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United States Department of Agriculture

Agricultural Research Service

Research Project: CHEMICAL BIOLOGY OF INSECT AND PLANT SIGNALING SYSTEMS

Location: Chemistry Research Unit

Title: Complex marine natural products as potential epigenetic and production regulators of antibiotics from a marine Pseudomonas aeruginosa

Authors
item Wang, Bin -
item Waters, Amanda -
item Sims, James
item Fullmer, Alexis -
item Ellison, Serena -
item Hamann, Mark -

Submitted to: Microbial Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 8, 2013
Publication Date: April 9, 2013
Citation: Wang, B., Waters, A.L., Sims, J.W., Fullmer, A., Ellison, S., Hamann, M.T. 2013. Complex marine natural products as potential epigenetic and production regulators of antibiotics from a marine Pseudomonas aeruginosa. Microbial Ecology. 65:1068-1075.

Interpretive Summary: In nature microbial communities are in constant battle with chemical stressors and competing organisms. Many microbes make bioactive metabolites as a response to these conditions and these natural products have potential as therapeutic agents. The promise of new therapeutic agents from microbes is hindered by inconsistencies in large scale production from purified microbes. Scientists at the USDA-ARS Center for Medical, Agricultural and Veterinary Entomology in Gainesville, Florida, in collaboration with scientists from the Department of Pharmacognosy at the University of Mississippi have used an orthogonal approach to gain insight into conditions that impact the production of bioactive metabolites from a marine isolate of Pseudomonas aeruginosa. A collection of microbes from marine sediment produced a number of metabolites with antimicrobial, antifungal and antimalarial activities. Using P. aeruginosa, various natural products were tested as culture additives as well as co-culturing with a Bacillus sp. isolated in the same area. We show that the best condition is using a seed oil mix as the carbon source, a sublethal dose of the kinase inhibitor sceptrin and co-culture with Bacillus sp. A better understanding of the mechanisms underlying increased production of antimalarials will prove useful in developing practical applications to produce bioactive microbial metabolites.

Technical Abstract: Marine microbes are capable of producing secondary metabolites for defense and competition. Factors exerting an impact on secondary metabolite production of microbial communities included bioactive natural products and co-culturing. These external influences may have practical applications such as increased yields or the generation of new metabolites from otherwise silent genes in addition to reducing or limiting the production of undesirable metabolites. In this paper, we discuss the metabolic profiles of a marine Pseudomonas aeruginosa in the presence of a number of potential chemical epigenetic regulators, adjusting carbon sources and co-culturing with other microbes to induce a competitive response. As a result of these stressors certain groups of antibiotics or antimalarial agents were increased most notably when treating P. aeruginosa with sceptrin and co-culturing with another Pseudomonas sp. An interesting cross-talking event between these two Pseudomonas species when cultured together and exposed to sceptrin was observed.

Last Modified: 4/18/2014
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