The cyanobacterial genus Lyngbya was once thought to be a cosmopolitan genus, inhabiting nearly every biome across the globe. However, utilization of genetic, and more recently genomic, sequencing has revealed that this morphologically homogenous taxon in fact comprises distinct evolutionary clades, leading to the plethora of newly described Cyanobacterial genera split from Lyngbya. Despite this, no comparisons can be made to L. confervoides, and thus begging the question: who is Lyngbya? To answer this, we collected cyanobacterial tufts from intertidal pools in Cádiz, Spain, in line with the original descriptions of L. confervoides from Agardh and Gomont. Morphological and genetic characterization were conducted on two Lyngbya-like strains isolated from the type location. We identified strain BLCC-M349 to match the original description and iconograph, thereby designating it as the epitype of L. confervoides with BLCC-M349 serving as the reference strain. The descriptions of both Lyngbya and L. confervoides are emended and sequences of the 16S rRNA gene, the 16S-23S ITS rRNA region, and the genome are provided. Additionally, we describe a novel species of Okeania as well as synonymize select species of Capilliphycus to Lyngbya.

Cyanobacteria generate structurally complex peptides with diverse biological functions and vast chemical diversity, yet the enzymatic logic that produces their many documented unusual β-amino acid-containing polyketide units remains incompletely understood. Here we show that the recently described genus Floridanema harbors biosynthetic systems that unify the production of tychonamides and pahayokolide-like peptides, including the assembly of the signature residues 3-amino-2,5,7-trihydroxy-8-phenyloctanoic acid (Atpoa) and 3-amino-2,5,7,8-tetrahydroxy-10-methylundecanoic acid (Athmu). Using an integrated "pathways-to-products" strategy combining comparative genomics, bioinformatics analyses, and structure elucidation by NMR and MS, we link previously cryptic gene clusters to new metabolites and define shared architectural features across these pathways. Furthermore, we identified a ketoreductase in multiple pathways predicted to reduce α-keto acids and generate the starting unit in the Athmu moiety. These results support a common evolutionary origin or convergent phenomenon for constructing β-amino polyketide building blocks within cyanobacterial hybrid assembly lines. Together, our findings reposition Floridanema as a central source organism for these peptide families and establish biosynthetic principles that can be leveraged to predict, discover, and engineer related natural products.

Dapis , along with other benthic cyanobacteria, forms large extensive proliferations (i.e., blooms, mats) that cover sand and seagrass beds across the coasts of Florida, United States. As these benthic cyanobacteria become more prevalent, especially in areas like the Indian River Lagoon (IRL), Sarasota Bay, Lemon Bay, Tampa Bay, and the Florida Keys, it is necessary to understand their diversity. To explore the diversity and identify the causative species of these nuisance marine benthic mats, growing and rafting mats were sampled. Three cyanobacterial isolates from marine mats across Florida were characterized and revealed to represent three novel species of Dapis , but with differing morphological features than those of previously described species. With the support of 16S rRNA gene sequence phylogeny, morphological evaluations, 16S–23S ITS rRNA region pairwise distances, and phylogenomic analyses, we have presented three novel species of Dapis . We have also provided taxonomically validated sets of Dapis genomes from several species.

There has been an explosion of new Cyanobacterial taxa described within the last two decades. Cyanobacteria exhibit incredible ecological versatility and morphological variability, and thousands of species have already been described using "traditional" approaches (e.g., morphological features). However, DNA sequencing and other molecular tools have provided extensive evidence that the diversity of cyanobacteria is not necessarily congruent with morphology, as many morphological genera (e.g., Phormidium, Leptolyngbya, and Nostoc) are polyphyletic, and species within the genera are often morphologically indistinguishable, thus cryptic. Further confounding systematic assessments, newly erected taxa are often based on a single strain with one or two 16S rRNA gene sequences, may have incomplete formal descriptions, and lack indication of the employed species concepts. Here we have proposed a set of guidelines for cyanobacterial taxonomists. We have focused on the whole process of erecting new taxa: sampling, sequencing (including genomes), phylogenetic inference, phenotype characterization, species concepts, formal descriptions, and codes of nomenclature. Our hope is that these guidelines will help with the laborious but ever-rewarding task of identifying and describing the taxa within the world of cyanobacteria.

