Students in the Biology Department at East Georgia State College (EGSC) in Swainsboro made presentations at the 2021 annual meeting of the Georgia Academy of Science held virtually Friday, April 16, to Sunday, April 18, 2021. The presentations were the result of experiments done by students enrolled in the environmental toxicology and/or the undergraduate research classes and were classified as “works in progress.” Two oral presentations were made.
The first one, entitled “Development of a High Throughput Monitoring System for the Presence of Cyanobacteria,” was presented by Jessica L. Jones with co-authors Bret A. White, Monique N. Johnson, and Dr. Julius E. Schneider (class instructor). The presentation focused on the fact that filters commonly used to collect algae in the monitoring of environmental water bodies differ in their binding of phycocyanin, a blue pigment in cyanobacteria. Such binding is detrimental to the monitoring procedure because it is the unbound phycocyanin extracted from the cyanobacteria (in the presence of the filter) that is used as an indicator of the amount of cyanobacteria in the water. Other data presented showed the effect of freezing on the efficiency of the extraction process, which in the case for the cyanobacterial species Limnothrix, was a minimal effect, although for other species freezing and thawing of the bacteria does increase the efficiency of extraction. This result provides evidence that cyanobacterial species differ in their cell wall and/or membrane structure.
A second presentation was made by Monique N. Johnson with co-authors Carley K. Stapleton, Shanice McGuire, Joshua M. Horne, and Dr. Julius E. Schneider. The talk was entitled “Protection by Fructose from Denaturation of Phycocyanin by Octanol.” Extraction and measurement of chlorophyll and phycocyanin from water samples in order to estimate the amounts of algae and cyanobacteria, respectfully, is an established environmental monitoring method. Typically, the two pigments are extracted and measured separately, as chlorophyll is hydrophobic, and phycocyanin is a hydrophilic protein. The group has been exploring the simultaneous extraction and measurement of these pigments with a biphasic octanol-water system. During vigorous mixing of the cyanobacteria, both pigments are released from the cells; chlorophyll accumulates in the upper octanol phase, phycocyanin in the lower, aqueous phase. After centrifugation, the phases separate cleanly, and the two pigments are removed and measured by their color intensities. Results were presented that showed that the presence of high concentrations of fructose in the aqueous phase of the extraction process resulted in higher levels of the blue pigment phycocyanin compared to an aqueous phase of water alone. This result is attributed to the likelihood that octanol has a denaturing effect on the phycocyanin during the mixing phase, and that fructose inhibits this activity. It has been reported that fructose protects phycocyanin from heat denaturation, a finding that led to this experiment. It was also shown that, due to the higher viscosity of the 3M fructose added to the aqueous phase, a lengthier mixing step is required to release a peak amount of phycocyanin.
“We are all so proud of Jessica and Monique for representing EGSC at the Georgia Academy of Sciences. We are also very thankful to the USG to provide funding to support undergraduate research,” said David Chevalier, interim dean of the School of Mathematics and Natural Sciences.
“East Georgia State College was well represented at the annual meeting of the Georgia Academy of Sciences, having presentations by two groups of students who presented the results of their research projects. Students making their first presentations at a scientific meeting are often intimidated by the prospect, but East Georgia has a record of success in this endeavor. We are proud of these undergraduate achievements,” said Associate Professor John Cadle.
This work was conducted as part a course-embedded undergraduate research experience for the BIOL 4750 Environmental Toxicology during Fall 2020 and a one-one-on undergraduate research project during Fall 2020 and Spring 2021.
This research was supported by the East Georgia State College Biology Department and a STEM IV Initiative grant from the University System of Georgia.