cyanobacteria

Barbamide Displays Affinity for Membrane-Bound Receptors and Impacts Store-Operated Calcium Entry in Mouse Sensory Neurons

Abstract

Marine cyanobacteria are a rich source of bio-active metabolites that have been utilized as leads for drug discovery and pharmacological tools for basic science research. Here, we describe the re-isolation of a well-known metabolite, barbamide, from Curaçao on three different occasions and the characterization of barbamide’s biological interactions with targets of the mammalian nervous system. Barbamide was originally discovered as a molluscicidal agent from a filamentous marine cyanobacterium. In our hands, we found little evidence of toxicity against mammalian cell cultures. However, barbamide showed several affinities when screened for binding affinity for a panel of 45 receptors and transporters known to be involved in nociception and sensory neuron activity. We found high levels of binding affinity for the dopamine transporter, the kappa opioid receptor, and the sigma receptors (sigma-1 and sigma-2 also known as transmembrane protein 97; TMEM97). We tested barbamide in vitro in isolated sensory neurons from female mice to explore its functional impact on calcium flux in these cells. Barbamide by itself had no observable impact on calcium flux. However, barbamide enhanced the effect of the TRPV1 agonist capsaicin and enhanced store-operated calcium entry (SOCE) responses after depletion of intracellular calcium. Overall, these results demonstrate the biological potential of barbamide at sensory neurons with implications for future drug development projects surrounding this molecule

 

Date
2023
Data type
Scientific article
Theme
Research and monitoring
Journal
Geographic location
Curacao

Cyanobacterial mats as benthic reservoirs and vectors for coral black band disease pathogens

Abstract
The concurrent rise in the prevalence of conspicuous benthic cyanobacterial mats and the incidence of coral diseases independently markmajor axes of degradation of coral reefs globally. Recent advances have uncovered the potential for the existence of interactions between the expanding cover of cyanobacterial mats and coral disease, especially black band disease (BBD), and this intersection represents both an urgent conservation concern and a critical challenge for future research. Here, we propose links between the transmission of BBD and benthic cyanobacterial mats. We provide molecular and ecophysiological evidence suggesting that cyanobacterial mats may create and maintain physically favorable benthic refugia for BBD pathogens while directly harboring BBD precursor assemblages, and discuss how mats may serve as direct (mediated via contact) and indirect (mediated via predator–prey–pathogen relationships) vectors for BBD pathogens. Finally, we identify and outline future priority research directions that are aligned with actionable management practices and priorities to support evidence-based coral conservation practices.

Date
2022
Data type
Scientific article
Theme
Research and monitoring
Geographic location
Bonaire

Coral inventory Bonaire, 2014 and 2017

 

  • zone    DO = DROP-OFF at ~10m depth, LT= Lower Terrace at ~5m depth
  • length transect in cm
  • rugosity    measure for 3-dimensional complexity reef:  length transect following substrate (cm) / plain length transect (cm)
  • Average heigh in cm of coral colonies along transect
  • date
  • Depth in meters
  • start.time   
  • end.time  
  • latitude
  • longitude
  • Crustose coralline algal cover (proportion)
  • Coral cover (proportion)
  • cayno bacterial cover (proportion)
  • macroalgal cover (proportion)
  • other cover (proportion)
  • rubble cover (proportion)
  • sand cover (proportion)
  • soft coral cover (proportion)
  • sponge cover (proportion)
  • bare substrate cover (proportion)
  • turf cover (proportion)
  • Transect to left (L) from starting point and to right (R) from starting point
  • MPA=Marine Protected Area, ND=No Diving, NF=No Fishing
  • Entry into water, either from boat or from shore

     
Date
2017
Data type
Raw data
Theme
Research and monitoring
Geographic location
Bonaire
Image

Large scale, medium scale, and small scale patterns of benthic cyanobacteria & the possibility of groundwater association on a coral reef

