs

“…In fact, this genus has recently undergone revisions (Suda et al, 2002) and its polyphyly was also inferred by others (Ishida et al, 2001;Marquardt & Palinska, 2007;Suda et al, 2002). Similarly to Joyner et al (2008), a polyphyletic origin of the genus Lyngbya was also inferred from the 16S rRNA gene tree, justifying its taxonomic revision. This might be related to the fact that traditional criteria used for classification of the Oscillatoriales at the genus level predominantly rely on the characteristics of external sheaths and colony formation, rather than on cellular features (Marquardt & Palinska, 2007).…”

Co-occurrence of dinoflagellate and cyanobacterial harmful algal blooms in southwest Florida coastal waters: dual nutrient (N and P) input controls

“…The observed N and P co-stimulation of L. majuscula primary production demonstrates the potential for these nutrients to individually and jointly enhance growth of this benthic HAB, an observation that has also recently been made for L. majuscula populations in Moreton Bay, a subtropical estuarine and coastal embayment in Australia (Albert et al 2005, Ahern et al 2007). These findings further illustrate the metabolic flexibility of the genus Lyngbya, freshwater and marine species which are capable of at least partially satisfying their N requirements through N 2 fixation (Paerl et al 1991, Phlips et al 1991, Olson et al 1999, Lundgren et al 2003, Joyner et al 2008.…”

“…The observed N and P co-stimulation of L. majuscula primary production demonstrates the potential for these nutrients to individually and jointly enhance growth of this benthic HAB, an observation that has also recently been made for L. majuscula populations in Moreton Bay, a subtropical estuarine and coastal embayment in Australia (Albert et al 2005, Ahern et al 2007). These findings further illustrate the metabolic flexibility of the genus Lyngbya, freshwater and marine species which are capable of at least partially satisfying their N requirements through N 2 fixation (Paerl et al 1991, Phlips et al 1991, Olson et al 1999, Lundgren et al 2003, Joyner et al 2008.Even though members of this genus are capable of diazotrophy, they are also capable of growth on com- Nutrient stimulation of Lyngbya majuscula primary productivity was consistently lower and much slower, relative to controls, than responses observed in Karenia spp. In part, the less profound stimulatory response in L. majuscula may have been a reflection of the inherently slower growth rates and doubling times for this benthic cyanobacterium (and filamentous cyanobacteria in general), when compared to published doubling times for diatoms, cryptophytes, and other representative eukaryotic phytoplankton taxa , Reynolds 2006.…”

Seven new species ofOculatella(Pseudanabaenales, Cyanobacteria): taxonomically recognizing cryptic diversification

“…In Cyanobacteria, the presence of cryptic species has been reported in Microcoleus steenstrupii Boye-Petersen (Boyer et al, 2002), Phormidium retzii (Ag.) Gomont ex Gomont (Casamatta et al, 2003), Synechococcus spongiarum Usher et al (Erwin & Thacker, 2008), Lyngbya wollei (Farlow ex Gomont) Speziale et Dyck (Joyner et al, 2008) and Leptolyngbya valderiana (Gomont) Anagn. et Komárek (Premanandh et al, 2009), but in none of these studies was the cryptic diversity taxonomically recognized.…”