We report two metagenomic libraries of freshwater cyanobacterial harmful algal blooms (cyanoHABs) from Ohio, USA. One sample was collected from a Planktothrix-dominated bloom in Grand Lake St. Marys, and another from a mixed Dolichospermum and Microcystis-dominated cyanoHAB in the western basin of Lake Erie.

Stormwater ponds (SWPs) host distinct microbial communities. Here, we use 16S rRNA metabarcoding to characterize bacterial communities in four SWPs in South Florida, USA. A total of 37,002 amplicon sequence variants were identified, Cyanophyceae was the dominant class in pond A, while Gammaproteobacteria dominated the other ponds.

Cyanobacterial harmful algal blooms (cyanoHABs) are a growing global concern due to their negative impacts on freshwater lakes and river ecosystems. HABs impact local and regional economies by restricting fisheries resources, recreational and commercial waterways, and threatening drinking water sources. To control HABs, researchers are developing short- and long-term mitigation strategies by exploiting natural, bacterial-derived products as targeted chemical control reagents to reduce the severity of HABs. In this study, we characterized the cyanocidal and ecotoxicological properties of tryptoline, tryptamine, isatin and other commercially available, bacterially derived compounds against both lab-adapted and field collected freshwater cyanobacterial strains that collectively include genera from Microcystis, Umezakia, Raphidiopsis, Dolichospermum, Planktothrix, Vulcanococcus, Anabaena and Synechocystis. Initially, chemicals were assessed for their ability to control cyanobacteria by screening them on cyanobacteria lawn plates. Those chemicals that created zones of clearing underwent further testing through liquid assay studies, where biomass was monitored using chlorophyll extractions. Results indicate that tryptoline was the most effective chemical at all concentrations tested leading to a 52 % reduction in algal biomass and this was independent of initial algal biomass, whereas tryptamine reduced algal biomass by 25 % and was most effective at low to medium algal cell densities. In addition, tryptoline was more toxic to the cyanobacteria strains in both the single and repeated exposures compared to tryptamine due to its increased resistance to degradation compared to tryptamine which had degraded 27.9 % after 72 h. The acute and chronic toxicity studies using the standard non-target zooplankton Ceriodaphnia dubia and fish Pimephales promelas resulted in hazard values for tryptoline that indicate it could be difficult to achieve an acceptable margin of safety to avoid non-target species effects when using this chemical in a cyanoHAB treatment. In contrast, tryptamine was at least 2 times less toxic to both non-target species than trypoline (e.g., Pimephales promelas 96-hour LC50 for tryptamine was 26.97 mg/L compared to had an 96-hour LC50 of 2.9 mg/L for tryptoline). Results from these studies collectively provide further data on the feasibility of bacterial-derived algaecides with regards to multi-treatment regimens and optimal cyanobacterial bloom densities. These studies also provide relevant non-target species testing and safety factors for those chemicals demonstrating the most effective algaecide activity.

Secondary metabolite profiling of a recently described new cyanobacterial species Floridanema aerugineum identified abundant amounts of the polyketide-peptide tychonamide A. Investigation of the biosynthetic gene clusters in the F. aerugineum genome identified a putative tychonamide biosynthetic gene cluster with module and domain architecture consistent with the tychonamide A structure. High resolution liquid chromatography-mass spectrometry/MS (LC-MS/MS) identified new tychonamide analogs C-E (1-3), and bioactivity predictions led us to test the protease inhibition activities of the tychonamides. The results of this analysis illustrated the biosynthesis of the 3-amino-2,5,7-trihydroxy-8-phenyloctanoic acid moiety (Atpoa) in tychonamide A, further deduced the absolute configuration of tychonamide A, and uncovered new biological activities (human neutrophil elastase inhibition) that may be relevant in environmental science and pharmaceutical development.

