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Extramural Research

Grantee Research Project Results

Grantee Research Project Results

Ecological Physiology of the Black Band Disease Cyanobacterium Phormidium corallyticum: Dark Metabolic Capabilities

EPA Grant Number: U916224
Title: Ecological Physiology of the Black Band Disease Cyanobacterium Phormidium corallyticum: Dark Metabolic Capabilities
Investigators: Ragoonath, Davecia N.
Institution: Florida International University
EPA Project Officer: Just, Theodore J.
Project Period: January 1, 2003 through June 20, 2006
Project Amount: $120,740
RFA: Minority Academic Institutions (MAI) Fellowships for Graduate Environmental Study (2003)
Research Category: Academic Fellowships , Fellowship - Natural and Life Sciences , Biology/Life Sciences



The objectives of this research project are to: (1) investigate the physiological processes of photoheterotrophy, fermentation, dark aerobic respiration, and potential anaerobic respiration using a laboratory culture of Phormidium corallyticum; and (2) expand our knowledge of the overall etiology and ecology of P. corallyticum and define its role in black band disease (BBD). BBD is a microbial consortium that commonly infects scleractinian and gorgonian corals, degrading coral tissue and leaving bare coral skeleton. It is dominated by the gliding, filamentous cyanobacterium P. corallyticum and includes sulfate-reducing and sulfide-oxidizing bacteria. Although P. corallyticum's photoautotrophic physiological capabilities have been established, little is known of its dark or photoheterotrophic metabolism.


Analyses of growth rates using different organic carbon compounds, identification of fermentation end products, and potential use of alternate electron acceptors will determine heterotrophic capabilities of this cyanobacterium. In addition, this species will be sequenced and subjected to phylogenetic analysis. Heterotrophic growth and survival under aerobic and anaerobic light and dark conditions were measured and compared with photoautotrophic growth. The highest growth rate was obtained via photoautotrophy. The next highest growth rate was via (dark) anaerobic heterotrophy, and the lowest growth (and limited survival) occurred via (dark) aerobic heterotrophy.

Supplemental Keywords:

fellowship, Phormidium corallyticum, black band disease, BBD, physiology, metabolic.

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The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.

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