Project Significance:


Created by George Rice, Montana State University


Volunteer diver Sam Vasilevsky collecting a sponge sample at Conch Reef, Key Largo. (photo by Jayme Lohr)


Research conducted at this Microbial Observatory will enhance understanding of large-scale microbial diversity by focusing on the diversity of microbial communities in the microcosm of sponges. The project has great potential for discovery of new marine bioactive compounds. Marine sponges have been shown to be a prolific source of these valuable compounds, many of which may be derived from the associated microbes. The project will contribute to a fundamental understanding of the scope and function of signaling compounds produced by bacteria, which can be applied in efforts to manipulate bacterial behavior by interference with signaling pathways. Elucidation of these compounds and signaling pathways has untold potential for development in industrial and medical applications.


Methods of Study:



The prokaryotic communities associated with the sponges Microciona prolifera from the Chesapeake Bay and Xestospongia muta, Ircinia strobilina, Axinella corrugata, Monanchora unguifera and Mycale laxissima from Key Largo, Florida are being characterized by 16S rRNA community analysis.


  • The location of predominant bacterial groups is being confirmed by fluorescent in situ hybridization.

  • Variation in microbial communities between individual sponges of the same species is being investigated to determine how stable their make up is on a spatial and temporal basis (season to season).

  • Community analysis will reveal whether there are unique microbes associated with individual species of sponges and/or ubiquitous microbes found in all marine sponges, and these analyses are being used to design strategies for culturing predominant Bacteria and Archaea.

  • Isolates that can be cultured are being screened for production of signaling compounds produced within the tightly packed microbial communities of the sponges.

  • Indicator systems are being employed to detect signaling compounds, which are biologically active acylated homoserine lactones (acyl-HSLs) isolated from Gram-negative bacterial isolates and whole sponge tissue.
  • The role that signaling compounds play in bacterial colonization of sponges is being investigated.


Image on left is of Dr. Feng Chen, Anthony Agyapong, and Ammar Hanif taking a plankton sample from the Chesapeake Bay. Image on right is of Dr. Russell Hill explaining PCR amplification of DNA to a group of students.



Copyright on all images and material by Russell Hill, 2005.