Limited effective and scalable techniques are available to offset harmful algal blooms proactively. Because light is an influential component of many physiological processes in photoautotrophs, limiting availability could alter growth rates and composition of the algal assemblage. In this research, the U.S. Environmental Protection Agency registered product Aquashade (R) was evaluated, comprised of two colorants, erioglaucine and tartrazine, which are designed to absorb specific light wavelengths upon application to water resources. This study was undertaken using 1 and 2 mg/L Aquashade in South Florida, United States. Our initial data show that Aquashade was able to decrease total algal abundance and decrease cyanobacterial proportion of the algal assemblage at 1 month after treatment (MAT) in mesocosm trials in two Florida ponds. Sustained decreases in cyanobacteria were measured through 4 MAT, although these levels were similar to control mesocosms where there was a shift to more beneficial planktonic green algae possibly due to temperature. Managing intensity and specificity of available light wavelengths can provide water resource managers with an additional avenue toward altering phytoplankton assemblage composition.

Cyanobacterial harmful algal blooms (cyanoHABs) occur in fresh water globally. These can degrade water quality and produce toxins, resulting in ecological and economic damages. Thus, short-term management methods (i.e., algaecides) are necessary to rapidly mitigate the negative impacts of cyanoHABs. In this study, we assess the efficacy of a hydrogen peroxide-based algaecide (PAK® 27) on a Microcystis dominated bloom which occurred within the Pahokee Marina on Lake Okeechobee, Florida, USA. We observed a significant reduction in chlorophyll a (96.81%), phycocyanin (93.17%), and Microcystis cell counts (99.92%), and a substantial reduction in microcystins (86.7%) 48 h after treatment (HAT). Additionally, there was a significant shift in bacterial community structure 48 HAT, which coincided with an increase in the relative abundance of photosynthetic protists. These results indicate that hydrogen peroxide-based algaecides are an effective treatment method for cyanoHAB control and highlight their effects on non-target microorganisms (i.e., bacteria and protists).

Cyanobacteria exhibit a vast diversity from polar to tropical environments. Though much work has been done on elucidating their biodiversity, knowledge on the occurrence, diversity and toxicity of benthic cyanobacteria is limited when compared to the planktonic forms. Integrating molecular techniques with ecological and morphological analyses has become essential in untangling cyanobacterial diversity, particularly for benthic taxa such as the cryptic "Lyngbya." Molecular markers such as the 16S rRNA gene and whole genome sequencing have significantly improved the taxonomy of cyanobacteria. Building on these advancements, this study characterizes benthic cyanobacterial isolates from various locations in Florida, USA, and Orange Walk, Belize, resulting in the identification of a novel genus, Floridanema, and four new species (F. aerugineum, F. evergladense, F. flaviceps, and F. fluviatile). This new genus commonly occurs in canals, ponds, lakes and rivers. By integrating ecological, morphological, and genomic analyses, this study provides support for the family Aerosakkonemataceae and the establishment of the order Aerosakkonematales. The LC-MS data revealed that Floridanema strains do not produce microcystins, nodularin-R, or anabaenopeptins.

Shallow lakes are typically dominated by macrophytes, which have important functional roles regulating trophic conditions and creating biological habitat. Macrophytes have been shown to strongly influence water chemistry and shape microbial communities in shallow lakes. In Florida, many large, shallow lakes are dominated by alien invasive, submersed macrophytes, such as hydrilla (Hydrilla verticillata [L.F.] Royle) and are intensively managed to reduce infestations and contain the spread of these alien invasive macrophytes. In this study, we investigated the effects of large (40 ha) herbicidal and mechanical control treatments on a large lake located in Central Florida that resulted in the reduction of Hydrilla and concomitant changes in water chemistry and microbial communities (both bacteria and protists [microbial eukaryotes]). We observed a considerable decrease in macrophyte coverage associated with plant control treatments as well as a temporal change in macrophyte coverage in Lake Tohopekaliga. We found that changes in macrophyte coverage, regardless of treatment type, significantly affected the water chemistry of the lake, resulting in a sharp increase of chlorophyll a concentration as well as an increase in turbidity with the decrease of macrophyte coverage. Moreover, the decline in macrophytes led to decreases in microbial community diversity with over-representation of phototrophic functional groups. Specifically, we observed an increase in cyanobacteria with the decrease in macrophyte coverage. Our study highlights the advantages and disadvantages of macrophyte control. Although there was an initial decrease in macrophyte coverage associated with the chemical and mechanical control of aquatic plants, after a few months, we found a considerable increase in coverage. In addition, the increase of cyanobacterial relative abundance demonstrates the possible consequences of aquatic plant control such as cyanobacterial blooms if there is a continued decline of macrophytes.

