K. David Hambright



Department of Biology
730 Van Vleet Oval, 304 Sutton Hall
Norman, OK 73019
Phone: (405) 325-7435

Lake Texoma

Cyanobacterial Community Ecology: Phycospheres or Interactomes?
Undergraduate/Graduate Course for Spring 2019

Advanced Topics in Limnology (Biology 4663/5663)
Credit: 3 hours
Instructor: Dave Hambright
Time/Place: Wednesdays at 9-11:30 a.m. / 312 Sutton Hall

Limnology is the study of inland waters, and extends across a variety of scientific disciplines (biology, chemistry, ecology, evolutionary biology, physics, and geology). This course is designed to allow students who have previously taken Ecology of Lakes, Stream Ecology or an equivalent course in other biological or environmental sciences to gain a more detailed understanding within focused topics in limnology.

In recent years, freshwater harmful algal blooms composed of toxigenic cyanobacteria (cyanoHABs) have reached unprecedented levels globally. These events are fueled by excessive nutrient inputs from rapidly expanding agricultural and urban development, as well as by a changing climate (e.g., warming and altered precipitation patterns). CyanoHABs are threatening the viability and sustainability of freshwater lakes and reservoirs, as they alter food webs and energy flow. Importantly, cyanoHAB toxins pose substantial health risks to humans, pets, livestock, and wildlife. Rather than focusing strictly on nutrients and climate (the more traditional foci of cyanoHAB ecological research), this course will use the published literature to examine the potential interactions between cyanobacteria and the complex and diverse bacterial communities that co-occur with them. Early study of cyanobacteria community dynamics identified a host of other bacteria are often associated with cyanobacteria; perhaps a cyanobacterial microbiome. This phenomenon was termed the ‘phycosphere,’ and was believed to represent an assemblage of loosely interacting and non-interacting bacteria, where only a few of the many bacteria taxa serve some function to support the cyanobacteria. Genomic and transcriptomic approaches have revealed that bacteria, including cyanobacteria, have simplified, streamlined genomes, which may be reflected in the loss of metabolic or other key functional biochemical pathways. Consequently, it has been hypothesized that cyanobacterial communities may exist as ‘interactomes,’ coevolved communities of mutualistic and synergistic interacting bacteria species. Our goal will be to address the question of whether cyanobacterial assemblages constitute a ‘phycosphere’ of co-occurring bacterial taxa which may or may not be interacting or an ‘interactome’ of co-existing, mutually beneficial interacting taxa.

The course is intended for graduate and advanced undergraduate students with a background in limnology, community ecology, and microbiology. Class meetings will be structured around student-led discussion of key primary research papers focused on the phycosphere, the interactome, microbiomes, and the ecological concepts of syntrophy, co-occurrence, and co-existence. Familiarity with cyanobacteria, genomics and transcriptomics, biochemistry/gene function, and related topics is not a must, but would be extremely helpful.

Grades will be based on students’ grasp of assigned papers (as evidenced by written summaries and critiques) and the ability to summarize and synthesize the body of literature discussed during class meetings. Ultimately, students will prepare a jointly co-authored written review of the current state of knowledge with respect to the cyanobacterial microbiome. Students will hone skills in critical thinking, as well as in comprehension and conveyance of ideas through weekly reading, writing, and discussion-based exercises. Grades will be based on class participation (50%) and writing assignments (50%).

PREREQUISITES: Ecology of Lakes (BIOL 4463), Stream Ecology (BIOL 4423), Graduate standing, or with permission.

For further information contact Dr. Dave Hambright by email at dhambright@ou.edu; or by phone at 325-7435.


Last Modified 10 June, 2021
K.D. Hambright, Department of Biology, 730 Van Vleet Oval, 304 Sutton Hall | Norman, OK 73019 | 405-325-7435 | dhambright@ou.edu