Cyanobacteria presence in the marine ecosystem is biologically significant due to its versatile nature. This phylum is responsible for destructive red tides and black band disease as well as building up the limestone in reefs. Nodularia cf. spumigena has been an indicator of groundwater off of the coast of Bahamas and may provide insight into where Bonaire‟s groundwater enters the marine ecosystem. Bonaire is a tropical oceanic island with a fringing coral reef located in the south Caribbean Sea and, although the population of the island is small (~16,000), it has developed a population center of residential and commercial use in Kralendijk, a coastal city. To compare how the benthic cyanobacteria mats off of Bonaire relate to this growing population, a three-fold study was conducted. A large scale pattern of cyanobacteria was studied at nine sites on the leeward side, a medium scale pattern was studied at four sites off the coast of Kralendijk in between two known nutrient outputs, and tests of mean levels of Escherichia coli and total coliforms inside and outside the cyanobacteria mats were completed. Video transects were used to determine percent cover of the large and medium scale patterns and IDEXX technology was used to test pore water inside and outside the mats for two types of bacteria associated with human waste. No definite patterns of groundwater or population center were directly linked to benthic cyanobacteria cover. The large scale did show a higher average cyanobacteria cover throughout the three-year study, indicating that there may be a relationship between the hydrology of the island and nutrient circulation. The medium scale showed an inverse relationship between turf algae and cyanobacteria.

This student research was retrieved from Physis: Journal of Marine Science XII (Fall 2012)19: 9-15 from CIEE Bonaire.

Date
2012
Data type
Other resources
Theme
Research and monitoring
Geographic location
Bonaire
Author

Caldora penicillata gen. nov., comb. nov. (Cyanobacteria), a pantropical marine species with biomedical relevance

Many tropical marine cyanobacteria are prolific producers of bioactive secondary metabolites with ecological relevance and promising pharmaceutical applications. One species of chemically rich, tropical marine cyanobacteria that was previously identified as Symploca hydnoides or Symploca sp. corresponds to the traditional taxonomic definition of Phormidium penicillatum. In this study, we clarified the taxonomy of this biomedically and ecologically important cyanobacterium by comparing recently collected specimens with the original type material and the taxonomic description of P. penicillatum. Molecular phylogenetic analyses of the 16S rRNA gene and the 16S-23S internal transcribed spacer regions showed that P. penicillatum formed an independent clade sister to the genus Symploca, and distantly related toPhormidium and Lyngbya. We propose the new genus Caldora for this clade, with Caldora penicillata comb. nov. as the type species and designate as the epitype the recently collected strain FK13-1. Furthermore, the production of bioactive secondary metabolites among various geographically dispersed collections of C. penicillata showed that this species consistently produced the metabolite dolastatin 10 and/or the related compound symplostatin 1, which appear to be robust autapomorphic characters and chemotaxonomic markers for this taxon.

Date
2015
Data type
Scientific article
Theme
Research and monitoring

Bonaire National Marine Park—Algal Survey and Inventory

The Littler’s team [including Barrett Brooks, Don Hurlbert, Barbara Watanabe and Larry Gorenflo (Conservation International)] traveled to the island of Bonaire, Netherlands Antilles (1 Nov 06 to 14 Nov 06). The purpose of this expedition was to assist the Ministry of Nature Affairs for the Netherlands Antilles (MINA) and the Center for Applied Biodiversity Science at Conservation International to assess the current status of Bonaire’s marine flora. The team collected over 300 specimens from the upper reef to a depth of 56 m. This assessment increased the known species reported from Bonaire by 35% (Appendix II, List of Species). The marine flora is typical of many Caribbean reefs with no specific areas of extremely high diversity or unique species composition. Also included in this evaluation are over 100 digital images (Appendix III), properly identified to the species level in most cases. These images may be used by managers in web sites, oral presentation, training manuals, brouchures, etc., to make marine plant identification possible for Bonaire’s many divers, volunteers, conservationists or interested agencies.
The team surveyed the health of the reefs using key indicator species (recognized from our >30 continuous years of coral-reef research) in reference to the growing problems associated with eutrophication and overfishing along tropical and subtropical shorelines worldwide. The ecological responses of corals and macroalgae to nutrient enrichment and release from predation have been repeatedly cited as priority areas in need of further research (National Research Council, 2000; Littler & Littler 2006).

Date
2006
Data type
Other resources
Theme
Research and monitoring
Geographic location
Bonaire