Cyanobacterial harmful algae blooms (cyanoHABs) are a global threat to water resources, and lake managers need effective strategies to suppress or control them. Algaecides may have negative environmental impacts, and their use is becoming restricted. Nanobubble ozone technology (NBOT) is an emerging water treatment option with potentially fewer negative impacts. We assessed the effectiveness of NBOT in treating Planktothrix cyanoHAB from Grand Lake St Marys (GLSM, Ohio USA) in a mesocosm (2,000L) experiment and two 4-week trials in a GLSM embayment (Sunset Beach, SBE; similar to 4.7 & lowast;10(7) L). In mesocosms, the medium (1.21 +/- 0.08 ozone to dissolved organic carbon ratio, O-3:DOC) and high (2.04 +/- 0.07 O-3:DOC) doses decreased both chlorophyll a (chl-a) and phycocyanin by 98-99% and microcystins by 62% and 92%, respectively. The low dose (0.68 +/- 0.05 O-3:DOC) decreased chl-a and phycocyanin by over 70%. No effect was observed for chl-a nor microcystins in both oxygen-only nanobubble mesocosm treatments and the SBE NBOT trial. The average O-3:DOC at SBE was less than the low NBOT mesocosm experiment dose, and the percentage of water treated was lower. DOC chemistry, as indicated by SUVA(254,) was more oxidized at the NBOT outlet than the inlet in the SBE trial, suggesting interaction with ozone. However, no differences were observed 3m from the outlet, indicating minimal treatment reach. The mesocosm experiment highlighted NBOT's ability to control cyanoHABs, but the limited effectiveness of NBOT at SBE was likely due to high cyanobacteria biomass and DOC at the onset of treatment, low O-3:DOC, and low percentage of lake water instantaneously treated.

Lake Mattamuskeet, the largest lake in North Carolina, USA, has undergone decades-long eutrophication causing reduced water quality and promoting cyanobacterial blooms that may produce toxins. It is therefore necessary to evaluate the cyanobacterial diversity of the lake and their toxigenic potential. We present draft genomes of Microcystis, Pelatocladus, Raphidiopsis, and Umezakia strains isolated from Lake Mattamuskeet. The whole-genome shotgun projects for Umezakia ovalisporum BLCC-F208, Microcystis sp. BLCC-F209, Microcystis sp. BLCC-F210, Pelatocladus sp. BLCC-F211, U. ovalisporum BLCC-F215, and Raphidiopsis BLCC-F218 have been deposited in GenBank under accession numbers JBHFLK000000000, JBHFLL000000000, CP169647, JBHFLM000000000, JBHFLN000000000, and JBHFLO000000000, respectively. Based on the genomic analysis, several biosynthetic gene clusters (BCGs) with varying degrees of similarity to known toxic and bioactive compound gene clusters were identified across the different cyanobacterial strains.

Here, we report the draft genome sequences of nine bacterial species isolated from eutrophic waters associated with cyanobacterial harmful algal blooms with cyanocidal potential.

Lake Okeechobee is a large eutrophic, shallow, subtropical lake in south Florida, United States. Due to decades of nutrient loading and phosphorus rich sediments, the lake is eutrophic and frequently experiences cyanobacterial harmful algal blooms (cyanoHABs). In the past, surveys of the phytoplankton community structure in the lake have been conducted by morphological studies, whereas molecular based studies have been seldom employed. With increased frequency of cyanoHABs in Lake Okeechobee (e.g., 2016 and 2018 Microcystis-dominated blooms), it is imperative to determine the diversity of cyanobacterial taxa that exist within the lake and the limnological parameters that drive bloom-forming genera. A spatiotemporal study of the lake was conducted over the course of 1 year to characterize the (cyano)bacterial community structure, using 16S rRNA metabarcoding, with coincident collection of limnological parameters (e.g., nutrients, water temperature, major ions), and cyanotoxins. The objectives of this study were to elucidate spatiotemporal trends of community structure, identify drivers of community structure, and examine cyanobacteria-bacterial relationships within the lake. Results indicated that cyanobacterial communities within the lake were significantly different between the wet and dry season, but not between periods of nitrogen limitation and co-nutrient limitation. Throughout the year, the lake was primarily dominated by the picocyanobacterium Cyanobium. The bloom-forming genera Cuspidothrix, Dolichospermum, Microcystis, and Raphidiopsis were highly abundant throughout the lake and had disparate nutrient requirements and niches within the lake. Anatoxin-a, microcystins, and nodularins were detected throughout the lake across both seasons. There were no correlated (cyano)bacteria shared between the common bloom-forming cyanobacteria Dolichospermum, Microcystis, and Raphidiopsis. This study is the first of its kind to use molecular based methods to assess the cyanobacterial community structure within the lake. These data greatly improve our understanding of the cyanobacterial community structure within the lake and the physiochemical parameters which may drive the bloom-forming taxa within Lake Okeechobee.

Benthic cyanobacterial mats (BCMs) are natural phenomena in marine environments. Reports of BCMs occurring across coastal marine environments have increased, partly driven by nutrient loading and climate change; thus, there is a need to understand the diversity involved in the proliferations and potential toxicity of the BCMs. Furthermore, marine cyanobacterial mats are observed growing on and affecting the health of corals with one specific cyanobacterial genus, Roseofilum, dominating the microbial mats associated with black band disease (BBD), a destructive polymicrobial disease that affects corals. To explore the diversity of Roseofilum, cyanobacterial mats from various marine habitats were sampled, and individual isolates were identified based on morphology, 16S rRNA gene phylogenies, 16S-23S ITS rRNA region sequence dissimilarities, and phylogenomics. Four novel species of Roseofilum were isolated from benthic marine mats, three from the coasts of Florida, United States (R. capinflatum sp. nov., R. casamattae sp. nov., and R. acuticapitatum sp. nov.) and one from the coast of France (R. halophilum sp. nov.). Our analyses revealed that Roseofilum associated with coral BBD and those not associated with corals but rather from coastal benthic mats are systematically distinct based on both phylogenetic and phylogenomic analyses. Enzyme-linked immunosorbent assay (ELISA) and LC-MS data indicated that microcystin production was found in one of the four species.

Cyanobacteria are photosynthetic bacteria that occupy various habitats across the globe, playing critical roles in many of Earth's biogeochemical cycles both in both aquatic and terrestrial systems. Despite their well-known significance, their taxonomy remains problematic and is the subject of much research. Taxonomic issues of Cyanobacteria have consequently led to inaccurate curation within known reference databases, ultimately leading to problematic taxonomic assignment during diversity studies. Recent advances in sequencing technologies have increased our ability to characterize and understand microbial communities, leading to the generation of thousands of sequences that require taxonomic assignment. We herein propose CyanoSeq (https://zenodo.org/record/7569105), a database of cyanobacterial 16S rRNA gene sequences with curated taxonomy. The taxonomy of CyanoSeq is based on the current state of cyanobacterial taxonomy, with ranks from the domain to genus level. Files are provided for use with common naive Bayes taxonomic classifiers, such as those included in DADA2 or the QIIME2 platform. Additionally, FASTA files are provided for creation of de novo phylogenetic trees with (near) full-length 16S rRNA gene sequences to determine the phylogenetic relationship of cyanobacterial strains and/or ASV/OTUs. The database currently consists of 5410 cyanobacterial 16S rRNA gene sequences along with 123 Chloroplast, Bacterial, and Vampirovibrionia (formally Melainabacteria) sequences.